WorldWideScience

Sample records for m-3 organic particulate

  1. Quality and Quantity of Particulate Organic Carbon in a Coral Reef at Tioman Island, Malaysia

    International Nuclear Information System (INIS)

    Nakajima, R.; Toda, T.; Shibata, A.

    2011-01-01

    The quality and quantity of particulate organic carbon (POC) were investigated in a fringing coral reef of Tioman Island, Malaysia to better understand the food sources for reef meso-zooplankton. Phytoplankton biomass in the water column was on average 0.22 (± 0.07) mg Chl-a m-3, of which pico phytoplankton was the most important (size <3 μm, 50-70 % of the total Chl-a). The proportion of C biomass by phytoplankton and other plankton to particulate organic carbon (POC) was low (6 % and 5 %, respectively) and the major portion of POC was occupied by detritus (89 %), suggesting that the diet of particle-feeding or suspension feeding meso-zooplankton would chiefly consist of detritus. (author)

  2. Observations on particulate organic nitrates and unidentified components of NOy

    DEFF Research Database (Denmark)

    Nielsen, T.; Egeløv, A.H.; Granby, K.

    1995-01-01

    A method to determine the total content of particulate organic nitrates (PON) has been developed and ambient air measurements of PON, NO, NO2, HNO3, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), gas NOy and particulate inorganic nitrate have been performed in the spring and early...... summer al an agricultural site in Denmark and compared with measurements of ozone, H2O2, SO2, formic acid, acetic acid and methane sulphonic acid. The gas NOy detector determines the sum NO + NO2 + HNO2 + HNO3 + PAN + PPN + gas phase organic nitrates + 2 x N2O5 + NO3. The content of residual gas NOy...... = gas NOy + particulate inorganic nitrate). Residual gas NOy was much higher than the particulate fraction of organic nitrates (PON). PON was only 0.25 +/- 0.11% of concentrations of photochemical oxidants in connection with high-pressure systems suggesting atmospheric processes being the major source...

  3. Temporal and spatial variations in particulate matter, particulate organic carbon and attenuation coefficient in Cochin Backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.

    Nine stations over a stretch of 21 km of Periyar river estuary were sampled during January to December 1981. Particulate matter varied from 3-253 mg.1 super(1) at the surface and 24.8-257mg.1 super(1) at the bottom. Particulate organic carbon ranged...

  4. Seasonal and diurnal variations of particulate nitrate and organic matter at the IfT research station Melpitz

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2011-12-01

    Full Text Available Ammonium nitrate and several organic compounds such as dicarboxylic acids (e.g. succinic acid, glutaric acid, some Polycyclic Aromatic Hydrocarbon (PAHs or some n-alkanes are semi-volatile. The transition of these compounds between the gas and particulate phase may significantly change the aerosol particles radiative properties, the heterogeneous chemical properties, and, naturally, the total particulate mass concentration. To better assess these time-dependent effects, three intensive field experiments were conducted in 2008–2009 at the Central European EMEP research station Melpitz (Germany using an Aerodyne Aerosol Mass Spectrometer (AMS. Data from all seasons highlight organic matter as being the most important particulate fraction of PM1 in summer (59% while in winter, the nitrate fraction was more prevalent (34.4%. The diurnal variation of nitrate always showed the lowest concentration during the day while its concentration increased during the night. This night increase of nitrate concentration was higher in winter (ΔNO3 = 3.6 μg m3 than in summer (ΔNO3 = 0.7 μg m3. The variation in particulate nitrate was inherently linked to the gas-to-particle-phase equilibrium of ammonium nitrate and the dynamics of the atmosphere during day. The results of this study suggest that during summer nights, the condensation of HNO3 and NH3 on pre-existing particles represents the most prevalent source of nitrate, whereas during winter, nighttime chemistry is the predominant source of nitrate. During the summer 2008's campaign, a clear diurnal evolution in the oxidation state of the organic matter became evident (Organic Mass to Organic Carbon ratio (OM/OC ranging from 1.65 during night to 1.80 during day and carbon oxidation state (OSc from −0.66 to −0.4, which could be correlated to hydroxyl radical (OH and ozone

  5. Direct sampling of sub-µm atmospheric particulate organic matter in sub-ng m-3 mass concentrations by proton-transfer-reaction mass spectrometry

    Science.gov (United States)

    Armin, W.; Mueller, M.; Klinger, A.; Striednig, M.

    2017-12-01

    A quantitative characterization of the organic fraction of atmospheric particulate matter is still challenging. Herein we present the novel modular "Chemical Analysis of Aerosol Online" (CHARON) particle inlet system coupled to a new-generation proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF 6000 X2, Ionicon Analytik, Austria) that quantitatively detects organic analytes in real-time and sub-pptV levels by chemical ionization with hydronium reagent ions. CHARON consists of a gas-phase denuder for stripping off gas-phase analytes (efficiency > 99.999%), an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. With typical particle enrichment factors of around 30 for particle diameters (DP) between 120 nm and 1000 nm (somewhat reduced enrichment for 60 nm 6000) and excellent mass accuracies (< 10 ppm) chemical compositions can be assigned and included in further analyses. In addition to a detailed characterization of the CHARON PTR-TOF 6000 X2 we will present first results on the chemical composition of sub-µm particulate organic matter in the urban atmosphere in Innsbruck (Austria).

  6. Exposure to carbon monoxide, respirable suspended particulates, and volatile organic compounds while commuting by bicycle

    International Nuclear Information System (INIS)

    Bevan, M.A.J.; Proctor, C.J.; Baker-Rogers, J.; Warren, N.D.

    1991-01-01

    A portable air sampling system has been used to assess exposures to various substances while commuting by bicycle in an urban area. The major source of pollutants in this situation is motor vehicle exhaust emissions. Carbon monoxide, measured by electrochemical detection, was found at peak concentrations in excess of 62 ppm, with mean values over 16 individual 35-mm journeys being 10.5 ppm. Respirable suspended particulates, averaged over each journey period, were found at higher concentrations (mean 130 μg m -3 ) than would be expected in indoor situations. Mean exposure to benzene (at 56 μg m -3 ) and other aromatic volatile organic compounds was also relatively high. The influence of wind conditions on exposure was found to be significant. Commuting exposures to carbon monoxide, respirable suspended particulates, and aromatic VOCs were found to be higher than exposures in a busy high street and on common parkland

  7. Chlorophyll a, Phaeopigments and particulate organic carbon in the northern and western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Radhakrishna, K.; Bhattathiri, P.M.A.; Devassy, V.P.

    Distribution of chl a at surface closely corresponds to the surface flow patterns. Integral mean concentration (IMC) of chl a in inshore waters (depth 200 m) is double than that in the offshore waters (depth 200 m) while IMC of particulate organic...

  8. Temperature dependence of photodegradation of dissolved organic matter to dissolved inorganic carbon and particulate organic carbon

    Czech Academy of Sciences Publication Activity Database

    Porcal, Petr; Dillon, P. J.; Molot, L. A.

    2015-01-01

    Roč. 10, č. 6 (2015), e0128884 E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GAP503/12/0781; GA ČR(CZ) GA15-09721S Institutional support: RVO:60077344 Keywords : dissolved organic carbon * particulate organic carbon * photodegradation * temperature Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.057, year: 2015

  9. Origin of particulate organic carbon in the marine atmosphere as indicated by it stable carbon isotopic composition

    International Nuclear Information System (INIS)

    Chesselet, R.; Fontugne, M.; Buat-Menard, P.; Ezat, U.; Lambert, C.E.

    1981-01-01

    Organic carbon concentration and isotopic composition were determined in samples of atmospheric particulate matter collected in 1979 at remote marine locations (Enewetak atoll, Sargasso Sea) during the SEAREX (Sea-Air Exchange) program field experiments. Atmospheric Particulate Organic Carbon (POC) concentrations were found to be in the range of 0.3 to 1.2 mg. m -3 , in agreement with previous literature data. The major mass of POC was found on the smallest particles (r 13 C/ 12 C of the small particles is close to the one expected (d 13 C = 26 +- 2 0 //sub infinity/) for atmospheric POC of continental origin. For all the samples analysed so far, it appears that more than 80% of atmospheric POC over remote marine areas is of continental origin. This can be explained either by long-range transport of small sized continental organic aserosols or by the production of POC in the marine atmosphere from a vapor phase organic carbon pool of continental origin. The POC in the large size fraction of marine aerosols ( 13 C = -21 +- 2 0 / 00 ) for POC associated with sea-salt droplets transported to the marine atmosphere

  10. Kuwaiti oil fires—Particulate monitoring

    Science.gov (United States)

    Husain, Tahir; Amin, Mohamed B.

    The total suspended particulate (TSP) matters using a high-volume sampler and inhalable particulate matters using PM-10 samplers were collected at various locations in the Eastern Province of Saudi Arabia during and after the Kuwaiti oil fires. The collected samples were analysed for toxic metals and oil hydrocarbon concentrations including some carcinogenic organic compounds in addition to gravimetric analysis. The concentration values of particulate matters were determined on a daily basis at Dhahran. Abqaiq, Rahima, Tanajib and Jubail locations. The analyses of the filters show a high concentration of the inhalable particulate at various locations, especially when north or northwest winds were blowing. It was found that the inhalable particulate concentration exceeded the Meteorology and Environmental Protection Administration (MEPA) permissible limit of 340 μg m- 3 at most of these locations during May-October 1991. A trend between the total suspended particulate and inhalable particulate measured concurrently at the same locations was observed and a regression equation was developed to correlate PM-10 data with the total suspended particulate data.

  11. Can particulate organic matter reveal emerging changes in soil organic carbon?

    DEFF Research Database (Denmark)

    Simonsson, Magnus; Kirchmann, Holger; Magid, Jakob

    2014-01-01

    different cropping systems, N fertilizer applications, and organic amendments, we found that C and N in the fine to medium sand fraction (0.063-0.600 mm, "Fraction B") showed considerably larger relative errors according to ANOVA (RMSE was 11-20% of the mean), slightly lower values of the F statistic......This study assessed whether particulate organic matter (POM) in sand fractions, isolated by wet sieving after treatment with Na hexametaphosphate, can be a sensitive indicator of incipient changes in the content and composition of soil organic matter. In five long-term field experiments including......, and slightly less contrast between treatments than total organic C and N (RMSE 3-9% of the mean). Imprecision in laboratory procedures only explained part of the increase in RMSE for C and N in Fraction B compared with total C and N; within-field spatial variability most likely had a greater influence...

  12. Submicron particulate organic matter in the urban atmosphere: a new method for real-time measurement, molecular-level characterization and source apportionment

    Science.gov (United States)

    Müller, Markus; Eichler, Philipp; D'Anna, Barbara; Tan, Wen; Wisthaler, Armin

    2017-04-01

    We used a novel chemical analytical method for measuring submicron particulate organic matter in the atmosphere of three European cities (Innsbruck, Lyon, Valencia). Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) was used in combination with the "chemical analysis of aerosol online" (CHARON) inlet for detecting particulate organic compounds on-line (i.e. without filter pre-collection), in real-time (1-min time resolution), at ng m-3 concentrations, with molecular-level resolution (i.e. obtaining molecular weight and elemental composition information). The CHARON-PTR-ToF-MS system monitored molecular tracers associated with different particle sources including levoglucosan from biomass combustion, PAHs from vehicular traffic, nicotine from cigarette smoking, and monoterpene oxidation products secondarily formed from biogenic emissions. The tracer information was used for interpreting positive matrix factorization (PMF) data which allowed us to apportion the sources of submicron particulate organic matter in the different urban environments. This work was funded through the PIMMS ITN, which was supported by the European Commission's 7th Framework Programme under grant agreement number 287382.

  13. Semivolatile Particulate Organic Material Southern Africa during SAFARI 2000

    Science.gov (United States)

    Eatough, D. J.; Eatough, N. L.; Pang, Y.; Sizemore, S.; Kirchstetter, T. W.; Novakov, T.

    2005-01-01

    During August and September 2000, the University of Washington's Cloud and Aerosol Research Group (CARG) with its Convair-580 research aircraft participated in the Southern African Fire-Atmosphere Research Initiative (SAFARI) 2000 field study in southern Africa. Aboard this aircraft was a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS), which was used to determine semivolatile particulate material with a diffusion denuder sampler. Denuded quartz filters and sorbent beds in series were used to measure nonvolatile and semivolatile materials, respectively. Results obtained with the PC-BOSS are compared to those obtained with conventional quartz-quartz and Teflon-quartz filter pack samplers. Various 10-120 min integrated samples were collected during flights through the h e troposphere, in the atmospheric boundary layer, and in plumes from savanna fires. Significant fine particulate semivolatile organic compounds (SVOC) were found in all samples. The SVOC was not collected by conventional filter pack samplers and therefore would not have been determined in previous studies that used only filter pack samplers. The SVOC averaged 24% of the fine particulate mass in emissions from the fires and 36% of the fine particulate mass in boundary layer samples heavily impacted by aged emissions from savanna fires. Concentrations of fine particulate material in the atmospheric mixed layer heavily impacted by aged savanna frre emissions averaged 130 micrograms per cubic meter. This aerosol was 85% carbonaceous mated.

  14. Organic, elemental and inorganic carbon in particulate matter of six urban environments in Europe

    Directory of Open Access Journals (Sweden)

    M. Sillanpää

    2005-01-01

    Full Text Available A series of 7-week sampling campaigns were conducted in urban background sites of six European cities as follows: Duisburg (autumn, Prague (winter, Amsterdam (winter, Helsinki (spring, Barcelona (spring and Athens (summer. The campaigns were scheduled to include seasons of local public health concern due to high particulate concentrations or findings in previously conducted epidemiological studies. Aerosol samples were collected in parallel with two identical virtual impactors that divide air particles into fine (PM2.5 and coarse (PM2.5-10 size ranges. From the collected filter samples, elemental (EC and organic (OC carbon contents were analysed with a thermal-optical carbon analyser (TOA; total Ca, Ti, Fe, Si, Al and K by energy dispersive X-ray fluorescence (ED-XRF; As, Cu, Ni, V, and Zn by inductively coupled plasma mass spectrometry (ICP/MS; Ca2+, succinate, malonate and oxalate by ion chromatography (IC; and the sum of levoglucosan+galactosan+mannosan (∑MA by liquid chromatography mass spectrometry (LC/MS. The campaign means of PM2.5 and PM2.5-10 were 8.3-29.6 µg m-3 and 5.4-28.7 µg m-3, respectively. The contribution of particulate organic matter (POM to PM2.5 ranged from 21% in Barcelona to 54% in Prague, while that to PM2.5-10 ranged from 10% in Barcelona to 27% in Prague. The contribution of EC was higher to PM2.5 (5-9% than to PM2.5-10 (1-6% in all the six campaigns. Carbonate (C(CO3, that interferes with the TOA analysis, was detected in PM2.5-10 of Athens and Barcelona but not elsewhere. It was subtracted from the OC by a simple integration method that was validated. The CaCO3 accounted for 55% and 11% of PM2.5-10 in Athens and Barcelona, respectively. It was anticipated that combustion emissions from vehicle engines affected the POM content in PM2.5 of all the six sampling campaigns, but a comparison of mass concentration ratios of the selected inorganic and organic tracers of common sources of organic material to POM suggested

  15. Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

    Science.gov (United States)

    Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G. E.; Leiva Guzmán, Manuel A.

    2014-01-01

    Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3) and the United States Environmental Protection Agency standard (15 µg/m3) for fine particulate matter. PMID:24587753

  16. Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

    Directory of Open Access Journals (Sweden)

    Richard Toro Araya

    2014-01-01

    Full Text Available Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007, concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August and warm (September to February seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41% than in the warm season (44 ± 18%. On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3 and the United States Environmental Protection Agency standard (15 µg/m3 for fine particulate matter.

  17. Carbonaceous aerosols in fine particulate matter of Santiago Metropolitan Area, Chile.

    Science.gov (United States)

    Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G E; Leiva Guzmán, Manuel A

    2014-01-01

    Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m(3)) and the United States Environmental Protection Agency standard (15 µg/m(3)) for fine particulate matter.

  18. Global chemical composition of ambient fine particulate matter for exposure assessment.

    Science.gov (United States)

    Philip, Sajeev; Martin, Randall V; van Donkelaar, Aaron; Lo, Jason Wai-Ho; Wang, Yuxuan; Chen, Dan; Zhang, Lin; Kasibhatla, Prasad S; Wang, Siwen; Zhang, Qiang; Lu, Zifeng; Streets, David G; Bittman, Shabtai; Macdonald, Douglas J

    2014-11-18

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004-2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m(3)), secondary inorganic aerosol (11.1 ± 5.0 μg/m(3)), and mineral dust (11.1 ± 7.9 μg/m(3)). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m(3) over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m(3)) could be almost as large as from fossil fuel combustion sources (17 μg/m(3)). These estimates offer information about global population exposure to the chemical components and sources of PM2.5.

  19. Chemical characteristics and source apportionment of fine particulate organic carbon in Hong Kong during high particulate matter episodes in winter 2003

    Science.gov (United States)

    Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Schauer, James J.; Yuan, Zibing; Lau, Alexis K. H.; Louie, Peter K. K.

    2013-02-01

    PM2.5 samples were collected at six general stations and one roadside station in Hong Kong in two periods of high particulate matter (PM) in 2003 (27 October-4 November and 30 November-13 December). The highest PM2.5 reached 216 μg m- 3 during the first high PM period and 113 μg m- 3 during the second high PM period. Analysis of synoptic weather conditions identified individual sampling days under dominant influence of one of three types of air masses, that is, local, regional and long-range transported (LRT) air masses. Roadside samples were discussed separately due to heavy influences from vehicular emissions. This research examines source apportionment of fine organic carbon (OC) and contribution of secondary organic aerosol on high PM days under different synoptic conditions. Six primary OC (POC) sources (vehicle exhaust, biomass burning, cooking, cigarette smoke, vegetative detritus, and coal combustion) were identified on the basis of characteristic organic tracers. Individual POC source contributions were estimated using chemical mass balance model. In the roadside and the local samples, OC was dominated by the primary sources, accounting for more than 74% of OC. In the samples influenced by regional and LRT air masses, secondary OC (SOC), which was approximated to be the difference between the total measured OC and the apportioned POC, contributed more than 54% of fine OC. SOC was highly correlated with water-soluble organic carbon and sulfate, consistent with its secondary nature.

  20. Elemental Composition In Airborne Particulate Sample Of Bandung and Lembang Region In 1999

    International Nuclear Information System (INIS)

    Hidayat, Achmad

    2003-01-01

    Concentration of airborne particulate of Bandung higher than that of Lembang. The PM2.5 fraction was in the range of 4,3 μg/m 3 to 21,1 μg/m 3 for Bandung area, and 2,9 μg/m 3 to 19,2 μg/m 3 for Lembang area for 24 hours sampling time. The PM10 fraction of Bandung area was in the range of 12,1 μg/m 3 to 44, 1 μg/m 3 , where a s the PM10 fraction of Lembang area was in the range of 5,2 μg/m 3 to 30,6 μg/m 3 . The data much lower than that of National ambient air quality standard for 24 hours, 65 μg/m 3 and 150 μg/m 3 for PM2.5 fraction and PM10 fraction respectively. No clear correlation either concentration of fine or coarse particulate to rainfall. For teen elements, which were Al, Br, Ca, Ce, CI, Cr, Fe, I, Mn, Na, Sb, Sc, V and Zn, were detected. The elements of Br, Ce, CI, Cr, I, Sb and Zn were enriched in fine and coarse of Bandung and Lembang samples, where as AI, Ca, Mn, Na and V were not enriched. The special element of Fe was enriched in fine particulate of Lembang, where as in particulate of Bandung was not enriched. Analysis of coarse particulate samples indicated the similar results to fine particulate except for Ce. The results of analysis explained that pollutant source of Bandung and Lembang were the same. Some elements such as Br, CI and I possibly come from organic material burning; Br and CI could be from motor vehicle; Cr, and Zn could be from paint factory; Zn and Sb could be from refuse incineration; while Ce could be from electronic factory. The calculation results indicated that enrichment factor of elements in fine particulate higher than that of coarse particulate. Furthermore the enrichment factor of element in airborne particulate of Bandung area was higher than that of airborne particulate of Lembang

  1. Fine scale distributions of porosity and particulate excess 210Pb, organic carbon and CaCO3 in surface sediments of the deep equatorial Pacific

    International Nuclear Information System (INIS)

    Jahnke, R.A.; Emerson, S.R.; Cochran, J.K.; Hirschberg, D.J.

    1986-01-01

    Sediment samples were recovered from the central equatorial Pacific Ocean, sectioned at 1-mm intervals, and analyzed for porosity, organic carbon, excess 210 Pb and CaCO 3 . Steep porosity gradients were measured in the upper 1 cm of the sediment column with extremely high values observed near the sediment surface. Similarly, particulate organic carbon contents are highest at the sediment surface, decrease sharply in the upper 1 cm, and are relatively constant between 1 and 5 cm. CaCO 3 values, on the other hand, are lowest at the sediment surface and increase to a constant value below 5-10 mm depth. At the carbonate ooze sites, excess 210 Pb is present throughout the upper 5 cm of the sediments suggesting relatively rapid particle mixing rates. However, extremely high excess 210 Pb activities (> 100 dpm/g) are observed at the sediment surface with sharp gradients present in the upper 1 cm which would suggest slow rates of mixing. This apparent contradiction along with the major features of the CaCO 3 and particulate organic carbon profiles can be explained by a particle-selective feeding mechanism in which organic carbon, excess 210 Pb-enriched particles are preferentially maintained at the sediment surface via ingestion and defecation by benthic organisms. (orig.)

  2. Particulate organic matter predicts bacterial productivity in a river dominated estuary

    Science.gov (United States)

    Crump, B. C.

    2015-12-01

    Estuaries act as coastal filters for organic and inorganic fluvial materials in which microbial, biogeochemical, and ecological processes combine to transform organic matter and nutrients prior to export to the coastal ocean. The function of this estuarine 'bioreactor' is linked to the residence times of those materials and to rates of microbial heterotrophic activity. Our ability to forecast the impact of global change on estuarine bioreactor function requires an understanding of the basic controls on microbial community activity and diversity. In the Columbia River estuary, the microbial community undergoes a dramatic seasonal shift in species composition during which a spring bacterioplankton community, dominated by Flavobacteriaceae and Oceanospirillales, is replaced by a summer community, dominated by Rhodobacteraceae and several common marine taxa. This annual shift occurs in July, following the spring freshet, when river flow and river chlorophyll concentration decrease and when estuarine water residence time increases. Analysis of a large dataset from 17 research cruises (1990-2014) showed that the composition of particulate organic matter in the estuary changes after the freshet with decreasing organic carbon and nitrogen content, and increasing contribution of marine and autochthonous estuarine organic matter (based on PO13C and pigment ratios). Bacterial production rates (measured as leucine or thymidine incorporation rates) in the estuary respond to this change, and correlate strongly with labile particulate nitrogen concentration and temperature during individual sampling campaigns, and with the concentration of chlorophyll in the Columbia River across all seasons. Regression models suggest that the concentration of labile particulate nitrogen and the rate of bacterial production can be predicted from sensor measurements of turbidity, salinity, and temperature in the estuary and chlorophyll in the river. These results suggest that the quality of

  3. Aged riverine particulate organic carbon in four UK catchments

    International Nuclear Information System (INIS)

    Adams, Jessica L.; Tipping, Edward; Bryant, Charlotte L.; Helliwell, Rachel C.; Toberman, Hannah; Quinton, John

    2015-01-01

    The riverine transport of particulate organic matter (POM) is a significant flux in the carbon cycle, and affects macronutrients and contaminants. We used radiocarbon to characterise POM at 9 riverine sites of four UK catchments (Avon, Conwy, Dee, Ribble) over a one-year period. High-discharge samples were collected on three or four occasions at each site. Suspended particulate matter (SPM) was obtained by centrifugation, and the samples were analysed for carbon isotopes. Concentrations of SPM and SPM organic carbon (OC) contents were also determined, and were found to have a significant negative correlation. For the 7 rivers draining predominantly rural catchments, PO 14 C values, expressed as percent modern carbon absolute (pMC), varied little among samplings at each site, and there was no significant difference in the average values among the sites. The overall average PO 14 C value for the 7 sites of 91.2 pMC corresponded to an average age of 680 14 C years, but this value arises from the mixing of differently-aged components, and therefore significant amounts of organic matter older than the average value are present in the samples. Although topsoil erosion is probably the major source of the riverine POM, the average PO 14 C value is appreciably lower than topsoil values (which are typically 100 pMC). This is most likely explained by inputs of older subsoil OC from bank erosion, or the preferential loss of high- 14 C topsoil organic matter by mineralisation during riverine transport. The significantly lower average PO 14 C of samples from the River Calder (76.6 pMC), can be ascribed to components containing little or no radiocarbon, derived either from industrial sources or historical coal mining, and this effect is also seen in the River Ribble, downstream of its confluence with the Calder. At the global scale, the results significantly expand available information for PO 14 C in rivers draining catchments with low erosion rates. - Highlights:

  4. Lability of Secondary Organic Particulate Matter

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Pengfei; Li, Yong Jie; Wang, Yan; Giles, Mary K.; Zaveri, Rahul A.; Bertram, Allan K.; Martin, Scot T.

    2016-10-24

    Accurate simulations of the consenctrations of atmospheric organic particulate matter (PM) are needed for predicting energy flow in the Earth’s climate system. In the past, simulations of organic PM widely assume equilibrium partitioning of semivolatile organic compounds (SVOCs) between the PM and surrounding vapor. Herein, we test this assumption by measuring evaporation rates and associated vapor mass concentration of organic films representative of atmospheric PM. For films representing anthropogenic PM, evaporation rates and vapor mass concentrations increased above a threshold relative humidity (RH), indicating equilibrium partitioning above a transition RH but not below. In contrast for films representing biogenic PM, no threshold was observed, indicating equilibrium partitioning at all RHs. The results suggest that the mass lability of atmospheric organic PM can differ in consequential ways among Earth’s natural biomes, polluted regions, and regions of land-use change, and these differences need to be considered when simulating atmospheric organic PM.

  5. Measurement of emissions of fine particulate organic matter from Chinese cooking

    Science.gov (United States)

    He, Ling-Yan; Hu, Min; Huang, Xiao-Feng; Yu, Ben-De; Zhang, Yuan-Hang; Liu, De-Quan

    Cooking emissions may contribute significantly to atmospheric organic particles in urban environment in China, and thus need to be examined first for its chemical compositions and characteristics. The particulate organic emissions of the two cooking styles of Chinese cuisine, that is, Hunan Cooking and Cantonese Cooking, were characterized in Shenzhen. More than half of the PM 2.5 mass is due to organic compounds, and over 90 species of organic compounds were identified and quantified, accounting for 26.1% of bulk organic particle mass and 20.7% of PM 2.5. Fatty acids, diacids and steroids were the major organic compounds emitted from both styles of cooking. Of the quantified organic mass, over 90% was fatty acids. The mass of organic species, and the molecular distribution of n-alkanes and PAHs indicated the dissimilarities between the two different cooking styles, but generally the major parts of the organic particulate emissions of the two restaurants were similar, showing less difference than between Chinese and American cooking.

  6. Characterization with 3H-haloperidol of the dopamine receptor in the rat kidney particulate preparation

    International Nuclear Information System (INIS)

    Nakajima, Tohru; Kuruma, Isami

    1980-01-01

    The dopamine receptor of rat kidney particulate preparation was identified and characterized by the use of 3 H-haloperidol binding. Binding of 3 H-haloperidol to the kidney particulate preparation was slow and saturable. The dissociation constants (K sub(D)) were 0.41 nM and 5.88 nM, respectively, according to the model of two classes of independent binding sites. Maximal binding of high affinity site was obtained with 166 fmole/mg protein which was about 40% of the total receptor density. A wide variety of neuroleptics at specifically low concentrations in nanomolar range inhibited the 3 H-haloperidol binding. There was an excellent correlation between the affinity of numerous neuroleptics for the kidney particulate preparation and that for the brain striatum. (author)

  7. Particulate organic matter in shelf waters of Prinsesse Asrid Kyst, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Bhosle, N.B.

    In the coastal and estuarine waters of Goa, particulate organic carbon (POC) varied from 0.52 to 2.51 mg l-1 and from 0.28 to 5.24 mg l-1 and particulate phosphorus (PP) varied from 0.71 to 5.18 mu g l-1 and from 0.78 to 20.34 mu g l-1, respectively...

  8. Cytotoxicity and genotoxicity properties of particulate matter fraction 2.5 μm

    Science.gov (United States)

    Bełcik, Maciej K.; Trusz-Zdybek, Agnieszka; Zaczyńska, Ewa; Czarny, Anna; Piekarska, Katarzyna

    2017-11-01

    In the ambient is more than 2,000 chemical substances, some of them are absorbed on the surface of the particulate matter and may causes many health problems. Air pollution is responsible for more than 3.2 million premature deaths which classifies it as a second place environmental risk factor. Especially dangerous for health are polycyclic aromatic hydrocarbons and their nitro- and amino derivatives which shows mutagenic and carcinogenic properties. Air pollutions were also classified by International Agency for Research on Cancer to group which carcinogenic properties on human were proved by available knowledge. Air pollutions, including particulate matter are one of the biggest problem in Polish cities. World Health Organization in report published in May 2016 set many of Polish cities on the top of the list most polluted in European Union. The article presents results of mutagenicity, genotoxicity and cytotoxicity researches conducted on a particulate matter fraction 2.5 μm collected during all year long in Wroclaw agglomeration. The material were collected on filters using high-flow air aspirator and extracted using dichloromethane. Additionally it was fractionated into 2 parts containing: all pollutants and only polycyclic aromatic hydrocarbons. Dry residue of this fractions were dissolving in DMSO and tested using biological methods. Biological methods include mutagenicity properties which are investigated by Salmonella assay (Ames assay). Other biological method was comet assay and 4 parameter cytotoxicity test PAN-I assay. Results of the conducted experiments shows differences in mutagenic, genotoxic and cytotoxic properties between seasons of collection and between volume of dust pollutions fractions. The worst properties shows particles collected in autumn and winter season and this containing only polycyclic aromatics hydrocarbons. Results showed also some correlations in results obtained during different methods and properties.

  9. Iron persistence in a distal hydrothermal plume supported by dissolved-particulate exchange

    Science.gov (United States)

    Fitzsimmons, Jessica N.; John, Seth G.; Marsay, Christopher M.; Hoffman, Colleen L.; Nicholas, Sarah L.; Toner, Brandy M.; German, Christopher R.; Sherrell, Robert M.

    2017-02-01

    Hydrothermally sourced dissolved metals have been recorded in all ocean basins. In the oceans' largest known hydrothermal plume, extending westwards across the Pacific from the Southern East Pacific Rise, dissolved iron and manganese were shown by the GEOTRACES program to be transported halfway across the Pacific. Here, we report that particulate iron and manganese in the same plume also exceed background concentrations, even 4,000 km from the vent source. Both dissolved and particulate iron deepen by more than 350 m relative to 3He--a non-reactive tracer of hydrothermal input--crossing isopycnals. Manganese shows no similar descent. Individual plume particle analyses indicate that particulate iron occurs within low-density organic matrices, consistent with its slow sinking rate of 5-10 m yr-1. Chemical speciation and isotopic composition analyses reveal that particulate iron consists of Fe(III) oxyhydroxides, whereas dissolved iron consists of nanoparticulate Fe(III) oxyhydroxides and an organically complexed iron phase. The descent of plume-dissolved iron is best explained by reversible exchange onto slowly sinking particles, probably mediated by organic compounds binding iron. We suggest that in ocean regimes with high particulate iron loadings, dissolved iron fluxes may depend on the balance between stabilization in the dissolved phase and the reversibility of exchange onto sinking particles.

  10. Aged riverine particulate organic carbon in four UK catchments

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Jessica L., E-mail: jesams@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP (United Kingdom); Tipping, Edward, E-mail: et@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP (United Kingdom); Bryant, Charlotte L., E-mail: charlotte.bryant@glasgow.ac.uk [NERC Radiocarbon Facility, East Kilbride G75 0QF, Scotland (United Kingdom); Helliwell, Rachel C., E-mail: rachel.helliwell@hutton.ac.uk [The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH Scotland (United Kingdom); Toberman, Hannah, E-mail: hannahtoberman@hotmail.com [Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster, LA1 4AP (United Kingdom); School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP (United Kingdom); Quinton, John, E-mail: j.quinton@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2015-12-01

    The riverine transport of particulate organic matter (POM) is a significant flux in the carbon cycle, and affects macronutrients and contaminants. We used radiocarbon to characterise POM at 9 riverine sites of four UK catchments (Avon, Conwy, Dee, Ribble) over a one-year period. High-discharge samples were collected on three or four occasions at each site. Suspended particulate matter (SPM) was obtained by centrifugation, and the samples were analysed for carbon isotopes. Concentrations of SPM and SPM organic carbon (OC) contents were also determined, and were found to have a significant negative correlation. For the 7 rivers draining predominantly rural catchments, PO{sup 14}C values, expressed as percent modern carbon absolute (pMC), varied little among samplings at each site, and there was no significant difference in the average values among the sites. The overall average PO{sup 14}C value for the 7 sites of 91.2 pMC corresponded to an average age of 680 {sup 14}C years, but this value arises from the mixing of differently-aged components, and therefore significant amounts of organic matter older than the average value are present in the samples. Although topsoil erosion is probably the major source of the riverine POM, the average PO{sup 14}C value is appreciably lower than topsoil values (which are typically 100 pMC). This is most likely explained by inputs of older subsoil OC from bank erosion, or the preferential loss of high-{sup 14}C topsoil organic matter by mineralisation during riverine transport. The significantly lower average PO{sup 14}C of samples from the River Calder (76.6 pMC), can be ascribed to components containing little or no radiocarbon, derived either from industrial sources or historical coal mining, and this effect is also seen in the River Ribble, downstream of its confluence with the Calder. At the global scale, the results significantly expand available information for PO{sup 14}C in rivers draining catchments with low erosion rates

  11. Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway

    International Nuclear Information System (INIS)

    Sysalová, Jiřina; Sýkorová, Ivana; Havelcová, Martina; Száková, Jiřina; Trejtnarová, Hana; Kotlík, Bohumil

    2012-01-01

    Urban particulate matter was collected in the most exposed area of Prague, near a busy highway, in order to provide petrographic and chemical characterization useful for health impact assessment in that locality or other applications. Samples were collected from filters of the air conditioning system in two years, 2009 and 2010, and sieved into four grain-size fractions: 0.507–0.119 mm, 0.119–0.063 mm, 3 extracted solutions. A composition of inorganic and carbonaceous particles of natural and anthropogenic origin and their morphology were studied by optical and electron microscopy. Organic solvent extracts of the samples were analyzed using gas chromatography to compare the organic compound distribution in fractions. Only slight differences between 2009 and 2010 years are visible. The relatively high extractable part of most investigated elements confirms mobility and potential availability to organisms. The changes can be recognized in the petrographic and organic composition in samples from both years, which were likely the result of various inputs of source materials. Specific organic marker compounds indicate contribution from fossil fuels, plant materials and bacteria. -- Highlights: ► Uncommon urban particulate matter collected near the highway in years 2009 and 2010 was deeply characterized. ► Harmful organic compounds and toxic analytes were tested in grain-size fractions and completed with electron microscopy studies. ► Very similar concentration levels were found in elemental composition in samples from two years. ► Petrographic and organic compositions were different in both samples. ► Relatively high mobility of selected analytes was found in 2M HNO 3 extracted solutions.

  12. Evidence of molybdenum association with particulate organic matter under sulfidic conditions

    DEFF Research Database (Denmark)

    Dahl, Tais Wittchen; Chappaz, A.; Hoek, Joost

    2017-01-01

    , consisting of mainly Mo(IV)-sulfide compounds with molecular structures similar to Mo enzymes and to those found in natural euxinic sediments. Therefore, we propose that Mo removal in natural sulfidic waters can proceed via a non-Fe-assisted pathway that requires particulate organic matter (dead or living......The geochemical behavior of molybdenum (Mo) in the oceans is closely linked to the presence of sulfide species in anoxic environments, where Fe availability may play a key role in the Mo scavenging. Here, we show that Mo(VI) is reduced in the presence of particulate organic matter (represented...

  13. Simulating the effects of light intensity and carbonate system composition on particulate organic and inorganic carbon production in Emiliania huxleyi.

    Science.gov (United States)

    Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

    2015-05-07

    Coccolithophores play an important role in the marine carbon cycle. Variations in light intensity and external carbonate system composition alter intracellular carbon fluxes and therewith the production rates of particulate organic and inorganic carbon. Aiming to find a mechanistic explanation for the interrelation between dissolved inorganic carbon fluxes and particulate carbon production rates, we develop a numerical cell model for Emiliania huxleyi, one of the most abundant coccolithophore species. The model consists of four cellular compartments, for each of which the carbonate system is resolved dynamically. The compartments are connected to each other and to the external medium via substrate fluxes across the compartment-confining membranes. By means of the model we are able to explain several pattern observed in particulate organic and inorganic carbon production rates for different strains and under different acclimation conditions. Particulate organic and inorganic carbon production rates for instance decrease at very low external CO2 concentrations. Our model suggests that this effect is caused mainly by reduced HCO3(-) uptake rates, not by CO2 limitation. The often observed decrease in particulate inorganic carbon production rates under Ocean Acidification is explained by a downregulation of cellular HCO3(-) uptake. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Source areas and chemical composition of fine particulate matter in the Pearl River Delta region of China

    Science.gov (United States)

    Hagler, G. S. W.; Bergin, M. H.; Salmon, L. G.; Yu, J. Z.; Wan, E. C. H.; Zheng, M.; Zeng, L. M.; Kiang, C. S.; Zhang, Y. H.; Lau, A. K. H.; Schauer, J. J.

    Fine particulate matter (PM 2.5) was measured for 4 months during 2002-2003 at seven sites located in the rapidly developing Pearl River Delta region of China, an area encompassing the major cities of Hong Kong, Shenzhen and Guangzhou. The 4-month average fine particulate matter concentration ranged from 37 to 71 μg m -3 in Guangdong province and from 29 to 34 μg m -3 in Hong Kong. Main constituents of fine particulate mass were organic compounds (24-35% by mass) and sulfate (21-32%). With sampling sites strategically located to monitor the regional air shed patterns and urban areas, specific source-related fine particulate species (sulfate, organic mass, elemental carbon, potassium and lead) and daily surface winds were analyzed to estimate influential source locations. The impact of transport was investigated by categorizing 13 (of 20 total) sampling days by prevailing wind direction (southerly, northerly or low wind-speed mixed flow). The vicinity of Guangzhou is determined to be a major source area influencing regional concentrations of PM 2.5, with levels observed to increase by 18-34 μg m -3 (accounting for 46-56% of resulting particulate levels) at sites immediately downwind of Guangzhou. The area near Guangzhou is also observed to heavily impact downwind concentrations of lead. Potassium levels, related to biomass burning, appear to be controlled by sources in the northern part of the Pearl River Delta, near rural Conghua and urban Guangzhou. Guangzhou appears to contribute 5-6 μg m -3 of sulfate to downwind locations. Guangzhou also stands out as a significant regional source of organic mass (OM), adding 8.5-14.5 μg m -3 to downwind concentrations. Elemental carbon is observed to be strongly influenced by local sources, with highest levels found in urban regions. In addition, it appears that sources outside of the Pearl River Delta contribute a significant fraction of overall fine particulate matter in Hong Kong and Guangdong province. This is evident

  15. Characterization with /sup 3/H-haloperidol of the dopamine receptor in the rat kidney particulate preparation

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, T; Kuruma, I [Nippon Roche Research Center, Kanagawa (Japan)

    1980-12-01

    The dopamine receptor of rat kidney particulate preparation was identified and characterized by the use of /sup 3/H-haloperidol binding. Binding of /sup 3/H-haloperidol to the kidney particulate preparation was slow and saturable. The dissociation constants (K sub(D)) were 0.41 nM and 5.88 nM, respectively, according to the model of two classes of independent binding sites. Maximal binding of high affinity site was obtained with 166 fmole/mg protein which was about 40% of the total receptor density. A wide variety of neuroleptics at specifically low concentrations in nanomolar range inhibited the /sup 3/H-haloperidol binding. There was an excellent correlation between the affinity of numerous neuroleptics for the kidney particulate preparation and that for the brain striatum.

  16. Particulate organic nitrates: Sampling and night/day variation

    DEFF Research Database (Denmark)

    Nielsen, T.; Platz, J.; Granby, K.

    1998-01-01

    Atmospheric day and night concentrations of particulate organic nitrates (PON) and several other air pollutants were measured in the summer 1995 over an open-land area in Denmark. The sampling of PON was evaluated comparing 24 h samples with two sets of 12 h samples. These results indicate...... that the observed low contribution of PON to NO, is real and not the result of an extensive loss during the sampling. Empirical relationships between the vapour pressure and chemical formula of organic compounds were established in order to evaluate the gas/particle distribution of organic nitrates. A positive...

  17. Organic speciation of size-segregated atmospheric particulate matter

    Science.gov (United States)

    Tremblay, Raphael

    Particle size and composition are key factors controlling the impacts of particulate matter (PM) on human health and the environment. A comprehensive method to characterize size-segregated PM organic content was developed, and evaluated during two field campaigns. Size-segregated particles were collected using a cascade impactor (Micro-Orifice Uniform Deposit Impactor) and a PM2.5 large volume sampler. A series of alkanes and polycyclic aromatic hydrocarbons (PAHs) were solvent extracted and quantified using a gas chromatograph coupled with a mass spectrometer (GC/MS). Large volume injections were performed using a programmable temperature vaporization (PTV) inlet to lower detection limits. The developed analysis method was evaluated during the 2001 and 2002 Intercomparison Exercise Program on Organic Contaminants in PM2.5 Air Particulate Matter led by the US National Institute of Standards and Technology (NIST). Ambient samples were collected in May 2002 as part of the Tampa Bay Regional Atmospheric Chemistry Experiment (BRACE) in Florida, USA and in July and August 2004 as part of the New England Air Quality Study - Intercontinental Transport and Chemical Transformation (NEAQS - ITCT) in New Hampshire, USA. Morphology of the collected particles was studied using scanning electron microscopy (SEM). Smaller particles (one micrometer or less) appeared to consist of solid cores surrounded by a liquid layer which is consistent with combustion particles and also possibly with particles formed and/or coated by secondary material like sulfate, nitrate and secondary organic aerosols. Source apportionment studies demonstrated the importance of stationary sources on the organic particulate matter observed at these two rural sites. Coal burning and biomass burning were found to be responsible for a large part of the observed PAHs during the field campaigns. Most of the measured PAHs were concentrated in particles smaller than one micrometer and linked to combustion sources

  18. Origin and fate of particulate and dissolved organic matter in a naturally iron-fertilized region of the Southern Ocean

    Science.gov (United States)

    Tremblay, L.; Caparros, J.; Leblanc, K.; Obernosterer, I.

    2015-01-01

    Natural iron fertilization of high-nutrient low-chlorophyll (HNLC) waters induces annually occurring spring phytoplankton blooms off the Kerguelen Islands (Southern Ocean). To examine the origin and fate of particulate and dissolved organic matter (POM and DOM), D- and L-amino acids (AA) were quantified at bloom and HNLC stations. Total hydrolyzable AA accounted for 21-25% of surface particulate organic carbon (%POCAA) at the bloom sites, but for 10% at the HNLC site. A marked decrease in %POCAA with depth was observed at the most productive stations leading to values between 3 and 5% below 300 m depth. AA contributed to only 0.9-4.4% of dissolved organic carbon (%DOCAA) at all stations. The only consistent vertical trend was observed at the most productive station (A3-2) where %DOCAA decreased from ~ 2% in the surface waters to 0.9% near 300 m. These AA yields revealed that POM and DOM were more rapidly altered or mineralized at the bloom sites compared to the HNLC site. Alteration state was also assessed by trends in C / N ratio, %D-AA and degradation index. Different molecular markers indicated that POM mostly originated from diatoms and bacteria. The estimated average proportion of POM from intact phytoplankton cells in surface waters was 45% at the bloom station A3-2, but 14% at the HNLC site. Estimates based on D-AA yields indicated that ~ 15% of POM and ~ 30% of DOM was of bacterial origin (cells and cell fragments) at all stations. Surprisingly, the DOM in HNLC waters appeared less altered than the DOM from the bloom, had slightly higher dissolved AA concentrations, and showed no sign of alteration within the water column. Unfavorable conditions for bacterial degradation in HNLC regions can explain these findings. In contrast, large inputs of labile organic molecules and iron likely stimulate the degradation of organic matter (priming effect) and the production of more recalcitrant DOM (microbial carbon pump) during iron-fertilized blooms.

  19. Identification and semi-quantification of biogenic organic nitrates in ambient particulate matters by UHPLC/ESI-MS

    Science.gov (United States)

    Li, Rui; Wang, Xinfeng; Gu, Rongrong; Lu, Chunying; Zhu, Fanping; Xue, Likun; Xie, Huijun; Du, Lin; Chen, Jianmin; Wang, Wenxing

    2018-03-01

    Particulate biogenic organic nitrates (PBONs) are important components of secondary organic aerosols and play an important role in the tropospheric atmosphere chemistry. However, the concentrations and the chemistry of PBONs remain poorly understood due to the lack of accurate measurement techniques on specific organic nitrates. In this study, ultra high performance liquid chromatography/electrospray mass spectrometry was applied in detection of individual PBONs in ambient atmosphere. Total five kinds of PBONs were identified in PM2.5 samples collected in urban Ji'nan in spring according to characteristic fragments of NO2, NO3, HNO3, CO2, and H2O, including monoterpene hydroxyl nitrate (MW = 215, MHN215), pinene keto nitrate (MW = 229, PKN229), limonene di-keto nitrate (MW = 247, LDKN247), oleic acid keto nitrate (MW = 359, OAKN359), and oleic acid hydroxyl nitrate (MW = 361, OAHN361). Among them, three kinds of PBONs originated from biogenic volatile organic compounds of pinene and limonene and two kinds of PBONs came from chemical conversion of oleic acid. The concentrations of these PBONs were roughly quantified with surrogate standards of (1R,2R,5R)-(+)-2-hydroxy-3-pinanone and ricinoleic acid. The average concentrations of MHN215, PKN229, LDKN247, OAKN359, and OAHN361 were 111.6 ± 23.0, 93.1 ± 49.6, 55.3 ± 7.4, 23.4 ± 14.5, 36.8 ± 18.3 ng m-3, respectively. The total concentration of these PBONs was 325.4 ± 116.7 ng m-3, contributing to 1.64 ± 0.34‰ of PM2.5.

  20. Satellite observation of particulate organic carbon dynamics in ...

    Science.gov (United States)

    Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical processes that influence POC sources and sinks. Using field observations and satellite ocean color products, we developed a nw multiple regression algorithm to estimate POC on the Louisiana Continental Shelf (LCS) from satellite observations. The algorithm had reliable performance with mean relative error (MRE) of ?40% and root mean square error (RMSE) of ?50% for MODIS and SeaWiFS images for POC ranging between ?80 and ?1200 mg m23, and showed similar performance for a large estuary (Mobile Bay). Substantial spatiotemporal variability in the satellite-derived POC was observed on the LCS, with high POC found on the inner shelf (satellite data with carefully developed algorithms can greatly increase

  1. Late summer particulate organic carbon export and twilight zone remineralisation in the Atlantic sector of the Southern Ocean

    Science.gov (United States)

    Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

    2013-02-01

    As part of the GEOTRACES Bonus-GoodHope (BGH) expedition (January-March 2008) in the Atlantic sector of the Southern Ocean, particulate organic carbon (POC) export was examined from the surface to the mesopelagic twilight zone using water column distributions of total 234Th and biogenic particulate Ba (Baxs). Surface POC export production was estimated from steady state and non steady state modelling of 234Th fluxes, which were converted into POC fluxes, using the POC/234Th ratio of large, potentially sinking particles (> 53 μm) collected via in situ pumps. Deficits in 234Th activities were observed at all stations from the surface to the bottom of the mixed layer, yielding 234Th export fluxes from the upper 100 m of 496 ± 214 dpm m-2 d-1 to 1195 ± 158 dpm m-2 d-1 for the steady state model and of 149 ±517 dpm m-2 d-1 to 1217 ± 231 dpm m-2 d-1 for the non steady state model. Using the POC/234Thp ratio of sinking particles (ratios varied from 1.7 ± 0.2 μmol dpm-1 to 4.8 ± 1.9 μmol dpm-1) POC export production at 100 m was calculated to range between 0.9 ± 0.4 and 5.1 ± 2.1 mmol C m-2 d-1,assuming steady state and between 0.3 ± 0.9 m-2 d-1 and 4.9 ± 3.3 mmol C m-2 d-1, assuming non steady state. From the comparison of both approaches, it appears that during late summer export decreased by 56 to 16% for the area between the sub-Antarctic zone and the southern Antarctic Circumpolar Current Front (SACCF), whereas it remained rather constant over time in the HNLC area south of the SACCF. POC export represented only 6 to 54% of new production, indicating that export efficiency was, in general, low, except in the vicinity of the SACCF, where export represented 56% of new production. Attenuation of the POC sinking flux in the upper mesopelagic waters (100-600 m depth interval) was evidenced both, from excess 234Th activities and from particulate biogenic Ba (Baxs) accumulation. Excess 234Th activities, reflected by 234Th/238U ratios as large as 1.21 ± 0

  2. Seasonal and spatial distribution of particulate organic matter in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L.; Bhosle, N.B.; Matondkar, S.G.P.; Bhushan, R.

    spatial differences were observed for the offshore stations in SPIM (Table 1). 3.4. POC and % POC In the Bay of Bengal, the surface POC concentrations ranged from 4.3 to 11.1 µMC, 3.1 to 10.9 µMC, and 4.3 to 9.0 µMC in the SWM, FIM, and SPIM.... This is NIO contribution no. 4435. 10 References Bale, A., Morris, A., 1998. Organic carbon in suspended particulate material in the North Sea: effect of mixing resuspended and background particles. Cont. Shelf Res. 18, 1333 –1345. Bates, N. R., Dennis, A...

  3. Molecular distribution and degradation status of combined aldoses in sinking particulate organic matter

    Science.gov (United States)

    Panagiotopoulos, C.; Sempéré, R.

    2003-04-01

    Particulate samples were collected by using floating sediment traps (50--300 m) and in situ pumps (30 and 200 m) in the Southern Indian Ocean (Polar Front Zone (PFZ) and Sub-Tropical Zone (STZ)), Mediterranean Sea (Ligurian and Ionian Seas) and Atlantic Ocean (Upwelling (UPW) of Agadir-Morocco). They were studied for monosaccharide composition after acid hydrolysis (HCl 0.09 M, 20 h, 100^oC) by using High Performance Anion Exchange Chromatography followed by Pulsed Amperometric Detection (HPAEC-PAD). Our results indicated that higher PCHO yields (calculated as PCHO-C/POC ratios) were associated to higher C:N ratios (Med. Sea sample, PCHO yields = 12.7 ± 7.7%; C:N ratios = 8.3 ± 1.6; n = 12) whether the opposite trend was found for Southern Ocean samples (PCHO yields = 3.3 ± 0.75%; C:N ratios = 5.7 ± 0.59, n = 5) indicating significant variability in the sugar content of particles which might be due to the degradation degree of the particles as well as to the initial chemical composition of plankton. Alternatively, other processes such as high production of extracellular polysaccharides (type transparent exopolymer polysaccharides (TEP)) due to phosphorus limitation of some phytoplanktonic species may increase the sugar content in Mediterranean particles and the C/N ratio. In any case, glucose appeared to be the most abundant monosaccharide in Mediterranean Sea or UPW samples (range 23--59 wt% of the total aldoses) whereas ribose (17--39 wt%) and galactose (range 10--28 wt%) were the predominant aldoses in Southern Indian Ocean. These sugars (glucose + ribose) exhibited a strong negative relationship with C:N (r = -0.53, p >0.01; n = 30) in sediment traps (data from this study) and sediment (data from literature) particulate material which further indicates that these two monosaccharides are selectively extracted from the carbohydrate pool in sediment. In vitro biodegradation experiments performed with large particles (>60 μm) sampled using in situ pumps in

  4. Effects of airborne particulate matter on alternative pre-mRNA splicing in colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Buggiano, Valeria; Petrillo, Ezequiel; Alló, Mariano; Lafaille, Celina [Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires (Argentina); Redal, María Ana [Instituto de Ciencias Básicas y Medicina Experimental, Hospital Italiano de Buenos Aires (Argentina); Alghamdi, Mansour A. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Khoder, Mamdouh I. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah (Saudi Arabia); Shamy, Magdy [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Muñoz, Manuel J., E-mail: mmunoz@fbmc.fcen.uba.ar [Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires (Argentina); and others

    2015-07-15

    Alternative pre-mRNA splicing plays key roles in determining tissue- and species-specific cell differentiation as well as in the onset of hereditary disease and cancer, being controlled by multiple post- and co-transcriptional regulatory mechanisms. We report here that airborne particulate matter, resulting from industrial pollution, inhibits expression and specifically affects alternative splicing at the 5′ untranslated region of the mRNA encoding the bone morphogenetic protein BMP4 in human colon cells in culture. These effects are consistent with a previously reported role for BMP4 in preventing colon cancer development, suggesting that ingestion of particulate matter could contribute to the onset of colon cell proliferation. We also show that the underlying mechanism might involve changes in transcriptional elongation. This is the first study to demonstrate that particulate matter causes non-pleiotropic changes in alternative splicing. - Highlights: • Airborne particulate matter (PM10) affects alternative splicing in colon cells. • PM10 upregulates one of the two mRNA variants of the growth factor BMP-4. • This variant has a longer 5′ unstranslated region and introduces an upstream AUG. • By regulating BMP-4 mRNA splicing PM10 inhibits total expression of BMP-4 protein. • BMP-4 downregulation was previously reported to be associated to colon cancer.

  5. Coarse Particulate Organic Matter: Storage, Transport, and Retention

    Energy Technology Data Exchange (ETDEWEB)

    Tiegs, Scott [Oakland University, Rochester, MI; Lamberti, Gary A. [University of Notre Dame, IN; Entrekin, Sally A. [University of Central Arkansas; Griffiths, Natalie A. [ORNL

    2017-08-01

    Coarse particulate organic matter, or CPOM, is a basal energy and nutrient resource in many stream ecosystems and is provided by inputs from the riparian zone, incoming tributaries, and to a lesser extent from in-stream production. The ability of a stream to retain CPOM or slow its transport is critical to its consumption and assimilation by stream biota. In this chapter, we describe basic exercises to measure (1) the amount of CPOM in the streambed and (2) the retention of CPOM from standardized particle releases. We further describe advanced exercises that (1) experimentally enhance the retentiveness of a stream reach and (2) measure organic carbon transport and turnover (i.e., spiraling) in the channel.

  6. Coarse Particulate Organic Matter: Storage, Transport, and Retention

    Energy Technology Data Exchange (ETDEWEB)

    Tiegs, Scott [Oakland University, Rochester, MI; Lamberti, Gary A. [University of Notre Dame, IN; Entrekin, Sally A. [University of Central Arkansas; Griffiths, Natalie A. [ORNL

    2017-06-01

    Coarse particulate organic matter, or CPOM, is a basal energy and nutrient resource in many stream ecosystems and is provided by inputs from the riparian zone, incoming tributaries, and to a lesser extent from in-stream production. The ability of a stream to retain CPOM or slow its transport is critical to its consumption and assimilation by stream biota. In this chapter, we describe basic exercises to measure (1) the amount of CPOM in the streambed and (2) the retention of CPOM from standardized particle releases. We further describe advanced exercises that (1) experimentally enhance the retentiveness of a stream reach and (2) measure organic carbon transport and turnover (i.e., spiraling) in the channel.

  7. Organic and elemental carbon bound to particulate matter in the air of printing office and beauty salon

    Science.gov (United States)

    Rogula-Kopiec, Patrycja; Pastuszka, Józef S.; Rogula-Kozłowska, Wioletta; Mucha, Walter

    2017-11-01

    The aim of this study was to determine the role of internal sources of emissions on the concentrations of total suspended particulate matter (TSP) and its sub-fraction, so-called respirable PM (PM4; fraction of particles with particle size ≤ 4 µm) and to estimate to which extent those emissions participate in the formation of PM-bound elemental (EC) and organic (OC) carbon in two facilities - one beauty salon and one printing office located in Bytom (Upper Silesia, Poland). The average concentration of PM in the printing office and beauty salon during the 10-day measurement period was 10 and 4 (PM4) and 8 and 3 (TSP) times greater than the average concentration of PM fractions recorded in the same period in the atmospheric air; it was on average: 204 µg/m3 (PM4) and 319 µg/m3 (TSP) and 93 µg/m3 (PM4) and 136 µg/m3 (TSP), respectively. OC concentrations determined in the printing office were 38 µg/m3 (PM4) and 56 µg/m3 (TSP), and those referring to EC: 1.8 µg/m3 (PM4) and 3.5 µg/m3 (TSP). In the beauty salon the average concentration of OC for PM4 and TSP were 58 and 75 µg/m3, respectively and in case of EC - 3.1 and 4.7 µg/m3, respectively. The concentrations of OC and EC within the those facilities were approximately 1.7 (TSP-bound EC, beauty salon) to 4.7 (TSP-bound OC, printing office) times higher than the average atmospheric concentrations of those compounds measured in both PM fractions at the same time. In both facilities the main source of TSP-and PM4-bound OC in the indoor air were the chemicals - solvents, varnishes, paints, etc.

  8. Impacts of traffic emissions on atmospheric particulate nitrate and organics at a downwind site on the periphery of Guangzhou, China

    Science.gov (United States)

    Qin, Yi Ming; Tan, Hao Bo; Jie Li, Yong; Schurman, Misha I.; Li, Fei; Canonaco, Francesco; Prévôt, André S. H.; Chan, Chak K.

    2017-09-01

    Particulate matter (PM) pollution on the peripheries of Chinese megacities can be as serious as in cities themselves. Given the substantial vehicular emissions in inner-city areas, the direct transport of primary PM (e.g., black carbon and primary organics) and effective formation of secondary PM from precursors (e.g., NOx and volatile organic compounds) can contribute to PM pollution in buffer zones between cities. To investigate how traffic emissions in inner-city areas impact these adjacent buffer zones, a suite of real-time instruments were deployed in Panyu, downwind from central Guangzhou, from November to December 2014. Nitrate mass fraction was higher on high-PM days, with the average nitrate-to-sulfate ratio increasing from around 0.35 to 1.5 as the PM mass concentration increased from 10 to 160 µg m-3. Particulate nitrate was strongly correlated with excess ammonium (([NH4+] / [SO42-] - 1.5) × [SO42-]), with higher concentrations in December than in November due to lower temperatures. The organic mass fraction was the highest across all PM1 levels throughout the campaign. While organic aerosols (OA) were dominated by secondary organic aerosols (SOA = semi-volatile oxygenated organic aerosols + low-volatility oxygenated organic aerosols) as a campaign average, freshly emitted hydrocarbon-like organic aerosols (HOA) contributed up to 40 % of OA during high-OA periods, which typically occurred at nighttime and contributed 23.8 to 28.4 % on average. This was due to daytime traffic restrictions on heavy-duty vehicles in Guangzhou, and HOA almost increased linearly with total OA concentration. SOA increased as odd oxygen (Ox = O3 + NO2) increased during the day due to photochemistry. A combination of nighttime traffic emissions and daytime photochemistry contributed to the buildup of PM in Panyu. The mitigation of PM pollution in inner-city areas by reducing vehicular traffic can potentially improve air quality in peripheral areas.

  9. Multispectral remote-sensing algorithms for particulate organic carbon (POC): The Gulf of Mexico

    OpenAIRE

    Son, Young Baek; Gardner, Wilford D.; Mishonov, Alexey V.; Richardson, Mary Jo

    2009-01-01

    To greatly increase the spatial and temporal resolution for studying carbon dynamics in the marine environment, we have developed remote-sensing algorithms for particulate organic carbon (POC) by matching in situ POC measurements in the Gulf of Mexico with matching SeaWiFS remote-sensing reflectance. Data on total particulate matter (PM) as well as POC collected during nine cruises in spring, summer and early winter from 1997-2000 as part of the Northeastern Gulf of Mexico (NEGOM) study were ...

  10. Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

    Science.gov (United States)

    Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical process...

  11. Characteristics and source appointment of atmospheric particulate mercury over East China Sea: Implication on the deposition of atmospheric particulate mercury in marine environment.

    Science.gov (United States)

    Duan, Lian; Cheng, Na; Xiu, Guangli; Wang, Fujiang; Chen, Ying

    2017-05-01

    Total Suspended Particulate (TSP) samples were collected at Huaniao Island in northern East China Sea (ECS) from March 2012 to January 2013. Chemical analysis were conducted to measure the concentration of total particulate mercury (TPM) and speciated particulate mercury including HCl-soluble particulate mercury (HPM), elemental particulate mercury (EPM) and residual particulate mercury (RPM). The bromine (Br) and iodine (I) on particles were also detected. The mean concentration of TPM during the study period was 0.23 ± 0.15 ng m -3 , while the obviously seasonal variation was found that the concentrations of TPM in spring, summer, fall and winter were 0.34 ± 0.20 ng m -3 , 0.15 ± 0.03 ng m -3 , 0.15 ± 0.05 ng m -3 and 0.27 ± 0.26 ng m -3 , respectively. The statistically strong correlation of bromine and iodine to HPM was only found in spring with r = 0.81 and 0.77 (p mercury due to the deposition of mercury over the sea. The cluster of air mass across the sea had low concentration of HPM in winter, which suggested that the oxidation of mercury in winter might be related to other oxidants. During the whole sampling period, the air mass from the north of China contributed to the higher concentration of TPM in Huaniao Island. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Seasonal Variation in the Quality of Dissolved and Particulate Organic Matter Exchanged Between a Salt Marsh and Its Adjacent Estuary

    Science.gov (United States)

    Osburn, C. L.; Mikan, M.; Etheridge, J. R.; Burchell, M. R.; Birgand, F.

    2015-12-01

    Salt marshes are transitional ecosystems between terrestrial and marine environments. Along with mangroves and other vegetated coastal habitats, salt marshes rank among the most productive ecosystems on Earth, with critical global importance for the planet's carbon cycle. Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October of 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components modeled, we used multiple linear regression to identify tracers for recalcitrant DOM; labile soil-derived source DOM; detrital POM; and planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m-2 yr-1 and labile DOC export was 49 g C m-2 yr-1. The marsh also exported 41 g C m-2 yr-1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m-2 yr-1. Using the DOM and POM quality results obtained via fluorescence measurements and scaling up to global salt marsh area, we estimated that the potential release of CO2 from the respiration of salt marsh DOC and POC transported to estuaries could be 11 Tg C yr-1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.

  13. Highly Viscous States Affect the Browning of Atmospheric Organic Particulate Matter.

    Science.gov (United States)

    Liu, Pengfei; Li, Yong Jie; Wang, Yan; Bateman, Adam P; Zhang, Yue; Gong, Zhaoheng; Bertram, Allan K; Martin, Scot T

    2018-02-28

    Initially transparent organic particulate matter (PM) can become shades of light-absorbing brown via atmospheric particle-phase chemical reactions. The production of nitrogen-containing compounds is one important pathway for browning. Semisolid or solid physical states of organic PM might, however, have sufficiently slow diffusion of reactant molecules to inhibit browning reactions. Herein, organic PM of secondary organic material (SOM) derived from toluene, a common SOM precursor in anthropogenically affected environments, was exposed to ammonia at different values of relative humidity (RH). The production of light-absorbing organonitrogen imines from ammonia exposure, detected by mass spectrometry and ultraviolet-visible spectrophotometry, was kinetically inhibited for RH atmospheric brown carbon production and associated influences on energy balance.

  14. Relationship between indoor and outdoor carbonaceous particulates in roadside households

    Energy Technology Data Exchange (ETDEWEB)

    Funasaka, K.; Miyazaki, T.; Tsuruho, K. [Osaka City Institute of Public Health and Environmental Sciences (Japan); Tamura, K. [The National Institute for Minamata Disease, Kumamoto (Japan); Mizuno, T. [Mie University (Japan). Dept. of Chemistry for Materials; Kuroda, K. [Osaka City University Medical School (Japan). Dept. of Preventive Medicine and Environmental Health

    2000-07-01

    Concentrations of particulate matter (PM) and carbonaceous particulates in indoor and outdoor air at roadside private households were measured in Osaka, Japan. The particulate samples were collected on filters using a portable AND sampler capable of separating particles into three different size ranges: over 10 {mu}m, 2-10 {mu}m (coarse) and below 2 {mu}m (fine) in aerodynamic diameter. The filters were weighed and then analyzed for elemental carbon (EC) and organic carbon (OC) by thermal oxidation using a CHN CORDER. The results showed that indoor fine PM concentration is considerably affected by fine EC and the fine EC in indoor air is significantly correlated to that in outdoor air, r = 0.86 (n = 30, p < 0.001). A simple estimation from EC content ratio in diesel exhaust particles indicated that about 30% of indoor particulates of less than 10 {mu}m (PM10) were contributed from diesel exhaust. Additionally, the size characteristics of outdoor PM at roadside and background sites were examined using Andersen Cascade Impactors. (author)

  15. Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

    Science.gov (United States)

    Huang, Changchun; Jiang, Quanliang; Yao, Ling; Yang, Hao; Lin, Chen; Huang, Tao; Zhu, A.-Xing; Zhang, Yimin

    2018-03-01

    We examined the relationship between, and variations in, particulate organic carbon (POC) and particulate organic nitrogen (PON) based on previously acquired ocean and inland water data. The latitudinal dependency of POC / PON is significant between 20 and 90° N but weak in low-latitude areas and in the Southern Hemisphere. The mean values of POC / PON in the Southern Hemisphere and Northern Hemisphere were 7.40 ± 3.83 and 7.80 ± 3.92, respectively. High values of POC / PON appeared between 80-90 (12.2 ± 7.5) and 70-80° N (9.4 ± 6.4), while relatively low POC / PON was found from 20 (6.6 ± 2.8) to 40° N (6.7 ± 2.7). The latitudinal variation of POC / PON in the Northern Hemisphere is much stronger than in the Southern Hemisphere due to the influence of more terrestrial organic matter. Higher POC and PON could be expected in coastal waters. POC / PON growth ranged from 6.89 ± 2.38 to 7.59 ± 4.22 in the Northern Hemisphere, with an increasing rate of 0.0024 km from the coastal to open ocean. Variations of POC / PON in lake water also showed a similar latitude-variation tendency of POC / PON with ocean water but were significantly regulated by the lakes' morphology, trophic state and climate. Small lakes and high-latitude lakes prefer relatively high POC / PON, and large lakes and low-latitude lakes tend to prefer low POC / PON. The coupling relationship between POC and PON in oceans is much stronger than in inland waters. Variations in POC, PON and POC / PON in inland waters should receive more attention due to the implications of these values for the global carbon and nitrogen cycles and the indeterminacy of the relationship between POC and PON.

  16. Processes and modeling of hydrolysis of particulate organic matter in aerobic wastewater tratment - A review

    DEFF Research Database (Denmark)

    Morgenroth, Eberhard Friedrich; Kommedal, Roald; Harremoës, Poul

    2002-01-01

    Carbon cycling and the availability of organic carbon for nutrient removal processes are in most wastewater treatment systems restricted by the rate of hydrolysis of slowly biodegradable (particulate) organic matter. To date, the mechanisms of hydrolysis are not well understood for complex...

  17. Bioavailable dissolved and particulate organic carbon flux from coastal temperate rainforest watersheds

    Science.gov (United States)

    Fellman, J.; Hood, E. W.; D'Amore, D. V.; Moll, A.

    2017-12-01

    Coastal temperate rainforest (CTR) watersheds of southeast Alaska have dense soil carbon stocks ( 300 Mg C ha-1) and high specific discharge (1.5-7 m yr-1) driven by frontal storms from the Gulf of Alaska. As a result, dissolved organic carbon (DOC) fluxes from Alaskan CTR watersheds are estimated to exceed 2 Tg yr-1; however, little is known about the export of particulate organic carbon (POC). The magnitude and bioavailability of this land-to-ocean flux of terrigenous organic matter ultimately determines how much metabolic energy is translocated to downstream and coastal marine ecosystems in this region. We sampled streamwater weekly from May through October from four watersheds of varying landcover (gradient of wetland to glacial coverage) to investigate changes in the concentration and flux of DOC and POC exported to the coastal ocean. We also used headspace analysis of CO2 following 14 day laboratory incubations to determine the flux of bioavailable DOC and POC exported from CTR watersheds. Across all sites, bioavailable DOC concentrations ranged from 0.2 to 1.9 mg L-1 but were on average 0.6 mg L-1. For POC, bioavailable concentrations ranged from below detection to 0.3 mg L-1 but were on average 0.1 mg L-1. The concentration, flux and bioavailability of DOC was higher than for POC highlighting the potential importance of DOC as a metabolic subsidy to downstream and coastal environments. Ratios of DOC to POC decreased during high flow events because the increase in POC concentrations with discharge exceeds that for DOC. Overall, our findings suggest that projected increases in precipitation and storm intensity will drive changes in the speciation, magnitude and bioavailability of the organic carbon flux from CTR watersheds.

  18. SEASONAL ABUNDANCE OF ORGANIC MOLECULAR MARKERS IN URBAN PARTICULATE MATTER FROM PHILADELPHIA, PA

    Science.gov (United States)

    Organic molecular markers were measured in airborne particulate matter (PM10) from the City of Philadelphia North Broad Street air quality monitoring site to identify the seasonal abundances of key tracer compounds together with their dominant sources. Daily PM10...

  19. Variation of particulate organic carbon and its relationship with bio-optical properties during a phytoplankton bloom in the Pearl River estuary

    International Nuclear Information System (INIS)

    Wang Guifen; Zhou Wen; Cao Wenxi; Yin Jianping; Yang Yuezhong; Sun Zhaohua; Zhang Yuanzhi; Zhao Jun

    2011-01-01

    Highlights: → A study about relationship between POC and optical properties during a phytoplankton bloom. → Empirical algorithms for retrieving POC concentration from optical data were developed. → Phytoplankton carbon and it's ratio to Chl-a are estimated and discussed. → Demonstrates that marine optical buoy can be a new platform for monitoring biogeochemical cycle. - Abstract: In this study, variations in the particulate organic carbon (POC) were monitored during a phytoplankton bloom event, and the corresponding changes in bio-optical properties were tracked at one station (114.29 o E, 22.06 o N) located in the Pearl River estuary. A greater than 10-fold increase in POC (112.29-1173.36 mg m -3 ) was observed during the bloom, with the chlorophyll a concentration (Chl-a) varying from 0.984 to 25.941 mg m -3 . A power law function is used to describe the relationship between POC and Chl-a, and the POC:Chl-a ratio tends to change inversely with Chl-a. Phytoplankton carbon concentration is indirectly estimated using the conceptual model proposed by , and this carbon is found to contribute 47.21% (±10.65%) to total POC. The estimated carbon-to-chlorophyll ratio of phytoplankton in diatom-dominated waters is found to be comparable with results reported in the literature. Empirical algorithms for determining the concentrations of Chl-a and POC were developed based on the relationships of these variables with the blue-to-green reflectance ratio. With these bio-optical models, the levels of particulate organic carbon and Chl-a could be predicted from the radiometric data measured by a marine optical buoy, which showed much more detailed information about the variability in biogeochemical parameters during this bloom event.

  20. Advanced Hybrid Particulate Collector Project Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.

    1995-11-01

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the best method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting

  1. Particulate organic matter in the coastal and estuarine waters of Goa and its relationship with phytoplankton production

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Qasim, S.Z.

    In the coastal and estuarine waters of Goa, particulate organic carbon (POC) varied from 0.52 to 2.51 mg l-1 and from 0.28 to 5.24 mg l-1 and particulate phosphorus (PP) varied from 0.71 to 5.18 mu g l-1 and from 0.78 to 20.34 mu g l-1, respectively...

  2. Fine particulate matter (PM) and organic speciation of fireplace emissions

    International Nuclear Information System (INIS)

    Purvis, C.R.; McCrillis, R.C.; Kariher, P.H.

    2000-01-01

    This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an ongoing project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory-built fireplaces. RWC wood smoke particles <10 microm (PM10) consist primarily of a mixture of organic compounds that have condensed into droplets; therefore, the size distribution and total mass are influenced by temperature of the sample during its collection. During the series 1 tests (15 tests), the dilution tunnel used to cool and dilute the stack gases gave an average mixed gas temperature of 47.3 C and an average dilution ration of 4.3. Averages for the PM2.5 (particles <2.5 microm) and PM10 fractions were 74 and 84%, respectively. For the series 2 tests, the dilution tunnel was modified, reducing the average mixed gas temperatures to 33.8 C and increasing the average dilution ratio to 11.0 in tests completed to date. PM2.5 and PM10 fractions were 83 and 91%, respectively. Since typical winter-time mixed gas temperatures would usually be less than 10 C, these size fraction results probably represent the lower bound; the PM10 and PM2.5 size fraction results might be higher at typical winter temperatures. The particles collected on the first stage were light gray and appeared to include inorganic ash. Particles collected on the remainder of the stages were black and appeared to be condensed organics because there was noticeable lateral bleeding of the collected materials into the filter substrate. Total particulate emission rates ranged from 10.3 to 58.4 g/h; corresponding emission factors ranged from 3.3 to 14.9 g/kg of dry wood burned. A wide range of Environmental Protection Agency (EPA) Method 8270 semivolatile organic compounds were found in the emissions; of the 17 target compounds quantified, major constituents are phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, and naphthalene

  3. Sorption of polycyclic aromatic hydrocarbons on particulate organic matters

    International Nuclear Information System (INIS)

    Guo Xueyan; Luo Lei; Ma Yibing; Zhang Shuzhen

    2010-01-01

    Particulate organic matter (POM) is a key organic matter fraction which can influence soil fertility. Its interactions with hydrophobic organic pollutants (HOCs) have not been characterized and the mechanisms of retention of HOCs by POM remain unclear. In the present study, sorption behaviors of polycyclic aromatic hydrocarbons (PAHs) naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR) by POMs separated from different soils were examined and the POMs were characterized by elemental analysis, solid state 13 C NMR, and Fourier transform infrared spectroscopy (FT-IR). The results indicated that POMs were mainly composed of aliphatic components with high polarity. The different original POMs showed similar chemical composition and configuration. Sorption behaviors of PAHs indicated that there was no significant difference in sorption capacity among the POMs. Sorption of NAP and PHE by POMs displayed a nonlinear isotherm, while sorption of PYR yielded a linear isotherm. No significant hysteresis and ionic strength effect were observed for PAH desorption from the POMs.

  4. Distribution and sources of particulate organic matter in the Indian monsoonal estuaries during monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Krishna, M.S.; Prasad, V.R.; Kumar, B.S.K.; Naidu, S.A.; Rao, G.D.; Viswanadham, R.; Sridevi, T.; Kumar, P.P.; Reddy, N.P.C.

    The distribution and sources of particulate organic carbon (POC) and nitrogen (PN) in 27 Indian estuaries were examined during the monsoon using the content and isotopic composition of carbon and nitrogen. Higher phytoplankton biomass was noticed...

  5. The dynamic ocean biological pump: Insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic

    Science.gov (United States)

    Lam, Phoebe J.; Doney, Scott C.; Bishop, James K. B.

    2011-09-01

    We have compiled a global data set of 62 open ocean profiles of particulate organic carbon (POC), CaCO3, and opal concentrations collected by large volume in situ filtration in the upper 1000 m over the last 30 years. We define concentration-based metrics for the strength (POC concentration at depth) and efficiency (attenuation of POC with depth in the mesopelagic) of the biological pump. We show that the strength and efficiency of the biological pump are dynamic and are characterized by a regime of constant and high transfer efficiency at low to moderate surface POC and a bloom regime where the height of the bloom is characterized by a weak deep biological pump and low transfer efficiency. The variability in POC attenuation length scale manifests in a clear decoupling between the strength of the shallow biological pump (e.g., POC at the export depth) and the strength of the deep biological pump (POC at 500 m). We suggest that the paradigm of diatom-driven export production is driven by a too restrictive perspective on upper mesopelagic dynamics. Indeed, our full mesopelagic analysis suggests that large, blooming diatoms have low transfer efficiency and thus may not export substantially to depth; rather, our analysis suggests that ecosystems characterized by smaller cells and moderately high %CaCO3 have a high mesopelagic transfer efficiency and can have higher POC concentrations in the deep mesopelagic even with relatively low surface or near-surface POC. This has negative implications for the carbon sequestration prospects of deliberate iron fertilization.

  6. [Distribution and source of particulate organic carbon and particulate nitrogen in the Yangtze River Estuary in summer 2012].

    Science.gov (United States)

    Xing, Jian-Wei; Xian, Wei-Wei; Sheng, Xiu-Zhen

    2014-07-01

    Based on the data from the cruise carried out in August 2012 in the Yangtze River Estuary and its adjacent waters, spatial distributions of particulate organic carbon (POC), particulate nitrogen (PN) and their relationships with environmental factors were studied, and the source of POC and the contribution of phytoplankton to POC were analyzed combined with n (C)/n (N) ratio and chlorophyll a (Chl a) in the Yangtze River Estuary in summer 2012. The results showed that the concentrations of POC in the Yangtze River Estuary ranged from 0.68 mg x L(-1) to 34.80 mg x L(-1) in summer and the average content was 3.74 mg x L(-1), and PN contents varied between 0.03 mg x L(-1) and 9.13 mg x L(-1) with an average value of 0.57 mg x L(-1). Both of them presented that the concentrations in bottom layers were higher than those in the surface. POC and PN as well as total suspended matter (TSM) showed a extremel similar horizontal distribution trend that the highest values appeared in the near of the mouth and southwest of the survey waters, and decreased rapidly as toward the open seas, both of them showed higher contents in coastal zones and lower in outer sea. There was a fairly good positive linear relationship between POC and PN, which indicated that they had the same source. POC and PN expressed significantly positive correlations with TSM and chemical oxygen demand (COD), but showed relatively weak correlations with salinit and chlorophyll a, which demonstrated that terrestrial inputs had a strong influence on the distribution of POC and PN, and phytoplankton production was not the major source of organic matters in the Yangtze River Estuary. Both the n (C)/n (N) ratio and POC/Chl a analysis showed that the main source of POC was terrestrial inputs, and organic debris was the main existence form of POC. Quantitative analysis showed the biomass of phytoplankton only made an average of 2.54% contribution to POC in the Yangtze Rive Estuary in summer and non-living POC

  7. Hydrolysis and degradation of filtrated organic particulates in a biofilm reactor under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Janning, K.F.; Mesterton, K.; Harremoës, P.

    1997-01-01

    Two experiments were performed in order to investigate the anoxic and the aerobic degradation of filtrated organic matter in a biofilter. In submerged lab: scale reactors with Biocarbone media as filter material, accumulated particulate organic matter from pre-settled wastewater served as the only...

  8. Determination of metallo-organic and particulate wear metals in lubricating oils associated with hybrid ceramic bearings by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Russell, Robin Ann

    It is possible to increase both the performance and operating environment of jet engines by using hybrid ceramic bearings. Our laboratory is concerned with investigating lubricating fluids for wear metals associated with silicon nitride ball bearings and steel raceways. Silicon nitride is characterized by low weight, low thermal expansion, high strength, and corrosion resistance. These attributes result in longer engine lifetimes than when metallic ball bearings are used. Before the routine use of ceramic ball bearings can be realized, the wear mechanisms of the materials should be thoroughly understood. One important variable in determining wear degradation is the concentration of metal present in the lubricating oils used with the bearings. A complete method for analyzing used lubricating oils for wear metal content must accurately determine all metal forms present. Oil samples pose problems for routine analysis due to complex organic matrices. Nebulizing these types of samples into an Inductively Coupled Plasma - Mass Spectrometer introduces many problems including clogging of the sample cone with carbon and increasing interferences. In addition, other techniques such as Atomic Absorption Spectrometry and Atomic Emission Spectrometry are particle size dependent. They are unable to analyze particles greater than 10 mum in size. This dissertation describes a method of analyzing lubricating oils for both metallo-organic and particulate species by ICP-MS. Microwave digestion of the oil samples eliminates the need for elaborate sample introduction schemes as well as the use of a modified carrier gas. Al, Cr, Fe, Mg, Mo, Ni, Ti, and Y have been determined in both aqueous and organic media. Metallo-organic solutions of these metals were successfully digested, nebulized into the ICP, and the singly charged ions measured by mass spectrometry. Metal particulates in oil matrices have also been quantitatively determined by the above method. Linear analytical curves were

  9. Enhanced levels of atmospheric low-molecular weight monocarboxylic acids in gas and particulates over Mt. Tai, North China, during field burning of agricultural wastes

    Science.gov (United States)

    Mochizuki, Tomoki; Kawamura, Kimitaka; Nakamura, Shinnosuke; Kanaya, Yugo; Wang, Zifa

    2017-12-01

    To understand the source and atmospheric behaviour of low molecular weight monocarboxylic acids (monoacids), gaseous (G) and particulate (P) organic acids were collected at the summit of Mt. Tai in the North China Plain (NCP) during field burning of agricultural waste (wheat straw). Particulate organic acids were collected with neutral quartz filter whereas gaseous organic acids were collected with KOH-impregnated quartz filter. Normal (C1-C10), branched (iC4-iC6), hydroxy (lactic and glycolic), and aromatic (benzoic) monoacids were determined with a capillary gas chromatography employing p-bromophenacyl esters. We found acetic acid as the most abundant gas-phase species whereas formic acid is the dominant particle-phase species. Concentrations of formic (G/P 1 570/1 410 ng m-3) and acetic (3 960/1 120 ng m-3) acids significantly increased during the enhanced field burning of agricultural wastes. Concentrations of formic and acetic acids in daytime were found to increase in both G and P phases with those of K+, a field-burning tracer (r = 0.32-0.64). Primary emission and secondary formation of acetic acid is linked with field burning of agricultural wastes. In addition, we found that particle-phase fractions (Fp = P/(G + P)) of formic (0.50) and acetic (0.31) acids are significantly high, indicating that semi-volatile organic acids largely exist as particles. Field burning of agricultural wastes may play an important role in the formation of particulate monoacids in the NCP. High levels (917 ng m-3) of particle-phase lactic acid, which is characteristic of microorganisms, suggest that microbial activity associated with terrestrial ecosystem significantly contributes to the formation of organic aerosols.

  10. Particulate carbon and nitrogen determinations in tracer studies: The neglected variables

    International Nuclear Information System (INIS)

    Collos, Yves; Jauzein, Cécile; Hatey, Elise

    2014-01-01

    We address two issues in the determination of particulate carbon and nitrogen in suspended matter of aquatic environments. One is the adsorption of dissolved organic matter on filters, leading to overestimate particulate matter. The second is the material loss during filtration due to fragile algal cells breaking up. Examples from both laboratory cultures and natural samples are presented. We recommend using stacked filters in order to estimate the first and filtering different volumes of water in order to evaluate the second. - Highlights: • Adsorption of dissolved organic matter on GF/F filters saturates below 1 ml. • Such adsorption can overestimate (up to 5 fold at low volumes) particulate matter. • Plankton breakage during filtration underestimates (up to 3 fold) particulate matter. • Different volumes should be filtered to detect biases in PC and PN concentrations. • Adsorbed organic carbon is higher in surface ocean than in mid-waters

  11. Preliminary studies of airborne particulate emmisions from the Ampellum S.A. copper smelter, Zlatna, Romania

    Directory of Open Access Journals (Sweden)

    Ben J. Williamson

    2003-04-01

    Full Text Available Preliminary studies have been carried on the characterization of particulate emissions from the Ampellum S.A. copper smelter in the town of Zlatna, Romania. The particulates studied were collected on polycarbonate filters using air pump apparatus and on the surfaces of lichens. Mass of total suspended particulates (TSP and PM10 varied from 19 to 230 μg/m3 and 3 to 146 μg/m3, respectively (PM10/TSP = 0.14 to 1.0, depending on wind direction and proximity to the smelter. Particulates on collection filters from a site directly downwind from the smelter have a mean equivalent spherical diameter (ESD of 0.94 μm (s.d. 1.1 and are dominantly made up of material with the composition of anglesite (PbSO4. The remainder of the material is a heterogeneous mixture of silicates and Fe-, Pb- and Cu-bearing phases. Particulates > 5 μm ESD are rare on the TSP filters, mainly due to the restricted sampling durations possible with the equipment used (<3 hours. Particulates have therefore been studied in the lichen Acarospora smaragdula, which was growing on posts downwind from the smelter and which was found to contain high levels and a broader range of particulates compared with the filters (<5 to 100 μm in diameter. Larger particles include 20-30 μm diameter Fe-rich spherules, which occasionally have Pb- and S-rich encrustations on their surfaces. The nature and possible health effects of the particulates are discussed and recommendations made for future studies.

  12. Chlorophyll 'a' particulate organic carbon and suspended load from the mangrove areas of Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Sheeba, P.; Devi, K.S.; Balasubramanian, T.; Sankaranarayanan, V.N.

    Chlorophyll 'a' Particulate Organic Carbon and suspended load were estimated for one year from two distinct mangrove areas of Cochin backwaters, viz. Puthuvypeen and Nettoor. Environmental parameters like tau degrees C, S ppt and pH were also...

  13. Evaluation of sampling inhalable PM10 particulate matter (≤ 10 μm) using co-located high volume samplers

    International Nuclear Information System (INIS)

    Rajoy, R R S; Dias, J W C; Rego, E C P; Netto, A D Pereira

    2015-01-01

    This paper presents the results of the determination of the concentrations of atmospheric particulate matter ≤ 10 μm (PM10), collected simultaneously by six PM10 high volume samplers from two different manufacturers installed in the same location. Fifteen samples of 24 h were obtained with each equipment at a selected urban area of Rio de Janeiro city. The concentration of PM10 ranged between 10.73 and 54.04 μg m3 . The samplers were considered comparable to each other, as the adopted methodology presented good repeatability

  14. Modeling the Current and Future Roles of Particulate Organic Nitrates in the Southeastern United States.

    Science.gov (United States)

    Pye, Havala O T; Luecken, Deborah J; Xu, Lu; Boyd, Christopher M; Ng, Nga L; Baker, Kirk R; Ayres, Benjamin R; Bash, Jesse O; Baumann, Karsten; Carter, William P L; Edgerton, Eric; Fry, Juliane L; Hutzell, William T; Schwede, Donna B; Shepson, Paul B

    2015-12-15

    Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate radicals (the primary source of particle-phase organic nitrates in the Southeast United States), secondary organic aerosol (SOA) models can underestimate yields. Furthermore, SOA parametrizations do not explicitly take into account organic nitrate compounds produced in the gas phase. In this work, we developed a coupled gas and aerosol system to describe the formation and subsequent aerosol-phase partitioning of organic nitrates from isoprene and monoterpenes with a focus on the Southeast United States. The concentrations of organic aerosol and gas-phase organic nitrates were improved when particulate organic nitrates were assumed to undergo rapid (τ = 3 h) pseudohydrolysis resulting in nitric acid and nonvolatile secondary organic aerosol. In addition, up to 60% of less oxidized-oxygenated organic aerosol (LO-OOA) could be accounted for via organic nitrate mediated chemistry during the Southern Oxidants and Aerosol Study (SOAS). A 25% reduction in nitrogen oxide (NO + NO2) emissions was predicted to cause a 9% reduction in organic aerosol for June 2013 SOAS conditions at Centreville, Alabama.

  15. The impact of total suspended particulate concentration on workers’ health at ceramic industry

    Science.gov (United States)

    Sintorini, M. M.

    2018-01-01

    Ceramic production process pollutes the air with particulate matter at high concentration and has negative impact on the workers. The objective of this research was to determine the particulate concentration in the air and to analyse its impact on the workers. This research used cross sectional method to correlate the particulate concentration, temperature, humidity, smoke level and level of workers’ compliance with safety regulations. Sampling was conducted from April to May 2012 in three locations, i.e. exposure area (Mass Preparation I, II) and non-exposure area (Forming area). In the exposure area (Mass Preparation I and II) where the particulate concentrations were 22.3673 mg/m3 and 14.8277 mg/m3, and 58.33%, the workers had bad health status. In the non-exposure area, where the particulate concentration was 3.2185 mg/m3 and 25% the workers had bad health status. The Odds Ratio among the workers in exposure area was 4.2 times higher than the workers in the non-exposure area.

  16. Development of the GC-MS organic aerosol monitor (GC-MS OAM) for in-field detection of particulate organic compounds

    Science.gov (United States)

    Cropper, Paul M.; Overson, Devon K.; Cary, Robert A.; Eatough, Delbert J.; Chow, Judith C.; Hansen, Jaron C.

    2017-11-01

    Particulate matter (PM) is among the most harmful air pollutants to human health, but due to its complex chemical composition is poorly characterized. A large fraction of PM is composed of organic compounds, but these compounds are not regularly monitored due to limitations in current sampling and analysis techniques. The Organic Aerosol Monitor (GC-MS OAM) combines a collection device with thermal desorption, gas chromatography and mass spectrometry to quantitatively measure the carbonaceous components of PM on an hourly averaged basis. The GC-MS OAM is fully automated and has been successfully deployed in the field. It uses a chemically deactivated filter for collection followed by thermal desorption and GC-MS analysis. Laboratory tests show that detection limits range from 0.2 to 3 ng for 16 atmospherically relevant compounds, with the possibility for hundreds more. The GC-MS OAM was deployed in the field for semi-continuous measurement of the organic markers, levoglucosan, dehydroabietic acid, and polycyclic aromatic hydrocarbons (PAHs) from January to March 2015. Results illustrate the significance of this monitoring technique to characterize the organic components of PM and identify sources of pollution.

  17. Chemical characterization of organic particulate matter from on-road traffic in Sao Paulo, Brazil

    NARCIS (Netherlands)

    Oyama, Beatriz Sayuri; Andrade, Maria de Fatima; Herckes, Pierre; Dusek, Ulrike; Rockmann, Thomas; Holzinger, Rupert

    2016-01-01

    This study reports emission of organic particulate matter by light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) in the city of Sao Paulo, Brazil, where vehicles run on three different fuel types: gasoline with 25% ethanol (called gasohol, E25), hydrated ethanol (E100), and diesel (with 5%

  18. Chemical characterization of organic particulate matter from on-road traffic in Sao Paulo, Brazil

    NARCIS (Netherlands)

    Oyama, Beatriz Sayuri; Andrade, Maria de Fatima; Herckes, Pierre; Dusek, Ulrike; Rockmann, Thomas; Holzinger, Rupert

    2016-01-01

    This study reports emission of organic particulate matter by light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) in the city of São Paulo, Brazil, where vehicles run on three different fuel types: gasoline with 25 % ethanol (called gasohol, E25), hydrated ethanol (E100), and diesel (with 5 %

  19. Nighttime residential wood burning evidenced from an indirect method for estimating real-time concentration of particulate organic matter (POM)

    International Nuclear Information System (INIS)

    Sciare, J.; Sarda-Esteve, R.; Favez, O.; Cachier, H.; Aymoz, G.; Laj, P.

    2008-01-01

    Real-time analyzers of selected chemical components (sulfate, nitrate, Black Carbon) and integrative aerosol parameters (particulate matter and light scattering coefficient) were implemented for a 2-week campaign (November-December 2005) in a suburban area of Clermont-Ferrand (France) in order to document fast changes in the chemical composition of submicron aerosols. Measurements of particulate organic matter (POM) were not available in the field but were indirectly estimated from time-resolved (3-min) reconstruction of the light scattering coefficient. This methodology offered the opportunity to investigate almost real-time and artifact-free POM concentrations even at low concentrations (typically below 0.1 mu g m(-3)). The overall uncertainties associated with this POM calculation were of the order of 20%, which are comparable to those commonly referred in literature for POM calculation or measurements. A chemical mass balance (CMB) of PM1 was performed using the derived POM concentrations and showed a very good correlation (slope = 0.93; r(2) = 0.91, N = 663) with real-time PM1 measurements obtained from R and P TEOM-FDMS, demonstrating the consistency of our approach. Important diurnal variations were observed in POM concentrations, with a dominant contribution of POM from fossil fuel origin during daytime and a dominant contribution of POM from residential wood burning at night. POM was calculated to contribute as much as 70% of PM1 during our study, pointing out the major role of carbonaceous aerosols at this period of the year at our residential area. (authors)

  20. Rational design of organic superconductors through the use of the large, discrete molecular anions M(CF3)4-(M = Cu, Ag, Au) and SO3CF2CH2SF5-

    International Nuclear Information System (INIS)

    Schlueter, J.A.; Geiser, U.; Williams, J.M.

    1996-01-01

    A new approach to synthesis of organic superconductors has recently been pioneered which involves the use of large discrete molecular anions as the charge-compensating entities in these charge transfer salts. The organic electron-donor molecule bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) has been electrocrystallized with the novel organometallic M(CF 3 ) 4 - (M=Cu, Ag, Au) anions in a variety of 1,1,2-trihaloethane solvents. Over 20 organic superconductors have been synthesized which can be described by (ET) 2 M(CF 3 ) 4 (1,1,2- trihaloethane). These solvated salts are shown to have highly anisotropic physical properties which can be tuned via modifications of each of their three molecular components: ET electron donor molecule, M(CF 3 ) 4 - anion, and neutral 1,1,2- trihaloethane solvent molecule. Superconductivity has also been observed in an ET salt containing the discrete SF 5 CH 2 CF 2 SO 3 - anion with onset temperature near 5.2 K

  1. Evaluation of traffic exhaust contributions to ambient carbonaceous submicron particulate matter in an urban roadside environment in Hong Kong

    Science.gov (United States)

    Lee, Berto Paul; Kwok Keung Louie, Peter; Luk, Connie; Keung Chan, Chak

    2017-12-01

    Road traffic has significant impacts on air quality particularly in densely urbanized and populated areas where vehicle emissions are a major local source of ambient particulate matter. Engine type (i.e., fuel use) significantly impacts the chemical characteristics of tailpipe emission, and thus the distribution of engine types in traffic impacts measured ambient concentrations. This study provides an estimation of the contribution of vehicles powered by different fuels (gasoline, diesel, LPG) to carbonaceous submicron aerosol mass (PM1) based on ambient aerosol mass spectrometer (AMS) and elemental carbon (EC) measurements and vehicle count data in an urban inner city environment in Hong Kong with the aim to gauge the importance of different engine types to particulate matter burdens in a typical urban street canyon. On an average per-vehicle basis, gasoline vehicles emitted 75 and 93 % more organics than diesel and LPG vehicles, respectively, while EC emissions from diesel vehicles were 45 % higher than those from gasoline vehicles. LPG vehicles showed no appreciable contributions to EC and thus overall represented a small contributor to traffic-related primary ambient PM1 despite their high abundance (˜ 30 %) in the traffic mix. Total carbonaceous particle mass contributions to ambient PM1 from diesel engines were only marginally higher (˜ 4 %) than those from gasoline engines, which is likely an effect of recently introduced control strategies targeted at commercial vehicles and buses. Overall, gasoline vehicles contributed 1.2 µg m-3 of EC and 1.1 µ m-3 of organics, LPG vehicles 0.6 µg m-3 of organics and diesel vehicles 2.0 µg m-3 of EC and 0.7 µg m-3 of organics to ambient carbonaceous PM1.

  2. Evaluation of airborne particulates and fungi during hospital renovation.

    Science.gov (United States)

    Overberger, P A; Wadowsky, R M; Schaper, M M

    1995-07-01

    This study was conducted over 30 weeks on a hospital floor undergoing partial renovation. Some patients housed on the floor were immunosuppressed, including bone marrow transplant recipients. The construction zone was placed under negative pressure and was separated from patient rooms by existing hospital walls and via erection of a temporary barrier. Other control measures minimized patient exposure to airborne materials. Air sampling was done for 3 weeks prior to construction, 24 weeks during construction, and 3 weeks after renovation was completed. Airborne particulate concentrations, total spore counts, particle size, and fungal species were assessed. At the beginning of the renovation there were increases in airborne particulates (from 0.2 to 2.0 mg/m3) and fungal spores (from 3.5 to 350 colony forming units (CFU/m3), but only in the construction zone. Throughout the remainder of the renovation, particulate and fungal spore levels fluctuated inside the construction zone but remained close to baseline values in the patient area. When renovation was completed, particulates and spore counts inside the construction zone decreased to preconstruction levels. The primary fungus isolated from air samples was Penicillium. This study demonstrated that control measures were effective in reducing exposures of hospitalized patients to airborne particulates and spores and in reducing the increased risk of aspergillosis and other fungal infections associated with hospital construction projects. The data from this study may be useful in establishing exposure guidelines for other health care settings.

  3. Influence of particulate matter on microfouling biomass in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Nandakumar, K.; Wagh, A.B.

    ~ E :; :; 00 " " 200 '\\00 6001&. I&. Olslonc. from rne St>cre tn. miles! Leg , 0----4L~2 L~3 Leo .; Log $ Fig.3 Suspended matter (A), and particulate organic carbon (B) of surface seawater. and microfouling biomass as dry weight (C) and organic carbon...

  4. Measurements of particulate matter and 3,4-benzopyrene in Zurich

    Energy Technology Data Exchange (ETDEWEB)

    Waibel, M; Wanner, H U

    1974-01-01

    Measurements of particulate matter and 3,4 benzoyrene were carried out at six measuring points in and around Zurich in 1971/72. The measuring points differed according to their immediate surroundings; they were subdivided into industrial zone, heavy traffic spots, residential area, and recreation ground. The correlations were calculated to clarify the connections between emissions and meteorological influences including temperature, inversions, humidity, air pressure, wind strength, visibility, and sunlight. The annual average values for the aerosol concentration were highest (160-181 microgram/cu m) where traffic is very heavy. An industrial center and a residential area of the old part of the city assumed a middle position. The modern residential section of Triemli measured the lowest concentration, 100 micrograms/cu m. The annual average concentrations for BaP were 5.3 ng/cu m for the industrial center, 5.5 and 7/7 ng/cu m for Paradeplatz and Albisriederplatz and 4.1 ng/cu m for Triemli. A high BaP concentration of 6.4 ng/cu m was measured in the old residential section. A correlation between the aerosol concentration of the air and the mortality from stomach cancer was found. Particularly pronounced was the influence of air pollution on mortality due to respiratory diseases. It tripled from the zone with lowest aerosol concentration (less than 80 micrograms/cu m) to the zone with highest air pollution (more than 135 micrograms/cu m). Compared to West German and U.S. cities the aerosol and BaP concentrations measured in Zurich were rather high.

  5. ANALYSIS OF PARTICULATE ORGANIC MATTER IN HOLOCENE SEDIMENTS OF COASTAL PLAIN FROM PERO BEACH, CABO FRIO, RIO DE JANEIRO, BRAZIL

    Directory of Open Access Journals (Sweden)

    Taísa Camila Silveira de Souza

    2016-06-01

    Full Text Available The study of palynofacies along a core drilled on the coastal plain of Cabo Frio, State of Rio de Janeiro, was carried out in order to contribute to the knowledge of the paleoenvironmental evolution of the Pero Beach region. The ages obtained from 14C datings allowed to verify that the studied core records the past 6761 ± 130 yrs cal BP. Thirty samples were prepared by standard methodology for palynofacies. About three hundred particles of the particulate organic material was classified and recorded for each sample. Statistical methods were employed for the associations of particulate organic matter (R-mode cluster analysis and levels (samples; Q-mode cluster analysis analyzed along the core. Furthermore, the ratio Phytoclast - Total Organic Carbon (Phy-TOC was used to verify the proximity of the source area. The three major groups of particulate organic matter found along the studied core are Phytoclasts, Amorphous Organic Matter (AOM and Palynomorphs. The samples showed in general, a predominance of phytoclasts (73.2%, followed by AOM (18.6% and Palynomorphs (8.2%. Supported by statistical analysis, it was possible to deduce that the study area evolved since the middle Holocene from a marine environment to a paleolagoon.

  6. The investigation of atmospheric particulate matter pollution in Suzhou

    International Nuclear Information System (INIS)

    Chen Yi'ou; Zhang Yuliang; Wang Ya; Wang Pei; Tian Hailin

    2012-01-01

    Objective: To investigate the pollution status, vertical distribution and concentration variation within 24 hours of total suspended particles (TSPs), particulate matter ≤10 μm (PM10), particulate matter ≤5 (PM5) and particulate matter ≤2.5 μm (PM2.5) in major functional areas of Suzhou and the protective effect of different type masks on particulate matter. Methods: (1) The concentration of atmospheric TSPs, PM10, PM5 and PM2.5 in seven functional areas in Suzhou was monitored for three consecutive days. (2) A residential building of 25 stories was chosen and the concentration of TSPs, PM10, PM5, PM2.5 was detected at the 1st, 5th, 10th, 15th, 20 th and the 25th floor respectively. (3) The concentrations of the four particulate matter were detected every two-hours for three consecutive days to investigate how concentration of particulate matter varies within 24 hours. (4) The concentration of the four kinds of particulate matter was analyzed with the sampling head of monitor wrapped with disposable non-woven medical mask, fashion-type mask, gauze mask or activated carbon anti-dust mask respectively, and the protective effect of the four masks on particulate matter was compared. Results: (1) The concentration of PM2.5 was higher than the national health limit in all seven functional areas in Suzhou. (2) No significant difference in vertical distribution of particulate matter was found among different floors in residential buildings (P>0.05). (3) Two small peaks of particulate matter appeared in the morning and evening respectively while the top appeared at dawn (P< 0.05). (4) Disposable non-woven medical mask showed the best protective effect on particulate matter among the four tested masks. Conclusion: PM2.5 is the main particulate matter in Suzhou area. In addition the 4 kinds of particulate matter: TSP, PM10, PM5 and PM2.5 are of higher concentration in the early morning. No significant difference was detected from an altitude of less than 75 meters

  7. Regions of pollution with particulate matter in Poland

    Directory of Open Access Journals (Sweden)

    Rawicki Kacper

    2018-01-01

    Full Text Available The study presents the temporal and spatial variability of particulate matter concentration in Poland in the calendar winter season (December-February. The basis for the study were the hourly and daily values of particulate matter PM10 concentration from the period 2005/06 – 2014/15, obtained from 33 air pollution monitoring stations. In Poland, the obligation to monitor the concentration of the finer fraction of particles smaller than 2.5µm in aerodynamic diameter was introduced only in 2010. Consequently, data on PM2.5 concentration refer to a shorter period, i.e. 2009/10 – 2014/15, and were obtained from 23 stations. Using the cluster analysis (k-means method, three regions of comparable variability of particulate matter concentration were delineated. The largest region, i.e. Region I, comprises the northern and eastern central area of Poland, and its southern boundary is along the line Gorzów Wlkp-Bydgoszcz-Konin-Łódź-Kielce-Lublin. Markedly smaller Region II is located to the south of Region I. By far the smallest area was designated to Region III which covers the south west area of Poland. The delineated regions show a marked variability in terms of mean concentration of both PM fractions in winter (PM10: region I - 33 µg·m-3, region II - 55 µg·m-3, region III - 83 µg·m-3; PM2,5: region I - 35 µg·m-3, region II - 50 µg·m-3, region III - 60 µg·m-3 and, in the case of PM10, the frequency of excessive daily limit value.

  8. Regions of pollution with particulate matter in Poland

    Science.gov (United States)

    Rawicki, Kacper; Czarnecka, Małgorzata; Nidzgorska-Lencewicz, Jadwiga

    2018-01-01

    The study presents the temporal and spatial variability of particulate matter concentration in Poland in the calendar winter season (December-February). The basis for the study were the hourly and daily values of particulate matter PM10 concentration from the period 2005/06 - 2014/15, obtained from 33 air pollution monitoring stations. In Poland, the obligation to monitor the concentration of the finer fraction of particles smaller than 2.5µm in aerodynamic diameter was introduced only in 2010. Consequently, data on PM2.5 concentration refer to a shorter period, i.e. 2009/10 - 2014/15, and were obtained from 23 stations. Using the cluster analysis (k-means method), three regions of comparable variability of particulate matter concentration were delineated. The largest region, i.e. Region I, comprises the northern and eastern central area of Poland, and its southern boundary is along the line Gorzów Wlkp-Bydgoszcz-Konin-Łódź-Kielce-Lublin. Markedly smaller Region II is located to the south of Region I. By far the smallest area was designated to Region III which covers the south west area of Poland. The delineated regions show a marked variability in terms of mean concentration of both PM fractions in winter (PM10: region I - 33 µg·m-3, region II - 55 µg·m-3, region III - 83 µg·m-3; PM2,5: region I - 35 µg·m-3, region II - 50 µg·m-3, region III - 60 µg·m-3) and, in the case of PM10, the frequency of excessive daily limit value.

  9. Use of historical uranium air sampling data to estimate worker exposure potential to airborne radioactive particulate in a uranium processing facility.

    Science.gov (United States)

    Methner, M M; Feng, H A; Utterback, D F

    2001-12-01

    Historical industrial hygiene monitoring records from a uranium processing plant were collected and analyzed to characterize exposure potential to airborne radioactive particulate. More than 2,100 samples were collected during the period of 1954-1968. The data was organized by job title, plant number, and year of measurement. Laboratory analysis of air samples indicated a wide range of potential exposures to the alpha-emitting particulate. Logarithmic transformation of the data was necessary to approximate Gaussian distributions. Geometric Mean (GM) values were used as the measure of central tendency within years. GM values ranged from 23-49 disintegrations per minute per cubic meter of air sampled (dpm/m3) with the years 1963 and 1964 being significantly higher than other years (ANOVA: p exposure potential across plants, GM ranged from 20-68 dpm/m3, with plants 5 and 8 being significantly higher than the others (ANOVA: p Exposure potential for specific job titles across the plants varied widely. GM for clerks was the lowest (11 dpm/m3) while furnace operators were the highest (235 dpm/m3). Other job titles with potentially high exposures were chemical operators, forklift operators, machine operators, and furnace operators. This analysis indicates the magnitude and distributions of worker exposure to alpha-emitting airborne particulate. Additional analysis and epidemiologic studies are planned for this facility.

  10. A study of chemical forms of polonium-210 and lead-210 in air particulates in phosphate mines and Tartous port

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Al-Kharfan, K.; Khalili, H.; Hasan, M.

    2003-03-01

    Chemical forms of polonium-210 and lead-210 in air particulates of two areas having different climate conditions (Phosphate mines and Tartous port) have been studied. Air particulates were collected at six periods covering the climate changes from September 2000 until February 2002. Total suspended particulates (TSP) concentration was varied between 1827 and 9722 μg/M 3 and 197 and 1135 μg/m 3 in phosphate mines and Tartous port respectively; all of these values were higher than the maximum permissible concentration according to the Syrian standard (120 μg/m 3 ). Results of 210 po and 210 Pb extraction from the air particulates using selective solutions have shown that inorganic and insoluble 210 Po and 210 Pb (attached to silica and not soluble in mineral acids) ratio was high in phosphate mine air particulates and reached a value of 94% and 77% respectively. While the amount of lead 210 attached to organic compounds has reached a value of 24%. In addition, small variations in total inorganic and insoluble 210 Po and 210 Pb during the year were observed with little differences between polonium 210 ratio in both Tartous port and phosphate mines, which indicated that variations in climate conditions may affect the chemical forms. In both cases, inorganic and insoluble polonium 210 and lead 210 ratio was high; this may lead to their attachment to lung cells and their transfer via body streams. Moreover, the date obtained in this study can be utilized to calculate the radiation dose due to inhalation of radon gas and its decay daughters in the Syrian phosphate sites. (author)

  11. Biogeochemical consequences of vertical and lateral transport of particulate organic matter in the southern North Sea: A multiproxy approach

    NARCIS (Netherlands)

    Le Guitton, M.; Soetaert, K.; Sinninghe Damsté, J.S.; Middelburg, J.J.

    2015-01-01

    Vertical and lateral transports are of importance in continental shelf systems such as the North Sea andplay a major role in the processing of organic matter. We investigated the biogeochemical consequencesof these transports on particulate organic matter at the molecular level in the southern North

  12. Toxic potential of organic constituents of submicron particulate matter (PM1) in an urban road site (Barcelona).

    Science.gov (United States)

    Mesquita, Sofia R; van Drooge, Barend L; Dall'Osto, Manuel; Grimalt, Joan O; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

    2017-06-01

    Atmospheric particulate matter (PM) is a recognized risk factor contributing to a number of diseases in human populations and wildlife globally. Organic matter is a major component of PM, but its contribution to overall toxicity of PM has not been thoroughly evaluated yet. In the present work, the biological activity of organic extracts from PM1 (particles with less than 1 μm of aerodynamic diameter) collected from an urban road site in the centre of Barcelona (NE Spain) was evaluated using a yeast-based assay (AhR-RYA) and different gene expression markers in zebrafish embryos. Dioxin-like activity of the extracts correlated to primary emissions from local traffic exhausts, reflecting weekday/weekend alternance. Expression levels of cyp1a and of gene markers for key cellular processes and development (ier2, fos) also correlated to vehicle emissions, whereas expression of gene markers related to antioxidant defence and endocrine effects (gstal, hao1, ttr) was strongly reduced in samples with strong contribution from regional air masses with aged secondary organic species or with strong influence of biomass burning emissions. Our data suggest that the toxic potential of PM1 organic chemical constituents strongly depends on the emission sources and on the process of ageing from primary to secondary organic aerosols.

  13. Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA: A combined approach to sampling and analysis

    Science.gov (United States)

    Kolker, A.; Engle, M.A.; Orem, W.H.; Bunnell, J.E.; Lerch, H.E.; Krabbenhoft, D.P.; Olson, M.L.; McCord, J.D.

    2008-01-01

    Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM2.5) is based on meeting average 24 hour (35 ?? m-3) and yearly (15 ??g m-3) mass-per-unit-volume limits, regardless of PM2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM2.5 and determine potential environmental/human health impacts. To address these important non-regulatory issues an integrated approach is generally used that includes (1) field sampling of atmospheric particulate matter on filter media, using a size-limiting cyclone, or with no particle-size limitation; and (2) chemical extraction of exposed filters and analysis of separate particulate-bound fractions for total mercury, trace elements and organic constituents, utilising different USGS laboratories optimised for quantitative analysis of these substances. This combination of sampling and analysis allowed for a more detailed interpretation of PM2.5 sources and potential effects, compared to measurements of PM2.5 abundance alone. Results obtained using this combined approach are presented for a 2006 air sampling campaign in Shenandoah National Park (Virginia, USA) to assess sources of atmospheric contaminants and their potential impact on air quality in the Park. PM2.5 was collected at two sampling sites (Big Meadows and Pinnacles) separated by 13.6 km. At both sites, element concentrations in PM2.5 were low, consistent with remote or rural locations. However, element/Zr crustal abundance enrichment factors greater than 10, indicating anthropogenic input, were found for Hg, Se, S, Sb, Cd, Pb, Mo, Zn and Cu, listed in decreasing order of enrichment. Principal component analysis showed that four element associations accounted for 84% of the PM 2.5 trace element variation; these associations are interpreted to represent: (1) crustal sources (Al, REE); (2) coal combustion (Se, Sb), (3) metal production

  14. Modelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxes

    Science.gov (United States)

    Brigolin, Daniele; Rabouille, Christophe; Bombled, Bruno; Colla, Silvia; Vizzini, Salvatrice; Pastres, Roberto; Pranovi, Fabio

    2018-03-01

    This work presents the result of a study carried out in the north-western Adriatic Sea, by combining two different types of biogeochemical models with field sampling efforts. A longline mussel farm was taken as a local source of perturbation to the natural particulate organic carbon (POC) downward flux. This flux was first quantified by means of a pelagic model of POC deposition coupled to sediment trap data, and its effects on sediment bioirrigation capacity and organic matter (OM) degradation pathways were investigated constraining an early diagenesis model by using original data collected in sediment porewater. The measurements were performed at stations located inside and outside the area affected by mussel farm deposition. Model-predicted POC fluxes showed marked spatial and temporal variability, which was mostly associated with the dynamics of the farming cycle. Sediment trap data at the two sampled stations (inside and outside of the mussel farm) showed average POC background flux of 20.0-24.2 mmol C m-2 d-1. The difference of organic carbon (OC) fluxes between the two stations was in agreement with model results, ranging between 3.3 and 14.2 mmol C m-2 d-1, and was primarily associated with mussel physiological conditions. Although restricted, these changes in POC fluxes induced visible effects on sediment biogeochemistry. Observed oxygen microprofiles presented a 50 % decrease in oxygen penetration depth (from 2.3 to 1.4 mm), accompanied by an increase in the O2 influx at the station below the mussel farm (19-31 versus 10-12 mmol O2 m-2 d-1) characterised by higher POC flux. Dissolved inorganic carbon (DIC) and NH4+ concentrations showed similar behaviour, with a more evident effect of bioirrigation underneath the farm. This was confirmed through constraining the early diagenesis model, of which calibration leads to an estimation of enhanced and shallower bioirrigation underneath the farm: bioirrigation rates of 40 yr-1 and irrigation depth of 15 cm were

  15. Water and organic nitrate detection in an AMS. Laboratory characterization and application to ambient measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mensah, Amewu A.

    2011-08-12

    Atmospheric aerosols were studied by three different means. Laboratory experiments determined the relative ionization efficiency of water (RIE{sub H2O}) in an Aerodyne Aerosol Mass Spectrometers (AMS), simulation chamber experiments gave insight to the reaction products of biogenic volatile organic compounds (BVOC) oxidation products, and the findings were applied to two field campaign measurements at Cabauw, NL, in May 2008 and February 2009. Knowing the liquid water content of aerosol particles is vital for the assessment of their climate forcing potential. A value of 2 for RIE{sub H2O} was determined by studying oxalate salts with different amounts of crystal water. BVOCs contribute much more to the global budget of VOCs than anthropogenic ones but oxidation products in terms of secondary organic aerosol often correlate to anthropogenic tracers such as NO{sub x} from fossil fuel burning. In atmospheric simulation chamber experiments, organic nitrates from BVOC-NO{sub 3} oxidation showed higher vapor pressures than pure organic compounds produced in the same reactions. Organic nitrates comprised up to approx. 41 % of the particulate phase. A specific fragmentation ratio of nitrate (NO{sub 2}{sup +}/NO{sup +}) of 0.1 was found by high resolution AMS analysis differing strongly from the value of 0.4 known for the most abundant ambient NO{sub 3} specie (NH{sub 4}NO{sub 3}). Ambient average particulate mass loadings were 9.72 {mu}g/m{sup 3} dominated by organics (40 %) in 2008 and 5.62 {mu}g/m{sup 3} dominated by nitrate (42 %) in 2009. Data comparison to collocated instruments showed good agreement. Positive Matrix Factorization analysis of the particulate organic fraction distinguished semi and low volatile oxygenated organic aerosol (OOA) as well as hydrocarbon like organic aerosol (HOA) in both campaigns. An additional highly oxygenated OA with a mass spectrum very similar to fulvic acid was found in 2008. The average contribution of organic nitrate to the

  16. Biogeochemical consequences of vertical and lateral transport of particulate organic matter in the southern North Sea: A multiproxy approach

    NARCIS (Netherlands)

    le Guitton, M.; Soetaert, K.; Sinninghe Damsté, J.S.; Middelburg, J.J.

    2015-01-01

    Vertical and lateral transports are of importance in continental shelf systems such as the North Sea and play a major role in the processing of organic matter. We investigated the biogeochemical consequences of these transports on particulate organic matter at the molecular level in the southern

  17. A Prototype Sensor for In Situ Sensing of Fine Particulate Matter and Volatile Organic Compounds.

    Science.gov (United States)

    Ng, Chee-Loon; Kai, Fuu-Ming; Tee, Ming-Hui; Tan, Nicholas; Hemond, Harold F

    2018-01-18

    Air pollution exposure causes seven million deaths per year, according to the World Health Organization. Possessing knowledge of air quality and sources of air pollution is crucial for managing air pollution and providing early warning so that a swift counteractive response can be carried out. An optical prototype sensor (AtmOptic) capable of scattering and absorbance measurements has been developed to target in situ sensing of fine particulate matter (PM2.5) and volatile organic compounds (VOCs). For particulate matter testing, a test chamber was constructed and the emission of PM2.5 from incense burning inside the chamber was measured using the AtmOptic. The weight of PM2.5 particles was collected and measured with a filter to determine their concentration and the sensor signal-to-concentration correlation. The results of the AtmOptic were also compared and found to trend well with the Dylos DC 1100 Pro air quality monitor. The absorbance spectrum of VOCs emitted from various laboratory chemicals and household products as well as a two chemical mixtures were recorded. The quantification was demonstrated, using toluene as an example, by calibrating the AtmOptic with compressed gas standards containing VOCs at different concentrations. The results demonstrated the sensor capabilities in measuring PM2.5 and volatile organic compounds.

  18. Characteristics of organic compounds in aerosol particulate matter from Dhahran city, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed I. Rushdi

    2017-05-01

    Full Text Available Organic chemical pollutants in atmospheric particulate matter (PM have a potential toxicity hazard resulting in human responses that vary from no discernible effect to premature death. The formation and sources of PM also affect air quality of metropolitan areas as well as climate change. The new developments and industrial activities in the Middle East, especially Saudi Arabia, are expected to contribute to the natural, regional, and anthropogenic input sources of organic matter (OM. Here we report the occurrence, concentrations and sources of organic tracers, including n-alkanes, polycyclic aromatic hydrocarbons (PAHs, plasticizers, and petroleum biomarkers, in ambient atmospheric PM from the city of Dhahran, Saudi Arabia. The major compounds were unresolved complex mixtures (UCM of branched and cyclic hydrocarbons (489 ± 296 ng m−3, plasticizers (131 ± 119 ng m−3 for phenyl phosphates, 87 ± 42 ng m−3 for phthalates, n-alkanes (73 ± 53 ng m−3, hopane biomarkers (11 ± 8 ng m−3, n-alkanones (6.7 ± 6.3 ng m−3, PAHs (2.0 ± 2.1 ng m−3, n-alkanols (1.2 ± 1.2 ng m−3, sterane biomarkers (0.4 ± 0.3 ng m−3, and sterols (0.5 ± 0.4 ng m−3. Obviously, UCM and plasticizers were the major components (56 ± 9% and 26 ± 10% of the total extracts, respectively in the PM of Dhahran, which might have adverse public health effects. The major sources of this OM are emissions from industrial factories north of the city, plastics and biomass burning, and petroleum product combustion (traffic/refining.

  19. The effect of typhoon on particulate organic carbon flux in the southern East China Sea

    Directory of Open Access Journals (Sweden)

    C.-C. Hung

    2010-10-01

    Full Text Available Severe tropical storms play an important role in triggering phytoplankton blooms, but the extent to which such storms influence biogenic carbon flux from the euphotic zone is unclear. In 2008, typhoon Fengwong provided a unique opportunity to study the in situ biological responses including phytoplankton blooms and particulate organic carbon fluxes associated with a severe storm in the southern East China Sea (SECS. After passage of the typhoon, the sea surface temperature (SST in the SECS was markedly cooler (∼25 to 26 °C than before typhoon passage (∼28 to 29 °C. The POC flux 5 days after passage of the typhoon was 265 ± 14 mg C m−2 d−1, which was ∼1.7-fold that (140–180 mg C m−2 d−1 recorded during a period (June–August, 2007 when no typhoons occurred. A somewhat smaller but nevertheless significant increase in POC flux (224–225 mg C m−2 d−1 was detected following typhoon Sinlaku which occurred approximately 1 month after typhoon Fengwong, indicating that typhoon events can increase biogenic carbon flux efficiency in the SECS. Remarkably, phytoplankton uptake accounted for only about 5% of the nitrate injected into the euphotic zone by typhoon Fengwong. It is likely that phytoplankton population growth was constrained by a combination of light limitation and grazing pressure. Modeled estimates of new/export production were remarkably consistent with the average of new and export production following typhoon Fengwong. The same model suggested that during non-typhoon conditions approximately half of the export of organic carbon occurs via convective mixing of dissolved organic carbon, a conclusion consistent with earlier work at comparable latitudes in the open ocean.

  20. Contributions of biomass/biofuel burning to organic aerosols and particulate matter in Tanzania, East Africa, based on analyses of ionic species, organic and elemental carbon, levoglucosan and mannosan

    Science.gov (United States)

    Mkoma, S. L.; Kawamura, K.; Fu, P. Q.

    2013-10-01

    Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania, East Africa, in 2011 during wet and dry seasons and were analysed for carbonaceous components, levoglucosan, mannosan and water-soluble inorganic ions. The contributions of biomass/biofuel burning to the organic carbon (OC) and particulate matter (PM) mass were estimated to be 46-52% and 87-13%, respectively. The mean mass concentrations of PM2.5 and PM10 were 28 ± 6 μg m-3 and 47 ± 8 μg m-3 in wet season, and 39 ± 10 μg m-3 and 61 ± 19 μg m-3 in dry season, respectively. Total carbon (TC) accounted for 16-19% of the PM2.5 mass and 13-15% of the PM10 mass. On average, 86 to 89% of TC in PM2.5 and 87 to 90% of TC in PM10 was OC, of which 67-72% and 63% was found to be water-soluble organic carbon (WSOC) in PM2.5 and PM10, respectively. We found that concentrations of levoglucosan and mannosan (specific organic tracers of pyrolysis of cellulose) well correlated with non-sea-salt potassium (nss-K+) (r2 = 0.56-0.75), OC (r2 = 0.75-0.96) and WSOC (r2 = 0.52-0.78). The K+ / OC ratios varied from 0.06 to 0.36 in PM2.5 and from 0.03 to 0.36 in PM10 with slightly higher ratios in dry season. Mean percent ratios of levoglucosan and mannosan to OC were found to be 3-4% for PM2.5 and PM10 in both seasons. We found lower levoglucosan / K+ ratios and higher K+ / EC (elemental carbon) ratios in the biomass-burning aerosols from Tanzania than those reported from other regions. This feature is consistent with the high levels of potassium reported in the soils of Morogoro, Tanzania, suggesting an importance of direct emission of potassium by soil resuspension although K+ is present mostly in fine particles. It is also likely that biomass burning of vegetation of Tanzania emits high levels of potassium that may be enriched in plant tissues. The present study demonstrates that emissions from mixed biomass- and biofuel-burning activities largely influence the air quality in Tanzania.

  1. Nitrogen and Triple Oxygen Isotopic Analyses of Atmospheric Particulate Nitrate over the Pacific Ocean

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Iwamoto, Yoko; Ishino, Sakiko; Furutani, Hiroshi; Miki, Yusuke; Miura, Kazuhiko; Uematsu, Mitsuo; Yoshida, Naohiro

    2017-04-01

    for atmospheric particulate NO3- originated from Central North Pacific Ocean showed the possibility of atmospheric particulate NO3- formation pathway is reaction NO2 with halogen oxides. At the presentation, we discuss the sources and formation pathways of atmospheric particulate NO3- by using stable isotopic analyses for each region. References J. N. Galloway, A. R. Townsend, J. Willem Erisman, M. Bekunda, Z. Cai, J. R. Freney, L. A. Martinelli, S. P. Seitzinger, M. A. Sutton, Biogeochemistry, 70, 153-226, 2004 T. W. Kim, K. Lee, R. G. Najjar, H.D. Jeong, H. J. Jeong, Science 334, 505-509, 2011 E. M. Elliott, C. Kendall, S. D. Wankel, D. A. Burns, E. W. Boyer, K. Harlin, D. J. Bain, and T. J. Butler, Environ. Sci. Technol., 41, 7661-7667, 2007 G. Michalski, Z. Scott, M. Kabiling, and M. H. Thiemens, Geophys. Res. Lett., 30, 1870, 2003 M. H. Thiemens, Annu. Rev. Earth Planet. Sc., 34, 217-262, 2006

  2. [Impacts of Land Use Changes on Soil Light Fraction and Particulate Organic Carbon and Nitrogen in Jinyun Mountain].

    Science.gov (United States)

    Lei, Li-guo; Jiang, Chang-sheng; Hao, Qing-ju

    2015-07-01

    Four land types including the subtropical evergreen broad-leaved forest, sloping farmland, orchard and abandoned land were selected to collect soil samples from 0 to 60 cm depth at the same altitude of sunny slope in the Jinyun Mountain in this study. Soil light fraction organic carbon and nitrogen ( LFOC and LFON), and particulate organic carbon and nitrogen (POC and PON) were determined and the distribution ratios and C/N ratios were calculated. The results showed that the contents of LFOC and LFON decreased significantly by 71. 42% and 38. 46% after the forest was changed into sloping farmland (P 0. 05), while the contents of LFOC and LFON increased significantly by 3. 77 and 1. 38 times after the sloping farmland was changed into abandoned land (P organic carbon and nitrogen accumulation; on the contrary, sloping farmland was easy to lose soil labile carbon and nitrogen. The LFOC and LFON distribution ratios were significantly reduced by 31. 20% and 30. 08%, respectively after the forest was changed into the sloping farmland, and increased by 18. 74% and 20. 33% respectively after the forest was changed into the orchard. Nevertheless, the distribution ratios of LFOC and LFON were changed little by converting the forest into the sloping farmland and orchard. The distribution ratios of LFOC, LFON, POC and PON all increased significantly after the farmland was abandoned (P organic carbon and nitrogen was enhanced after forest reclamation, while reduced after the sloping farmland was abandoned. The ratios of carbon to nitrogen in soil organic matter, light fraction organic matter and particulate organic matter were in the order of abandoned land (12. 93) > forest (8. 53) > orchard (7. 52) > sloping farmland (4. 40), abandoned land (16. 32) > forest (14. 29) > orchard (11. 32) > sloping farmland (7. 60), abandoned land (23. 41) > sloping farmland (13. 85 ) > forest (10. 30) > orchard (9. 64), which indicated that the degree of organic nitrogen mineralization was

  3. Carbon and nitrogen isotopic compositions of particulate organic matter and biogeochemical processes in the eutrophic Danshuei Estuary in northern Taiwan

    International Nuclear Information System (INIS)

    Liu, K.-K.; Kao, S.-J.; Wen, L.-S.; Chen, K.-L.

    2007-01-01

    The Danshuei Estuary is distinctive for the relatively short residence time (1-2 d) of its estuarine water and the very high concentration of ammonia, which is the dominant species of dissolved inorganic nitrogen in the estuary, except near the river mouth. These characteristics make the dynamics of nitrogen cycling distinctively different from previously studied estuaries and result in unusual isotopic compositions of particulate nitrogen (PN). The δ 15 N PN values ranging from - 16.4 per mille to 3.8 per mille lie in the lower end of nitrogen isotopic compositions (- 16.4 to + 18.7 per mille ) of suspended particulate matter observed in estuaries, while the δ 13 C values of particulate organic carbon (POC) and the C/N (organic carbon to nitrogen) ratios showed rather normal ranges from - 25.5 per mille to - 19.0 per mille and from 6.0 to 11.3, respectively. There were three major types of particulate organic matter (POM) in the estuary: natural terrigenous materials consisting mainly of soils and bedrock-derived sediments, anthropogenic wastes and autochthonous materials from the aquatic system. During the typhoon induced flood period in August 2000, the flux-weighted mean of δ 13 C POC values was - 24.4 per mille , that of δ 15 N PN values was + 2.3 per mille and that of C/N ratio was 9.3. During non-typhoon periods, the concentration-weighted mean was - 23.6 per mille for δ 13 C POC , - 2.6 per mille for δ 15 N PN and 8.0 for C/N ratio. From the distribution of δ 15 N PN values of highly polluted estuarine waters, we identified the waste-dominated samples and calculated their mean properties: δ 13 C POC value of - 23.6 ± 0.7 per mille , δ 15 N PN value of - 3.0 ± 0.1 per mille and C/N ratio of 8.0 ± 1.4. Using a three end-member mixing model based on δ 15 N PN values and C/N ratios, we calculated contributions of the three major allochthonous sources of POC, namely, wastes, soils and bedrock-derived sediments, to the estuary. Their contributions

  4. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction

  5. Iatroscan-measured particulate and dissolved lipids in the Almeria-Oran frontal system (Almofront-1, May 1991)

    Science.gov (United States)

    Gérin, C.; Goutx, M.

    1994-08-01

    The Chromarod-Iatroscan system was used to measure dissolved and particulate lipids at six sites representative of the main hydrological zones of the Almeria-Oran frontal system in May 1991. Concentrations ranged from 9 to 113 μg 1 -1 and from 3 to 84 μg 1 -1 respectively. Particulate carbon was estimated on a CHN Leco analyzer. Dissolved lipid concentrations were highly variable with depth and exhibited clear signatures of phytoplankton degradation throughout the profiles. In the 300-400 m layer, particulate wax esters denoted the presence of deep zooplankton which may be benefit from the downward fluxes of organic matter from the frontal zone. In surface water, high concentrations of dissolved lipids and particulate carbon marked the presence of the jet front. Particulate lipid classes in samples were related to the presence of zooplankton and to the physiological state of cells rather than to phytoplankton biomass. Particulate triglyceride concentrations (storage lipids in phytoplankton) increased from the left to the right border of the jet core and further southwards, culminating in the Atlantic anticyclonic gyre. The distribution of particulate lipids to carbon and chlorophyllatios and the increasing level of triglycerides from the jet and southwards suggested a rapid removal of the frontal production by physical transports. The ability of anticyclonic structures to enhance accumulations of energetically rich compounds and thus to play a role as fertilizers of the oligotrophic waters of the Mediterranean Sea is discussed.

  6. A Prototype Sensor for In Situ Sensing of Fine Particulate Matter and Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    Chee-Loon Ng

    2018-01-01

    Full Text Available Air pollution exposure causes seven million deaths per year, according to the World Health Organization. Possessing knowledge of air quality and sources of air pollution is crucial for managing air pollution and providing early warning so that a swift counteractive response can be carried out. An optical prototype sensor (AtmOptic capable of scattering and absorbance measurements has been developed to target in situ sensing of fine particulate matter (PM2.5 and volatile organic compounds (VOCs. For particulate matter testing, a test chamber was constructed and the emission of PM2.5 from incense burning inside the chamber was measured using the AtmOptic. The weight of PM2.5 particles was collected and measured with a filter to determine their concentration and the sensor signal-to-concentration correlation. The results of the AtmOptic were also compared and found to trend well with the Dylos DC 1100 Pro air quality monitor. The absorbance spectrum of VOCs emitted from various laboratory chemicals and household products as well as a two chemical mixtures were recorded. The quantification was demonstrated, using toluene as an example, by calibrating the AtmOptic with compressed gas standards containing VOCs at different concentrations. The results demonstrated the sensor capabilities in measuring PM2.5 and volatile organic compounds.

  7. Isotopic composition of nitrate and particulate organic matter in a pristine dam reservoir of western India: Implications for biogeochemical processes

    Digital Repository Service at National Institute of Oceanography (India)

    Bardhan, P.; Naqvi, S.W.A.; Karapurkar, S.G.; Shenoy, D.M.; Kurian, S.; Naik, H.

    , 767–779, 2017 www.biogeosciences.net/14/767/2017/ doi:10.5194/bg-14-767-2017 © Author(s) 2017. CC Attribution 3.0 License. Isotopic composition of nitrate and particulate organic matter in a pristine dam reservoir of western India: implications... basis. Samples for nitrate isotopic measurements were col- lected from 2011. The facility for nitrate isotope analysis was Biogeosciences, 14, 767–779, 2017 www.biogeosciences.net/14/767/2017/ P. Bardhan et al.: Isotopic composition of nitrate and POM...

  8. Impacts of a heavy storm of rain upon dissolved and particulate organic C, N and P in the main river of a vegetation-rich basin area in Japan.

    Science.gov (United States)

    Li, Fusheng; Yuasa, Akira; Muraki, Yuzo; Matsui, Yoshihiko

    2005-06-01

    The impacts of a heavy storm of rain upon the dissolved and particulate organic matter (OM), nitrogen (N) and phosphorus (P) in the main river of the vegetation-rich Nagara River basin were investigated using water samples collected along the river line during a critical typhoon-induced heavy rain storm event. Besides, based on a high performance size-exclusion chromatography (HPSEC) system, the variance of dissolved OM (DOM) in its molecular weight (MW) characteristics was also assessed. From the MW standpoint, DOM components merged into the river along the river line resembled those present in its headwater. The MW range changed only slightly from 1010 to 5900 at the upstream (US), to 1130-5900 and 1200-5900 Da at the midstream (MS) and downstream (DS), respectively, while the corresponding weight-averaged MW (M(w)) decreased from 3669 to 3330 and 2962 Da. The heavy storm of rain enhanced the content of DOM; however, apart from a small larger-MW fraction (about 5900-6800 Da), the newly emerged DOM constituents exhibited an MW range similar to those existed before the storm. Due also to the storm of rain, total P and N (TP and TN) changed markedly in the ranges of 6.6-11.9, 8.3-40.6 and 48.4-231.3 microg/l for TP, and 145.4-296.0, 502.2-1168.7 and 1342.7-1927.3 microg/l for TN at the US, MS and DS, respectively. The larger values of TP and TN generally appeared for samples at elevated river water levels. The enhanced presence of P was found largely attributed to its particulate form; while, for N, the contribution from its dissolved form was significant. The newly emerged suspended particles via the storm-water contained lower content of OM, N and P, and a general decreasing trend of the particulate OM, N and P along the river line was also confirmed. The C/N ratio in the dissolved form varied in 0.7-6.7 and decreased downstream, while, that in the particulate form 2.3-17.3. Suspended particles that emerged in the river water during the storm exhibited larger C

  9. Study of particulates and heavy elements in air of some Syrian cities

    International Nuclear Information System (INIS)

    Othman, I.; Al-Oudat, M.; Al-Rayes, A. H.; Al- Kharfan, K.

    1999-11-01

    A study of air pollution in different sites of five Syrian cities (Damascus, Aleppo, Tartous, Homs, and Sweda) was carried out. The concentration of total suspended particulate (TSP), particulate less than 10 microns (PM 10) and less than 3 microns (PM 3) were measured using high volume air sampler (HVAS). Heavy element concentration, Pb, Cd, Zn, and Cu were also determined using anodic stripping voltametry. The result showed that TSP, PM 10 and PM 3 were higher than WHO standards in several times. Mean lead concentrations ranged between 0.58 and 2.96 μg/m 3 and 0.56 and 1.53 μg/m 3 in Damascus and Aleppo respectively, while in the other cities these concentrations were less than WHO standards (0.5 - 1 μg/m 3 ). (author)

  10. Transformation of soil organic matter in a Japanese larch forest. Radiocarbon and stable carbon isotope compositions versus soil depth

    International Nuclear Information System (INIS)

    Liu Wei; Moriizumi, Jun; Yamazawa, Hiromi; Iida, Takao

    2008-01-01

    Soil organic matter at a depth of 0-55 cm, collected from a Japanese larch forest area, was separated into particulate organic matter (size >53 μm), particulate organic matter (size 14 C and δ 13 C values were determined. The Δ 14 C values of particulate matters decreased greatly from 128 per mille to -278 per mille, indicating a relative increase of resistant organic components in particulate matters. That of humic acid matter decreased from 183 per mille to -139 per mille. For these of organic matter fractions at the same depth, the Δ 14 C values of particulate matter (size >53μm) are smallest and those of humic acid matter are the largest. That indicates that a high contribution of young organic matter to the humic acid matter exists and transformation tendency of particulate matter may be from coarse to small in the particulate size. Positive Δ 14 C values appeared at a depth of 10 cm, 25 cm, and 35 cm for the particulate organic matter (size >53μm), particulate organic matter (size 14 C values of the humic acid matter also infects that the bomb carbon has reached the depth of 35 cm. Additionally, the Δ 14 C values of these three kinds of organic matters ranged from 50 per mille to 183 per mille at a depth of 0-7 cm, which were not smaller than that of litter in the forest area, indicating high proportion of modern, plants-derived soil organic matter in this depth ranges. The δ 13 C values increased from -28 per mille to -23 per mille with the increase depth of 0-55 cm. The δ 13 C values of humic acid matter are approximately less than that of particulate matters at the same depth, which may be explained as a high contribution of young organic matter to the humic acid matter. (author)

  11. Barium in Twilight Zone suspended matter as a potential proxy for particulate organic carbon remineralization: Results for the North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Dehairs, F.; Jacquet, S.; Savoye, N.; Van Mooy, B.A.S.; Buesseler, K.; Bishop, J.K.B.; Lamborg, C.H.; Elskens, M.; Baeyens, W.; Boyd, P.W.; Casciotti, K.L.; Monnin, C.

    2008-04-10

    This study focuses on the fate of exported organic carbon in the twilight zone at two contrasting environments in the North Pacific: the oligotrophic ALOHA site (22 degrees 45 minutes N 158 degrees W; Hawaii; studied during June-July 2004) and the mesotrophic Subarctic Pacific K2 site (47 degrees N, 161 degrees W; studied during July-August 2005). Earlier work has shown that non-lithogenic, excess particulate Ba (Ba{sub xs}) in the mesopelagic water column is a potential proxy of organic carbon remineralization. In general Ba{sub xs} contents were significantly larger at K2 than at ALOHA. At ALOHA the Ba{sub xs} profiles from repeated sampling (5 casts) showed remarkable consistency over a period of three weeks, suggesting that the system was close to being at steady state. In contrast, more variability was observed at K2 (6 casts sampled) reflecting the more dynamic physical and biological conditions prevailing in this environment. While for both sites Ba{sub xs} concentrations increased with depth, at K2 a clear maximum was present between the base of the mixed layer at around 50m and 500m, reflecting production and release of Ba{sub xs}. Larger mesopelagic Ba{sub xs} contents and larger bacterial production in the twilight zone at the K2 site indicate that more material was exported from the upper mixed layer for bacterial degradation deeper, compared to the ALOHA site. Furthermore, application of a published transfer function (Dehairs et al., 1997) relating oxygen consumption to the observed Ba{sub xs} data indicated that the latter were in good agreement with bacterial respiration, calculated from bacterial production. These results corroborate earlier findings highlighting the potential of Ba{sub xs} as a proxy for organic carbon remineralization. The range of POC remineralization rates calculated from twilight zone excess particulate Ba contents did also compare well with the depth dependent POC flux decrease as recorded by neutrally buoyant sediment traps

  12. Application of Cyclone to Removal of Hot Particulate in Hot Cell

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin

    2005-01-01

    The size and main ingredient of hot particulate generated during the nuclide experiment in hot cells of nuclear facilities were 0.5300 μm and UO 2 . A cyclone filter equipment which consists of a cyclone and Bag/HEPA filter was devised to remove hot particulate generated during the nuclide experiment in hot cells of nuclear facilities. The experimental conditions to maximize the collection efficiency of hot particulate were suggested through experiments done with the cyclone filter equipment. With the large size of simulated particulate, the collection efficiency of the particulate was high. When the size of simulated particulate was more than 5 μm, the collection efficiency of the particulate was more than 80% and when the size of simulated particulate was less than 1.0 μm, the collection efficiency decreased by less than. If the inflow velocity of simulated particulate was increased, the collection efficiency of the particulate was also increased. When the inflow velocity of simulated particulate was more than 12 m/sec, the collection efficiency was higher than , but after 17 m/sec inflow velocity, no change observed. The collection efficiency of the simulated particulate can be enhanced with the length of vortex finder inside the chamber. With the length of vortex finder, 7.2 cm, the observed collection efficiency of the particulate was the maximum. Moreover, when the sub-cone was attached under the cyclone, the collection efficiency of cyclone increased 2%. It was found that effect by attachment of sub-cone was not serious.

  13. Particulate carbohydrates in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Nandakumar, K.; Venkat, K.

    Particulate matter collected from 77 water samples over a 3000 m water column was analyzed for particulate carbohydrates (PCHO). PCHO in the surface waters ranged from 43 to 143 mu g.l-1, and below 250 m it was 16.PCHO showed large variations at all...

  14. Source apportionment of fine (PM1.8) and ultrafine (PM0.1) airborne particulate matter during a severe winter pollution episode.

    Science.gov (United States)

    Kleeman, Michael J; Riddle, Sarah G; Robert, Michael A; Jakober, Chris A; Fine, Phillip M; Hays, Michael D; Schauer, James J; Hannigan, Michael P

    2009-01-15

    Size-resolved samples of airborne particulate matter (PM) collected during a severe winter pollution episode at three sites in the San Joaquin Valley of California were extracted with organic solvents and analyzed for detailed organic compounds using GC-MS. Six particle size fractions were characterized with diameter (Dp) < 1.8 microm; the smallest size fraction was 0.056 < Dp < 0.1 microm which accounts for the majority of the mass in the ultrafine (PM0.1) size range. Source profiles for ultrafine particles developed during previous studies were applied to the measurements at each sampling site to calculate source contributions to organic carbon (OC) and elemental carbon (EC) concentrations. Ultrafine EC concentrations ranged from 0.03 microg m(-3) during the daytime to 0.18 microg m(-3) during the nighttime. Gasoline fuel, diesel fuel, and lubricating oil combustion products accounted for the majority of the ultrafine EC concentrations, with relatively minor contributions from biomass combustion and meat cooking. Ultrafine OC concentrations ranged from 0.2 microg m(-3) during the daytime to 0.8 microg m(-3) during the nighttime. Wood combustion was found to be the largest source of ultrafine OC. Meat cooking was also identified as a significant potential source of PM0.1 mass but further study is required to verify the contributions from this source. Gasoline fuel, diesel fuel, and lubricating oil combustion products made minor contributions to PM0.1 OC mass. Total ultrafine particulate matter concentrations were dominated by contributions from wood combustion and meat cooking during the current study. Future inhalation exposure studies may wish to target these sources as potential causes of adverse health effects.

  15. Particulate organic compounds in the atmosphere surrounding an industrialised area of Prato (Italy)

    Science.gov (United States)

    Cincinelli, Alessandra; Mandorlo, Stefano; Dickhut, Rebecca M.; Lepri, Luciano

    Atmospheric aerosols were collected during the period from May 2000 through January 2001 at 13 different sites in and around the Baciacavallo sewage treatment plant in Prato (Italy). The urban area surrounding the plant contains significant textile industrial activity and a main arterial road. Aerosol-associated n-alkane, polycyclic aromatic hydrocarbon (PAH), nonylphenol (NP) and nonylphenolethoxylate (NPnEO) ( n=1-3) concentrations were measured in order to evaluate contributions from the sewage treatment plant, naturally produced aerosols, transportation and industrial activities to the air quality in the vicinity of the sewage treatment plant. Aerosol-associated n-alkane concentrations ranged from 36.7 to 205 ng/m 3 and their possible origin was determined by the presence of typical petroleum characteristics such as the unresolved complex mixture and an odd/even carbon ratio (Carbon Preference Index). PAH concentrations ranged from 0.855 to 24.2 ng/m 3, in accordance with those generally found for urban aerosols in Europe. NP and NPnEO ( n=1-3), as well as fine aerosol particulate matter (PM 10) were significantly correlated with relative wind direction with increased levels observed in the ambient atmosphere when the relative wind direction was from the Baciacavallo sewage treatment plant. This study confirms the use of NP and NPnEO ( n=1-3) as markers of sewage treatment emissions and the importance of the contribution of aerosols produced by sewage treatment plant aeration tanks to the local atmospheric composition.

  16. Gaseous and particulate air pollutants in the Northeastern Mediterranean Coast

    International Nuclear Information System (INIS)

    Soner Erduran, M.; Tuncel, Semra G.

    2001-01-01

    The concentrations of sulfur dioxide (SO 2 ), ammonia (NH 3 ) and particulate matter were measured for a 6-month period and the concentration of gas phase nitric acid (HNO 3 ) was measured for a 1-month period in the North-eastern Mediterranean atmosphere (Kuecuek Calticak, Antalya) using a 'filter pack' system that was developed and optimised in our laboratory. Among all the gas phase pollutants, HNO 3 had the lowest concentration (0.42 μg m -3 ) followed by ammonia. Most of the measured parameters showed variation in time depending on strengths of source regions and meteorological conditions. Nitric acid is found mostly in particulate form, but gas to particulate partitioning of SO 2 shows seasonal variation. Wind trajectory analyses indicate that the major contribution to the observed concentrations come mostly from Eastern Europe and Blacksea regions as well as the southern sector

  17. Semivolatile Organic Compounds (SOCs) in Fine Particulate Matter (PM2.5) during Clear, Fog, and Haze Episodes in Winter in Beijing, China.

    Science.gov (United States)

    Wang, Ting; Tian, Mi; Ding, Nan; Yan, Xiao; Chen, She-Jun; Mo, Yang-Zhi; Yang, Wei-Qiang; Bi, Xin-Hui; Wang, Xin-Ming; Mai, Bi-Xian

    2018-05-01

    Few efforts have been made to elucidate the influence of weather conditions on the fate of semivolatile organic compounds (SOCs). Here, daily fine particulate matter (PM 2.5 ) during clear, haze, and fog episodes collected in the winter in Beijing, China was analyzed for polycyclic aromatic hydrocarbons (PAHs), brominated flame retardants (BFRs), and organophosphate flame retardants (OPFRs). The total concentrations of PAHs, OPFRs, and BFRs had medians of 45.1 ng/m 3 and 1347 and 46.7 pg/m 3 , respectively. The temporal pattern for PAH concentrations was largely dependent on coal combustion for residential heating. OPFR compositions that change during colder period were related to enhanced indoor emissions due to heating. The mean concentrations of SOCs during haze and fog days were 2-10 times higher than those during clear days. We found that BFRs with lower octanol and air partition coefficients tended to increase during haze and fog episodes, be removed from PM 2.5 during clear episodes, or both. For PAHs and OPFRs, pollutants that are more recalcitrant to degradation were prone to accumulate during haze and fog days. The potential source contribution function (PSCF) model indicated that southern and eastern cities were major source regions of SOCs at this site.

  18. Assessment of inhalation dose sensitivity by physicochemical properties of airborne particulates containing naturally occurring radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Young; Choi, Cheol Kyu; Kim, Yong Geon; Choi, Won Chul; Kim, Kwang Pyo [Kyung Hee University, Seoul (Korea, Republic of)

    2015-12-15

    Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of 0.01μm sized particulates were higher than doses due to 100μm sized particulates by factors of about 100 and 50 for {sup 238}U and {sup 230}Th, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of 11 g·cm{sup -3} and 0.7 g·cm{sup -3} resulted in dose difference by about 60 %. For {sup 238}U, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of {sup 238}U was about 9 times higher than dose for absorption F. For {sup 230}Th, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of {sup 230}Th was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and

  19. Autoxidation as a major player in the fate of terrestrial particulate organic matter in seawater

    Science.gov (United States)

    Galeron, Marie-Aimée.; Radakovitch, Olivier; Charrière, Bruno; Vaultier, Frédéric; Rontani, Jean-François

    2017-05-01

    The Rhône River plays a major role in the Mediterranean Sea, being both its main freshwater source and its major particulate matter provider. This survey of the fate of terrestrial particulate organic matter (POM) was conducted along the salinity gradient of the Rhône River plume, between 2012 and 2014. It revealed that autoxidation acts rapidly and intensely upon the POM's arrival at sea, with α-amyrin and β-amyrin autoxidation rates going from 12.9 ± 2.9% to 45.0 ± 6.4% and 10.7 ± 4.0% to 50.3 ± 4.4%, respectively, between fresh water (salinity 0) and seawater (salinity 38). These compounds, being unambiguous markers of the terrestrial origin of POM, allow us to unequivocally characterize the POM as terrestrial. While it was originally believed that a desorption of redox-active trace metal ions was the favoring factor that kick-started this intense autoxidation, this study evidences no trace metal desorption in the Rhône River mixing zone and hence no correlation between high autoxidation rates and the presence of trace metal ions. Autoxidation rates however were very well correlated with salinity levels within the river plume, with r2 reaching 0.801, 0.962, and 0.943 for sitosterol, α-amyrin, and β-amyrin, respectively, in November 2014.

  20. Alginate/hydrophobic HPMC (60M particulate systems: new matrix for site-specific and controlled drug delivery

    Directory of Open Access Journals (Sweden)

    Kajal Ghosal

    2011-12-01

    Full Text Available This study aimed to obtain site-specific and controlled drug release particulate systems. Some particulates were prepared using different concentrations of sodium alginate (Na-Alg alone and others were formulated using different proportions of Na-Alg with hydroxypropyl methylcellulose (HPMC stearoxy ether (60M viscosity grade, a hydrophobic form of conventional HPMC, using diclofenac potassium (DP by ion-exchange methods. Beads were characterized by encapsulation efficiency, release profile, swelling, and erosion rate. The suitability of common empirical (zero-order, first-order and Higuchi and semi-empirical (Ritger-Peppas and Peppas-Sahlin models was studied to describe the drug release profile. The Weibull model was also studied. Models were tested by non-linear least-square curve fitting. A general purpose mathematical software (MATLAB was used as an analysis tool. In addition, instead of the widely used linear fitting of log-transformed data, direct fitting was used to avoid any sort of truncation or transformation errors. The release kinetics of the beads indicated a purely relaxation-controlled delivery, referred to as case II transport. Weibull distribution showed a close fit. The release of DP from Na-Alg particulates was complete in 5-6 hours, whereas from Na-Alg hydrophobic HPMC particulate systems, release was sustained up to 10 hours. Hydrophobic HPMC with Na-Alg is an excellent matrix to formulate site-specific and controlled drug release particulate systems.Este estudo teve como objetivo a obtenção de sistemas particulados para a liberação controlada de fármacos em sítios de ação específicos. Algumas partículas foram preparadas utilizando-se diferentes concentrações de alginato de sódio (Na-Alg e outras foram formuladas por diferentes proporções de Na-Alg com estearoxílico éter de hidroxipropilmetilcelulose (HPMC (grau de viscosidade 60M, uma forma hidrofóbica do convencional HPMC, utilizando o diclofenaco de pot

  1. Source apportionment of particulate matter and trace gases near a major refinery near the Houston Ship Channel

    Science.gov (United States)

    Wallace, Henry W.; Sanchez, Nancy P.; Flynn, James H.; Erickson, Mathew H.; Lefer, Barry L.; Griffin, Robert J.

    2018-01-01

    From February 7 to 27, 2015, a mobile air quality laboratory was deployed to a location proximate to a major refinery, the Port of Houston, and several neighborhoods to conduct measurements of atmospheric trace gases and particulate matter. Two statistical models were utilized to apportion the sources of pollution impacting this site and the denizens of the nearby neighborhoods. Positive matrix factorization (PMF) was performed on the organic signal of the aerosol mass spectra, resulting in five factors totaling an average of 4.1 μg/m3 of the organic aerosol: hydrocarbon-like (0.67 μg/m3), cooking (0.35 μg/m3) biomass burning (1.14 μg/m3), low-volatility oxidized (1.15 μg/m3), and semi-volatile oxidized (0.78 μg/m3). Principal component analysis was performed on daytime and nighttime data, including concentrations from PMF output, of other PM1 components, and of trace gases. This generated five daytime and five nighttime factors that explained 74.5% and 73.0% of the variance, respectively. The most important factors impacting this site were from mobile source exhaust and petrochemical aromatic compound emissions. Together these two factors also constitute most of the observed carcinogens.

  2. Sensitive determination of total particulate phosphorus and particulate inorganic phosphorus in seawater using liquid waveguide spectrophotometry.

    Science.gov (United States)

    Ehama, Makoto; Hashihama, Fuminori; Kinouchi, Shinko; Kanda, Jota; Saito, Hiroaki

    2016-06-01

    Determining the total particulate phosphorus (TPP) and particulate inorganic phosphorus (PIP) in oligotrophic oceanic water generally requires the filtration of a large amount of water sample. This paper describes methods that require small filtration volumes for determining the TPP and PIP concentrations. The methods were devised by validating or improving conventional sample processing and by applying highly sensitive liquid waveguide spectrophotometry to the measurements of oxidized or acid-extracted phosphate from TPP and PIP, respectively. The oxidation of TPP was performed by a chemical wet oxidation method using 3% potassium persulfate. The acid extraction of PIP was initially carried out based on the conventional extraction methodology, which requires 1M HCl, followed by the procedure for decreasing acidity. While the conventional procedure for acid removal requires a ten-fold dilution of the 1M HCl extract with purified water, the improved procedure proposed in this study uses 8M NaOH solution for neutralizing 1M HCl extract in order to reduce the dilution effect. An experiment for comparing the absorbances of the phosphate standard dissolved in 0.1M HCl and of that dissolved in a neutralized solution [1M HCl: 8M NaOH=8:1 (v:v)] exhibited a higher absorbance in the neutralized solution. This indicated that the improved procedure completely removed the acid effect, which reduces the sensitivity of the phosphate measurement. Application to an ultraoligotrophic water sample showed that the TPP concentration in a 1075mL-filtered sample was 8.4nM with a coefficient of variation (CV) of 4.3% and the PIP concentration in a 2300mL-filtered sample was 1.3nM with a CV of 6.1%. Based on the detection limit (3nM) of the sensitive phosphate measurement and the ambient TPP and PIP concentrations of the ultraoligotrophic water, the minimum filtration volumes required for the detection of TPP and PIP were estimated to be 15 and 52mL, respectively. Copyright © 2016

  3. Room temperature large self-biased magnetoelectric effect in non-lead based piezoelectric and magnetostrictive (0−3) particulate composite system

    International Nuclear Information System (INIS)

    Kumari, Mukesh; Prakash, Chandra; Chatterjee, Ratnamala

    2017-01-01

    In this work, room temperature magnetoelectric properties of (0−3) particulate composites of non lead based piezoelectric BNTKNNLTS [0.97(Bi 0.5 Na 0.5 TiO 3 )–0.03(K 0.47 Na 0.47 Li 0.06 Nb 0.74 Sb 0.06 Ta 0.2 O 3 ) and magnetostrictive CZFMO (Co 0.6 Zn 0.4 Fe 1.7 Mn 0.3 O 4 ) are presented. Composite samples of (1-x)(BNTKNNLTS)-x(CZFMO) , with x=0.1 and 0.5, are synthesized by solid state reaction route. X-ray diffraction confirms the single phase formation of parent phases and the presence of two phases in the composites. Similar sintering conditions of the two individual components lead to optimal ferroelectric and ferromagnetic properties in the composites. A large self-biased magnetoelectric (ME) coupling ~74 mV/cm.Oe for the sample with x=0.1 (measured in longitudinally magnetized-transversely polarized configuration) is observed at room temperature. - Highlights: • Modified BNT-CFO based (0−3) particulate composites have been synthesized. • Similar sintering conditions of two components lead to optimal multiferroicity. • A large self-biased ME coupling ~74 mV/cm. Oe is obtained at room temperature.

  4. Characterization of coarse particulate matter in school gyms.

    Science.gov (United States)

    Braniš, Martin; Šafránek, Jiří

    2011-05-01

    We investigated the mass concentration, mineral composition and morphology of particles resuspended by children during scheduled physical education in urban, suburban and rural elementary school gyms in Prague (Czech Republic). Cascade impactors were deployed to sample the particulate matter. Two fractions of coarse particulate matter (PM(10-2.5) and PM(2.5-1.0)) were characterized by gravimetry, energy dispersive X-ray spectrometry and scanning electron microscopy. Two indicators of human activity, the number of exercising children and the number of physical education hours, were also recorded. Lower mass concentrations of coarse particulate matter were recorded outdoors (average PM(10-2.5) 4.1-7.4 μg m(-3) and PM(2.5-1.0) 2.0-3.3 μg m(-3)) than indoors (average PM(10-2.5) 13.6-26.7 μg m(-3) and PM(2.5-1.0) 3.7-7.4 μg m(-3)). The indoor concentrations of coarse aerosol were elevated during days with scheduled physical education with an average indoor-outdoor (I/O) ratio of 2.5-16.3 for the PM(10-2.5) and 1.4-4.8 for the PM(2.5-1.0) values. Under extreme conditions, the I/O ratios reached 180 (PM(10-2.5)) and 19.1 (PM(2.5-1.0)). The multiple regression analysis based on the number of students and outdoor coarse PM as independent variables showed that the main predictor of the indoor coarse PM concentrations is the number of students in the gym. The effect of outdoor coarse PM was weak and inconsistent. The regression models for the three schools explained 60-70% of the particular dataset variability. X-ray spectrometry revealed 6 main groups of minerals contributing to resuspended indoor dust. The most abundant particles were those of crustal origin composed of Si, Al, O and Ca. Scanning electron microscopy showed that, in addition to numerous inorganic particles, various types of fibers and particularly skin scales make up the main part of the resuspended dust in the gyms. In conclusion, school gyms were found to be indoor microenvironments with high

  5. Amino sugars in suspended particulate matter from the Bay of Bengal during the summer monsoon of 2001

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L.; De; Matondkar, S.G.P.; Bhosle, N.B.

    and pseudopeptidoglycan (Brock et al 1994). AS are also important con- stituents of many biopolymers such as polysac- charides, glycoproteins and glycolipids (Sharon 1965). Moreover, chitin, a polymer of amino sugar, N-acetyl glucosamine (Muzzarelli 1977; Benner.../F glass fibre filters (0.7?m pore size) for the analysis of particu- late organic carbon (POC), particulate nitrogen (PN) and amino sugars (AS) concentration and composition. 2.3 Analysis of samples The SPM samples were de-carbonated overnight using fuming...

  6. Improved method for minimizing sulfur loss in analysis of particulate organic sulfur.

    Science.gov (United States)

    Park, Ki-Tae; Lee, Kitack; Shin, Kyoungsoon; Jeong, Hae Jin; Kim, Kwang Young

    2014-02-04

    The global sulfur cycle depends primarily on the metabolism of marine microorganisms, which release sulfur gas into the atmosphere and thus affect the redistribution of sulfur globally as well as the earth's climate system. To better quantify sulfur release from the ocean, analysis of the production and distribution of organic sulfur in the ocean is necessary. This report describes a wet-based method for accurate analysis of particulate organic sulfur (POS) in the marine environment. The proposed method overcomes the considerable loss of sulfur (up to 80%) that occurs during analysis using conventional methods involving drying. Use of the wet-based POS extraction procedure in conjunction with a sensitive sulfur analyzer enabled accurate measurements of cellular POS. Data obtained using this method will enable accurate assessment of how rapidly sulfur can transfer among pools. Such information will improve understanding of the role of POS in the oceanic sulfur cycle.

  7. Solid-state 13C NMR experiments reveal effects of aggregate size on the chemical composition of particulate organic matter in grazed steppe soils

    Science.gov (United States)

    Steffens, M.; Kölbl, A.; Kögel-Knabner, I.

    2009-04-01

    Grazing is one of the most important factors that may reduce soil organic matter (SOM) stocks and subsequently deteriorate aggregate stability in grassland topsoils. Land use management and grazing reduction are assumed to increase the input of OM, improve the soil aggregation and change species composition of vegetation (changes depth of OM input). Many studies have evaluated the impact of grazing cessation on SOM quantity. But until today little is known about the impact of grazing cessation on the chemical quality of SOM in density fractions, aggregate size classes and different horizons. The central aim of this study was to analyse the quality of SOM fractions in differently sized aggregates and horizons as affected by increased inputs of organic matter due to grazing exclusion. We applied a combined aggregate size, density and particle size fractionation procedure to sandy steppe topsoils with different organic matter inputs due to different grazing intensities (continuously grazed = Cg, winter grazing = Wg, ungrazed since 1999 = Ug99, ungrazed since 1979 = Ug79). Three different particulate organic matter (POM; free POM, in aggregate occluded POM and small in aggregate occluded POM) and seven mineral-associated organic matter fractions were separated for each of three aggregate size classes (coarse = 2000-6300 m, medium = 630-2000 m and fine =

  8. Complexity analysis in particulate matter measurements

    Directory of Open Access Journals (Sweden)

    Luciano Telesca

    2011-09-01

    Full Text Available We investigated the complex temporal fluctuations of particulate matter data recorded in London area by using the Fisher-Shannon (FS information plane. In the FS plane the PM10 and PM2.5 data are aggregated in two different clusters, characterized by different degrees of order and organization. This results could be related to different sources of the particulate matter.

  9. Nature and sources of suspended particulate organic matter in a tropical estuary during the monsoon and pre-monsoon: Insights from stable isotopes (delta 13C POC, delta 15 N TPN) and carbohydrate signature compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    zooplankton, and then known aliquots (0.25 to 1.5 L) were filtered through pre-combusted (450 °C, 4h) 47 mm GF/F filter papers (0.7 µm, Whatman) for the measurements of suspended particulate matter (SPM), particulate organic carbon (POC), δ13CPOC, δ15NTPN... analysis. 2.3. Determination of bulk parameters and stable isotopes GF/F (0.7 µm, 47 mm) filter containing particulate matter was washed with UV-Milli-Q- water to remove salt and the filter was dried at 40 °C for 24 h. Filter was cooled and weighed...

  10. Characterization of particulate amines

    International Nuclear Information System (INIS)

    Gundel, L.A.; Chang, S.G.; Clemenson, M.S.; Markowitz, S.S.; Novakov, T.

    1979-01-01

    The reduced nitrogen compounds associated with ambient particulate matter are chemically characterized by means of ESCA and proton activation analysis. Ambient particulate samples collected on silver filters in Berkeley, California were washed with water and organic solvents, and ESCA and proton activation analysis were performed in order to determine the composition of various nitrogen compounds and the total nitrogen content. It is found that 85% of the amines originally present in ambient particulate matter can be removed by water extraction, whereas the ammonium and nitrate are completely removed. An observed increase in ammonium ion in the extract, compared with its concentration in the original sample, coupled with the commensurate decrease in amine concentration, is attributed to the hydrolysis of amide groups, which may cause analytical methods based on extraction to yield erroneous results

  11. Seasonal Variability of Airborne Particulate Matter and Bacterial Concentrations in Colorado Homes

    Directory of Open Access Journals (Sweden)

    Nicholas Clements

    2018-04-01

    Full Text Available Aerosol measurements were collected at fifteen homes over the course of one year in Colorado (USA to understand the temporal variability of indoor air particulate matter and bacterial concentrations and their relationship with home characteristics, inhabitant activities, and outdoor air particulate matter (PM. Indoor and outdoor PM2.5 concentrations averaged (±st. dev. 8.1 ± 8.1 μg/m3 and 6.8 ± 4.5 μg/m3, respectively. Indoor PM2.5 was statistically significantly higher during summer compared to spring and winter; outdoor PM2.5 was significantly higher for summer compared to spring and fall. The PM2.5 I/O ratio was 1.6 ± 2.4 averaged across all homes and seasons and was not statistically significantly different across the seasons. Average indoor PM10 was 15.4 ± 18.3 μg/m3 and was significantly higher during summer compared to all other seasons. Total suspended particulate bacterial biomass, as determined by qPCR, revealed very little seasonal differences across and within the homes. The qPCR I/O ratio was statistically different across seasons, with the highest I/O ratio in the spring and lowest in the summer. Using one-minute indoor PM10 data and activity logs, it was observed that elevated particulate concentrations commonly occurred when inhabitants were cooking and during periods with elevated outdoor concentrations.

  12. Controlling exposure to DPM : diesel particulate filters vs. biodiesel

    International Nuclear Information System (INIS)

    Bugarski, A.D.; Shi, X.C.

    2009-01-01

    In order to comply with Mine Safety and Health Administration regulations, mining companies are required to reduce miners exposures to diesel particulate matter (DPM) to 160 μg/m 3 of total carbon. Diesel particulate filter (DPF) systems, disposable filter elements (DFEs), and diesel oxidation catalysts (DOCs) are among the most effective strategies and technologies for curtailing DPM at its source. Substituting diesel fuel with biodiesel blends is also considered to be a plausible solution by many underground mine operators. Studies were conducted at the National Institute for Occupational Safety and Health Diesel Laboratory at Lake Lynn Experimental Mine to evaluate various control technologies and strategies available to the underground mining industry to reduce exposure to DPM. The physical, chemical and toxicological properties of diesel aerosols (DPM) emitted by engines in an underground mine were also evaluated. The DPF and DFE systems were found to be highly effective in reducing total particulate and elemental carbon mass concentrations, total aerosol surface concentrations and, in most cases, concentrations of diesel aerosols in occupational settings such as underground mines. Soy methyl ester (SME) biodiesel fuels had the potential to reduce the mine air concentrations of total DPM, although the rate of reduction varied depending on engine operating conditions. The disadvantage of using biodiesel fuels was an increase in the fraction of particle-bound volatile organics and concentration of aerosols for light-load engine operating conditions.

  13. Health risk assessment of occupational exposure to particulate-phase polycyclic aromatic hydrocarbons associated with Chinese, Malay and Indian cooking.

    Science.gov (United States)

    Wei See, Siao; Karthikeyan, Sathrugnan; Balasubramanian, Rajasekhar

    2006-03-01

    Food cooking using liquefied petroleum gas (LPG) has received considerable attention in recent years since it is an important source of particulate air pollution in indoor environments for non-smokers. Exposure to organic compounds such as polycyclic aromatic hydrocarbons (PAHs) contained in particles is of particular health concern since some of these compounds are suspected carcinogens. It is therefore necessary to chemically characterize the airborne particles emitted from gas cooking to assess their possible health impacts. In this work, the levels of fine particulate matter (PM(2.5)) and 16 priority PAHs were determined in three different ethnic commercial kitchens, specifically Chinese, Malay and Indian food stalls, where distinctive cooking methods were employed. The mass concentrations of PM(2.5) and PAHs, and the fraction of PAHs in PM(2.5) were the highest at the Malay stall (245.3 microg m(-3), 609.0 ng m(-3), and 0.25%, respectively), followed by the Chinese stall (201.6 microg m(-3), 141.0 ng m(-3), and 0.07%), and the Indian stall (186.9 microg m(-3), 37.9 ng m(-3), and 0.02%). This difference in the levels of particulate pollution among the three stalls may be attributed to the different cooking methods employed at the food stalls, the amount of food cooked, and the cooking time, although the most sensitive parameter appears to be the predominant cooking method used. Frying processes, especially deep-frying, produce more air pollutants, possibly due to the high oil temperatures used in such operations. Furthermore, it is found that frying, be it deep-frying at the Malay stall or stir-frying at the Chinese stall, gave rise to an abundance of higher molecular weight PAHs such as benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene whereas low-temperature cooking, such as simmering at the Indian stall, has a higher concentration of lower molecular weight PAHs. In addition, the correlation matrices and diagnostic ratios of PAHs were

  14. Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L

    for particulate organic carbon (POC) and particulate organic nitrogen (PON), delta sup(13) C sub(POC), total hydrolysable amino acid enantiomers (L- and D- amino acids) concentration and composition. Delta sup(13)C sub(POC) values were depleted (-32 to -25 ppt...

  15. Determinants of exposure to fine particulate matter (PM 2.5) for waiting passengers at bus stops

    Science.gov (United States)

    Hess, Daniel Baldwin; Ray, Paul David; Stinson, Anne E.; Park, JiYoung

    2010-12-01

    This research evaluates commuter exposure to particulate matter during pre-journey commute segments for passengers waiting at bus stops by investigating 840 min of simultaneous exposure levels, both inside and outside seven bus shelters in Buffalo, New York. A multivariate regression model is used to estimate the relation between exposure to particulate matter (PM 2.5 measured in μg m -3) and three vectors of determinants: time and location, physical setting and placement, and environmental factors. Four determinants have a statistically significant effect on particulate matter: time of day, passengers' waiting location, land use near the bus shelter, and the presence of cigarette smoking at the bus shelter. Model results suggest that exposure to PM 2.5 inside a bus shelter is 2.63 μg m -3 (or 18 percent) higher than exposure outside a bus shelter, perhaps due in part to the presence of cigarette smoking. Morning exposure levels are 6.51 μg m -3 (or 52 percent) higher than afternoon levels. Placement of bus stops can affect exposure to particulate matter for those waiting inside and outside of shelters: air samples at bus shelters located in building canyons have higher particulate matter than bus shelters located near open space.

  16. Determination of Dibenzacridines in the Particulate Phase of Cigarette Smoke

    Directory of Open Access Journals (Sweden)

    Sasaki TA

    2014-12-01

    Full Text Available This study attempted to resolve a controversy related to the presence of dibenz[a,j]acridine and dibenz[a,h]acridine in the particulate phase of cigarette smoke. Smoking was performed using FTC conditions (35 mL puff volume, 2 sec. puff, 1 min. interval on a Borgwaldt RM 20/CS smoking machine. The particulate phase of forty cigarettes was collected on 92 mm Cambridge filter pads. Pads were combined to analyze the particulate phase of the mainstream smoke from between 120 and 320 cigarettes. In an initial scheme of analysis, the pads were extracted with an acidic aqueous solution. This aqueous solution was then washed with CH2Cl2 and the organic phase discarded. The aqueous solution was then changed to basic and extracted with CH2Cl2, which was concentrated and analyzed via GC/MS. The dibenzacridine could not be detected utilizing this scheme, even when the pads had been spiked with a few thousand nanograms of dibenzacridine. After using several other organic solvents (cyclohexane, CHCl3, and benzene to eliminate the possibility that the extraction efficiency of CH2Cl2 was poor, it was determined that dibenzacridine was being discarded with the first CH2Cl2 wash. A successful separation scheme was developed by extracting the smoked pad with an aqueous acidic solution, followed by extraction of the aqueous phase with CH2Cl2without pH change. The CH2Cl2 extract was concentrated under nitrogen and 1 µL injected for GC/MS analysis. Quantification was achieved by spiking the pads with dibenz[a,j]acridine-d13 as an internal standard at a level equal to 1.7-2.5 ng/cig. The limit of detection for this technique was approximately 0.5 ng/cig. The chromatographic separation was performed with a 30 m BPX-5 column (0.25 mm i.d., 0.25 µm film thickness. Mass spectral data were acquired in selected ion monitoring (SIM mode with m/z = 279 for the two dibenzacridine isomers and m/z = 292 for the deuterated internal standard. Three commercial cigarettes were

  17. Advanced Fine Particulate Characterization Methods

    Energy Technology Data Exchange (ETDEWEB)

    Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

    2007-01-31

    The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

  18. [Sample preparation methods for chromatographic analysis of organic components in atmospheric particulate matter].

    Science.gov (United States)

    Hao, Liang; Wu, Dapeng; Guan, Yafeng

    2014-09-01

    The determination of organic composition in atmospheric particulate matter (PM) is of great importance in understanding how PM affects human health, environment, climate, and ecosystem. Organic components are also the scientific basis for emission source tracking, PM regulation and risk management. Therefore, the molecular characterization of the organic fraction of PM has become one of the priority research issues in the field of environmental analysis. Due to the extreme complexity of PM samples, chromatographic methods have been the chief selection. The common procedure for the analysis of organic components in PM includes several steps: sample collection on the fiber filters, sample preparation (transform the sample into a form suitable for chromatographic analysis), analysis by chromatographic methods. Among these steps, the sample preparation methods will largely determine the throughput and the data quality. Solvent extraction methods followed by sample pretreatment (e. g. pre-separation, derivatization, pre-concentration) have long been used for PM sample analysis, and thermal desorption methods have also mainly focused on the non-polar organic component analysis in PM. In this paper, the sample preparation methods prior to chromatographic analysis of organic components in PM are reviewed comprehensively, and the corresponding merits and limitations of each method are also briefly discussed.

  19. Particulate and soluble 210Pd activities in the deep sea

    International Nuclear Information System (INIS)

    Somayajulu, B.L.K.; Craig, H.

    1976-01-01

    Particulate and soluble, 210 Pb activities have been measured by filtration of large-volume water samples at two stations in the South Atlantic. Particulate phase 210 Pb (caught by a 0.4-μm filter) varies from 0.3% of total 210 Pb in equatorial surface water to 15% in the bottom water. The 'absolute activity' of 210 Pb per unit mass of particulate matter is about 10 7 times the activity of soluble 210 Pb per unit mass of water, but because the mass ratio of particulate matter to water is about 10 -8 , the particulate phase carries only about 10% of the total activity. In Antarctic surface water the particulate phase carries 40% of the total 210 Pb activity; the absolute activity of this material is about the same as in other water masses and the higher fraction is due to the much larger concentration of suspended matter in surface water in this region. In the equatorial Atlantic the particulate phase 210 Pb activity increases with depth, by a factor of 40 from surface to bottom, and by a factor of 4 from the Antarctic Intermediate water core to the Antarctic Bottom Water. (Auth.)

  20. Temporal variations in C-13 and C-14 concentrations in particulate organic matter from the southern North Sea

    NARCIS (Netherlands)

    Megens, L.; Plicht, J. van der; Leeuw, J.W. de

    As a new approach for the characterization and determination of the origin of particulate organic matter (POM) in coastal waters, we measured the 14C activity and 13C/12C isotope ratios and applied molecular analysis by means of AMS, IRMS and pyrolysis-GCMS for both bulk samples and isolated

  1. The APE nebuliser - a new delivery system for the alveolar targeting of particulate technetium 99m diethylene triamine penta-acetic acid

    International Nuclear Information System (INIS)

    Miller, R.F.; Semple, S.J.G.; Jarritt, P.H.; Lui, D.; Kidery, J.; Ell, P.J.

    1991-01-01

    We report the validation of a new delivery system - aerosol production equipment (known by the acronym APE), which generates a particulate aerosol of technetium 99m diehtylene triamine penta-acetic acid (DTPA) with a mass-median aerodynamic diameter of 0.35 μm and a geometric standard deviation of 1.8. Twenty subjects were studied; in group 1 were 12 healthy men with normal spirometry; in group 2 were 8 men with AIDS who had mildly abnormal lung function following an episode of pneumocystic pneumonia-spirometry FEV 1 3.08 (0.73) L, FVC 4.83 (0.82) L [mean (SD)]. The APE nebulizer was used to form a particulate aerosol with 200 MBq of 99m Tc DTPA, which was collected in a 35 l reservoir of air, which was subsequently inhaled. The mean (SD) inhalation time was 4.7 (0.44) min. The output of the nebulizer (% of activity inhaled) was 82%. Using planar imaging, the penetration index (right lung) in group 1 was 0.93 (0.18), mean (SD), and in group 2 it was 0.91 (0.12). There was virtually no tracheal deposition and extrapulmonary deposition (oropharynx and stomach) was less than 5% of the aerosol delivered. Single-photon emission tomography (SPET) studies carried out in five patients from group 1 confirmed homogeneous intrapulmonary deposition of 99m Tc-DTPA. In view of the excellent intrapulmonary deposition of 99m Tc-DTPA produced by the APE nebulizer, it may provide an alternative to conventional ventilation studies using radioactive gases. (orig.)

  2. Evaluation of the impact of general phosphate fertilizers factories company on the surrounding environment by determining natural radionuclides and some trace elements in air particulates

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Al-Kharfan, K.; Al-Hamwi, A.; Al-Shamali, K.

    2004-01-01

    Natural radionuclides and some trace element levels in air particulates of the areas surrounding the phosphate fertilizers factory in Homs have been determined Mean total air particulates concentration ranged from 31 μg/m3 in Kerba Al-Teen in Autumn period. While trace element concentrations in air particulates were relatively high in air particulates collected from AECS center and other sites situated north east of the factory; about 1.7 ng/m3 in AECS site and 1.7 ng/m3 in Abel for uranium and cadmium, respectively. In addition, radioactivity analysis of air particulates has shown low levels of polonium 210 and lead 210; a value of 2 mBq/m3 in Kerba Al-Teen has not been exceeded. However, air particulate, natural radionuclides and the studied trace elements concentrations in the surrounding areas were within the natural levels. Therefore, air emissions from the factory containing radioactive materials and trace elements are relatively low. This is due to strict control procedures on transport and loading processes of phosphate in addition to the high efficiency of filters used for air emissions from the phosphate fertilizers factory during the study period (2002). (author)

  3. Evaluation of the impact of general phosphate fertilizers factories company on the surrounding environment by determining natural radionuclides and some trace elements in air particulates

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Al-Kharfan, K.; Al-Hamwi, A.; Al-Shmali, K.; Abdul Haleem, M.

    2003-12-01

    Natural radionuclides and some trace element levels in air particulates of the areas surrounding the phosphate fertilizers factory in Homs have been determined mean total air particulates concentration ranged from 31μg/m 3 in Kerba Al-Teen in autumn period. While trace element concentrations in air particulates were relatively high in air particulates collected from AECS center and other sites situated north east of the factory: about 1.7 ng/m 3 in AECS site and 1.7 ng/m 3 in Abel for uranium and cadmium, respectively. In addition, radioactivity analysis of air particulates have shown low levels of polonium 210 and lead 210, a value of 2 mBg/m 3 in Kerba Al-Teen has not been exceeded. However, air particulate, natural radionuclides and the studied trace elements concentrations in the surrounding areas were within the natural levels. Therefore, air emissions from the factory containing radioactive materials and trace elements are relatively low. This is due to strict control procedures on transport and loading processes of phosphate in addition to the high efficiency of filters used for air emissions from the phosphate fertilizers factory during the study period (2002).(author)

  4. Characteristic of ambient airborne and respirable particulate around a non formal industrial area

    International Nuclear Information System (INIS)

    Muhayatun Santoso; Diah Dwiana Lestiani; Mariana Marselina; Rita Mukhtar

    2016-01-01

    Characterization of airborne particulate matter and respirable particulate in Parung Panjang district especially on surrounding non formal used batteries industrial area has been carried out to follow up the previous results with respect to high concentrations of lead detected in Serpong area. Sampling of airborne particulate matter in Parung Panjang was conducted using Gent stacked filter unit sampler, while the respirable particulate matter samples collected using personal dust sampler in Parung Panjang as a non formal Industrial area and Sukarasa village as a control, during 2011-2012. The concentration of masses were determined gravimetrically, while for elemental concentrations by X-Ray based methods. The average of mass concentration of air ambient PM 2.5 and PM 10 in Parung Panjang were 27.3 ± 13.7 and 77.5 ± 17.1 μg.m -3 , respectively. While the average concentration of respirable particulate in non formal industrial and control areas were 260 ± 233 and 82 ± 38 μg.m -3 , respectively. The percentage of average Pb concentration in PM 2.5 and PM 2.5-10 were contribute up to 45 and 10 % of the mass concentration, respectively. The maximum percentage concentration of Pb in respirable particulate in industrial and control area were 12.11 and 0.27 %, respectively. These results showed that the Pb concentrations in respirable particulate in industrial area were significantly tens times higher than in the control area. The high concentration of Pb in Parung Panjang was the main key element came from the used lead battery industry and one of pollutant source that contributed to the Pb pollution in Serpong area. (author)

  5. Increase of anaerobic degradation of particulate organic matter in full-scale biogas plants by mechanical maceration

    DEFF Research Database (Denmark)

    Hartmann, Hinrich; Angelidaki, Irini; Ahring, Birgitte Kiær

    2000-01-01

    of a macerator make it attractive to use this pretreatment method for a more complete degradation of particulate organic matter. investigation of the size distribution of the fibers showed that a change in biogas potential was not correlated to a smaller size of the fibers. Results from the macerators indicate......% by pretreatment of the whole feed in the macerator before the reactor was observed. implementation concepts with a treatment of the fibers alone after separation from the manure showed to be not efficient due to a low recovery of organic matter in the fibers by the separation unit. The low operational costs...

  6. Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean

    OpenAIRE

    Druffel, E. R. M; Bauer, J. E; Griffin, S.

    2005-01-01

    We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC Δ14C results revealed postbomb carbon in river and ocean waters...

  7. Metal/nonmetal diesel particulate matter rule

    Energy Technology Data Exchange (ETDEWEB)

    Tomko, D.M. [United States Dept. of Labor, Mine Safety and Health Administration, Pittsburgh, PA (United States). Safety and Health Technology Center; Stackpole, R.P. [United States Dept. of Labor, Mine Safety and Health Administration, Triadelphia, WV (United States). Approval and Certification Center; Findlay, C.D. [United States Dept. of Labor, Mine Safety and Health Administration, Arlington, VA (United States). Metal/Nonmetal Safety and Health; Pomroy, W.H. [United States Dept. of Labor, Mine Safety and Health Administration, Duluth, MN (United States). Metal/Nonmetal North Central District

    2010-07-01

    The American Mine Safety and Health Administration (MSHA) issued a health standard in January 2001 designed to reduce exposure to diesel particulate matter (DPM) in underground metal and nonmetal mines. The rule established an interim concentration limit for DPM of 400 {mu}g/m{sup 3} of total carbon, to be followed in 2004 by a final limit of 160 {mu}g/m{sup 3} of total carbon. The 2001 rule was challenged in federal court by various mining trade associations and mining companies. The rule was subsequently amended. This paper highlighted the major provisions of the 2006 final rule and summarized MSHAs current compliance sampling procedures. The concentration limit was changed to a permissible exposure limit and the sampling surrogate was changed from total carbon to elemental carbon. The MSHA published a new rule in 2006 which based the final limit on a miner's personal exposure rather than a concentration limit. The final limit was phased in using 3 steps over 2 years. This paper also discussed engineering controls and a recent MSHA report on organic carbon, elemental carbon and total carbon emissions from a diesel engine fueled with various blends of standard diesel and biodiesel. In May 2008, about two-thirds of all underground metal/nonmetal mines achieved and maintained compliance with the rule. 20 refs.

  8. Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    S. Moukhtar

    2011-11-01

    Full Text Available A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter is presented. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. Particulate matter was collected on quartz fibre filters using dichotomous high volume air samplers. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography and solid phase extraction. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyltrifluoroacetamide, was added for Gas Chromatography-Mass Spectrometry analysis. The second half of the sample was stored in a refrigerator. For samples with concentrations exceeding 1 ng μl−1, the second half of the sample was used for measurement of stable carbon isotope ratios by Gas Chromatography-Isotope Ratio Mass Spectrometry.

    The procedure described in this paper provides a method for the analysis of methylnitrophenols in atmospheric particulate matter at concentrations as low as 0.3 pg m3 and for stable isotope ratios with an accuracy of better than ±0.5‰ for concentrations exceeding 100 pg m3.

    In all atmospheric particulate matter samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol, with concentrations ranging from the low pg m3 range in rural areas to more than 200 pg m3 in some samples from a suburban location.

  9. Small-angle light scattering by airborne particulates: Environnement S.A. continuous particulate monitor

    International Nuclear Information System (INIS)

    Renard, Jean-Baptiste; Gaubicher, Bertrand; Thaury, Claire; Mineau, Jean-Luc

    2010-01-01

    Airborne particulate matter may have an effect on human health. It is therefore necessary to determine and control in real time the evolution of the concentration and mass of particulates in the ambient air. These parameters can be obtained using optical methods. We propose here a new instrument, 'CPM' (continuous particulate monitor), for the measurement of light scattered by ambient particulates at small angles. This geometry allows simultaneous and separate detections of PM10, PM2.5 and PM1 fractions of airborne particulate matter, with no influence of their chemical nature and without using theoretical calculations. The ambient air is collected through a standard sampling head (PM10 inlet according to EN 12341, PM2.5 inlet according to EN 14907; or PM1, TSP inlets, standard US EPA inlets). The analysis of the first measurements demonstrates that this new instrument can detect, for each of the seven defined size ranges, real-time variations of particulate content in the ambient air. The measured concentrations (expressed in number per liter) can be converted into total mass concentrations (expressed in micrograms per cubic meter) of all fractions of airborne particulate matters sampled by the system. Periodic comparison with a beta-attenuation mass monitor (MP101M Beta Gauge Analyzer from Environnement S.A. company) allows the calculation of a calibration factor as a function of the mean particulate density that is used for this conversion. It is then possible to provide real-time relative variations of aerosol mass concentration

  10. Room temperature large self-biased magnetoelectric effect in non-lead based piezoelectric and magnetostrictive (0−3) particulate composite system

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Mukesh [Magnetics & Advanced Ceramics Laboratory, Indian Institute of Technology, Delhi-110016 India (India); Prakash, Chandra [Solid State Physics Laboratory Timarpur, Delhi-110054 India (India); Chatterjee, Ratnamala, E-mail: rmala@physics.iitd.ac.in [Magnetics & Advanced Ceramics Laboratory, Indian Institute of Technology, Delhi-110016 India (India)

    2017-05-01

    In this work, room temperature magnetoelectric properties of (0−3) particulate composites of non lead based piezoelectric BNTKNNLTS [0.97(Bi{sub 0.5}Na{sub 0.5}TiO{sub 3})–0.03(K{sub 0.47}Na{sub 0.47}Li{sub 0.06}Nb{sub 0.74}Sb{sub 0.06}Ta{sub 0.2}O{sub 3}) and magnetostrictive CZFMO (Co{sub 0.6}Zn{sub 0.4}Fe{sub 1.7}Mn{sub 0.3}O{sub 4}) are presented. Composite samples of (1-x)(BNTKNNLTS)-x(CZFMO){sub ,} with x=0.1 and 0.5, are synthesized by solid state reaction route. X-ray diffraction confirms the single phase formation of parent phases and the presence of two phases in the composites. Similar sintering conditions of the two individual components lead to optimal ferroelectric and ferromagnetic properties in the composites. A large self-biased magnetoelectric (ME) coupling ~74 mV/cm.Oe for the sample with x=0.1 (measured in longitudinally magnetized-transversely polarized configuration) is observed at room temperature. - Highlights: • Modified BNT-CFO based (0−3) particulate composites have been synthesized. • Similar sintering conditions of two components lead to optimal multiferroicity. • A large self-biased ME coupling ~74 mV/cm. Oe is obtained at room temperature.

  11. Dearborn GC-MS organic speciation data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ambient particulate matter organic speciation data from July - August, 2011. This dataset is associated with the following publication: Lynam, M., T. Dvonch, J....

  12. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  13. Characterization of coarse particulate matter in school gyms

    International Nuclear Information System (INIS)

    Branis, Martin; Safranek, Jiri

    2011-01-01

    We investigated the mass concentration, mineral composition and morphology of particles resuspended by children during scheduled physical education in urban, suburban and rural elementary school gyms in Prague (Czech Republic). Cascade impactors were deployed to sample the particulate matter. Two fractions of coarse particulate matter (PM 10-2.5 and PM 2.5-1.0 ) were characterized by gravimetry, energy dispersive X-ray spectrometry and scanning electron microscopy. Two indicators of human activity, the number of exercising children and the number of physical education hours, were also recorded. Lower mass concentrations of coarse particulate matter were recorded outdoors (average PM 10-2.5 4.1-7.4 μg m -3 and PM 2.5-1.0 2.0-3.3 μg m -3 ) than indoors (average PM 10-2.5 13.6-26.7 μg m -3 and PM 2.5-1.0 3.7-7.4 μg m -3 ). The indoor concentrations of coarse aerosol were elevated during days with scheduled physical education with an average indoor-outdoor (I/O) ratio of 2.5-16.3 for the PM 10-2.5 and 1.4-4.8 for the PM 2.5-1.0 values. Under extreme conditions, the I/O ratios reached 180 (PM 10-2.5 ) and 19.1 (PM 2.5-1.0 ). The multiple regression analysis based on the number of students and outdoor coarse PM as independent variables showed that the main predictor of the indoor coarse PM concentrations is the number of students in the gym. The effect of outdoor coarse PM was weak and inconsistent. The regression models for the three schools explained 60-70% of the particular dataset variability. X-ray spectrometry revealed 6 main groups of minerals contributing to resuspended indoor dust. The most abundant particles were those of crustal origin composed of Si, Al, O and Ca. Scanning electron microscopy showed that, in addition to numerous inorganic particles, various types of fibers and particularly skin scales make up the main part of the resuspended dust in the gyms. In conclusion, school gyms were found to be indoor microenvironments with high concentrations of

  14. Comparative toxicity and endocrine disruption potential of urban and rural atmospheric organic PM1 in JEG-3 human placental cells.

    Science.gov (United States)

    van Drooge, Barend L; Marqueño, Anna; Grimalt, Joan O; Fernández, Pilar; Porte, Cinta

    2017-11-01

    Outdoor ambient air particulate matter and air pollution are related to adverse effects on human health. The present study assesses the cytotoxicity and ability to disrupt aromatase activity of organic PM 1 extracts from rural and urban areas at equivalent air volumes from 2 to 30 m 3 , in human placental JEG-3 cells. Samples were chemically analyzed for particle bounded organic compounds with endocrine disrupting potential, i.e. PAH, O-PAH, phthalate esters, but also for organic molecular tracer compounds for the emission source identification. Rural samples collected in winter were cytotoxic at the highest concentration tested and strongly inhibited aromatase activity in JEG-3 cells. No cytotoxicity was detected in summer samples from the rural site and the urban samples, while aromatase activity was moderately inhibited in these samples. In the urban area, the street site samples, collected close to intensive traffic, showed stronger inhibition of aromatase activity than the samples simultaneously collected at a roof site, 50 m above ground level. The cytotoxicity and endocrine disruption potential of the samples were linked to combustion products, i.e. PAH and O-PAH, especially from biomass burning in the rural site in winter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Satellite-Derived Distributions, Inventories and Fluxes of Dissolved and Particulate Organic Matter Along the Northeastern U.S. Continental Margin

    Science.gov (United States)

    Mannino, A.; Hooker, S. B.; Hyde, K.; Novak, M. G.; Pan, X.; Friedrichs, M.; Cahill, B.; Wilkin, J.

    2011-01-01

    Estuaries and the coastal ocean experience a high degree of variability in the composition and concentration of particulate and dissolved organic matter (DOM) as a consequence of riverine and estuarine fluxes of terrigenous DOM, sediments, detritus and nutrients into coastal waters and associated phytoplankton blooms. Our approach integrates biogeochemical measurements, optical properties and remote sensing to examine the distributions and inventories of organic carbon in the U.S. Middle Atlantic Bight and Gulf of Maine. Algorithms developed to retrieve colored DOM (CDOM), Dissolved (DOC) and Particulate Organic Carbon (POC) from NASA's MODIS-Aqua and SeaWiFS satellite sensors are applied to quantify the distributions and inventories of DOC and POC. Horizontal fluxes of DOC and POC from the continental margin to the open ocean are estimated from SeaWiFS and MODIS-Aqua distributions of DOC and POC and horizontal divergence fluxes obtained from the Northeastern North Atlantic ROMS model. SeaWiFS and MODIS imagery reveal the importance of estuarine outflow to the export of CDOM and DOC to the coastal ocean and a net community production of DOC on the shelf.

  16. Organic and inorganic speciation of particulate matter formed during different combustion phases in an improved cookstove.

    Science.gov (United States)

    Leavey, Anna; Patel, Sameer; Martinez, Raul; Mitroo, Dhruv; Fortenberry, Claire; Walker, Michael; Williams, Brent; Biswas, Pratim

    2017-10-01

    Residential solid fuel combustion in cookstoves has established health impacts including bladder and lung cancers, cataracts, low birth weight, and pneumonia. The chemical composition of particulate matter (PM) from 4 commonly-used solid fuels (coal, dung, ambient/dry applewood, and oakwood pellets), emitted from a gasifier cookstove, as well as propane, were examined. Temporal changes between the different cookstove burn-phases were also explored. Normalized concentrations of non-refractory PM 1 , total organics, chloride, ammonium, nitrate, sulfate, and 41 particle-phase polycyclic aromatic hydrocarbons (PAHs) were measured using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a Thermal desorption Aerosol Gas chromatograph (TAG), respectively. Coal demonstrated the highest fraction of organic matter in its particulate emission composition (98%), followed by dung (94%). Coal and dung also demonstrated the highest numbers and concentrations of PAHs. While dry applewood emitted ten times lower organic matter compared to ambient applewood, a higher fraction of these organics was composed of PAHs, especially the more toxic ones such as benzo(a)pyrene (9.63ng/L versus 0.04ng/L), and benzo(b)fluoranthene (31.32ng/L versus 0.19ng/L). Data from the AMS demonstrated no clear trends for any of the combustion fuels over the different combustion phases unlike the previously reported trends observed for the physical characteristics. Of the solid fuels, pellets demonstrated the lowest emissions. Emissions from propane were below the quantification limit of the instruments. This work highlights the benefits of incorporating additional metrics into the cookstove evaluation process, thus enriching the existing PM data inventory. Copyright © 2017. Published by Elsevier Inc.

  17. Volatile organic compounds and particulate matter in child care facilities in the District of Columbia: Results from a pilot study.

    Science.gov (United States)

    Quirós-Alcalá, L; Wilson, S; Witherspoon, N; Murray, R; Perodin, J; Trousdale, K; Raspanti, G; Sapkota, A

    2016-04-01

    Many young children in the U.S. spend a significant portion of their day in child care facilities where they may be exposed to contaminants linked to adverse health effects. Exposure data on volatile organic compounds (VOCs) and particulate matter (PM) in these settings is scarce. To guide the design of a larger exposure assessment study in urban child care facilities, we conducted a pilot study in which we characterized indoor concentrations of select VOCs and PM. We recruited 14 child care facilities in the District of Columbia (Washington, DC) and measured indoor concentrations of seven VOCs (n=35 total samples; 2-5 samples per facility): benzene, carbon tetrachloride, chloroform, ethylbenzene, o-xylene, p-xylene, and toluene in all facilities; and collected real-time PM measurements in seven facilities. We calculated descriptive statistics for contaminant concentrations and computed intraclass correlation coefficients (ICC) to evaluate the variability of VOC levels indoors. We also administered a survey to collect general health information on the children attending these facilities, and information on general housekeeping practices and proximity of facilities to potential sources of target contaminants. We detected six of the seven VOCs in the majority of child care facilities with detection frequencies ranging from 71% to 100%. Chloroform and toluene were detected in all samples. Median (range) concentrations for toluene, chloroform, benzene, o-xylene, ethylbenzene, and carbon tetrachloride were: 5.6µg/m(3) (0.6-16.5µg/m(3)), 2.8µg/m(3) (0.4-53.0µg/m(3)), 1.4µg/m(3) (below the limit of detection or air fresheners and/or scented candles were used in half of the facilities, and at least one child in each facility had physician-diagnosed asthma (median asthma prevalence rate=10.2%). We found quantifiable levels of VOCs and PM in the child care facilities sampled. Given that exposures to environmental contaminants during critical developmental stages may

  18. Report Task 2.3: Particulate waste and turbidity in (marine) RAS

    OpenAIRE

    Kals, J.; Schram, E.; Brummelhuis, E.B.M.; Bakel, van, B.

    2006-01-01

    Particulate waste management and removal is one of the most problematic parts of recirculation aquaculture systems (RAS). Particulate waste and thereby turbidity originates from three major sources: fish (faeces), feed and biofilm (heterotrophic bacteria and fungi). Based on size and density there are roughly four categories of particulate waste: settable, suspended, floatable and fine or dissolved solids. Specific problems related to high turbidity are a decreasing feed intake by fish, causi...

  19. Thorium-particulate matter interaction. Thorium complexing capacity of oceanic particulate matter: Theory

    International Nuclear Information System (INIS)

    Hirose, Katsumi; Tanque, Eiichiro

    1994-01-01

    The interaction between thorium and oceanic particulate matter was examined experimentally by using chemical equilibrium techniques. Thorium reacts quantitatively with the organic binding site of Particulate Matter (PM) in 0.1 mol/L HCl solution by complexation, which is equilibrated within 34 h. According to mass balance analysis, thorium forms a 1:1 complex with the organic binding site in PM, whose conditional stability constant is 10 6.6 L/mol. The Th adsorption ability is present even in 6.9 mol/L HCl solution although the amount of Th adsorption decreases with increasing acidity in the solution. Interferences to Th adsorption by Fe(III) suggests that other metals cannot react with PM in more than 0.1 mol/L HCl solutions when concentrations of other metals are the same level of Th. The competitive reaction between Th and Fe(III) occurs in higher Fe concentrations, which means that the organic binding site is nonspecific for Th. A vertical profile of Th complexing capacity of PM in the western North Pacific is characterized; that is, the Th complexing capacity shows a surface maximum and decreases rapidly with depth

  20. Hospital Admission for Respiratory and Cardiovascular Diseases Due to Particulate Matter in Ilam, Iran

    Directory of Open Access Journals (Sweden)

    Daryanoosh

    2016-09-01

    Full Text Available Background Particulate matter with an aerodynamic diameter lower than 10 µm (PM10 has the most undesired adverse effects on human health. Several studies reported a strong correlation between PM levels and hospital admissions owing to chronic and acute respiratory and cardiovascular diseases. Objectives The current study aimed to estimate the effect of PM10 as a primary pollutant on respiratory and cardiovascular hospitalizations in Ilam, Iran, in 2013. Methods PM10 data was taken from the Ilam environmental protection agency. The annual morbidity including hospital admission for respiratory and cardiovascular diseases due to PM10 exposure were estimated using relative risk (RR and baseline incidence (BI based on world health organization (WHO databases for AirQ2.2.3 model. Results The results showed that the maximum level of PM10 was obtained in summer with a concentration of 491 μg/m3. The cumulative number of excess cases admitted to the hospital for respiratory and cardiovascular diseases were 216 and 84, respectively. Approximately 3.95% of the cases hospitalized due to PM10 occurred during days with concentration levels lower than 20 μg/m3. The highest rate of person-days related to PM10 that led to heath effect among Ahvaz inhabitants was in concentration levels of 40 - 49 µg/m3. Conclusions To reduce the impacts of particulate matter on health status of people in Ilam, necessary training by health systems should be conducted for people, especially those with chronic lung and heart diseases, the elderly and children to reduce their activities on the dusty days.

  1. Thermal stability of inorganic and organic compounds in atmospheric particulate matter

    Science.gov (United States)

    Perrino, Cinzia; Marconi, Elisabetta; Tofful, Luca; Farao, Carmela; Materazzi, Stefano; Canepari, Silvia

    2012-07-01

    The thermal behaviour of atmospheric particulate matter (PM) has been investigated by using different analytical approaches to explore the added value offered by these technique in environmental studies. The thermogravimetric analysis (TGA), carried out on both certified material and real PM samples, has shown that several mass losses can be detected starting from 80 °C up to above 500 °C, when pyrolysis occur. Thermo-optical analysis of PM and ion chromatographic analysis of the residual have shown that the mass losses in the temperature range 80-180 °C are not justified by the release of either organic or inorganic compounds; it can be thus attributed to the release of weakly and strongly bound water. Release of water has also been evidenced in the temperature range 225-275 °C. The release of ammonium chloride and nitrate has been detected only above 80 °C. This indicates that the release of nitric acid, hydrochloric acid and ammonia, which is observed downstream of the filters during the sampling of atmospheric PM at ambient temperature, cannot be reproduced off-line, after the end of the sampling. We successfully explored one of the possible explanations, that is the desorption of HNO3, HCl and NH3 adsorbed on collected particles. NH4NO3 and NH4Cl, which can be thermally released by the filter, exhibit a different thermal behaviour from NaNO3 and NaCl, which are thermally stable up to 370 °C. This different behaviour can be used to discriminate between natural and secondary sources of atmospheric inorganic salts, as the interconversion that is observed when heating mixtures of pure salts resulted to be not relevant when heating real PM samples.

  2. Mass spectral chemical fingerprints reveal the molecular dependence of exhaust particulate matters on engine speeds.

    Science.gov (United States)

    Li, Yi; Zhang, Hua; Zhao, Zongshan; Tian, Yong; Liu, Kun; Jie, Feifan; Zhu, Liang; Chen, Huanwen

    2018-05-01

    Particulate matters (PMs) emitted by automobile exhaust contribute to a significant fraction of the global PMs. Extractive atmospheric pressure chemical ionization mass spectrometry (EAPCI-MS) was developed to explore the molecular dependence of PMs collected from exhaust gases produced at different vehicle engine speeds. The mass spectral fingerprints of the organic compounds embedded in differentially sized PMs (e.g., 0.22-0.45, 0.45-1.00, 1.00-2.00, 2.00-3.00, 3.00-5.00, and 5.00-10.00μm) generated at different engine speeds (e.g., 1000, 1500, 2000, 2500, and 3000r/min) were chemically profiled in the mass range of mass to charge ratio (m/z) 50-800. Organic compounds, including alcohols, aldehydes, and esters, were detected in all the PMs tested, with varied concentration levels for each individual PM sample. At relatively low engine speeds (≤1500r/min), the total amount of organic species embedded in PMs of 0.22-1.00μm was greater than in PMs of other sizes, while more organic species were found in PMs of 5.00-10.00μm at high engine speeds (≥3000r/min), indicating that the organic compounds distributed in different sizes of PMs strongly correlated with the engine speed. The experimental data showed that the EAPCI-MS technique enables molecular characterization of PMs in exhaust, revealing the chemical dependence of PMs on the engine speeds (i.e., the combustion conditions) of automobiles. Copyright © 2017. Published by Elsevier B.V.

  3. Characterisation of particulate matter on airborne pollen grains

    International Nuclear Information System (INIS)

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-01-01

    A characterization of the physical–chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles’ equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical–chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity. - Highlights: • Airborne pollen sorbs other PM found in suspension. • 84% of the particles sorbed belonged to the fine aerosol fraction. • Adsorbed PM presented daily physical–chemical variations. • Particles sorbed dominated by Si-rich, Organic-rich, SO-rich, Fe-rich and Cl-rich. - Airborne pollen is able to transport finer particulate matter, which presents daily physical–chemical variations.

  4. Chemical composition of phytoplankton and Particulate Organic Matter in the Ría de Vigo (NW Spain

    Directory of Open Access Journals (Sweden)

    A. F. Ríos

    1998-09-01

    Full Text Available Elemental (C, H, O, N, Si, P and biochemical composition (proteins, carbohydrates, lipids, phosphorus compounds, chlorophyll and opal in particulate organic matter, diatoms, other autotrophs, heterotrophs and detritus from natural plankton were established simultaneously by measuring relatively few components. Using standard techniques in marine chemistry on board ship, it is possible to infer a great deal about the composition and condition of the plankton. In addition, the organic matter content in terms of cell volume was determined for each group of plankton. Variation of chemical composition with depth was also considered. The ratio carbohydrates/lipids (Cbh/Lip was used as an indicator of the chemical quality of the plankton.

  5. Characterization of coarse particulate matter in school gyms

    Energy Technology Data Exchange (ETDEWEB)

    Branis, Martin, E-mail: branis@natur.cuni.cz [Charles University in Prague, Faculty of Science, Institute for Environmental Studies, Prague (Czech Republic); Safranek, Jiri [Charles University in Prague, Faculty of Physical Education, Department of Outdoor Sports, Prague (Czech Republic)

    2011-05-15

    We investigated the mass concentration, mineral composition and morphology of particles resuspended by children during scheduled physical education in urban, suburban and rural elementary school gyms in Prague (Czech Republic). Cascade impactors were deployed to sample the particulate matter. Two fractions of coarse particulate matter (PM{sub 10-2.5} and PM{sub 2.5-1.0}) were characterized by gravimetry, energy dispersive X-ray spectrometry and scanning electron microscopy. Two indicators of human activity, the number of exercising children and the number of physical education hours, were also recorded. Lower mass concentrations of coarse particulate matter were recorded outdoors (average PM{sub 10-2.5} 4.1-7.4 {mu}g m{sup -3} and PM{sub 2.5-1.0} 2.0-3.3 {mu}g m{sup -3}) than indoors (average PM{sub 10-2.5} 13.6-26.7 {mu}g m{sup -3} and PM{sub 2.5-1.0} 3.7-7.4 {mu}g m{sup -3}). The indoor concentrations of coarse aerosol were elevated during days with scheduled physical education with an average indoor-outdoor (I/O) ratio of 2.5-16.3 for the PM{sub 10-2.5} and 1.4-4.8 for the PM{sub 2.5-1.0} values. Under extreme conditions, the I/O ratios reached 180 (PM{sub 10-2.5}) and 19.1 (PM{sub 2.5-1.0}). The multiple regression analysis based on the number of students and outdoor coarse PM as independent variables showed that the main predictor of the indoor coarse PM concentrations is the number of students in the gym. The effect of outdoor coarse PM was weak and inconsistent. The regression models for the three schools explained 60-70% of the particular dataset variability. X-ray spectrometry revealed 6 main groups of minerals contributing to resuspended indoor dust. The most abundant particles were those of crustal origin composed of Si, Al, O and Ca. Scanning electron microscopy showed that, in addition to numerous inorganic particles, various types of fibers and particularly skin scales make up the main part of the resuspended dust in the gyms. In conclusion, school

  6. Dynamics of particulate phosphorus in a shallow eutrophic lake

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Ryuichiro, E-mail: r-shino@nies.go.jp [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Imai, Akio; Kohzu, Ayato; Tomioka, Noriko [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Furusato, Eiichi [Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570 (Japan); Satou, Takayuki; Sano, Tomoharu; Komatsu, Kazuhiro; Miura, Shingo; Shimotori, Koichi [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2016-09-01

    We tested the hypothesis that in shallow, eutrophic Lake Kasumigaura, the concentration of particulate phosphorus (PP) is controlled by biogenic P (P in living or dead phytoplankton and bacterial cells), rather than by resuspension of inorganic P in sediment. Increases in wind velocity and turbidity were associated with bottom shear stress exceeding the critical value for the lake (τ{sub c} = 0.15 N m{sup −2}); this increased turbidity was due to sediment resuspension. However, concentrations of PP; HCl-extractable, reactive P in PP (P-rP); and HCl-extractable, non-reactive P in PP (P-nrP) were not correlated with wind velocity (PP vs. wind velocity: r = 0.40, p > 0.05). Rather, the P-nrP concentration accounted for approximately 79% of PP, and the concentrations of PP, P-rP, and P-nrP were correlated with the particulate organic carbon (POC) concentration (POC vs. PP: r = 0.90, p < 0.01; POC vs. P-rP: r = 0.82, p < 0.01; POC vs. P-nrP: r = 0.86, p < 0.01). In our {sup 31}P nuclear magnetic resonance spectroscopy results, mononucleotides accounted for the largest proportion among the detected P compound classes. In addition, concentrations of mononucleotides, orthophosphate, and pyrophosphate were significantly higher in samples with high POC concentrations, whereas the DNA-P concentration was not. These results suggest that biogenic P affects PP concentrations more strongly than does sediment resuspension, and the production of biogenic P creates a pool of mononucleotides, a class of easily degradable P, even in shallow, eutrophic Lake Kasumigaura. - Highlights: • Biogenic P affected the PP concentration more than did sediment resuspension. • PP correlated with particulate organic carbon concentration but not wind velocity. • Mononucleotides accounted for the largest P compound class of organic P in PP.

  7. Air pollution studies in terms of particulate matters, elements and black carbon in the aerosols collected at Andravoahangy-Antananarivo

    International Nuclear Information System (INIS)

    HARINOELY, M.

    2012-01-01

    This work was performed at the Institut National des Sciences et Techniques Nucleaires (Madagascar-INSTN) in the framework of RAF/4/019 project organized by the International Atomic Energy Agency. The main objective of this work is to study the level of air pollution in terms of particulate matters, elements and black carbon in the site of Andravoahangy-Antananarivo and to transmit the results obtained to the competent authorities so that they can make decisions to reduce the impacts of air pollution on the population. The total reflection X-ray fluorescence spectrometer is used for qualitative and quantitative analyses of the elements contained in the aerosols and the reflectometer M43D for the determination of the black carbon concentrations. The results showed that the average concentrations of the particulate matters PM 2,5-10 are higher than those of PM 2,5 . The average concentrations of PM 10 in the aerosols are exceeding the World Health Organisation (WHO) and European Union guidelines, set at 50 μg.m -3 and those of PM 2,5 are higher than the 2005 WHO (25 μg.m -3 ) and the United States Environmental Protection Agency (35 μg.m -3 ) guidelines. The identified elements in the aerosols are Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb. The average concentrations of these elements are also higher in the coarse particles than in the fine particles. The concentrations of black carbon are higher in the fine particles, with a maximum value of 9.12 μg.m -3 . [fr

  8. PAHs concentration and toxicity in organic solvent extracts of atmospheric particulate matter and sea sediments.

    Science.gov (United States)

    Ozaki, Noriatsu; Takeuchi, Shin-ya; Kojima, Keisuke; Kindaichi, Tomonori; Komatsu, Toshiko; Fukushima, Takehiko

    2012-01-01

    The concentration of polycyclic aromatic hydrocarbons (PAHs) and the toxicity to marine bacteria (Vibrio fischeri) were measured for the organic solvent extracts of sea sediments collected from an urban watershed area (Hiroshima Bay) of Japan and compared with the concentrations and toxicity of atmospheric particulate matter (PM). In atmospheric PM, the PAHs concentration was highest in fine particulate matter (FPM) collected during cold seasons. The concentrations of sea sediments were 0.01-0.001 times those of atmospheric PM. 1/EC50 was 1-10 L g(-1) PM for atmospheric PM and 0.1-1 L g(-1) dry solids for sea sediments. These results imply that toxic substances from atmospheric PM are diluted several tens or hundreds of times in sea sediments. The ratio of the 1/EC50 to PAHs concentration ((1/EC50)/16PAHs) was stable for all sea sediments (0.1-1 L μg(-1) 16PAHs) and was the same order of magnitude as that of FPM and coarse particulate matter (CPM). The ratio of sediments collected from the west was more similar to that of CPM while that from the east was more similar to FPM, possibly because of hydraulic differences among water bodies. The PAHs concentration pattern analyses (principal component analysis and isomer ratio analysis) were conducted and the results showed that the PAHs pattern in sea sediments was quite different to that of FPM and CPM. Comparison with previously conducted PAHs analyses suggested that biomass burning residues comprised a major portion of these other sources.

  9. Chemical characterization of organic particulate matter from on-road traffic in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    B. S. Oyama

    2016-11-01

    Full Text Available This study reports emission of organic particulate matter by light-duty vehicles (LDVs and heavy-duty vehicles (HDVs in the city of São Paulo, Brazil, where vehicles run on three different fuel types: gasoline with 25 % ethanol (called gasohol, E25, hydrated ethanol (E100, and diesel (with 5 % biodiesel. The experiments were performed at two tunnels: Jânio Quadros (TJQ, where 99 % of the vehicles are LDVs, and RodoAnel Mário Covas (TRA, where up to 30 % of the fleet are HDVs. Fine particulate matter (PM2.5 samples were collected on quartz filters in May and July 2011 at TJQ and TRA, respectively. The samples were analyzed by thermal-desorption proton-transfer-reaction mass spectrometry (TD-PTR-MS and by thermal–optical transmittance (TOT. Emission factors (EFs for organic aerosol (OA and organic carbon (OC were calculated for the HDV and the LDV fleet. We found that HDVs emitted more PM2.5 than LDVs, with OC EFs of 108 and 523 mg kg−1 burned fuel for LDVs and HDVs, respectively. More than 700 ions were identified by TD-PTR-MS and the EF profiles obtained from HDVs and LDVs exhibited distinct features. Unique organic tracers for gasoline, biodiesel, and tire wear have been tentatively identified. nitrogen-containing compounds contributed around 20 % to the EF values for both types of vehicles, possibly associated with incomplete fuel burning or fast secondary production. Additionally, 70 and 65 % of the emitted mass (i.e. the OA originates from oxygenated compounds from LDVs and HDVs, respectively. This may be a consequence of the high oxygen content of the fuel. On the other hand, additional oxygenation may occur during fuel combustion. The high fractions of nitrogen- and oxygen-containing compounds show that chemical processing close to the engine / tailpipe region is an important factor influencing primary OA emission. The thermal-desorption analysis showed that HDVs emitted compounds with higher volatility, and with

  10. Comparative toxicity and endocrine disruption potential of urban and rural atmospheric organic PM1 in JEG-3 human placental cells

    International Nuclear Information System (INIS)

    Drooge, Barend L. van; Marqueño, Anna; Grimalt, Joan O.; Fernández, Pilar; Porte, Cinta

    2017-01-01

    Outdoor ambient air particulate matter and air pollution are related to adverse effects on human health. The present study assesses the cytotoxicity and ability to disrupt aromatase activity of organic PM 1 extracts from rural and urban areas at equivalent air volumes from 2 to 30 m 3 , in human placental JEG-3 cells. Samples were chemically analyzed for particle bounded organic compounds with endocrine disrupting potential, i.e. PAH, O-PAH, phthalate esters, but also for organic molecular tracer compounds for the emission source identification. Rural samples collected in winter were cytotoxic at the highest concentration tested and strongly inhibited aromatase activity in JEG-3 cells. No cytotoxicity was detected in summer samples from the rural site and the urban samples, while aromatase activity was moderately inhibited in these samples. In the urban area, the street site samples, collected close to intensive traffic, showed stronger inhibition of aromatase activity than the samples simultaneously collected at a roof site, 50 m above ground level. The cytotoxicity and endocrine disruption potential of the samples were linked to combustion products, i.e. PAH and O-PAH, especially from biomass burning in the rural site in winter. - Highlights: • Organic extracts of outdoor ambient air PM1 showed aromatase activity inhibition in exposed human placental JEG-3 cells. • Cytotoxicity and strongest endocrine disruption was observed in rural winter samples, while lowest inhibition was observed in urban background site 50 m above a busy street. • Cytotoxicity and aromatase activity inhibition in the samples were linked to combustion products, i.e. PAH and O-PAH, especially from biomass burning. - Organic extracts from ambient air PM 1 related to biomass burning are more cytotoxic and have stronger endocrine disruption potential than urban PM 1 .

  11. Thermal efficiency and particulate pollution estimation of four biomass fuels grown on wasteland

    Energy Technology Data Exchange (ETDEWEB)

    Kandpal, J.B.; Madan, M. [Indian Inst. of Tech., New Delhi (India). Centre for Rural Development and Technology

    1996-10-01

    The thermal performance and concentration of suspended particulate matter were studied for 1-hour combustion of four biomass fuels, namely Acacia nilotica, Leucaena leucocepholea, Jatropha curcus, and Morus alba grown in wasteland. Among the four biomass fuels, the highest thermal efficiency was achieved with Acacia nilotica. The suspended particulate matter concentration for 1-hour combustion of four biomass fuels ranged between 850 and 2,360 {micro}g/m{sup 3}.

  12. Relating hygroscopicity and composition of organic aerosol particulate matter

    CERN Document Server

    Duplissy, J; Prevot, A S H; Barmpadimos, I; Jimenez, J L; Gysel, M; Worsnop, D R; Aiken, A C; Tritscher, T; Canagaratna, M R; Collins, D R; Alfarra, M R; Metzger, A; Tomlinson, J; DeCarlo, P F; Weingartner, E; Baltensperger, U

    2011-01-01

    A hygroscopicity tandem differential mobility analyzer (HTDMA) was used to measure the water uptake (hygroscopicity) of secondary organic aerosol (SOA) formed during the chemical and photochemical oxidation of several organic precursors in a smog chamber. Electron ionization mass spectra of the non-refractory submicron aerosol were simultaneously determined with an aerosol mass spectrometer (AMS), and correlations between the two different signals were investigated. SOA hygroscopicity was found to strongly correlate with the relative abundance of the ion signal m/z 44 expressed as a fraction of total organic signal (f(44)). m/z 44 is due mostly to the ion fragment CO(2)(+) for all types of SOA systems studied, and has been previously shown to strongly correlate with organic O/C for ambient and chamber OA. The analysis was also performed on ambient OA from two field experiments at the remote site Jungfrau-joch, and the megacity Mexico City, where similar results were found. A simple empirical linear relation b...

  13. Characterization and sources assignation of PM2.5 organic aerosol in a rural area of Spain

    Science.gov (United States)

    Pindado, Oscar; Pérez, Rosa M. a.; García, Susana; Sánchez, Miguel; Galán, Pilar; Fernández, Marta

    The results from a year-long study of the organic composition of PM2.5 aerosol collected in a rural area influenced by a highway of Spain are reported. The lack of prior information related to the organic composition of PM2.5 aerosol in Spain, concretely in rural areas, led definition of the goals of this study. As a result, this work has been able to characterize the main organic components of atmospheric aerosols, including several compounds of SOA, and has conducted a multivariate analysis in order to assign sources of particulate matter. A total of 89 samples were taken between April 2004 and April 2005 using a high-volume sampler. Features and abundance of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), alcohols and acids were separately determined using gas chromatography/mass spectrometry and high performance liquid chromatography analysis. The Σ n-alkane and ΣPAHs ranged from 3 to 81 ng m -3 and 0.1 to 6 ng m -3 respectively, with higher concentrations during colder months. Ambient concentrations of Σalcohols and Σacids ranged from 21 to 184 ng m -3 and 39 to 733 ng m -3, respectively. Also, several components of secondary organic aerosol have been quantified, confirming the biogenic contribution to ambient aerosol. In addition, factor analysis was used to reveal origin of organic compounds associated to particulate matter. Eight factors were extracted accounting more than 83% of the variability in the original data. These factors were assigned to a typical high pollution episode by anthropogenic particles, crustal material, plant waxes, fossil fuel combustion, temperature, microbiological emissions, SOA and dispersion of pollutants by wind action. Finally, a cluster analysis was used to compare the organic composition between the four seasons.

  14. Novel mass spectrometric instrument for gaseous and particulate characterization and monitoring

    International Nuclear Information System (INIS)

    Coggiola, M.J.

    1993-04-01

    Under contract DE-AC21-92MC29116, SRI International will develop a unique new instrument that will be capable of providing real-time (< l minute), quantitative, chemical characterization of gaseous and particulate pollutants generated from DOE waste cleanup activities. The instrument will be capable of detecting and identifying volatile organic compounds, polynuclear aromatic hydrocarbons, heavy metals, and transuranic species released during waste cleanup activities. The instrument will be unique in its ability to detect and quantify in real-time these diverse pollutants in both vapor and particulate form. The instrument to be developed under this program will consist of several major components: (1) an isokinetic sampler capable of operating over a wide range of temperatures (up to 500 K) and flow rates; (2) a high pressure to low pressure transition and sampling region that efficiently separates particles from vapor-phase components for separate, parallel analyses; (3) two small mass spectrometers, one optimized for organic analysis using a unique field ionization source and one optimized for particulate characterization using thermal pyrolysis and electron-impact ionization (EI); and (4) a powerful personal computer for control and data acquisition

  15. An electrostatic sensor for the continuous monitoring of particulate air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Intra, Panich; Yawootti, Artit [Rajamangala University of Technology Lanna, Chiang Mai (Thailand); Tippayawong, Nakorn [Chiang Mai University, Chiang Mai (Thailand)

    2013-12-15

    We developed and evaluated a particulate air pollution sensor for continuous monitoring of size resolved particle number, based on unipolar corona charging and electrostatic detection of charged aerosol particles. The sensor was evaluated experimentally using combustion aerosol with particle sizes in the range between approximately 50 nm and several microns, and particle number concentrations larger than 10{sup 10} particles/m{sup 3}. Test results were very promising. It was demonstrated that the sensor can be used in detecting particle number concentrations in the range of about 2.02x10{sup 11} and 1.03x10{sup 12} particles/m{sup 3} with a response of approximately 100 ms. Good agreement was found between the developed sensor and a commercially available laser particle counter in measuring ambient PM along a roadside with heavy traffic for about 2 h. The developed sensor proved particularly useful for measuring and detecting particulate air pollution, for number concentration of particles in the range of 10{sup 8} to 10{sup 12} particles/m{sup 3}.

  16. High performance organic ultraviolet photodetectors based on m-MTDATA

    Science.gov (United States)

    Zhao, Zhongli; Bai, Xiaofeng; Shang, Yubin; Yang, Jikai; Li, Baozeng; Song, De

    2018-02-01

    We demonstrate highly efficient organic ultraviolet photodetectors using 4,4',4'' -tris[3-methyl-pheny(phenyl) amino] triphenylamine (m-MTDATA) and aluminum Tris(8-Hydroxyquinolinate) Synonym Alq3). The optimized photodetector delivers a photocurrent of 1.40 mA/cm2 at10 V, corresponding to a response of 127 mA/W under an illumination of 375 nm UV light irradiation with an intensity of 10.5 mW/cm2 and a detectivity of 2.15×1011 cm Hz1/2 /W. The high response is attributed to the larger band offset at m-MTDATA/ Alq3 heterojunction, the suppression of radiative decay of m-MTDATA and efficient electron transfer from m-MTDATA to Alq3. The working mechanism of harvesting high performance is also discussed in detail.

  17. Report Task 2.3: Particulate waste and turbidity in (marine) RAS

    NARCIS (Netherlands)

    Kals, J.; Schram, E.; Brummelhuis, E.B.M.; Bakel, van B.

    2006-01-01

    Particulate waste management and removal is one of the most problematic parts of recirculation aquaculture systems (RAS). Particulate waste and thereby turbidity originates from three major sources: fish (faeces), feed and biofilm (heterotrophic bacteria and fungi). Based on size and density there

  18. Chemical and biological characterization of urban particulate matter

    International Nuclear Information System (INIS)

    Agurell, E.; Alsberg, T.; Assefaz-Redda, Y.

    1990-11-01

    Airborne particulate matter has been collected on glass fiber filter by high volume sampling in the Goeteborg urban area. The samples were, after extraction with respect to organic components, tested for biological effect in the Salmonella mutagenicity assay, affinity to the cytosol TCDD receptor and toxicity towards a mammalian cell system and analysed chemically for selected polycyclic aromatic compounds. A series of samples collected simultaneously at a street level location and a rooftop site showed that most parameters associated with the organic compounds adsorbed to airborne particulate matter has similar concentrations at the two levels. The differences observed for the mutagenic effect in different strains and conditions showed that the rooftop samples had a different composition compared to the street samples indicating that atmospheric transformations have occurred. Chemical fractionation of representative samples showed that the distribution of mutagenic activity among different fractions is dissimilar to the distribution obtained in the fractionation of both gasoline and diesel engine exhaust particles. Partial least squares regression analysis showed qualitatively that diesel exhaust is a major source of airborne particulate mutagenic activity and source apportionment with chemical mass balance and multilinear regression corroborated this quantitatively. The multilinear regression analysis gave the result that the airborne activity in Salmonella TA90-S9 originated to 54±4% from diesel exhaust and to 26±3% from gasoline exhaust. The contribution is more equal for the activity measured with TA98+S9. The usefulness of short-term bioassays as an addition to chemical analysis of airborne particulate matter depends on whether only polycylic aromatic hydrocarbons (PAH) are major carcinogens, as has been suggested in the literature, or whether also other polycyclic aromatic compound (PAC) are of importance. (au)

  19. Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion

    International Nuclear Information System (INIS)

    Mastral, A.M.; Callen, M.S.; Garcia, T.

    1999-01-01

    The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale plant at different combustion conditions: temperature, percentage of oxygen excess, and total air flow. PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves

  20. Enhanced Input of Terrestrial Particulate Organic Matter Reduces the Resilience of the Clear-Water State of Shallow Lakes: A Model Study

    NARCIS (Netherlands)

    Lischke, B.; Hilt, S.; Janse, J.H.; Kuiper, J.J.; Mehner, T.; Mooij, W.M.; Gaedke, U.

    2014-01-01

    The amount of terrestrial particulate organic matter (t-POM) entering lakes is predicted to increase as a result of climate change. This may especially alter the structure and functioning of ecosystems in small, shallow lakes which can rapidly shift from a clear-water, macrophyte-dominated into a

  1. Atmospheric particulate pollution in Kenitra (Morocco)

    International Nuclear Information System (INIS)

    Zghaid, Mustapha; Noack, Yves; Boukla, Moussa; Benyaich, Fouad

    2009-01-01

    Cities of Morocco are exposed to a high atmospheric particulate pollution due to automobile traffic, industrialization, but also to soil dusts (in relation with aridity and desert proximity). Monitoring networks and data about air pollution still rare. The present study is a preliminary work about particulate and heavy metals pollution in Kenitra city. Aerosols had been collected with a PM10 sampler (Partisol), a dichotomous sampler (P M2.5 and P M2.5-10 fractions) and stacked filter unit (Gent type) with a fine fraction (below 2.5 um) and a coarse fraction. In summer, the average PM10 concentration is near 80 u g/N m 3 , above the EEC rule and OMS recommendations, but similar to some other african towns. The ratio P M2.5/PM 10 is low (below 0.5), with seasonal variation in relation with meteorology. The lead and nickel concentrations are also very low, in relation with the use of leaded gasoline and the oldness of many vehicles. This preliminary work reveals high levels of pollution (especially PM10, Pb and Ni) in the town of Kenitra. The major sources are traffic, soil dusts and resuspension of deposited particles. It is necessary to develop monitoring network and sanitary and and environmental impact studies in these cities [fr

  2. Visualization of soil particulate organic matter by means of X-ray CT?

    Science.gov (United States)

    Sleutel, Steven; Van Loo, Denis; Maenhout, Peter; Van Hoorebeke, Luc; Cnudde, Veerle; De Neve, Stefaan

    2014-05-01

    composition of the soil mineral matrix. Furthermore, techniques such as multiple-energy scanning and K-edge imaging, even in the future perhaps in combination with spectral resolving detectors or spectroscopic techniques can could further enhance the potential benefit from this study of X-ray CT staining agents. The high Z elements of the staining agents have unique and characteristic traits that can be detected or quantified with the abovementioned techniques and methods. We conclude that, given resolution limits and inherent presence of partial volume effects staining, X-ray CT-based localization of discrete SOM particles will be limited to a lower limit of 20-50 µm. Still, the improved 3D visualization of OM and soil pore space opens up possibilities for tailored lab experiments with measures of microbial activity, which could generate new insights in carbon cycling at small scales. In addition, we report on a lab incubation experiment in which CO2 respiration from soil cores was monitored (headspace GC analysis) and an X-ray CT approach yielded soil pore size distributions. We incubated a sandy loam soil (with application of ground grass or sawdust) in 18 small aluminium rings (Ø 1 cm, h 1 cm). Bulk density was adjusted to 1.1 or 1.3 Mg m-3 (compaction) and 6 rings were filled at a coarser Coarse Sand:Fine Sand:Silt+Clay ratio. While compaction induced a strong reduction in the cumulative C mineralization for both grass and sawdust substrates, artificial change to a coarser soil texture only reduced net C mineralization from the added sawdust. There thus appears to be a strong interaction effect between soil pore structure and substrate type on substrate decomposition. Correlation coefficients between the C mineralization rates and volumes of 7 pore size classes (from the X-ray CT data) also showed an increasing positive correlation with increasing pore size. Since any particulate organic matter initially present in the soil was removed prior to the experiment (sieving

  3. PARTICULATE MATTER CONCENTRATION AND EMISSION FACTOR IN THREE DIFFERENT LAYING HEN HOUSING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Annamaria Costa

    2009-09-01

    Full Text Available The aim of this study was to evaluate PM10 concentration in three different laying hens houses (traditional battery cages with aerated open manure storage, aviary system and vertical tiered cages with manure belts with forced air drying and to evaluate particulate matter emission into atmosphere during one year of observation. Internal and external temperature and relative humidity, ventilation rate, PM10 concentration have been continuously monitored in order to evaluate particulate matter concentration changes during the day and the season and to define PM10 emission factors. PM10 concentration was corrected by gravimetric technique to lower measurements error. In the aviary system house, TSP and fine particulate matter (particles smaller than 2.5 micron concentration was measured. Average yearly PM10 concentration was remarkably higher in the aviary system house with 0.215 mg m-3 vs 108 mg m-3 for the ventilated belt house and vs 0.094 mg m-3 for the traditional battery cages house. In the Aviary system housing, TSP concentration was 0.444 mg m-3 and PM2.5 was 0.032 mg m-3, highlighting the existence of a severe working environment for men and animals. Recorded values for PM10 emission were 0.433 mg h-1 hen-1 for battery cages housing type, 0.081 mg h-1 hen-1 for ventilated belt cages house, values lower than those available in literature, while the aviary system housing type showed the highest PM10 emission (1.230 mg h-1 hen-1 with appreciable peaks during the morning, together with the increased animal activity and daily farmer operations, as feed administration, cleaning and droppings removal.

  4. Migration of particulates in permeable rock columns

    International Nuclear Information System (INIS)

    Cropper, R.L.

    1982-01-01

    The migration of radioactive material through soil and permeable rock formations have become a major topic of concern due to the interest in the licensing of new radioactive waste disposal sites. Previously, research has been conducted in relation to deep repositories; however, similar situations arise in the vadose zone, where there is a higher probability of naturally-occurring particulates of organic nature and for the incursion of water. Test data has provided information which suggests that particulates will travel through porous media subject to various delay mechnisms and must be included in any consideration of waste migration. Data concerning particulate migration must and should be considered in the future when radioactive waste disposal sites are licensed

  5. Nitrogen oxides, ozone and heavy metals analysis of suspended particulate matter (spm) of air in Nairobi, Kenya

    International Nuclear Information System (INIS)

    Odhiambo, O.; Kinyua, A.M.; Gatebe, C.K.

    2001-01-01

    Motor vehicle emissions are a major source of air pollution in most urban centers. In Kenya, Nairobi city has the highest traffic density and is therefore a particular cause for concern due to the poor maintenance standards of most vehicles plus the use of leaded gasoline. This study was carried out to determine the levels of nitrogen oxides (nox), suspended particulate matter (PM10), ozone (O3) and heavy metals in the SPM collected from the ambient air of Nairobi city. Sampling was done once every week for a period of three months (February to April 2000). Hourly average concentrations of N0 2 , NO and O3 were measured simultaneously from 9.00 am to 5.00 p.m., at a roundabout connecting two main highways (University and Uhuru) in the city. PM10 was collected using Gent Stacked Filter Unit (SFU) air sampler on nuclepore filters (0.4 and 8.0 ?m pore size for fine and coarse filters respectively) which were weighed and analysed for trace elements by Energy Dispersive X-ray Fluorescent (EDXRF) technique. Nitrogen oxides were analysed with thermo electron's Chemiluminescent nox Model 14B analyser while ozone was by using DASIBI ozone monitor, Model 1003 AH. An automatic vehicle counter was used For determining the vehicle density at the sampling point. The findings of the study show that the values obtained for Pb, Mn, Fe, Br, Zn, Cu and Ca are within the Who guidelines. Lead concentrations ranged from 0.051 to 1.106?g/m3; Fe, 0.149 to 3.154?g/m3; Mn, 0.002 to 0.526?g/m3; Cu, lower limit of detection (LLD) to 0.15?g/m3; Br, LLD to 0.43?g/m3; Zn, LLD to 0.14 ?g/m3 and Ca 2.18 to 5.389?g/m3. Concentrations of NO 2 , NO and O3 were also within the 8-hour Who limits with levels ranging from 0.011-0.976 ppm for NO, 0.001-0.2628 ppm for NO 2 and LLD-0.1258 ppm for ozone. The O3 levels were slightly higher in the afternoons when solar intensity was high especially the days with cloud cover of less than 3 Oktas. PM10 levels were, however, above the Who guidelines for most of

  6. Distribution of gaseous and particulate organic composition during dark α-pinene ozonolysis

    Directory of Open Access Journals (Sweden)

    A. R. Rickard

    2010-03-01

    Full Text Available Secondary Organic Aerosol (SOA affects atmospheric composition, air quality and radiative transfer, however major difficulties are encountered in the development of reliable models for SOA formation. Constraints on processes involved in SOA formation can be obtained by interpreting the speciation and evolution of organics in the gaseous and condensed phase simultaneously. In this study we investigate SOA formation from dark α-pinene ozonolysis with particular emphasis upon the mass distribution of gaseous and particulate organic species. A detailed model for SOA formation is compared with the results from experiments performed in the EUropean PHOtoREactor (EUPHORE simulation chamber, including on-line gas-phase composition obtained from Chemical-Ionization-Reaction Time-Of-Flight Mass-Spectrometry measurements, and off-line analysis of SOA samples performed by Ion Trap Mass Spectrometry and Liquid Chromatography. The temporal profile of SOA mass concentration is relatively well reproduced by the model. Sensitivity analysis highlights the importance of the choice of vapour pressure estimation method, and the potential influence of condensed phase chemistry. Comparisons of the simulated gaseous- and condensed-phase mass distributions with those observed show a generally good agreement. The simulated speciation has been used to (i propose a chemical structure for the principal gaseous semi-volatile organic compounds and condensed monomer organic species, (ii provide evidence for the occurrence of recently suggested radical isomerisation channels not included in the basic model, and (iii explore the possible contribution of a range of accretion reactions occurring in the condensed phase. We find that oligomer formation through esterification reactions gives the best agreement between the observed and simulated mass spectra.

  7. Emission characteristics for gaseous- and size-segregated particulate PAHs in coal combustion flue gas from circulating fluidized bed (CFB) boiler.

    Science.gov (United States)

    Wang, Ruwei; Liu, Guijian; Sun, Ruoyu; Yousaf, Balal; Wang, Jizhong; Liu, Rongqiong; Zhang, Hong

    2018-07-01

    The partitioning behavior of polycyclic aromatic hydrocarbons (PAHs) between gaseous and particulate phases from coal-fired power plants (CFPPs) is critically important to predict PAH removal by dust control devices. In this study, 16 US-EPA priority PAHs in gaseous and size-segregated particulate phases at the inlet and outlet of the fabric filter unit (FFs) of a circulating fluidized bed (CFB) boiler were analyzed. The partitioning mechanisms of PAHs between gaseous and particulate phases and in particles of different size classes were investigated. We found that the removal efficiencies of PAHs are 45.59% and 70.67-89.06% for gaseous and particulate phases, respectively. The gaseous phase mainly contains low molecular weight (LMW) PAHs (2- and 3-ring PAHs), which is quite different from the particulate phase that mainly contains medium and high molecular weight (MMW and HMW) PAHs (4- to 6-ring PAHs). The fractions of LMW PAHs show a declining trend with the decrease of particle size. The gas-particle partitioning of PAHs is primarily controlled by organic carbon absorption, in addition, it has a clear dependence on the particle sizes. Plot of log (TPAH/PM) against logD p shows that all slope values were below -1, suggesting that PAHs were mainly adsorbed to particulates. The adsorption effect of PAHs in size-segregated PMs for HMW PAHs is more evident than LMW PAHs. The particle size distributions (PSDs) of individual PAHs show that most of PAHs exhibit bi-model structures, with one mode peaking in the accumulation size range (2.1-1.1 μm) and another mode peaking in coarse size range (5.8-4.7 μm). The intensities of these two peaks vary in function of ring number of PAHs, which is likely attributed to Kelvin effect that the less volatile HMW PAH species preferentially condense onto the finer particulates. The emission factor of PAHs was calculated as 3.53 mg/kg of coal burned, with overall mean EF PAH of 0.55 and 2.98 mg/kg for gaseous and particulate

  8. Organic particulate matter formation at varying relative humidity using surrogate secondary and primary organic compounds with activity corrections in the condensed phase obtained using a method based on the Wilson equation

    Science.gov (United States)

    Chang, E. I.; Pankow, J. F.

    2010-06-01

    Secondary organic aerosol (SOA) formation in the atmosphere is currently often modeled using a multiple lumped "two-product" (N·2p) approach. The N·2p approach neglects: 1) variation of activity coefficient (ζi) values and mean molecular weight solid #000; color: #000;">MW in the particulate matter (PM) phase; 2) water uptake into the PM; and 3) the possibility of phase separation in the PM. This study considers these effects by adopting an (N·2p)ζpsolid #000; color: #000;">MW,ζ approach (θ is a phase index). Specific chemical structures are assigned to 25 lumped SOA compounds and to 15 representative primary organic aerosol (POA) compounds to allow calculation of ζi and solid #000; color: #000;">MW values. The SOA structure assignments are based on chamber-derived 2p gas/particle partition coefficient values coupled with known effects of structure on vapor pressure pL,io (atm). To facilitate adoption of the (N·2p)ζpsolid #000; color: #000;">MW,θ approach in large-scale models, this study also develops CP-Wilson.1 (Chang-Pankow-Wilson.1), a group-contribution ζi-prediction method that is more computationally economical than the UNIFAC model of Fredenslund et al. (1975). Group parameter values required by CP-Wilson.1 are obtained by fitting ζi values to predictions from UNIFAC. The (N·2p)ζpsolid #000; color: #000;">MW,θ approach is applied (using CP-Wilson.1) to several real α-pinene/O3 chamber cases for high reacted hydrocarbon levels (ΔHC≈400 to 1000 μg m-3) when relative humidity (RH) ≍50%. Good agreement between the chamber and predicted results is obtained using both the (N·2p)ζpsolid #000; color: #000;">MW,θ and N·2p approaches, indicating relatively small water effects under these conditions. However, for a hypothetical α-pinene/O3 case at ΔHC=30 μg m-3 and RH=50%, the (N·2p)ζpsolid #000; color: #000;">MW,θ approach predicts that water uptake will lead to an organic PM level that is more double that predicted by the N·2p

  9. Experimental apparatus and analysis technique for studying the low Reynolds number hydrodynamic behavior of water-borne particulates

    International Nuclear Information System (INIS)

    Chase, R.R.P.; Tisue, G.T.

    1975-01-01

    A unique laboratory apparatus has been designed, constructed, and tested for analyzing the low Reynolds number hydrodynamic behavior of water-borne particulates. The system consists of an isothermal sedimentation chamber, collimated light sources, photographic optics, and monitoring devices. This apparatus is capable of providing dynamic information on water-borne particulates in the size range 2 μm to 700 μm, while simulating a realistic environment. Because of its flexibility, the equipment is being used to determine the kinematic behavior of gravitationally unstable organic mineral aggregates. The importance of organic mineral aggregates has been well established during the past decade. This material is believed to be a potential food source for marine biota at the lowest levels of the food chain. Organic mineral aggregates are also known to concentrate trace elements and other toxic substances and may be part of the control mechanism by which elemental concentrations are maintained in the water column. The benthic fluid mud layer and deep pelagic nepholoid layer consist, in part, of these sediments. Subsea petroleum reserves are thought to be the result of biogeochemical cycling of the organic-mineral complex. Undoubtedly, a fundamental study of these aggregates would be of value to many research interests

  10. Identification of chemical composition and measurement of V, As, Cr and Fe in Yogyakarta ambient air particulate by neutron activation method

    International Nuclear Information System (INIS)

    Gede-Sutresna W; Sutjipto

    1996-01-01

    Activation neutron analysis can be used to identify chemical composition and measure V, As, Cr and Fe contents in Yogyakarta ambient particulate. The air sampling has been done around Yogyakarta city such as: Gg. Narada Gandok around North Ring road (A1 post), Mentri Supeno cross road (A2 post), Purbanegaran GK II (A3 post), Wirobrajan cross road (A4 post), Adisutjipto (A5 post), and in front of Sentul market on JI. Sultan Agung with low volume sampler equipped with AP millipore fiber glass filter. Other places used for air sampling were around PPNY, JI. Babarsari (B1) and Jl. Gejayan (B2) by using high volume sampler equipped with TF A 21133 series filter. The filter was irradiated at Kartini reactor at the average of 1.04 x 10 1 1 n.cm -2 .s -1 on January 10, 1995. The V, As, Cr and Fe content in air around Yogyakarta respectively was: 81.5 - 264.9 ng/m 3 air; 56.7 - 596.4 ng/m 3 air; 30.5 - 153.8 ng/m 3 air and 22.4 - 108μg/m 3 air. The accuracy of the analysis method was checked by comparing the analysis result to the certificate label of the reference material SRM 1633a. The accuracy was: 21.1%; 13.9%; 7.7% and 13.3% for V, As, Cr and Fe. The V, As, Cr and Fe content in air particulate around Yogyakarta is still the below permissible level of the World Health Organization (WHO) in 1987

  11. Monitoring diesel particulate matter and calculating diesel particulate densities using Grimm model 1.109 real-time aerosol monitors in underground mines.

    Science.gov (United States)

    Kimbal, Kyle C; Pahler, Leon; Larson, Rodney; VanDerslice, Jim

    2012-01-01

    Currently, there is no Mine Safety and Health Administration (MSHA)-approved sampling method that provides real-time results for ambient concentrations of diesel particulates. This study investigated whether a commercially available aerosol spectrometer, the Grimm Portable Aerosol Spectrometer Model 1.109, could be used during underground mine operations to provide accurate real-time diesel particulate data relative to MSHA-approved cassette-based sampling methods. A subset was to estimate size-specific diesel particle densities to potentially improve the diesel particulate concentration estimates using the aerosol monitor. Concurrent sampling was conducted during underground metal mine operations using six duplicate diesel particulate cassettes, according to the MSHA-approved method, and two identical Grimm Model 1.109 instruments. Linear regression was used to develop adjustment factors relating the Grimm results to the average of the cassette results. Statistical models using the Grimm data produced predicted diesel particulate concentrations that highly correlated with the time-weighted average cassette results (R(2) = 0.86, 0.88). Size-specific diesel particulate densities were not constant over the range of particle diameters observed. The variance of the calculated diesel particulate densities by particle diameter size supports the current understanding that diesel emissions are a mixture of particulate aerosols and a complex host of gases and vapors not limited to elemental and organic carbon. Finally, diesel particulate concentrations measured by the Grimm Model 1.109 can be adjusted to provide sufficiently accurate real-time air monitoring data for an underground mining environment.

  12. Factors influencing particulate lipid production in the East Atlantic Ocean

    Science.gov (United States)

    Gašparović, B.; Frka, S.; Koch, B. P.; Zhu, Z. Y.; Bracher, A.; Lechtenfeld, O. J.; Neogi, S. B.; Lara, R. J.; Kattner, G.

    2014-07-01

    Extensive analyses of particulate lipids and lipid classes were conducted to gain insight into lipid production and related factors along the biogeochemical provinces of the Eastern Atlantic Ocean. Data are supported by particulate organic carbon (POC), chlorophyll a (Chl a), phaeopigments, Chl a concentrations and carbon content of eukaryotic micro-, nano- and picophytoplankton, including cell abundances for the latter two and for cyanobacteria and prokaryotic heterotrophs. We focused on the productive ocean surface (2 m depth and deep Chl a maximum (DCM). Samples from the deep ocean provided information about the relative reactivity and preservation potential of particular lipid classes. Surface and DCM particulate lipid concentrations (3.5-29.4 μg L-1) were higher than in samples from deep waters (3.2-9.3 μg L-1) where an increased contribution to the POC pool was observed. The highest lipid concentrations were measured in high latitude temperate waters and in the North Atlantic Tropical Gyral Province (13-25°N). Factors responsible for the enhanced lipid synthesis in the eastern Atlantic appeared to be phytoplankton size (micro, nano, pico) and the low nutrient status with microphytoplankton having the most expressed influence in the surface and eukaryotic nano- and picophytoplankton in the DCM layer. Higher lipid to Chl a ratios suggest enhanced lipid biosynthesis in the nutrient poorer regions. The various lipid classes pointed to possible mechanisms of phytoplankton adaptation to the nutritional conditions. Thus, it is likely that adaptation comprises the replacement of membrane phospholipids by non-phosphorus containing glycolipids under low phosphorus conditions. The qualitative and quantitative lipid compositions revealed that phospholipids were the most degradable lipids, and their occurrence decreased with increasing depth. In contrast, wax esters, possibly originating from zooplankton, survived downward transport probably due to the fast sinking

  13. Atmospheric oxidative chemistry of organic particulate emissions from fuel combustion.

    Science.gov (United States)

    2011-03-25

    "Construction and characterization of the University of Vermont Environmental Chamber (UVMEC) : were completed in this last phase of the project. The primary function of the UVMEC is to enable : tropospheric particulate formation and aging studies to...

  14. Particulate air pollution and mortality in a cohort of Chinese men.

    Science.gov (United States)

    Zhou, Maigeng; Liu, Yunning; Wang, Lijun; Kuang, Xingya; Xu, Xiaohui; Kan, Haidong

    2014-03-01

    Few prior cohort studies exist in developing countries examining the association of ambient particulate matter (PM) with mortality. We examined the association of particulate air pollution with mortality in a prospective cohort study of 71,431 middle-aged Chinese men. Baseline data were obtained during 1990-1991. The follow-up evaluation was completed in January, 2006. Annual average PM exposure between 1990 and 2005, including TSP and PM10, were estimated by linking fixed-site monitoring data with residential communities. We found significant associations between PM10 and mortality from cardiopulmonary diseases; each 10 μg/m(3) PM10 was associated with a 1.6% (95%CI: 0.7%, 2.6%), 1.8% (95%CI: 0.8%, 2.9%) and 1.7% (95%CI: 0.3%, 3.2%) increased risk of total, cardiovascular and respiratory mortality, respectively. For TSP, we observed significant associations only for cardiovascular morality. These data contribute to the scientific literature on long-term effects of particulate air pollution for high exposure settings typical in developing countries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Pollution level and distribution of PCDD/PCDF congeners between vapor phase and particulate phase in winter air of Dalian, China.

    Science.gov (United States)

    Wang, Wei; Qin, Songtao; Song, Yu; Xu, Qian; Ni, Yuwen; Chen, Jiping; Zhang, Xueping; Mu, Jim; Zhu, Xiuhua

    2011-06-01

    In December 2009, ambient air was sampled with active high-volume air samplers at two sites: on the roof of the No. l building of Dalian Jiaotong University and on the roof of the building of Dalian Meteorological Observatory. The concentrations and the congeners between vapor phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the air were measured. Sample analysis results showed that the concentrations of PCDD/Fs in particulate phase was higher than that in gaseous phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4 in all samples. The total I-TEQ value in gaseous phase and particulate phase was 5.5 and 453.8 fg/m(3) at Dalian Jiaotong University, 16.6 and 462.1 fg/m(3) at Dalian Meteorological Observatory, respectively. The I-TEQ value of Dalian atmosphere was 5.5-462.1 fg/m(3) which was lower than international standard, the atmospheric quality in Dalian is better. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  16. Emission of particulate matter from a desktop three-dimensional (3D) printer

    Science.gov (United States)

    Yi, Jinghai; LeBouf, Ryan F.; Duling, Matthew G.; Nurkiewicz, Timothy; Chen, Bean T.; Schwegler-Berry, Diane; Virji, M. Abbas; Stefaniak, Aleksandr B.

    2016-01-01

    ABSTRACT Desktop three-dimensional (3D) printers are becoming commonplace in business offices, public libraries, university labs and classrooms, and even private homes; however, these settings are generally not designed for exposure control. Prior experience with a variety of office equipment devices such as laser printers that emit ultrafine particles (UFP) suggests the need to characterize 3D printer emissions to enable reliable risk assessment. The aim of this study was to examine factors that influence particulate emissions from 3D printers and characterize their physical properties to inform risk assessment. Emissions were evaluated in a 0.5-m3 chamber and in a small room (32.7 m3) using real-time instrumentation to measure particle number, size distribution, mass, and surface area. Factors evaluated included filament composition and color, as well as the manufacturer-provided printer emissions control technologies while printing an object. Filament type significantly influenced emissions, with acrylonitrile butadiene styrene (ABS) emitting larger particles than polylactic acid (PLA), which may have been the result of agglomeration. Geometric mean particle sizes and total particle (TP) number and mass emissions differed significantly among colors of a given filament type. Use of a cover on the printer reduced TP emissions by a factor of 2. Lung deposition calculations indicated a threefold higher PLA particle deposition in alveoli compared to ABS. Desktop 3D printers emit high levels of UFP, which are released into indoor environments where adequate ventilation may not be present to control emissions. Emissions in nonindustrial settings need to be reduced through the use of a hierarchy of controls, beginning with device design, followed by engineering controls (ventilation) and administrative controls such as choice of filament composition and color. PMID:27196745

  17. Emission of particulate matter from a desktop three-dimensional (3D) printer.

    Science.gov (United States)

    Yi, Jinghai; LeBouf, Ryan F; Duling, Matthew G; Nurkiewicz, Timothy; Chen, Bean T; Schwegler-Berry, Diane; Virji, M Abbas; Stefaniak, Aleksandr B

    2016-01-01

    Desktop three-dimensional (3D) printers are becoming commonplace in business offices, public libraries, university labs and classrooms, and even private homes; however, these settings are generally not designed for exposure control. Prior experience with a variety of office equipment devices such as laser printers that emit ultrafine particles (UFP) suggests the need to characterize 3D printer emissions to enable reliable risk assessment. The aim of this study was to examine factors that influence particulate emissions from 3D printers and characterize their physical properties to inform risk assessment. Emissions were evaluated in a 0.5-m(3) chamber and in a small room (32.7 m(3)) using real-time instrumentation to measure particle number, size distribution, mass, and surface area. Factors evaluated included filament composition and color, as well as the manufacturer-provided printer emissions control technologies while printing an object. Filament type significantly influenced emissions, with acrylonitrile butadiene styrene (ABS) emitting larger particles than polylactic acid (PLA), which may have been the result of agglomeration. Geometric mean particle sizes and total particle (TP) number and mass emissions differed significantly among colors of a given filament type. Use of a cover on the printer reduced TP emissions by a factor of 2. Lung deposition calculations indicated a threefold higher PLA particle deposition in alveoli compared to ABS. Desktop 3D printers emit high levels of UFP, which are released into indoor environments where adequate ventilation may not be present to control emissions. Emissions in nonindustrial settings need to be reduced through the use of a hierarchy of controls, beginning with device design, followed by engineering controls (ventilation) and administrative controls such as choice of filament composition and color.

  18. Peatland use and transport of particulate organic matter in boreal headwater catchments

    Science.gov (United States)

    Marttila, Hannu; Karjalainen, Satu-Maaria; Nieminen, Mika; Kløve, Bjørn

    2014-05-01

    Peatland use can cause increased transport of particulate organic matter (POM) causing deteriorated water quality and especially siltation of stream beds. Even though topic has gained major attention among stakeholders it has received only minor efforts to solve the main sources and properties of transported particles. The development of effective management practices and evaluation of purification efficiency demands understanding of the sources of particulate matter in peat dominated catchments with various land uses and hydrological conditions. The objectives of this study were: (1) to determinate physical properties of POM in headwater brooks affected by different peatland uses, and; (2) to identity the sources of transported material by using sediment fingerprinting methods. For this purpose, two headwater catchments under peat extraction and peatland forestry land uses with 8 sampling points were monitored for 2 years using time integrated suspended sediment samplers. Data was completed by gap samples from 50 other headwater locations with different upstream land uses: pristine, peatland forestry and peat extraction. For the sources analysis, disturbed topsoil, stream bed sediment, banks of ditches and brooks, algae and various vegetation types were identified as the potential sediment sources. Stable isotopes (δ13C, δ15N) and C/N ratio were analyzed to discriminate between the possible sources. Results are further scaled against different land uses, landscape elements and seasonal hydrological conditions in headwaters. This paper presents the preliminary results from a two year study aiming to show various patterns in transport of POM in boreal headwater catchments. Due to strong land-water relationship in headwaters, further information on the properties of particles is needed to assess the downstream impacts of land use.

  19. Particulate Study on NeoProfen, a Neonatal Injectable Product.

    Science.gov (United States)

    Krishna, Aravind; Rice, Michael; Kester, Tom; Waters, Michael; Wilson, Terry

    2016-01-01

    NeoProfen or sterile ibuprofen L-lysine at 10 mg/mL ibuprofen, in 2 mL single-use Type I glass vials is often a first choice medication used to close a patent ductus arteriosus in neonatal patients from 500 to 1500 g body weight. Visible particulate matter was found in vials that were placed on a commercial stability program prior to the approved expiration date of 2 years. A combination of instrumental techniques including inductively coupled plasma-mass spectrometry, x-ray photoelectron spectroscopy, scanning electron microscopy energy dispersive x-ray spectrometry, and Raman and Fourier transform infrared microspectroscopy was used to evaluate stability, pilot batch and packaging samples in a root cause investigation. The particulate matter was shown to consist largely of ibuprofen aluminum salts of various stoichiometries. It developed over time by a substitution mechanism, in which the ibuprofen anion in solution reacts with the aluminum oxide network of the borosilicate glass giving the ibuprofen aluminum salt with =Al-OH remaining in the network. For corrective action an alternate Type I borosilicate glass vial with interior coating, not found in the original vial, was chosen for the product to prevent this occurrence. NeoProfen (sterile preservative-free ibuprofin L-lysine at 17 mg/mL in a single-use glass vial) is used to close a clinically significant patent ductus arteriosus in premature infants no more than 32 weeks gestational age. The neonatal population is especially sensitive to outside chemical, physical and environmental conditions because of incompletely developed organ systems, low birth weight and other underlying conditions. Two batches of this product were voluntarily recalled by the manufacturer, Lundbeck, and investigated for the source of particulate matter observed during a commercial stability testing program. This was found to result from an interaction between the product and the Type I borosilicate glass vial where ibuprofen

  20. Particulate Organic Matter Affects Soil Nitrogen Mineralization under Two Crop Rotation Systems.

    Directory of Open Access Journals (Sweden)

    Rongyan Bu

    Full Text Available Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N mineralization. The quantity and quality of particulate organic matter (POM and potentially mineralizable-N (PMN contents were measured in soils from 16 paired rice-rapeseed (RR/cotton-rapeseed (CR rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile, intermediate (25th and 75th percentiles, and high (90th percentile levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C and N (POM-N contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively than CR rotations (45.6% and 19.5%, respectively. Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils.

  1. Study of air pollution in terms of heavy metals and particulate matter at Ambodin'isotry using the technique of total reflection X-ray fluorescence

    International Nuclear Information System (INIS)

    AHMED, H.

    2011-01-01

    The present work is devoted to study the air pollution in terms of particulate matters and heavy metals in Ambodin'isotry in Antananarivo city by the method of total reflection X-ray fluorescence. This work has been done within the Institut National des Sciences et Techniques Nucleaires (Madagascar-INSTN). GENT air sampler has been used for the collections of the aerosol samples. This air sampler is placed at about 7 meters above the ground in order to avoid the contaminations. The samplings were carried out from 14 April to 29 August 2008. The duration of sampling is 24 hours. The results show that the analyzed aerosol samples contain the elements like the titanium , the chromium, the manganese, the iron, the nickel, the copper, the zinc, the bromine, the strontium and the lead. The average concentrations in element lead are lower than the standards ones adopted by the World Health Organization (WHO) (500 ng.m -3 ) and the United States Environmental Protection Agency (US EPA) (1500 ng.m -3 ). The total average concentrations in element lead are lower than the standards ones adopted by the World Health Organization (WHO) (500 ng.m -3 ). The total of average concentrations in lead doesn't present a danger for the population of Ambodin'isotry. The average concentrations of PM10 in the aerosols do not respect the guideline values of 50μg.m -3 adopted by the WHO and the European Union according to the directive 2005 and those of PM 2.5 exceed extensively the guideline values of the WHO (25μg.m -3 ) and of the US EPA (35μg.m -3 ). Consequently, the site of Ambodin'Isotry is polluted in term of airborne particulate matters. The calculation of enrichment factors by Mason's model shows the titanium, the iron, the nickel and the strontium are natural origin while the chromium, the nickel, the copper, the zinc, the bromine and the lead are from anthropogenic sources. [fr

  2. [Reduction of exposure to particulate matter in classrooms by improved cleaning: extent of exposure and results of a pilot study in Bavaria].

    Science.gov (United States)

    Twardella, D; Fromme, H; Dietrich, S; Dietrich, W C

    2009-02-01

    The aims of the research project were (I) to describe the exposure to particulate matter in Bavarian schools and identify predictors of increased exposure and (II) to evaluate whether exposure can be reduced by improving the ventilation and/or cleaning routine. Air quality was measured in 46 schools, two classrooms each, in the City of Munich and Dachau county. Each classroom was measured on one school day in both winter 2004/2005 and summer 2005. The continuously generated data on particulate matter during the teaching hours were summarised to daily medians and the possible association of the median concentration with classroom characteristics was tested using non-parametric methods. In winter, the median PM (2.5) concentration was 18.8 microg/m (3), in summer 12.7 microg/m (3). The median PM (10) concentration was 91.5 microg/m (3) in winter and 64.9 microg/m (3) in summer. Determinants of a high particulate matter concentration were the winter period, an increased number of pupils or decreased room size, a high CO(2) concentration, and a low class level. Following this survey, a pilot study on the effects of improved cleaning and ventilation routines was conducted in autumn 2005. Three conditions were tested in two classrooms of one school: (a) standard, (b) improved airing (3 min during short and 20 min during long breaks), and (c) improved airing and improved cleaning (thorough cleaning once and vacuuming before wet wiping). Each condition was implemented for 2 weeks and particulate matter concentrations measured concurrently. In both rooms a reduction of both PM (2.5) and PM (10) concentration was found following improved airing and a further reduction occurred when improved cleaning was introduced in addition. However, in a linear regression accounting for other factors (room, physical activity of the pupils, outdoor concentration of particulate matter) the effect of improved airing was no longer significant, while the effect of improved cleaning remained at

  3. Gaseous and particulate emissions from a DC arc melter.

    Science.gov (United States)

    Overcamp, Thomas J; Speer, Matthew P; Griner, Stewart J; Cash, Douglas M

    2003-01-01

    Tests treating soils contaminated with metal compounds and radionuclide surrogates were conducted in a DC arc melter. The soil melted, and glassy or ceramic waste forms with a separate metal phase were produced. Tests were run in the melter plenum with either air or N2 purge gases. In addition to nitrogen, the primary emissions of gases were CO2, CO, oxygen, methane, and oxides of nitrogen (NO(x)). Although the gas flow through the melter was low, the particulate concentrations ranged from 32 to 145 g/m3. Cerium, a nonradioactive surrogate for plutonium and uranium, was not enriched in the particulate matter (PM). The PM was enriched in cesium and highly enriched in lead.

  4. Disturbance of Soil Organic Matter and Nitrogen Dynamics: Implications for Soil and Water Quality

    Science.gov (United States)

    2004-06-30

    Elliott, E.T., 1992. Particulate soil organic- matter changes across a grassland cultivation sequence. Soil Sci. Soc. Am. J. 56, 777–783. Dale, V.H...C.A., Elliott, E.T., 1992. Particulate soil organic-matter changes across a grassland cultivation sequence. Soil Science Society of America Journal...1645-1650. Van Straalen, N.M. 1997. How to measure no effect. 2. Threshold effects in ecotoxicology . Environmetrics 8: 249-253. Verburg, P.S.J

  5. Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic

    Science.gov (United States)

    Lemaitre, Nolwenn; Planquette, Hélène; Planchon, Frédéric; Sarthou, Géraldine; Jacquet, Stéphanie; García-Ibáñez, Maribel I.; Gourain, Arthur; Cheize, Marie; Monin, Laurence; André, Luc; Laha, Priya; Terryn, Herman; Dehairs, Frank

    2018-04-01

    The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May-June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100-1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L-1), which was attributed to an intense bloom averaging 6 mg chl a m-3 between January and June 2014 and by an intense 1500 m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L-1), was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol C m-2 d-1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near

  6. Phenomenology and modeling of particulate corrosion product behavior in Hanford N Reactor primary coolant

    International Nuclear Information System (INIS)

    Bechtold, D.B.

    1983-01-01

    The levels and composition of filterable corrosion products in the Hanford N Reactor Primary Loop are measurable by filtration. The suspended crud level has ranged from 0.0005 ppM to 6.482 ppM with a median 0.050 ppM. The composition approximates magnetite. The particle size distribution has been found in 31 cases to be uniformly a log normal distribution with a count median ranging from 1.10 to 2.31 microns with a median of 1.81 microns, and the geometric standard deviation ranging from 1.60 to 2.34 with a median of 1.84. An auto-correcting inline turbidimeter was found to respond to linearly to suspended crud levels over a range 0.05 to at least 6.5 ppM by direct comparison with filter sample weights. Cause of crud bursts in the primary loop were found to be power decreases. The crud transients associated with a reactor power drop, several reactor shutdowns, and several reactor startups could be modeled consistently with each other using a simple stirred-tank, first order exchange model of particulate between makeup, coolant, letdown, and loosely adherent crud on pipe walls. Over 3/10 of the average steady running particulate crud level could be accounted for by magnetically filterable particulate in the makeup feed. A simulation model of particulate transport has been coded in FORTRAN

  7. Externality costs by emission. E. Particulates

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fossil-fuel-fired electricity generating systems, particularly coal and oil-fired facilities, are significant emitters of particulate matter. The major components of particulate emissions from a power plant include ash, which is made up of heavy metals, radioactive isotopes and hydrocarbons, and sulfates (SO 4 ) and nitrates (NO 3 ), which are formed by reaction of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ) in the atmosphere. The smallest ash particulates (including sulfates and nitrates) cause human respiratory effects and impaired visibility. Other effects may include materials damage due to soiling and possibly corrosion, damage to domestic and wild flora through deposition of particulates on foliage, and possible health effects on domestic animals and wild fauna. Several studies focus on the direct effects of high ambient levels of small particulates. This chapter reviews the available literature on the effects of particulate emissions on humans and their environment, and attempts to assign a cost figure to the environmental effects and human health impairments associated with particulate matter emissions. Specifically, this report focuses on the effects of particulates related to human health, visibility, flora, fauna and materials

  8. Methods of analysis for complex organic aerosol mixtures from urban emission sources of particulate carbon

    International Nuclear Information System (INIS)

    Mazurek, M.A.; Hildemann, L.M.; Simoneit, B.R.T.

    1990-10-01

    Organic aerosols comprise approximately 30% by mass of the total fine particulate matter present in urban atmospheres. The chemical composition of such aerosols is complex and reflects input from multiple sources of primary emissions to the atmosphere, as well as from secondary production of carbonaceous aerosol species via photochemical reactions. To identify discrete sources of fine carbonaceous particles in urban atmospheres, analytical methods must reconcile both bulk chemical and molecular properties of the total carbonaceous aerosol fraction. This paper presents an overview of the analytical protocol developed and used in a study of the major sources of fine carbon particles emitted to an urban atmosphere. 23 refs., 1 fig., 2 tabs

  9. Preliminary analysis of variability in concentration of fine particulate matter - PM1.0, PM2.5 and PM10 in area of Poznań city

    Directory of Open Access Journals (Sweden)

    Sówka Izabela

    2018-01-01

    Full Text Available It is commonly known, that suspended particulate matter pose a threat to human life and health, negatively influence the flora, climate and also materials. Especially dangerous is the presence of high concentration of particulate matter in the area of cities, where density of population is high. The research aimed at determining the variability of suspended particulate matter concentration (PM1.0, PM2.5 and PM10 in two different thermal seasons, in the area of Poznań city. As a part of carried out work we analyzed the variability of concentrations and also performed a preliminary analysis of their correlation. Measured concentrations of particulate matter were contained within following ranges: PM10 – 8.7-69.6 μg/m3, PM2.5 – 2.2-88.5 μg/m3, PM1.0 – 2.5-22.9 μg/m3 in the winter season and 1.0-42.8 μg/m3 (PM10, 1.2-40.3 μg/m3 (PM2.5 and 2.7-10.4 (PM1.0 in the summer season. Preliminary correlative analysis indicated interdependence between the temperature of air, the speed of wind and concentration of particulate matter in selected measurement points. The values of correlation coefficients between the air temperature, speed of wind and concentrations of particulate matter were respectively equal to: for PM10: -0.59 and -0.55 (Jana Pawła II Street, -0.53 and -0.53 (Szymanowskiego Street, for PM2.5: -0.60 and -0.53 (Jana Pawła II Street and for PM1.0 -0.40 and -0.59 (Jana Pawła II Street.

  10. Distribution of lead in relation to size of airborne particulate matter in Islamabad, Pakistan.

    Science.gov (United States)

    Shah, Munir H; Shaheen, N; Jaffar, M; Saqib, M

    2004-02-01

    Airborne particulate matter (PM) collected from two sampling stations in Islamabad, Pakistan, was analyzed for lead content and size gradation. A high volume air sampler was used to trap particulates on glass fiber filters for 8-12 h on a daily basis. Lead was estimated using a nitric acid digestion based AAS method on 44 samples from station 1 and 61 samples from station 2. Particle size fractions were categorized as 100 microm. The correlation between lead concentration and particle size was investigated. The results from two stations indicated average airborne lead concentrations of 0.505 and 0.185 microg/m3. Enhanced levels of lead were measured at a maximum of 4.075 microg/m3 at station 1 and 4.000 microg/m3 at station 2. PM 100 were found to constitute the local atmosphere in comparable proportions. A comparison of the lead levels is made with the existing permissible levels of this element laid down by different international agencies.

  11. Biological mechanisms and translocation kinetics of particulate plutonium

    International Nuclear Information System (INIS)

    Bruenger, F.W.; Stevens, W.; Atherton, D.R.; Roswell, R.L.; Smith, J.M.

    1981-01-01

    The dissolution and elimination of particulate 239 Pu from its initial sites of deposition in phagocytic organs (the liver, spleen, and lung), as well as its translocation and redeposition in soft tissue organs and skeleton have been investigated. Beagles were injected intravenously with particulate Pu and sacrificed sequentially at times ranging from 33 to 830 days after injection. Equations that describe the overall retention of Pu in liver, spleen, lung, and bone were calculated. Plutonium mobilized from these organs either re-entered the blood stream and redeposited in the skeleton and liver parenchyma or was excreted. The protracted translocation of Pu to bone surfaces potentially exposes all cells involved in osteogenesis to continuous α-radiation, a situation that could enhance the hazard of developing osteosarcoma. A kinetic model that describes the translocation of Pu from the phagocytic compartments to blood and its subsequent redistribution to bone, liver, and other organs was formulated

  12. Carbon isotopic ratio of suspended organic matter of the Gironde estuary. Application to particulate Zn and Pb distribution

    International Nuclear Information System (INIS)

    Fontugne, Michel; Jouanneau, J.M.

    1981-01-01

    In the Gironde estuary, the isotopic ratio of particulate organic carbon (P.O.C.), and the ratio metal/P.O.C. indicate the occurrence of two zones. Up-river, the concentration decreases due to the consumption of the organo-metallic phase and by mixing in the ''mud plug'' with terrestrial particles impoverished in metal and P.O.C. Down-stream, the mixing of metal rich terrestrial P.O.C. with poorer marine particles determines the metal concentrations [fr

  13. A 3D Monte Carlo Method for Estimation of Patient-specific Internal Organs Absorbed Dose for 99mTc-hynic-Tyr3-octreotide Imaging

    International Nuclear Information System (INIS)

    Momennezhad, Mehdi; Nasseri, Shahrokh; Zakavi, Seyed Rasoul; Parach, Ali Asghar; Ghorbani, Mahdi; Asl, Ruhollah Ghahraman

    2016-01-01

    Single-photon emission computed tomography (SPECT)-based tracers are easily available and more widely used than positron emission tomography (PET)-based tracers, and SPECT imaging still remains the most prevalent nuclear medicine imaging modality worldwide. The aim of this study is to implement an image-based Monte Carlo method for patient-specific three-dimensional (3D) absorbed dose calculation in patients after injection of 99m Tc-hydrazinonicotinamide (hynic)-Tyr 3 -octreotide as a SPECT radiotracer. 99m Tc patient-speci@@@@@@c S values and the absorbed doses were calculated with GATE code for each source-target organ pair in four patients who were imaged for suspected neuroendocrine tumors. Each patient underwent multiple whole-body planar scans as well as SPECT imaging over a period of 1-24 h after intravenous injection of 99m hynic-Tyr 3 -octreotide. The patient-specific S values calculated by GATE Monte Carlo code and the corresponding S values obtained by MIRDOSE program differed within 4.3% on an average for self-irradiation, and differed within 69.6% on an average for cross-irradiation. However, the agreement between total organ doses calculated by GATE code and MIRDOSE program for all patients was reasonably well (percentage difference was about 4.6% on an average). Normal and tumor absorbed doses calculated with GATE were slightly higher than those calculated with MIRDOSE program. The average ratio of GATE absorbed doses to MIRDOSE was 1.07 ± 0.11 (ranging from 0.94 to 1.36). According to the results, it is proposed that when cross-organ irradiation is dominant, a comprehensive approach such as GATE Monte Carlo dosimetry be used since it provides more reliable dosimetric results

  14. Gaseous and particulate emissions from prescribed burning in Georgia.

    Science.gov (United States)

    Lee, Sangil; Baumann, Karsten; Schauer, James J; Sheesley, Rebecca J; Naeher, Luke P; Meinardi, Simone; Blake, Donald R; Edgerton, Eric S; Russell, Armistead G; Clements, Mark

    2005-12-01

    Prescribed burning is a significant source of fine particulate matter (PM2.5) in the southeastern United States. However, limited data exist on the emission characteristics from this source. Various organic and inorganic compounds both in the gas and particle phase were measured in the emissions of prescribed burnings conducted at two pine-dominated forest areas in Georgia. The measurements of volatile organic compounds (VOCs) and PM2.5 allowed the determination of emission factors for the flaming and smoldering stages of prescribed burnings. The VOC emission factors from smoldering were distinctly higher than those from flaming except for ethene, ethyne, and organic nitrate compounds. VOC emission factors show that emissions of certain aromatic compounds and terpenes such as alpha and beta-pinenes, which are important precursors for secondary organic aerosol (SOA), are much higher from active prescribed burnings than from fireplace wood and laboratory open burning studies. Levoglucosan is the major particulate organic compound (POC) emitted for all these studies, though its emission relative to total organic carbon (mg/g OC) differs significantly. Furthermore, cholesterol, an important fingerprint for meat cooking, was observed only in our in situ study indicating a significant release from the soil and soil organisms during open burning. Source apportionment of ambient primary fine particulate OC measured at two urban receptor locations 20-25 km downwind yields 74 +/- 11% during and immediately after the burns using our new in situ profile. In comparison with the previous source profile from laboratory simulations, however, this OC contribution is on average 27 +/- 5% lower.

  15. Characteristics of particulate matter emissions from toy cars with electric motors.

    Science.gov (United States)

    Wang, Xiaofei; Williams, Brent J; Biswas, Pratim

    2015-04-01

    Aerosol emissions from toy cars with electric motors were characterized. Particle emission rates from the toy cars, as high as 7.47×10(7) particles/s, were measured. This emission rate is lower than other indoor sources such as smoking and cooking. The particles emitted from toy cars are generated from spark discharges inside the electric motors that power the toy cars. Size distribution measurements indicated that most particles were below 100 nm in diameter. Copper was the dominant inorganic species in these particles. By deploying aerosol mass spectrometers, high concentrations of particulate organic matter were also detected and characterized in detail. Several organic compounds were identified using a thermal desorption aerosol gas chromatography. The mass size distribution of particulate organic matter was bimodal. The formation mechanism of particulate organic matter from toy cars was elucidated. A possible new source of indoor air pollution, particles from electric motors in toy cars, was identified. This study characterized aerosol emissions from toy cars in detail. Most of these particles have a diameter less than 100 nm. Copper and some organics are the major components of these particles. Conditions that minimize these emissions were determined.

  16. Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

    Science.gov (United States)

    Vilcassim, M J Ruzmyn; Thurston, George D; Peltier, Richard E; Gordon, Terry

    2014-12-16

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m(3), with 1 min average peaks >100 μg/m(3), while real time PM2.5 levels ranged from 35 to 200 μg/m(3). Mean EC levels ranged from 9 to 12.5 μg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted.

  17. An overview of particulate emissions from residential biomass combustion

    Science.gov (United States)

    Vicente, E. D.; Alves, C. A.

    2018-01-01

    Residential biomass burning has been pointed out as one of the largest sources of fine particles in the global troposphere with serious impacts on air quality, climate and human health. Quantitative estimations of the contribution of this source to the atmospheric particulate matter levels are hard to obtain, because emission factors vary greatly with wood type, combustion equipment and operating conditions. Updated information should improve not only regional and global biomass burning emission inventories, but also the input for atmospheric models. In this work, an extensive tabulation of particulate matter emission factors obtained worldwide is presented and critically evaluated. Existing quantifications and the suitability of specific organic markers to assign the input of residential biomass combustion to the ambient carbonaceous aerosol are also discussed. Based on these organic markers or other tracers, estimates of the contribution of this sector to observed particulate levels by receptor models for different regions around the world are compiled. Key areas requiring future research are highlighted and briefly discussed.

  18. Airborne particulate concentrations and fluxes at an active uranium mill tailings site

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1978-01-01

    Direct measurements of airborne particulate concentrations and fluxes of transported mill tailing materials were measured at an active mill tailings site. Experimental measurement equipment consisted of meteorological instrumentation to automatically activate total particulate air samplers as a function of wind speed increments and direction, as well as particle cascade impactors to measure airborne respirable concentrations as a function of particle size. In addition, an inertial impaction device measured nonrespirable fluxes of airborne particles. Caclulated results are presented in terms of the airborne solid concentration in g/m 3 , the horizontal airborne mass flux in g/(m 2 -day) for total collected nonrespirable particles and the radionuclide concentrations in dpm/g as a function of particle diameter for respirable and nonrespirable particles

  19. Characterization of vehicular brake service personnel exposure to airborne asbestos and particulate.

    Science.gov (United States)

    Weir, F W; Tolar, G; Meraz, L B

    2001-12-01

    Evaluation of fibers and total particulate generated during the servicing of drum brakes on motor vehicles as well as during the resurfacing (arcing) of brake shoes was conducted. Conditions for the studies were based on review of contemporary (approximately 1950-1980) working practices in the industry. This work was conducted in two parts. Phase 1 estimated the release of asbestos fibers and total particulate during brake inspection and replacement of light-duty vehicle rear drum brakes at an auto/truck repair facility. Two distinct work practices were evaluated: One rear wheel from each vehicle was serviced using compressed air to remove dust while the second rear wheel was serviced without compressed air. Area and personal monitoring of fiber levels demonstrated counts (without compressed air) that ranged from 0.05 to 0.2 f/cc. Fiber counts when using compressed air averaged from 0.05 to 0.9 f/cc. Results from real-time aerosol monitoring indicated elevated dust levels for about 15 minutes after blow out. With shop doors open, dust levels increased to 5.0 mg/m3 at blow out and returned to 0.08 mg/m3 within two minutes. When the shop doors were closed, the dust levels reached 13.5 mg/m3 at blow out and decreased to 1.68 mg/m3 within one minute and to background within 14 minutes. The Phase 2 series evaluated the release of fibers and other particulate from are grinding. For operations conducted under conditions simulating a workplace, a mean of 0.19 f/cc +/- 0.16 was determined. Dust levels averaged 0.25 mg/m3 +/- 0.05. Brake service monitoring in these tests demonstrates that asbestos fiber concentrations, considered on a time weighted average basis, should not exceed currently acceptable workplace standards whether or not the worker uses compressed air, nor during the arc grinding process when arcing is conducted in accord with the design of the equipment.

  20. Particulate carbon in the atmosphere

    International Nuclear Information System (INIS)

    Surakka, J.

    1992-01-01

    Carbonaceous aerosols are emitted to the atmosphere in combustion processes. Carbon particles are very small and have a long residence time in the air. Black Carbon, a type of carbon aerosol, is a good label when transport of combustion emissions in the atmosphere is studied. It is also useful tool in air quality studies. Carbon particles absorb light 6.5 to 8 times stronger than any other particulate matter in the air. Their effect on decreasing visibility is about 50 %. Weather disturbances are also caused by carbon emissions e.g. in Kuwait. Carbon particles have big absorption surface and capacity to catalyze different heterogenous reactions in air. Due to their special chemical and physical properties particulate carbon is a significant air pollution specie, especially in urban air. Average particulate carbon concentration of 5.7 μg/m 2 have been measured in winter months in Helsinki

  1. Particulate emissions from biodiesel fuelled CI engines

    International Nuclear Information System (INIS)

    Agarwal, Avinash Kumar; Gupta, Tarun; Shukla, Pravesh C.; Dhar, Atul

    2015-01-01

    Highlights: • Physical and chemical characterization of biodiesel particulates. • Toxicity of biodiesel particulate due to EC/OC, PAHs and BTEX. • Trace metals and unregulated emissions from biodiesel fuelled diesel engines. • Influence of aftertreatment devices and injection strategy on biodiesel particulates. • Characterization of biodiesel particulate size-number distribution. - Abstract: Compression ignition (CI) engines are the most popular prime-movers for transportation sector as well as for stationary applications. Petroleum reserves are rapidly and continuously depleting at an alarming pace and there is an urgent need to find alternative energy resources to control both, the global warming and the air pollution, which is primarily attributed to combustion of fossil fuels. In last couple of decades, biodiesel has emerged as the most important alternative fuel candidate to mineral diesel. Numerous experimental investigations have confirmed that biodiesel results in improved engine performance, lower emissions, particularly lower particulate mass emissions vis-à-vis mineral diesel and is therefore relatively more environment friendly fuel, being renewable in nature. Environmental and health effects of particulates are not simply dependent on the particulate mass emissions but these change depending upon varying physical and chemical characteristics of particulates. Particulate characteristics are dependent on largely unpredictable interactions between engine technology, after-treatment technology, engine operating conditions as well as fuel and lubricating oil properties. This review paper presents an exhaustive summary of literature on the effect of biodiesel and its blends on exhaust particulate’s physical characteristics (such as particulate mass, particle number-size distribution, particle surface area-size distribution, surface morphology) and chemical characteristics (such as elemental and organic carbon content, speciation of polyaromatic

  2. Aqueous organic chemistry in the atmosphere: sources and chemical processing of organic aerosols.

    Science.gov (United States)

    McNeill, V Faye

    2015-02-03

    Over the past decade, it has become clear that aqueous chemical processes occurring in cloud droplets and wet atmospheric particles are an important source of organic atmospheric particulate matter. Reactions of water-soluble volatile (or semivolatile) organic gases (VOCs or SVOCs) in these aqueous media lead to the formation of highly oxidized organic particulate matter (secondary organic aerosol; SOA) and key tracer species, such as organosulfates. These processes are often driven by a combination of anthropogenic and biogenic emissions, and therefore their accurate representation in models is important for effective air quality management. Despite considerable progress, mechanistic understanding of some key aqueous processes is still lacking, and these pathways are incompletely represented in 3D atmospheric chemistry and air quality models. In this article, the concepts, historical context, and current state of the science of aqueous pathways of SOA formation are discussed.

  3. Electrostatic Dust Cloth: A Passive Screening Method to Assess Occupational Exposure to Organic Dust in Bakeries

    Directory of Open Access Journals (Sweden)

    Carla Viegas

    2018-02-01

    Full Text Available Organic dust is widespread in the environment including occupational settings, such as bakeries. Recently, a new collection device—the electrostatic dust cloth (EDC—has been described for the assessment of occupational exposures. The aim of this study was to investigate the suitability of EDC for identifying the distribution patterns and exposure concentrations of particulate matter and microbial contaminants such as fungi and bacteria in bakeries. Twelve bakeries were selected, and dust was allowed to settle for 13 to 16 days on EDCs (a total of 33 samples. Particle counts and size distribution (0.3 µm, 0.5 µm, 1 µm, 2.5 µm, 5 µm and 10 µm were measured with direct-reading equipment. Higher EDC mass was significantly correlated (p values < 0.05 with higher fungal load on dichloran glycerol (DG18 and with particle size distribution in the 0.3 µm, 0.5 µm, 1.0 µm and 10.0 µm range. Fungal levels on malt extract agar (MEA ranged from 0 to 2886 CFU/m2 EDC in the warehouse setting, 0 to 500 CFU/m2 EDC in the production setting, and 0 to 3135 CFU/m2 EDC in the store. Penicillium sp. (42.56% was the most frequent fungi. Total bacterial load ranged from 0 to 18,859 CFU/m2 EDC in the warehouse, 0 to 71,656 CFU/m2 EDC in production, and 0 to 21,746 CFU/m2 EDC in the store. EDC assessment provided a longer-term integrated sample of organic dust, useful for identifying critical worksites in which particulate matter and bio-burden exposures are elevated. These findings suggest that EDC can be applied as a screening method for particulate matter-exposure assessment and as a complementary method to quantify exposures in occupational environments.

  4. Temporal variability in terrestrially-derived sources of particulate organic carbon in the lower Mississippi River and its upper tributaries

    Science.gov (United States)

    Bianchi, Thomas S.; Wysocki, Laura A.; Stewart, Mike; Filley, Timothy R.; McKee, Brent A.

    2007-09-01

    In this study, we examined the temporal changes of terrestrially-derived particulate organic carbon (POC) in the lower Mississippi River (MR) and in a very limited account, the upper tributaries (Upper MR, Ohio River, and Missouri River). We used for the first time a combination of lignin-phenols, bulk stable carbon isotopes, and compound-specific isotope analyses (CSIA) to examine POC in the lower MR and upper tributaries. A lack of correlation between POC and lignin phenol abundances ( Λ8) was likely due to dilution effects from autochthonous production in the river, which has been shown to be considerably higher than previously expected. The range of δ 13C values for p-hydroxycinnamic and ferulic acids in POC in the lower river do support that POM in the lower river does have a significant component of C 4 in addition to C 3 source materials. A strong correlation between δ 13C values of p-hydroxycinnamic, ferulic, and vanillyl phenols suggests a consistent input of C 3 and C 4 carbon to POC lignin while a lack of correlation between these same phenols and POC bulk δ 13C further indicates the considerable role of autochthonous carbon in the lower MR POC budget. Our estimates indicate an annual flux of POC of 9.3 × 10 8 kg y -1 to the Gulf of Mexico. Total lignin fluxes, based on Λ8 values of POC, were estimated to be 1.2 × 10 5 kg y -1. If we include the total dissolved organic carbon (DOC) flux (3.1 × 10 9 kg y -1) reported by [Bianchi T. S., Filley T., Dria K. and Hatcher, P. (2004) Temporal variability in sources of dissolved organic carbon in the lower Mississippi River. Geochim. Cosmochim. Acta68, 959-967.], we get a total organic carbon flux of 4.0 × 10 9 kg y -1. This represents 0.82% of the annual total organic carbon supplied to the oceans by rivers (4.9 × 10 11 kg).

  5. Long-term particulate matter modeling for health effect studies in California - Part 2: Concentrations and sources of ultrafine organic aerosols

    Science.gov (United States)

    Hu, Jianlin; Jathar, Shantanu; Zhang, Hongliang; Ying, Qi; Chen, Shu-Hua; Cappa, Christopher D.; Kleeman, Michael J.

    2017-04-01

    Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0. 1). Recent epidemiological studies have identified associations between PM0. 1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0. 1 in California for a 9-year (2000-2008) modeling period with 4 km horizontal resolution to provide more insights about PM0. 1 OA for health effect studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2. 5) total organic carbon at six major urban sites had mean fractional bias of -0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2. 5 SOA / OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2-3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0. 1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0. 1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0. 1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0. 1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of

  6. Hyphenation of a carbon analyzer to photo-ionization mass spectrometry to unravel the organic composition of particulate matter on a molecular level.

    Science.gov (United States)

    Grabowsky, Jana; Streibel, Thorsten; Sklorz, Martin; Chow, Judith C; Watson, John G; Mamakos, Athanasios; Zimmermann, Ralf

    2011-12-01

    The carbonaceous fraction of airborne particulate matter (PM) is of increasing interest due to the adverse health effects they are linked to. Its analytical ascertainment on a molecular level is still challenging. Hence, analysis of carbonaceous fractions is often carried out by determining bulk parameters such as the overall content of organic compounds (OC) and elemental carbon (EC) as well as the total carbon content, TC (sum of OC and EC), however, no information about the individual substances or substance classes, of which the single fractions consist can be obtained. In this work, a carbon analyzer and a photo-ionization time-of-flight mass spectrometer (PI-TOF-MS) were hyphenated to investigate individual compounds especially from the OC fractions. The carbon analyzer enables the stepwise heating of particle samples and provides the bulk parameters. With the PI-TOF-MS, it is possible to detect the organic compounds released during the single-temperature steps due to soft ionization and fast detection of the molecular ions. The hyphenation was designed, built up, characterized by standard substances, and applied to several kinds of samples, such as ambient aerosol, gasoline, and diesel emission as well as wood combustion emission samples. The ambient filter sample showed a strong impact of wood combustion markers. This was revealed by comparison to the product pattern of the similar analysis of pure cellulose and lignin and the wood combustion PM. At higher temperatures (450 °C), a shift to smaller molecules occurred due to the thermal decomposition of larger structures of oligomeric or polymeric nature comparable to lignocelluloses and similar oxygenated humic-like substances. Finally, particulate matter from gasoline and diesel containing 10% biodiesel vehicle exhaust has been analyzed. Gasoline-derived PM exhibited large polycyclic aromatic hydrocarbons, whereas diesel PM showed a much higher total organic content. The detected pattern revealed a strong

  7. Tethering metal ions to photocatalyst particulate surfaces by bifunctional molecular linkers for efficient hydrogen evolution

    KAUST Repository

    Yu, Weili

    2014-08-19

    A simple and versatile method for the preparation of photocatalyst particulates modified with effective cocatalysts is presented; the method involves the sequential soaking of photocatalyst particulates in solutions containing bifunctional organic linkers and metal ions. The modification of the particulate surfaces is a universal and reproducible method because the molecular linkers utilize strong covalent bonds, which in turn result in modified monolayer with a small but controlled quantity of metals. The photocatalysis results indicated that the CdS with likely photochemically reduced Pd and Ni, which were initially immobilized via ethanedithiol (EDT) as a linker, were highly efficient for photocatalytic hydrogen evolution from Na2S-Na2SO3-containing aqueous solutions. The method developed in this study opens a new synthesis route for the preparation of effective photocatalysts with various combinations of bifunctional linkers, metals, and photocatalyst particulate materials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tethering metal ions to photocatalyst particulate surfaces by bifunctional molecular linkers for efficient hydrogen evolution

    KAUST Repository

    Yu, Weili; Isimjan, Tayirjan T.; Del Gobbo, Silvano; Anjum, Dalaver Hussain; Abdel-Azeim, Safwat; Cavallo, Luigi; Garcia Esparza, Angel T.; Domen, Kazunari; Xu, Wei; Takanabe, Kazuhiro

    2014-01-01

    A simple and versatile method for the preparation of photocatalyst particulates modified with effective cocatalysts is presented; the method involves the sequential soaking of photocatalyst particulates in solutions containing bifunctional organic linkers and metal ions. The modification of the particulate surfaces is a universal and reproducible method because the molecular linkers utilize strong covalent bonds, which in turn result in modified monolayer with a small but controlled quantity of metals. The photocatalysis results indicated that the CdS with likely photochemically reduced Pd and Ni, which were initially immobilized via ethanedithiol (EDT) as a linker, were highly efficient for photocatalytic hydrogen evolution from Na2S-Na2SO3-containing aqueous solutions. The method developed in this study opens a new synthesis route for the preparation of effective photocatalysts with various combinations of bifunctional linkers, metals, and photocatalyst particulate materials. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The separation of particulate within PFC decontamination wastewater generated by PFC decontamination

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin; Park, Jin Ho; Narayan, M.

    2005-01-01

    When PFC(Perfluoro carbonate) decontamination technology is applied to removal of radioactive contaminated particulate adhered at surface during the operation of nuclear research facilities, it is necessary to develop a filtration equipment to reuse of PFC solution due to high price, also to minimize the volume of second wastewater. Contaminated characteristics of hot particulate was investigated and a filtration process was presented to remove suspended radioactive particulate from PFC decontamination wastewater generated on PFC decontamination. The range of size of hot particulate adhered at the surface of research facilities measured by SEM was 0.1∼10μm. Hot particulate of more than 2μm in PFC contamination wastewater was removed by first filter and then hot particulate of more than 0.2μm was removed by second filter. Results of filter experiments showed that filtration efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic filter was 95∼97%. A ceramic filter showed a higher filtration efficiency with a little low permeate volume. Also, a ceramic of inorganic compound could be broken easily on experiment and has a high price but was highly stable at radioactivity in comparison of PVDF and PP of a macromolecule which generate H 2 gas in alpha radioactivity environment

  10. Measurement and modeling of diameter distributions of particulate matter in terrestrial solutions

    Science.gov (United States)

    Levia, Delphis F.; Michalzik, Beate; Bischoff, Sebastian; NäThe, Kerstin; Legates, David R.; Gruselle, Marie-Cecile; Richter, Susanne

    2013-04-01

    Particulate matter (PM) plays an important role in biogeosciences, affecting biosphere-atmosphere interactions and ecosystem health. This is the first known study to quantify and model PM diameter distributions of bulk precipitation, throughfall, stemflow, and organic layer (Oa) solution. Solutions were collected from a European beech (Fagus sylvatica L.) forest during leafed and leafless periods. Following scanning electron microscopy and image analysis, PM distributions were quantified and then modeled with the Box-Cox transformation. Based on an analysis of 43,278 individual particulates, median PM diameter of all solutions was around 3.0 µm. All PM diameter frequency distributions were skewed significantly to the right. Optimal power transformations of PM diameter distributions were between -1.00 and -1.56. The utility of this model reconstruction would be that large samples having a similar probability density function can be developed for similar forests. Further work on the shape and chemical composition of particulates is warranted.

  11. PCDD, PCDF, and PCB contamination of air and inhalable particulate in Rome

    International Nuclear Information System (INIS)

    Turrio-Baldassarri, L.; Carere, A.; Di Domenico, A.; Fuselli, S.; Iacovella, N.; Rodriguez, F.

    1994-01-01

    The isomer specific determination of PCDD, PCDF and PCB was carried out on samples of air and inhalable particulate from Rome. Samples were taken daily for six months and pooled to yield two samples per month. Normal PCDD + PCDF concentrations expressed in TEQ ranged from 48 to 87 fg/m 3 , while total PCB ranged from 0.1 to 1.4 ng/m 3 . The 2, 3, 7, 8-substituted PCDD and PCDF congener pattern is shown together with the PCB congener pattern. (orig.)

  12. Recycling and Resistance of Petrogenic Particulate Organic Carbon: Implications from A Chemical Oxidation Method

    Science.gov (United States)

    Zhang, T.; Li, G.; Ji, J.

    2013-12-01

    Petrogenic particulate organic carbon (OCpetro) represents a small fraction of photosynthetic carbon which escapes pedogenic-petrogenic degradation and gets trapped in the lithosphere. Exhumation and recycling of OCpetro are of significant importance in the global carbon cycle because OCpetro oxidation represents a substantial carbon source to the atmosphere while the re-burial of OCpetro in sediment deposits has no net effect. Though studies have investigated various behaviors of OCpetro in the surface environments (e.g., riverine mobilization, marine deposition, and microbial remineralization), less attention has been paid to the reaction kinetics and structural transformations during OCpetro oxidation. Here we assess the OCpetro-oxidation process based on a chemical oxidation method adopted from soil studies. The employed chemical oxidation method is considered an effective simulation of natural oxidation in highly oxidative environments, and has been widely used in soil studies to isolate the inert soil carbon pool. We applied this chemical method to the OCpetro-enriched black shale samples from the middle-lower Yangtze (Changjiang) basin, China, and performed comprehensive instrumental analyses (element analysis, Fourier transform infrared (FTIR) spectrum, and Raman spectrum). We also conducted step-oxidizing experiments following fixed time series and monitored the reaction process in rigorously controlled lab conditions. In this work, we present our experiment results and discuss the implications for the recycling and properties of OCpetro. Particulate organic carbon concentration of black shale samples before and after oxidation helps to quantify the oxidability of OCpetro and constrain the preservation efficiency of OCpetro during fluvial erosion over large river basin scales. FTIR and Raman analyses reveal clear structural variations on atomic and molecular levels. Results from the step-oxidizing experiments provide detailed information about the reaction

  13. Seasonal changes in particulate and dissolved organic matter composition and quality in the Lena River Delta

    Science.gov (United States)

    Mollenhauer, G.; Winterfeld, M.; Hefter, J.; Bodenstab, L.; Morgenstern, A.; Eulenburg, A.; Heim, B.; Koch, B.; Schefuss, E.; Moerth, C. M.; Rethemeyer, J.

    2016-12-01

    Arctic rivers are known to export large quantities of carbon by discharge of dissolved and particulate organic carbon (DOC, POC), and in a warming and progressively moister Arctic, these exports may increase resulting in a reduction of arctic continental carbon stocks. These rivers have highly variable discharge rates with a pronounced maximum during the spring freshet associated with highest concentrations of DOC and POC. Most studies investigating the isotopic composition and quality of carbon exported by Arctic rivers rely on samples taken in summer during base flow, which is due to the logistical challenges associated with sampling in the remote Arctic permafrost regions. Here we present a record of δ13C and Δ14C of DOC and POC collected between late May during the freshet and late August 2014 in the Lena River Delta. POC Δ14C shows an initial trend towards older values in the spring samples, which is reversed in summer, associated with a shift towards more depleted δ13C values. We interpret this aging trend as reflecting progressive thawing throughout the ice-free season, resulting in mobilization of progressively older carbon from deeper thawed layers. The summer reversal indicates admixture of aquatic organic matter. DOC Δ14C, in contrast, remains at relatively modern levels with rather constant δ13C values throughout the sampling period. We furthermore analysed the biomarker composition of Lena Delta particulate OM collected in spring and summer. From spring to summer, we observe trends in abundance of individual leaf-wax derived biomarkers indicating higher abundance of algal biomass in the summer particles. Trends in soil microbial biomarkers and compound-specific δD of leaf-wax lipids suggest a shift in sources towards higher contributions from the southern catchment in summer. DOC composition investigated with FT-ICR-MS changes from spring with higher abundances of compounds with high H/C and low O/C ratios to late summer, when fewer compounds

  14. Black Carbon and Particulate Matter (PM2.5) Concentrations in New York City’s Subway Stations

    Science.gov (United States)

    2015-01-01

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m3, with 1 min average peaks >100 μg/m3, while real time PM2.5 levels ranged from 35 to 200 μg/m3. Mean EC levels ranged from 9 to 12.5 μg/m3. At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m3, respectively. This study shows that both BC soot and PM levels in NYC’s subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

  15. Particulate organic constituents of surface waters of east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sreepada, R.A.; Bhat, K.L.; Parulekar, A.H.

    protein (PP) and particulate lipid (PL) fractions. High values of chlorophyll a (chl-a) characterized the coastal waters. In coastal waters, POC was dominatEd. by PCHO containing detrital matter, whereas actively growing phytoplankton significantly...

  16. Elemental quantification of airborne particulate matter in Bandung and Lembang area

    International Nuclear Information System (INIS)

    Sutisna; Achmad Hidayat; Dadang Supriatna

    2004-01-01

    ELEMENTAL QUANTIFICATION OF AIRBORNE PARTICULATE MATTER IN BANDUNG AND LEMBANG REGION: The contaminated airborne particulates by toxic gases and elements have a potential affect to the human health. Some toxic elements related to air pollution have carcinogenic affect. The quantification of those elements is important to monitor a level of pollutant contained in the airborne particulate. The aim of this work is to analyze the air particulate sample using instrumental neutron activation analysis and other related technique. Two sampling points of Bandung and Lembang that represent and urban and rural area respectively have been chosen to collect the air particulate sample. The samplings were carried out using Gent Stacked Filter Unit Sampler for 24 hours, and two cellulose filters of 8 μm and 0.45 μm pore size were used. Trace elements in the sample collected were determined using NAA based on a comparative method. Elemental distribution on PM 2.5 and PM 10 fraction of airborne particulate was analyzed, the enrichment factor was calculated using Al as reference elements, and the black carbons contents were determined using FEL Smoke Stain Reflectometer analyzed. The results are presented and discussed. (author)

  17. Particulate air pollution and daily mortality in Detroit.

    Science.gov (United States)

    Schwartz, J

    1991-12-01

    Particulate air pollution has been associated with increased mortality during episodes of high pollution concentrations. The relationship at lower concentrations has been more controversial, as has the relative role of particles and sulfur dioxide. Replication has been difficult because suspended particle concentrations are usually measured only every sixth day in the U.S. This study used concurrent measurements of total suspended particulates (TSP) and airport visibility from every sixth day sampling for 10 years to fit a predictive model for TSP. Predicted daily TSP concentrations were then correlated with daily mortality counts in Poisson regression models controlling for season, weather, time trends, overdispersion, and serial correlation. A significant correlation (P less than 0.0001) was found between predicted TSP and daily mortality. This correlation was independent of sulfur dioxide, but not vice versa. The magnitude of the effect was very similar to results recently reported from Steubenville, Ohio (using actual TSP measurements), with each 100 micrograms/m3 increase in TSP resulting in a 6% increase in mortality. Graphical analysis indicated a dose-response relationship with no evidence of a threshold down to concentrations below half of the National Ambient Air Quality Standards for particulate matter.

  18. Aerotrace. Measurement of particulates from an engine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, C D [DRA, Farnborough (United Kingdom)

    1998-12-31

    The effect of gas turbine operating conditions, inlet temperature, pressure and overall air fuel ratio, on particulate number density has been measured. Particulate number density was found to be proportional to combustor inlet pressure and decrease with increasing combustor inlet temperature. The relationship with air fuel ratio is more complex. The mechanism of particulate loss down sample lines has been elucidated and equations are presented to predict particulate losses for stainless steel and PTFE sample lines. (author) 3 refs.

  19. Aerotrace. Measurement of particulates from an engine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, C.D. [DRA, Farnborough (United Kingdom)

    1997-12-31

    The effect of gas turbine operating conditions, inlet temperature, pressure and overall air fuel ratio, on particulate number density has been measured. Particulate number density was found to be proportional to combustor inlet pressure and decrease with increasing combustor inlet temperature. The relationship with air fuel ratio is more complex. The mechanism of particulate loss down sample lines has been elucidated and equations are presented to predict particulate losses for stainless steel and PTFE sample lines. (author) 3 refs.

  20. A health-based assessment of particulate air pollution in urban areas of Beijing in 2000-2004

    International Nuclear Information System (INIS)

    Zhang Minsi; Song Yu; Cai Xuhui

    2007-01-01

    Particulate air pollution is a serious problem in Beijing. The annual concentration of particulate matter with aerodynamic diameter less than 10 μm (PM 10 ), ranging from 141 to 166 μg m -3 in 2000-2004, could be very harmful to human health. In this paper, we presented the mortality and morbidity effects of PM 10 pollution based on statistical data and the epidemiological exposure-response function. The economic costs to health during the 5 years were estimated to lie between US$1670 and $3655 million annually, accounting for about 6.55% of Beijing's gross domestic product each year. The total costs were apportioned into two parts caused by: the local emissions and long-range transported pollution. The contribution from local emissions dominated the total costs, accounting on average for 3.60% of GDP. However, the contributions from transported pollution cannot be neglected, and the relative percentage to the total costs from the other regions could account for about 45%. An energy policy and effective measures should be proposed to reduce particulate matter, especially PM 2.5 pollution in Beijing to protect public health. The Beijing government also needs to cooperate with the other local governments to reduce high background level of particulate air pollution

  1. Nickel and vanadium in air particulates at Dhahran (Saudi Arabia) during and after the Kuwait oil fires

    Science.gov (United States)

    Sadiq, M.; Mian, A. A.

    April-July 1991. Concentrations of these elements were largely below their proposed limits in the ambient air (for nickel-50 μg m -3, air; for vanadium—1 μg m -3 air). It is, therefore, anticipated that concentrations of nickel and vanadium in the air particulate samples were not a health concern during Kuwait oil fires at Dhahran, Saudi Arabia.

  2. Radiocarbon determination of particulate organic carbon in glacier ice from the Grenzgletscher (Monte Rosa)

    International Nuclear Information System (INIS)

    Steier, P.; Drosg, R.; Kutschera, W.; Wild, E.M.; Fedi, M.; Schock, M.; Wagenbach, D.

    2005-01-01

    Full text: Dating ice cores from cold glaciers via radiocarbon is still an unsolved problem. This work describes our approach towards extraction and AMS radiocarbon dating of the particulate organic carbon (POC) fraction in ice samples at VERA (Vienna Environmental Research Accelerator). First measurements were performed on 1 snow and 11 ice samples from Gorner Glacier and Colle Gnifetti in the Monte Rosa Mountain region (Swiss Alps). The sample masses used were between 0.3 kg and 1.4 kg ice yielding between 18 μg and 307 μg carbon as POC. The carbon contamination introduced during the sample processing varied between 9 μg and 33 μg C and originates mainly from the quartz filters and the rinsing liquids used. Minimum sample sizes for successful graphitization of carbon dioxide in our laboratory have been reduced to less than 10 μg carbon. The background in the graphitization process is approximately 0.5 μg carbon of 40 pMC. Scatter and outliers in the radiocarbon data suggest that presently a single radiocarbon date of glacial POC has limited significance. For the set of 11 ice samples, a calibrated age of 2100 BC to 900 AD (95% confidence level) is obtained. (author)

  3. JV Task 94 - Air Quality V: Mercury, Trace Elements, SO3, and Particulate Matter Conference

    Energy Technology Data Exchange (ETDEWEB)

    Thomas A. Erickson

    2007-01-31

    This final report summarizes the planning, preparation, facilitation and production, and summary of the conference entitled 'Air Quality V: Mercury, Trace Elements, SO{sub 3}, and Particulate Matter,' held September 18-21, 2005, in Arlington, Virginia. The goal of the conference was to build on the discussions of the first four Air Quality Conferences, providing further opportunity for leading representatives of industry, government, research institutions, academia, and environmental organizations to discuss the key interrelationships between policy and science shaping near-term regulations and controls and to assist in moving forward on emerging issues that will lead to acceptable programs and policies to protect human health, the environment, and economic growth. The conference was extremely timely, as it was the last large conference prior to publication of the U.S. Environmental Protection Agency's final regulations for mercury control from coal-fired utilities, and provided a forum to realistically assess the status of mercury controls in relation to the new regulations.

  4. Method of producing radioactive technetium-99M

    International Nuclear Information System (INIS)

    Karageozian, H.L.

    1979-01-01

    A chromatographic process of producing high purity and high yield radioactive Technetium-99m. A solution containing Molybdenum-99m and Technetium-99m is placed on a chromatographic column and eluted with a neutral solvent system comprising an organic solvent and from about 0.1 to less than about 10% of water or from about 1 to less than about 70% of a solvent selected from the group consisting of aliphatic alcohols having 1 to 6 carbon atoms. The eluted solvent system containing the Technetium-99m is then removed leaving the Technetium-99m as a dry, particulate residue

  5. Long-term Trends in Particulate Organic Carbon from a Low-Gradient Autotrophic Watershed

    Science.gov (United States)

    Fox, J.; Ford, W. I., III

    2014-12-01

    Recent insights from low-gradient streams dominated by fine surficial sediments have shown fluvial organic matter dynamics are governed by coupled hydrologic and biotic controls at event to seasonal timescales. Notwithstanding the importance of shorter timescales, quantity and quality of carbon in stream ecosystems at annual and decadal scales is of increased interest in order to understand if stream ecosystems are net stores or sinks of carbon and how stream carbon behaves under dynamic climate conditions. As part of an ongoing study in a low-gradient, agricultural watershed in the Bluegrass Region of Central Kentucky, an eight year dataset of transported particulate organic carbon (POC) was analyzed for the present study. The objective was to investigate if POC dynamics at multi-year timescales are governed by biotic or hydrologic processes. A statistical analysis using Empirical Mode Decomposition was performed on an 8 year dataset of transported sediment carbon, temperature, and log-transformed flowrates at the watershed outlet. Simulations from a previously validated, process-based, organic carbon model were utilized as further verification of drivers. Results from the analysis suggest that a 4 degree Celsius mean annual temperature shift corresponds to a 63% increase in organic carbon content at the main-stem, third order outlet and a 33% increase in organic carbon content at the main-stem inlet. Model and stable isotope results for the 8 year study support that long-term increases in organic carbon concentration are governed by biotic growth and humification of algal biomass in which increasing annual temperatures promote increased organic carbon production, relative to ecosystem respiration. This result contradicts conventional wisdom, suggesting projected warming trends will shift autotrophic freshwater systems to net heterotrophic, which has significant implications for the role of benthic stream ecosystems under changing climate conditions. Future work

  6. Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (South West Pacific)

    Science.gov (United States)

    Tedetti, M.; Marie, L.; Röttgers, R.; Rodier, M.; Van Wambeke, F.; Helias, S.; Caffin, M.; Cornet-Barthaux, V.; Dupouy, C.

    2015-10-01

    In the framework of the VAHINE project, we investigated the spectral characteristics and the variability of dissolved and particulate chromophoric materials throughout a 23 day mesocosm experiment conducted in the South West Pacific at the exit of the New Caledonian coral lagoon (22°29.073 S-166°26.905 E) from 13 January to 4 February 2013. Samples were collected in a mesocosm fertilized with phosphorus at 1, 6 and 12 m depth and in the surrounding waters. Light absorption coefficients of chromophoric dissolved organic matter (CDOM) (ag(λ)), particulate matter (ap(λ)) and CDOM + particulate matter (ag+p(λ)) were measured using a point-source integrating-cavity absorption meter (PSICAM), while fluorescent DOM (FDOM) components were determined from excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC). The evolutions of ag(λ), ap(λ) and ag+p(λ) in the mesocosm were similar to those of total chlorophyll a concentration, Synechococcus spp. and picoeukaryote abundances, bacterial production, particulate organic nitrogen and total organic carbon concentrations, with roughly a decrease from the beginning of the experiment to days 9-10, and an increase from days 9-10 to the end of the experiment. In the surrounding waters, the same trend was observed but the increase was much less pronounced, emphasizing the effect of the phosphorus fertilization on the mesocosm's plankton community. Correlations suggested that both Synechococcus cyanobacteria and heterotrophic bacteria were strongly involved in the production of CDOM and absorption of particulate matter. The increase in phytoplankton activities during the second part of the experiment led to a higher contribution of particulate material in the absorption budget at 442 nm. The three FDOM components identified (tryptophan-, tyrosine- and UVC humic-like fluorophores) did not follow the evolution of CDOM and particulate matter, proving that these were driven by different production

  7. Distribution of dissolved and particulate 226Ra, 210Pb and 210Po in the Bismarck Sea and western equatorial Pacific Ocean

    International Nuclear Information System (INIS)

    Peck, G.A.; Smith, J.D

    2000-01-01

    The distribution of the radionuclides 226 Ra, 210 Pb and 210 Po in the dissolved ( 210 Pb and 210 Po in the particulate (>0.45 μm) phases was measured in the upper 300 m of the Bismarck Sea off the Sepik River and along the equator from 143 deg E to 152 deg E in the western equatorial Pacific Ocean. 210 Pb and 210 Po occurred principally in the dissolved phase with a 210 Po/ 210 Pb ratio 210 Po/ 210 Pb ratios greater than 1.0. Box model calculations yielded an average atmospheric flux of 210 Pb of 4.5 mBq cm -2 year -1 to the ocean surface. The average residence times for dissolved 210 Po and dissolved 210 Pb were 0.27 years and 8.0 years respectively (in the mixed layer) and 1.45 years and 170 years (in the deeper layer). With an average residence time of 0.08 ± 0.03 years, particulate 210 Po varied little between the layers. The difference in 210 Po and 210 Pb residence times reflects the greater particle reactivity of 210 Po. The flux of particulate organic carbon was calculated to be 104 ± 21 mg m -2 day -1 from the upper 100 m and 180 ± 22 mg m -2 day -1 from 100-300 m. Copyright (2000) CSIRO Publishing

  8. Particulate versus non-particulate corticosteroids for transforaminal nerve root blocks. Comparison of outcomes in 494 patients with lumbar radiculopathy

    Energy Technology Data Exchange (ETDEWEB)

    Bensler, Susanne; Sutter, Reto; Pfirrmann, Christian W.A.; Peterson, Cynthia K. [Orthopaedic University Hospital Balgrist, Department of Radiology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland)

    2018-03-15

    We set out to compare outcomes in CT-guided lumbar transforaminal nerve root block patients receiving either particulate or non-particulate corticosteroids. This was a retrospective comparative effectiveness outcomes study on two cohorts of lumbar radiculopathy patients. 321 received particulate and 173 non-particulate corticosteroids at CT-guided transforaminal lumbar nerve root injections. The particulate steroid was used from October 2009 until May 2014 and the non-particulate steroid was used from May 2014. Pain levels were collected at baseline using an 11-point numerical rating scale (NRS) and at 1 day, 1 week and 1 month. Overall 'improvement' was assessed using the Patients' Global Impression of Change (PGIC) at these same time points (primary outcome). The proportions of patients 'improved' were compared between the two groups using the Chi-square test. The NRS change scores were compared using the unpaired t-test. A significantly higher proportion of patients treated with particulate steroids were improved at 1 week (43.2 % vs. 27.7 %, p = 0.001) and at 1 month (44.3 % vs. 33.1 %, p = 0.019). Patients receiving particulate steroids also had significantly higher NRS change scores at 1 week (p = 0.02) and 1 month (p = 0.007). Particulate corticosteroids have significantly better outcomes than non-particulate corticosteroids. (orig.)

  9. Source apportionment of PM10 mass and particulate carbon in the Kathmandu Valley, Nepal

    Science.gov (United States)

    Kim, Bong Mann; Park, Jin-Soo; Kim, Sang-Woo; Kim, Hyunjae; Jeon, Haeun; Cho, Chaeyoon; Kim, Ji-Hyoung; Hong, Seungkyu; Rupakheti, Maheswar; Panday, Arnico K.; Park, Rokjin J.; Hong, Jihyung; Yoon, Soon-Chang

    2015-12-01

    The Kathmandu Valley in Nepal is a bowl-shaped urban basin in the Himalayan foothills with a serious problem of fine particulate air pollution that impacts local health and impairs visibility. Particulate carbon concentrations have reached severe levels that threaten the health of 3.5 million local residents. Moreover, snow and ice on the Himalayan mountains are melting as a result of additional warming due to particulate carbon, especially high black carbon concentrations. To date, the sources of the Valley's particulate carbon and the impacts of different sources on particulate carbon concentrations are not well understood. Thus, before an effective control strategy can be developed, these particulate carbon sources must be identified and quantified. Our study has found that the four primary sources of particulate carbon in the Kathmandu Valley during winter are brick kilns, motor vehicles, fugitive soil dust, and biomass/garbage burning. Their source contributions are quantified using a recently developed new multivariate receptor model SMP. In contrast to other highly polluted areas such as China, secondary contribution is almost negligible in Kathmandu Valley. Brick kilns (40%), motor vehicles (37%) and biomass/garbage burning (22%) have been identified as the major sources of elemental carbon (black carbon) in the Kathmandu Valley during winter, while motor vehicles (47%), biomass/garbage burning (32%), and soil dust (13%) have been identified as the most important sources of organic carbon. Our research indicates that controlling emissions from motor vehicles, brick kilns, biomass/garbage burning, and soil dust is essential for the mitigation of the particulate carbon that threatens public health, impairs visibility, and influences climate warming within and downwind from the Kathmandu Valley. In addition, this paper suggests several useful particulate carbon mitigation methods that can be applied to Kathmandu Valley and other areas in South Asia with

  10. New method to determine the total carbonyl functional group content in extractable particulate organic matter by tandem mass spectrometry.

    Science.gov (United States)

    Dron, J; Zheng, W; Marchand, N; Wortham, H

    2008-08-01

    A functional group analysis method was developed to determine the quantitative content of carbonyl functional groups in atmospheric particulate organic matter (POM) using constant neutral loss scanning-tandem mass spectrometry (CNLS-MS/MS). The neutral loss method consists in monitoring the loss of a neutral fragment produced by the fragmentation of a precursor ion in a collision cell. The only ions detected are the daughter ions resulting from the loss of the neutral fragment under study. Then, scanning the loss of a neutral fragment characteristic of a functional group enables the selective detection of the compounds bearing the chemical function under study within a complex mixture. The selective detection of carbonyl functional groups was achieved after derivatization with pentafluorophenylhydrazine (PFPH) by monitoring the neutral loss of C(6)F(5)N (181 amu), which was characteristic of a large panel of derivatized carbonyl compounds. The method was tested on 25 reference mixtures of different composition, all containing 24 carbonyl compounds at randomly determined concentrations. The repeatability and calibration tests were satisfying as they resulted in a relative standard deviation below 5% and a linear range between 0.01 and 0.65 mM with a calculated detection limit of 0.0035 mM. Also, the relative deviation induced by changing the composition of the mixture while keeping the total concentration of carbonyl functional groups constant was less than 20%. These reliability experiments demonstrate the high robustness of the developed procedure for accurate carbonyl functional group measurement, which was applied to atmospheric POM samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

  11. Relationships between the surface concentration of particulate organic carbon and optical properties in the eastern South Pacific and eastern Atlantic Oceans

    Directory of Open Access Journals (Sweden)

    D. Stramski

    2008-02-01

    Full Text Available We have examined several approaches for estimating the surface concentration of particulate organic carbon, POC, from optical measurements of spectral remote-sensing reflectance, Rrs(λ, using field data collected in tropical and subtropical waters of the eastern South Pacific and eastern Atlantic Oceans. These approaches include a direct empirical relationship between POC and the blue-to-green band ratio of reflectance, RrsB/Rrs(555, and two-step algorithms that consist of relationships linking reflectance to an inherent optical property IOP (beam attenuation or backscattering coefficient and POC to the IOP. We considered two-step empirical algorithms that exclusively include pairs of empirical relationships and two-step hybrid algorithms that consist of semianalytical models and empirical relationships. The surface POC in our data set ranges from about 10 mg m3 within the South Pacific Subtropical Gyre to 270 mg m3 in the Chilean upwelling area, and ancillary data suggest a considerable variation in the characteristics of particulate assemblages in the investigated waters. The POC algorithm based on the direct relationship between POC and RrsB/Rrs(555 promises reasonably good performance in the vast areas of the open ocean covering different provinces from hyperoligotrophic and oligotrophic waters within subtropical gyres to eutrophic coastal upwelling regimes characteristic of eastern ocean boundaries. The best error statistics were found for power function fits to the data of POC vs. Rrs(443/Rrs(555 and POC vs. Rrs(490/Rrs(555. For our data set that includes over 50 data pairs, these relationships are characterized by the mean normalized bias of about 2% and the normalized root mean square error of about 20%. We

  12. Flux dependency of particulate/colloidal fouling in seawater reverse osmosis systems

    KAUST Repository

    Salinas Rodríguez, S. G.

    2012-01-01

    Fouling is the main operational problem in seawater reverse osmosis systems (SWRO). Particulate fouling is traditionally measured through the silt density index (SDI) and through the modified fouling index (MFI). In recent years, ultrafiltration membranes were used successfully at constant flux-MFI-UF-to measure particulate/colloidal fouling potential and tested in sea water applications. Furthermore, constant flux operation allows predicting the rate of fouling in RO systems. The objectives of this study are: (1) to measure the flux effect in MFI-UF with different membranes (100, 30 and 10 kDa) for raw seawater and pre-treated water before reverse osmosis in three different locations; (2) to study the particulate and colloidal fouling potential of seawater in reverse osmosis systems; (3) to project the increase in pressure due to cake resistance in reverse osmosis systems. In this research, flat ultrafiltration membranes (100, 50, 30 and 10 kDa) are used in a con- stant flux filtration mode to test and compare real seawaters from various locations (North and Mediterranean Sea) and from various full scale facilities including different pre-treatments (i.e., ultrafiltration and coagulation + dual media filtration). The operated fluxes range from 350 down to values close to real RO operation, 15l(m2h)-1. After each filtration test, the MFI-UF is calculated to assess the particulate fouling potential. The obtained results showed that: (1) the particulate and colloidal fouling potential is directly proportional to the applied flux during filtration. This proportionality is related to the compression of the cake deposit occurring at high flux values; (2) the higher the flux, the higher the required pressure, the less porous the cake and therefore the higher the specific cake resistance; (3) particulate and colloidal fouling potential of seawater is site specific and is influenced by pre-treatment. © 2012 Desalination Publications. All rights reserved.

  13. Next Generation Non-particulate Dry Nonwoven Pad for Chemical Warfare Agent Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Ramkumar, S S; Love, A; Sata, U R; Koester, C J; Smith, W J; Keating, G A; Hobbs, L; Cox, S B; Lagna, W M; Kendall, R J

    2008-05-01

    New, non-particulate decontamination materials promise to reduce both military and civilian casualties by enabling individuals to decontaminate themselves and their equipment within minutes of exposure to chemical warfare agents or other toxic materials. One of the most promising new materials has been developed using a needlepunching nonwoven process to construct a novel and non-particulate composite fabric of multiple layers, including an inner layer of activated carbon fabric, which is well-suited for the decontamination of both personnel and equipment. This paper describes the development of a composite nonwoven pad and compares efficacy test results for this pad with results from testing other decontamination systems. The efficacy of the dry nonwoven fabric pad was demonstrated specifically for decontamination of the chemical warfare blister agent bis(2-chloroethyl)sulfide (H or sulfur mustard). GC/MS results indicate that the composite fabric was capable of significantly reducing the vapor hazard from mustard liquid absorbed into the nonwoven dry fabric pad. The mustard adsorption efficiency of the nonwoven pad was significantly higher than particulate activated carbon (p=0.041) and was similar to the currently fielded US military M291 kit (p=0.952). The nonwoven pad has several advantages over other materials, especially its non-particulate, yet flexible, construction. This composite fabric was also shown to be chemically compatible with potential toxic and hazardous liquids, which span a range of hydrophilic and hydrophobic chemicals, including a concentrated acid, an organic solvent and a mild oxidant, bleach.

  14. Effects of Particulate Organic Matter Complexation and Photo-Irradiation on the Fate and Toxicity of Mercury(II) in Aqueous Systems

    Science.gov (United States)

    Gelfond, C. E.; Kocar, B. D.; Carrasquillo, A. J.

    2015-12-01

    This project investigates how interactions between mercury (Hg) and particulate organic matter (POM) affect the fate, transport, and toxicity of Hg in the environment. Previous studies have evaluated the coordination of dissolved organic matter (DOM) with Hg, but the coordination of POM with Hg has not been thoroughly addressed. Owing to a high density of reactive functional groups, POM will sorb appreciable quantities of Hg, resulting in a large pool of Hg susceptible to organic matter dependent transformations. Particulate organic carbon is also susceptible photolysis, hence chemical changes induced by irradiation by natural sunlight is also important. Further, photo-reduction of Hg(II) to elemental mercury in the presence of DOM has been observed, yet studies examining this process with Hg(II) complexed to POM are less exhaustive. Here, we illustrate that POM derived from fresh plant detritus is a powerful sorbent of Hg(II), and sorbent properties are altered during POM photolysis. Further, we examine redox transformations of Hg(II), and examine functional groups that contribute to mercury association with POM. Batch sorption isotherms of Hg to dark and irradiated POM from ground Phragmites australis ("common reed") were performed and data was collected using ICP-MS. Coordination of Hg to POM was lower in the irradiated samples, resulting from the decrease in Hg-associated (reduced) sulfur bearing functional groups as measured using X-ray adsorption near-edge spectroscopy (XANES) and extended x-ray adsorption fine structure (EXAFS). Further analysis of the dark and irradiated POM was performed using FT-IR microscopy and STXM to determine changes in distribution and alteration of functional groups responsible for Hg sorption to POM.

  15. Assessment of volatile organic compounds and particulate matter in a dental clinic and health risks to clinic personnel.

    Science.gov (United States)

    Hong, Yu-Jue; Huang, Yen-Ching; Lee, I-Long; Chiang, Che-Ming; Lin, Chitsan; Jeng, Hueiwang Anna

    2015-01-01

    This study was conducted to assess (1) levels of volatile organic compounds (VOCs) and particulate matter (PM) in a dental clinic in southern Taiwan and (2) dental care personnel's health risks associated with due to chronic exposure to VOCs. An automatic, continuous sampling system and a multi-gas monitor were employed to quantify the air pollutants, along with environmental comfort factors, including temperature, CO2, and relative humidity at six sampling sites in the clinic over eight days. Specific VOC compounds were identified and their concentrations were quantified. Both non-carcinogenic and carcinogenic VOC compounds were assessed based on the US Environmental Protection Agency's Principles of Health Risk Assessment in terms of whether those indoor air pollutants increased health risks for the full-time dental care professionals at the clinic. Increased levels of VOCs were recorded during business hours and exceeded limits recommended by the Taiwan Environmental Protection Agency. A total of 68 VOC compounds were identified in the study area. Methylene methacrylate (2.8 ppm) and acetone (0.176 ppm) were the only two non-carcinogenic compounds that posed increased risks for human health, yielding hazard indexes of 16.4 and 4.1, respectively. None of the carcinogenic compounds increased cancer risk. All detected PM10 levels ranged from 20 to 150 μg/m(3), which met the Taiwan EPA and international limits. The average PM10 level during business hours was significantly higher than that during non-business hours (P = 0.04). Improved ventilation capacity in the air conditioning system was recommended to reduce VOCs and PM levels.

  16. Atmospheric particulate mercury at the urban and forest sites in central Poland.

    Science.gov (United States)

    Siudek, Patrycja; Frankowski, Marcin; Siepak, Jerzy

    2016-02-01

    Particulate mercury concentrations were investigated during intensive field campaigns at the urban and forest sites in central Poland, between April 2013 and October 2014. For the first time, quantitative determination of total particulate mercury in coarse (PHg2.2) and fine (PHg0.7) aerosol samples was conducted in Poznań and Jeziory. The concentrations in urban fine and coarse aerosol fractions amounted to mercury concentrations. A strong impact of meteorological conditions (wind velocity, air mass direction, air temperature, and precipitation amount) on particulate mercury concentrations was also observed. In particular, higher variation and concentration range of PHg0.7 and PHg2.2 was reported for wintertime measurements. An increase in atmospheric particulate mercury during the cold season in the study region indicated that coal combustion, i.e., residential and industrial heating, is the main contribution factor for the selected particle size modes. Coarse particulate Hg at the urban site during summer was mainly attributed to anthropogenic sources, with significant contribution from resuspension processes and long-range transport. The highest values of PHg0.7 and PHg2.2 were found during westerly and southerly wind events, reflecting local emission from highly polluted areas. The period from late fall to spring showed that advection from the southern part of Poland was the main factor responsible for elevated Hg concentrations in fine and coarse particles in the investigated region. Moreover, September 2013 could be given as an example of the influence of additional urban activities which occurred approx. 10 m from the sampling site-construction works connected with replacement of the road surface, asphalting, etc. The concentrations of particulate Hg (>600.0 pg m(-3)) were much higher than during the following months when any similar situation did not occur. Our investigations confirmed that Hg in urban aerosol samples was predominantly related to local

  17. Global Particulate Matter Source Apportionment

    Science.gov (United States)

    Lamancusa, C.; Wagstrom, K.

    2017-12-01

    As our global society develops and grows it is necessary to better understand the impacts and nuances of atmospheric chemistry, in particular those associated with atmospheric particulate matter. We have developed a source apportionment scheme for the GEOS-Chem global atmospheric chemical transport model. While these approaches have existed for several years in regional chemical transport models, the Global Particulate Matter Source Apportionment Technology (GPSAT) represents the first incorporation into a global chemical transport model. GPSAT runs in parallel to a standard GEOS-Chem run. GPSAT uses the fact that all molecules of a given species have the same probability of undergoing any given process as a core principle. This allows GPSAT to track many different species using only the flux information provided by GEOS-Chem's many processes. GPSAT accounts for the change in source specific concentrations as a result of aqueous and gas-phase chemistry, horizontal and vertical transport, condensation and evaporation on particulate matter, emissions, and wet and dry deposition. By using fluxes, GPSAT minimizes computational cost by circumventing the computationally costly chemistry and transport solvers. GPSAT will allow researchers to address many pertinent research questions about global particulate matter including the global impact of emissions from different source regions and the climate impacts from different source types and regions. For this first application of GPSAT, we investigate the contribution of the twenty largest urban areas worldwide to global particulate matter concentrations. The species investigated include: ammonium, nitrates, sulfates, and the secondary organic aerosols formed by the oxidation of benzene, isoprene, and terpenes. While GPSAT is not yet publically available, we will incorporate it into a future standard release of GEOS-Chem so that all GEOS-Chem users will have access to this new tool.

  18. Application of Fast Neutron Activity for Analysing Element Content on the Air Particulate

    International Nuclear Information System (INIS)

    Elin Nuraini; Ngasifudin; Sunardi; Elisabeth

    2003-01-01

    The research on application of fast neutron activation analysis for analysing element content on the air particulate has been done. The research about analysis of the particulate matters contained in non industrial traffic territory of Surakarta and full industrial traffic territory of Karanganyar, had been done using Fast Neutron Activation Analysis Method. Fast Neutron Activation Analysis method is one of the element analysis method which it's basic principle causes radioactivity appearance from the samples after being irradiated by neutron. The qualitative analysis method is based on the measuring of specific energy which was radiated by radioactive's nucleus and quantitative analysis method is based on the measuring of the intensity of each peak gamma energy. The qualitative analysis results showed, some element were identified i.e : 51 V ; 200 Pb, 27 Al and 52 Cr. The result showed that Pb level is 2.21 ± 0.09x10 -1 mg/m 3 in non industrial traffic territory of Surakarta and 2.78 ± 0.11x10 -1 mg/m 3 full industrial traffic territory of Karanganyar, this value greater than threshold value according 6.0x10 -2 mg/m 3 . (author)

  19. Impact of short-term preconceptional exposure to particulate air pollution on treatment outcome in couples undergoing in vitro fertilization and embryo transfer (IVF/ET)

    Science.gov (United States)

    Maluf, Mariangela; Czeresnia, Carlos Eduardo; Januário, Daniela Aparecida Nicolosi Foltran; Saldiva, Paulo Hilário Nascimento

    2010-01-01

    Purpose To assess the potential effects of short-term exposure to particulate air pollution during follicular phase on clinical, laboratory, and pregnancy outcomes of women undergoing IVF/ET. Methods Retrospective cohort study of 400 first IVF/ET cycles of women exposed to ambient particulate matter during follicular phase. Particulate matter (PM) was categorized into quartiles (Q1: ≤30.48 µg/m3, Q2: 30.49–42.00 µg/m3, Q3: 42.01–56.72 µg/m3, and Q4: >56.72 µg/m3). Results Clinical, laboratory, or treatment variables were not affected by follicular phase PM exposure periods. Women exposed to Q4 period during the follicular phase of conception cycles had a higher risk of miscarriage (odds ratio, 5.05; 95% confidence interval: 1.04–25.51) when compared to women exposed to Q1–3 periods. Conclusion Our results show an association between brief exposure to high levels of ambient PM during the preconceptional period and early pregnancy loss, although no effect of this exposure on clinical, laboratory, and treatment outcomes was observed. PMID:20405197

  20. Particulate and dissolved spectral absorption on the continental shelf of the southeastern United States

    Science.gov (United States)

    Nelson, James R.; Guarda, Sonia

    1995-05-01

    Visible absorption spectra of particulate and dissolved materials were characterized on the continental shelf off the southeastern United States (the South Atlantic Bight), emphasizing cross-shelf and seasonal variability. A coastal front separates turbid coastal waters from clearer midshelf waters. Spatial and seasonal patterns were evident in absorption coefficients for phytoplankton, detritus, and colored dissolved organic matter (CDOM); spectral shape parameters for CDOM and detritus; and phytoplankton chlorophyll-specific absorption. The magnitude of CDOM absorption reflected seasonal differences in freshwater discharge and the salinity of the midshelf waters. In the spring of 1993 (high discharge), CDOM absorption at 443 nm was >10 times that of total particulate absorption between 12 and 50 km offshore (0.28-0.69 m-1 versus 0.027-0.062 m-1) and up to 10 times the CDOM absorption measured in the previous summer (low discharge). Phytoplankton chlorophyll-specific absorption in the blue increased with distance from shore (from shift in phytoplankton species composition (from predominantly diatoms inshore to a cyanobacteria-dominated assemblage midshelf in summer), pigment packaging, and higher carotenoid:chlorophyll with distance from shore.

  1. [Comparison of atmospheric particulate matter and aerosol optical depth in Beijing City].

    Science.gov (United States)

    Lin, Hai-Feng; Xin, Jin-Yuan; Zhang, Wen-Yu; Wang, Yue-Si; Liu, Zi-Rui; Chen, Chuan-Lei

    2013-03-01

    The pollution of particulate matter was serious in Beijing City from the synchronous observation of particulate matter mass concentration and aerosol optical characteristics in 2009. The annual mean concentrations of PM2.5 and PM10 were (65 +/- 14) microg x m(-3) and (117 +/- 31) microg x m(-3), respectively, which exceeded the national ambient air quality annual standards to be implemented in 2016. There were 35% and 26% days of 2009 that the daily standards were exceeded. There was a significant correlation between fine particulate (PM2.5) and inhalable particle (PM10), with a correlation coefficient (R) of approximately 0.90 (P 500 nm) and Angstrom exponent were (0.55 +/- 0.1) and (1.12 +/- 0.08), respectively. There were significant correlations between PM2.5, PM10 and AOD in the four seasons and the whole year, and the correlation coefficients were greater than or equal to 0.50. Furthermore, the correlation functions and coefficients had seasonal variations. The correlations were more significant in summer and autumn than in spring and winter. The annual correlation could cover up the seasonal systematic differences. The correlations between AOD revised by Mixed Layer Height and PM2.5 PM10 revised by Relative Humidity became stronger, and the exponential correlations were superior to the linear correlations.

  2. Controlling particulate matter under the Clean Air Act: a menu of options

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This document was prepared by STAPPA and ALAPCO to help US state and local air pollution control officials understand the effects of particulate matter (PM) on human health and air quality, the relative contribution of various sources to particulate emissions, and the effectiveness and costs of various approaches - including innovative ones - to minimizing these emissions. The document covers particulate matter with a nominal diameter of 10 microns ({mu}m) or less (PM{sub 10}), including `fine` PM of 2.5 microns or less in diameter (PM{sub 2.5}). Sections cover: the effects of particulate matter on human health; regulatory issues; characterization of particulate matter; emission control strategies for mobile sources (diesel engines, small nonroad engines, alternative fuels etc.), particulates from stationary sources (electric utilities, industry and commercial fuel combustion; mineral products industry, metallurgical industry etc.); particulates from area sources; and market-based strategies for controlling particulate matter. 2 apps.

  3. Fine Particulate Matter Pollution and Hospital Admissions for Respiratory Diseases in Beijing, China.

    Science.gov (United States)

    Xiong, Qiulin; Zhao, Wenji; Gong, Zhaoning; Zhao, Wenhui; Tang, Tao

    2015-09-22

    Fine particulate matter has become the premier air pollutant of Beijing in recent years, enormously impacting the environmental quality of the city and the health of the residents. Fine particles with aerodynamic diameters of 0~0.3 μm, 0.3~0.5 μm, and 0.5~1.0 μm, from the yeasr 2007 to 2012, were monitored, and the hospital data about respiratory diseases during the same period was gathered and calculated. Then the correlation between respiratory health and fine particles was studied by spatial analysis and grey correlation analysis. The results showed that the aerial fine particulate matter pollution was mainly distributed in the Zizhuyuan sub-district office. There was a certain association between respiratory health and fine particles. Outpatients with respiratory system disease in this study area were mostly located in the southeastern regions (Balizhuang sub-district office, Ganjiakou sub-district office, Wanshoulu sub-district office, and Yongdinglu sub-district office) and east-central regions (Zizhuyuan sub-district office and Shuangyushu sub-district office) of the study area. Correspondingly, PM₁ (particulate matter with aerodynamic diameter smaller than 1.0 um) concentrations in these regions were higher than those in any other regions. Grey correlation analysis results showed that the correlation degree of the fine particle concentration with the number of outpatients is high, and the smaller fine particles had more obvious effects on respiratory system disease than larger particles.

  4. Fine Particulate Matter Pollution and Hospital Admissions for Respiratory Diseases in Beijing, China

    Directory of Open Access Journals (Sweden)

    Qiulin Xiong

    2015-09-01

    Full Text Available Fine particulate matter has become the premier air pollutant of Beijing in recent years, enormously impacting the environmental quality of the city and the health of the residents. Fine particles with aerodynamic diameters of 0~0.3 μm, 0.3~0.5 μm, and 0.5~1.0 μm, from the yeasr 2007 to 2012, were monitored, and the hospital data about respiratory diseases during the same period was gathered and calculated. Then the correlation between respiratory health and fine particles was studied by spatial analysis and grey correlation analysis. The results showed that the aerial fine particulate matter pollution was mainly distributed in the Zizhuyuan sub-district office. There was a certain association between respiratory health and fine particles. Outpatients with respiratory system disease in this study area were mostly located in the southeastern regions (Balizhuang sub-district office, Ganjiakou sub-district office, Wanshoulu sub-district office, and Yongdinglu sub-district office and east-central regions (Zizhuyuan sub-district office and Shuangyushu sub-district office of the study area. Correspondingly, PM1 (particulate matter with aerodynamic diameter smaller than 1.0 um concentrations in these regions were higher than those in any other regions. Grey correlation analysis results showed that the correlation degree of the fine particle concentration with the number of outpatients is high, and the smaller fine particles had more obvious effects on respiratory system disease than larger particles.

  5. Determining Inorganic and Organic Carbon.

    Science.gov (United States)

    Koistinen, Jaana; Sjöblom, Mervi; Spilling, Kristian

    2017-11-21

    Carbon is the element which makes up the major fraction of lipids and carbohydrates, which could be used for making biofuel. It is therefore important to provide enough carbon and also follow the flow into particulate organic carbon and potential loss to dissolved organic forms of carbon. Here we present methods for determining dissolved inorganic carbon, dissolved organic carbon, and particulate organic carbon.

  6. The impact of co-combustion of polyethylene plastics and wood in a small residential boiler on emissions of gaseous pollutants, particulate matter, PAHs and 1,3,5- triphenylbenzene.

    Science.gov (United States)

    Tomsej, Tomas; Horak, Jiri; Tomsejova, Sarka; Krpec, Kamil; Klanova, Jana; Dej, Milan; Hopan, Frantisek

    2018-04-01

    The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m/z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m/z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Organic carbon in glacial fjords of Chilean Patagonia

    Science.gov (United States)

    Pantoja, Silvio; Gutiérrez, Marcelo; Tapia, Fabián; Abarzúa, Leslie; Daneri, Giovanni; Reid, Brian; Díez, Beatriz

    2016-04-01

    The Southern Ice Field in Chilean Patagonia is the largest (13,000 km2) temperate ice mass in the Southern hemisphere, yearly transporting ca. 40 km3 of freshwater to fjords. This volume of fresh and cold water likely affects adjacent marine ecosystems by changing circulation, productivity, food web dynamics, and the abundance and distribution of planktonic and benthic organisms. We hypothesize that freshwater-driven availability of inorganic nutrient and transport of organic and inorganic suspended matter, as well as microbes, become a controlling factor for productivity in the fjord associated with the Baker river and Jorge Montt glacier. Both appear to be sources of silicic acid, but not of nitrate and particulate organic carbon, especially during summer, when surface PAR and glacier thawing are maximal. In contrast to Baker River, the Jorge Montt glacier is also a source of dissolved organic carbon towards a proglacial fjord and the Baker Channel, indicating that a thorough chemical description of sources (tidewater glacier and glacial river) is needed. Nitrate in fiord waters reaches ca. 15 μM at 25 m depth with no evidence of mixing up during summer. Stable isotope composition of particulate organic nitrogen reaches values as low as 3 per mil in low-salinity waters near both glacier and river. Nitrogen fixation could be depleting δ15N in organic matter, as suggested by the detection at surface waters of nif H genes belonging to diazotrophs near the Montt glacier. As diazotrophs have also been detected in other cold marine waters (e.g. Baltic Sea, Arctic Ocean) as well as glaciers and polar terrestrial waters, there is certainly a potential for both marine and freshwater microbes to contribute and have a significant impact on the Patagonian N and C budgets. Assessing the impact of freshwater on C and N fluxes and the microbial community structure in Patagonian waters will allow understanding future scenarios of rapid glacier melting. This research was funded

  8. Diagenetic fractionation of carbon isotopes in particulate and dissolved organic matter in sediments from Skan Bay, Alaska

    International Nuclear Information System (INIS)

    Alperin, M.J.; Reeburgh, W.S.

    1991-01-01

    Isotope fractionation during organic matter diagenesis was investigated by measuring detailed depth distributions of stable carbon isotope ratios in sediment particulate organic carbon (POC) and dissolved organic carbon (DOC) reservoirs. The δ 13 C value of the POC shifted systematically from -19 per-thousand at the surface to -21 per-thousand at 10 cm. Significant trends were also apparent in the δ 13 C-DOC profile. Proceeding down-core, DOC became isotopically heavier between 0 and 5 cm and isotopically lighter at greater depths. Two mechanisms could account for the observed down-core shift in δ 13 C-POC: (a) temporal changes in the isotope ratios of deposited organic matter and (b) isotope fractionation associated with diagenesis. The δ 15 C-DOC depth distribution is sensitive to which mechanism controls the isotopic composition of the POC reservoir. A diagenetic model that couples POC and DOC reservoirs was used to discriminate between temporal changes and diagenetic alteration of the POC isotopic composition. The model indicated that observed trends in δ 13 C-POC and δ 13 C-DOC depth distributions are consistent with isotopic fractionation of POC during diagenesis

  9. A meta-analysis of exposure to particulate matter and adverse birth outcomes

    Directory of Open Access Journals (Sweden)

    Dirga Kumar Lamichhane

    2015-11-01

    Full Text Available Objectives The objective of this study was to conduct a systematic review to provide summarized evidence on the association between maternal exposure to particulate air pollution and birth weight (BW and preterm birth (PTB after taking into consideration the potential confounding effect of maternal smoking. Methods We systematically searched all published cohort and case-control studies examining BW and PTB association with particulate matter (PM, less than or equal to 2.5μm and 10.0 μm in diameter, PM2.5 and PM10, respectively from PubMed and Web of Science, from January 1980 to April 2015. We extracted coefficients for continuous BW and odds ratio (OR for PTB from each individual study, and meta-analysis was used to combine the coefficient and OR of individual studies. The methodological quality of individual study was assessed using a standard protocol proposed by Downs and Black. Forty-four studies met the inclusion criteria. Results In random effects meta-analyses, BW as a continuous outcome was negativelyassociated with 10 μg/m3 increase in PM10 (-10.31 g; 95% confidence interval [CI], -13.57 to -3.13 g; I-squared=0%, p=0.947 and PM2.5 (-22.17 g; 95% CI, -37.93 to -6.41 g; I-squared=92.3%, p <0.001 exposure during entire pregnancy, adjusted for maternal smoking. A significantly increased risk of PTB per 10 μg/m3 increase in PM10 (OR, 1.23; 95% CI, 1.04 to 1.41; I-squared=0%, p =0.977 and PM2.5 (OR, 1.14; 95% CI, 1.06 to 1.22; I-squared=92.5%, p <0.001 exposure during entire pregnancy was observed. Effect size of change in BW per 10 μg/m3 increase in PM tended to report stronger associations after adjustment for maternal smoking. Conclusions While this systematic review supports an adverse impact of maternal exposure to particulate air pollution on birth outcomes, variation in effects by exposure period and sources of heterogeneity between studies should be further explored.

  10. Analysis of Phytosterols and N-Alkanols in Atmospheric Organic Particulate Matter Collected in Vancouver During the Pacific 2001 Air Quality Study

    Science.gov (United States)

    Leithead, A.; Li, S.

    2002-12-01

    As part of Pacific 2001, HiVol samples were collected from 5 sites in the Vancouver area. The samples were extracted by accelerated solvent extraction (ACE), concentrated with nitrogen blow down, and separated into fractions by silica gel chromatography. For this portion of the study, an aliquot of one of the polar fraction was derivatized with BSTFA and analyzed by GC-FID and GC-MS. The results for n-alkanols and phytosterols will be reported and discussed. Previous studies have shown that the biogenic components of particulate matter are major constituents of the total organic material in atmospheric samples. Phytosterols are present in wood smoke, epicuticular waxes of many plants and microbial sources. In addition, cholesterol has been proposed as a potential tracer for emissions from cooking. The most abundant phytosterols are cholesterol, campesterol, stigmasterol and beta-sitosterol. It has been hypothesized that the phytosterol signature may be useful in identifying particulate matter from different source areas. The phytosterol signature for these samples will be reported and compared. The n-alkanol CPI and Cmax will also be reported. N-alkanols in atmospheric samples generally show a strong even to odd predominance indicating that their main source in particulate matter is biogenic. The n-alkanol signature for each sampling site will be compared.

  11. Discharge modulates stream metabolism dependence on fine particulate organic carbon in a Mediterranean WWTP-influenced stream

    Science.gov (United States)

    Drummond, J. D.; Bernal, S.; Meredith, W.; Schumer, R.; Martí Roca, E.

    2017-12-01

    Waste water treatment plant (WWTP) effluents constitute point source inputs of fine sediment, nutrients, carbon, and microbes to stream ecosystems. A range of responses to these inputs may be observed in recipient streams, including increases in respiration rates, which augment CO2 emissions to the atmosphere. Yet, little is known about which fractions of organic carbon (OC) contribute the most to stream metabolism in WWTP-influenced streams. Fine particulate OC (POC) represents ca. 40% of the total mass of OC in river networks, and is generally more labile than dissolved OC. Therefore, POC inputs from WWTPs could contribute disproportionately to higher rates of heterotrophic metabolism by stream microbial communities. The aim of this study was to investigate the influence of POC inputs from a WWTP effluent on the metabolism of a Mediterranean stream over a wide range of hydrologic conditions. We hypothesized that POC inputs would have a positive effect on respiration rates, and that the response to POC availability would be larger during low flows when the dilution capacity of the recipient stream is negligible. We focused on the easily resuspended fine sediment near the sediment-water interface (top 3 cm), as this region is a known hot spot for biogeochemical processes. For one year, samples of resuspended sediment were collected bimonthly at 7 sites from 0 to 800 m downstream of the WWTP point source. We measured total POC, organic matter (OM) content (%), and the associated metabolic activity of the resuspended sediment using the resazurin-resorufin smart tracer system as a proxy for aerobic ecosystem respiration. Resuspended sediment showed no difference in total POC over the year, while the OM content increased with decreasing discharge. This result together with the decreasing trend of total POC observed downstream of the point source during autumn after a long dry period, suggests that the WWTP effluent was the main contributor to stream POC. Furthermore

  12. NICKEL SPECIATION OF URBAN PARTICULATE MATTER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin C. Galbreath; Charlene R. Crocker; Carolyn M. Nyberg; Frank E. Huggins; Gerald P. Huffman

    2003-10-01

    A four-step sequential Ni extraction method, summarized in Table AB-1, was evaluated for identifying and quantifying the Ni species occurring in urban total suspended particulate (TSP) matter and fine particulate matter (<10 {micro}m [PM{sub 10}] and <2.5 {micro}m [PM{sub 2.5}] in aerodynamic diameter). The extraction method was originally developed for quantifying soluble, sulfidic, elemental, and oxidic forms of Ni that may occur in industrial atmospheres. X-ray diffraction (XRD) and x-ray absorption fine structure (XAFS) spectroscopy were used to evaluate the Ni species selectivity of the extraction method. Uncertainties in the chemical speciation of Ni in urban PM{sub 10} and PM{sub 2.5} greatly affect inhalation health risk estimates, primarily because of the large variability in acute, chronic, and cancer-causing effects for different Ni compounds.

  13. Origin and Distribution of PAHs in Ambient Particulate Samples at High Mountain Region in Southern China

    Directory of Open Access Journals (Sweden)

    Peng-hui Li

    2015-01-01

    Full Text Available To understand the deposition and transport of PAHs in southern China, a measurement campaign was conducted at a high-elevation site (the summit of Mount Heng, 1269 m A.S.L. from April 4 to May 31, 2009, and a total of 39 total suspended particulate samples were collected for measurement of PAH concentrations. The observed particulate-bound PAHs concentrations ranged from 1.63 to 29.83 ng/m3, with a mean concentration of 6.03 ng/m3. BbF, FLA, and PYR were the predominant compounds. Good correlations were found between individual PAHs and meteorological parameters such as atmospheric pressure, relative humidity, and ambient temperature. The backward trajectory analysis suggested that particulate samples measured at the Mount Heng region were predominantly associated with the air masses from southern China, while the air masses transported over northern and northwestern China had relative higher PAHs concentrations. Based on the diagnostic ratios and factor analysis, vehicular emission, coal combustion, industry emission, and unburned fossil fuels were suggested to be the PAHs sources at Mount Heng site. However, the reactivity and degradation of individual PAHs could influence the results of PAH source profiles, which deserves further investigations in the future.

  14. Inventory of primary particulates emissions; Inventaire des emissions de particules primaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    CITEPA carried out a national inventory on particulate emissions. This report presents the results of this study for a great number of sectors and it covers a larger number of sources than the previous CITEPA inventories on particles and some other inventories carried out by International organisms (TNO, IIASA). In particular, at the present time, fugitive dust emissions for some sources are rarely taken into account in inventories because of poor knowledge and they are still the subject of researches in order to validate the emission results. (author)

  15. Long-term exposure to fine particulate matter and incidence of diabetes in the Danish Nurse Cohort

    DEFF Research Database (Denmark)

    Hansen, Anne Busch; Ravnskjær, Line; Loft, Steffen

    2016-01-01

    AIMS/HYPOTHESIS: It has been suggested that air pollution may increase the risk of type 2 diabetes but data on particulate matter with diameter PM2.5) are inconsistent. We examined the association between long-term exposure to PM2.5 and diabetes incidence. METHODS: We used the Danish Nurse...... Cohort with 28,731 female nurses who at recruitment in 1993 or 1999 reported information on diabetes prevalence and risk factors, and obtained data on incidence of diabetes from National Diabetes Register until 2013. We estimated annual mean concentrations of PM2.5, particulate matter with diameter ... diabetes. We detected a significant positive association between PM2.5 and diabetes incidence (hazard ratio; 95% confidence interval: 1.11; 1.02-1.22 per interquartile range of 3.1μg/m(3)), and weaker associations for PM10 (1.06; 0.98-1.14 per 2.8μg/m(3)), NO2 (1.05; 0.99-1.12 per 7.5μg/m(3)), and NOx (1...

  16. Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway.

    Science.gov (United States)

    Sysalová, Jiřina; Sýkorová, Ivana; Havelcová, Martina; Száková, Jiřina; Trejtnarová, Hana; Kotlík, Bohumil

    2012-10-15

    Urban particulate matter was collected in the most exposed area of Prague, near a busy highway, in order to provide petrographic and chemical characterization useful for health impact assessment in that locality or other applications. Samples were collected from filters of the air conditioning system in two years, 2009 and 2010, and sieved into four grain-size fractions: 0.507-0.119 mm, 0.119-0.063 mm, origin and their morphology were studied by optical and electron microscopy. Organic solvent extracts of the samples were analyzed using gas chromatography to compare the organic compound distribution in fractions. Only slight differences between 2009 and 2010 years are visible. The relatively high extractable part of most investigated elements confirms mobility and potential availability to organisms. The changes can be recognized in the petrographic and organic composition in samples from both years, which were likely the result of various inputs of source materials. Specific organic marker compounds indicate contribution from fossil fuels, plant materials and bacteria. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Association between exposure to particulate matter and hospital admissions for respiratory disease in children

    Science.gov (United States)

    Cesar, Ana Cristina Gobbo; Nascimento, Luiz Fernando C; de Carvalho, João Andrade

    2013-01-01

    The aim of this study was to estimate the association between exposure to particulate matter less than 2.5 microns in diameter and hospitalization for respiratory disease. It was an ecological time series study with daily indicators of hospitalization for respiratory diseases in children up to 10 years old, living in Piracicaba, SP, Southeastern Brazil, between August 1, 2011 and July 31, 2012. A generalized additive Poisson regression model was used. The relative risks were RR = 1.008; 95%CI 1.001;1.016 for lag 1 and RR = 1.009; 95%CI 1.001;1.017 for lag 3. The increment of 10 μg/m3in particulate matter less than 2.5 microns in diameter implies increase in relative risk of between 7.9 and 8.6 percentage points. In conclusion, exposure to particulate matter less than 2.5 microns in diameter was associated with hospitalization for respiratory disease in children. PMID:24626559

  18. Development of Problem Sets for K-12 and Engineering on Pharmaceutical Particulate Systems

    Science.gov (United States)

    Savelski, Mariano J.; Slater, C. Stewart; Del Vecchio, Christopher A.; Kosteleski, Adrian J.; Wilson, Sarah A.

    2010-01-01

    Educational problem sets have been developed on structured organic particulate systems (SOPS) used in pharmaceutical technology. The sets present topics such as particle properties and powder flow and can be integrated into K-12 and college-level curricula. The materials educate students in specific areas of pharmaceutical particulate processing,…

  19. Influence of particulates on phosphorus loading exported from farm drainage during a storm event in the Everglades Agricultural Area

    Science.gov (United States)

    Bhadha, J. H.; Lang, T. A.; Daroub, S. H.

    2015-12-01

    The purpose of this study was to evaluate the influence of particulates on P loading captured during a single storm event. The Everglades Agricultural Area of Florida comprises 280,000 hectares of organic soil farmland artificially drained by ditches, canals and pumps. Phosphorus (P)-enriched suspended particulates in canals are susceptible to transport and can contribute significantly to the overall P loads in drainage water. A settling tank experiment was conducted to capture particulates during tropical storm Isaac in 2012 from three farms approximately 2.4 to 3.6 km2 in size. Farm canal discharge water was collected in a series of two 200 liter settling tanks over a seven-day drainage period, during tropical storm Isaac. Water from the settling tanks was siphoned through Imhoff settling cones, where the particulates were allowed to settle and collected for P-fractionation analyses, and compared to intact sediment cores collected from the bottom of the canals. The discharged particulates contained higher organic matter content (OM), total P, and labile P fractions compared to the canal bottom sediments. Based on the equilibrium P concentrations, surface sediments behave as a source of P to the water column. A seven-day continuous drainage event exported 4.7 to 11.1 metric tons of suspended solids per farm, corresponding to 32 to 63 kg of particulate P being lost to downstream ecosystems. Drainage associated to a single seven-day storm event exported up to 61% of the total annual farm P load. It is evident from this study that short-term, high-intensity storm events can skew annual P loads due to the export of significantly higher particulate matter from farm canals. Exported particulates rich in P can provide a supplemental source of nutrients if captured and replenished back into the farmlands, as a sustainable farming practice.

  20. Evaluation of particulate filtration efficiency of retrofit particulate filters for light duty vehicles

    International Nuclear Information System (INIS)

    Van Asch, R.; Verbeek, R.

    2009-10-01

    In the light of the currently running subsidy programme for particulate filters in the Netherlands, the Dutch ministry of spatial planning and environment (VROM) asked TNO to execute a desk study to evaluate the particulates filtration efficiency of retrofit particulate filters for light duty vehicles (passenger cars and vans). The typical retrofit particulate filters for light duty vehicles are also called 'open' or 'half-open' filters, because a part of the exhaust gas can pass through the particulate filter unfiltered. From design point they are very different from the majority of the factory installed particulate filters, which are also called wall-flow or 'closed' particulate filters. Due to these differences there is a large difference in filtration efficiency. Whereas the 'dosed' particulate filters show a filtration efficiency of larger than 90%, the filtration efficiency of 'open' particulate filters is generally lower (type approval minimum 30%), and strongly dependent on the conditions of use. The objective of the current project was to assess the average filtration efficiency of retrofit (open) particulate fillters on light duty vehicles in real world day to day driving, based on available literature data. Also, the reasons of a possible deviation with the type approval test results (minimum filtration efficiency of 30%) was investigated.

  1. Internal friction and longitudinal modulus behaviour of multiferroic PbZr0.52Ti0.48O3+Ni0.93Co0.02Mn0.05Fe1.95O4-δ particulate composites

    International Nuclear Information System (INIS)

    Ramana, M Venkata; Sreenivasulu, G; Reddy, N Ramamanohar; Kumar, K V Siva; Murty, B S; Murthy, V R K

    2007-01-01

    Multiferroic particulate composites with composition xNi 0.93 Co 0.02 Mn 0.5 Fe 1.95 O 4-δ + (1 - x)PbZr 0.52 Ti 0.48 O 3 where the molar fraction x varies as 0, 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by the conventional ceramic method. The presence of two phases was confirmed by x-ray diffraction and scanning electron microscopy. The temperature variation of the longitudinal modulus (L) and the internal friction (Q -1 ) of these particulate composites at 104.387 kHz was studied in the wide temperature range 30-420 deg. C. The temperature variation of the longitudinal modulus (L) in each composition of these particulate composites showed two abrupt minima. One minimum coincided with the ferroelectric-paraelectric Curie transition temperature (θ E ) and the other with the ferrimagnetic-paramagnetic Curie transition (θ M ) temperature. The internal friction (Q -1 ) measurements also showed two sharp peaks in each composition corresponding to those temperatures where the minima were noticed in the temperature variation of the longitudinal modulus behaviour. The Curie transition temperature of pure ferrite was found to be 560 deg. C. Addition of 10% of ferrite to ferroelectric in a magnetoelectric (ME) composite resulted in a 360 deg. C fall in θ M and with a further increase in ferrite content the θ M variation was found to be very nominal. However, no significant ferroelectric Curie transition temperature shift could be noticed. This behaviour is explained in the light of structural phase transitions in these multiferroic particulate composites. These ME composites were prepared with a view to using them as ME sensors and transducers

  2. Benthic response to the sedimentation of particulate organic matter at the BIOTRANS station, 47°N, 20°W

    Science.gov (United States)

    Pfannkuche, O.

    The benthic response to the sedimentation of particulate organic matter (POM) was investigated during 1985-1990 at 47°N, 20°W (BIOTRANS station). The first noticeable annual sedimentation of phytodetritus, as indicated by chlorophyll a concentrations in the sediment, occurred as early as late April-early May. Maximum amounts were found in June-July. Two different sedimentation pulses to the sea bed are described that demonstrate interannual variation: the occurrence of salp faecal pellets early in the year 1988 and the massive fall out of a plankton bloom in summer 1986, which deposited approximately 15 mmol C m -2. The benthic reaction to POM pulses was quite diverse. The mega-, macro- and meiobenthos showed no change in biomass, whereas bacterial biomass doubled between March and July. This corresponds to a seasonal maximum of total adenylate biomass. The relative abundance of Foraminifera among the meiobenthos increased during the summer. Benthic activity (ATP, ratio ATP/ETSA), as well as in situ sediment community oxygen consumption rates (SCOC), showed distinct seasonal maxima in July-August of 0.75 mmol C m -2 day -1. Based on SCOC and the carbon demand for growth, a benthic carbon consumption of 0.94 mmol C m -2 day -1 was estimated. This represents about 1.1% of spring bloom primary production and 9.6% of the export flux beneath the 150 m layer, measured during the North Atlantic Bloom Experiment. Bacteria and protozoans colonizing the epibenthic phytodetrital layer were responsible for 60-80% of the seasonal increase in SCOC. The strong reaction of the smaller benthic size groups (bacteria, protozoans) to POM pulses stresses their particular importance for sediment-water interface flux rates.

  3. Simulated reaction of formaldehyde and ambient atmospheric particulate matter using a chamber

    Institute of Scientific and Technical Information of China (English)

    Yueyue Chen; Jia Liu; Jing Shang; Tong Zhu

    2017-01-01

    The reaction of HCHO with Beijing winter's real ambient particulate matter (PM) inside a 3.3 m3 Teflon Chamber was conducted in this study.NO2,O3 and H2O gases were removed from the ambient aerosol before entering into the chamber.The decays of HCHO were monitored (acetylacetone spectrophotometry method) during the reactions at different PM number concentrations (Na) and relative humidities (RHs),and the formed particulate formate was detected by IC and XPS techniques.The results showed that when RH was 10%-15%,the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days (with number concentration (Na) < 200,000 particle/L,0.35-22.5 μm) compared to dirty days (Na > 200,000 particle/L,0.35-22.5 μm).When RH increased to 30%-45%,PM can hardly have significant influences on the decay of HCHO.The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM Na and RH conditions.This is a first study related to the "real" ambient PM reacted with HCHO and suggested that in the clean and low RH days,PM could be an effective medium for the conversion of HCHO to formate.

  4. The exposure assessment of airborne particulates matter (PM10 & PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

    Science.gov (United States)

    Mohddin, S. A.; Aminuddin, N. M.

    2014-02-01

    Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM2.5 as one of the crucial parameters is highly recommended.

  5. 99mTc-N4-[Tyr3]Octreotate Versus 99mTc-EDDA/HYNIC-[Tyr3]Octreotide: an intrapatient comparison of two novel Technetium-99m labeled tracers for somatostatin receptor scintigraphy.

    Science.gov (United States)

    Gabriel, Michael; Decristoforo, Clemens; Maina, Theodosia; Nock, Berthold; vonGuggenberg, Elisabeth; Cordopatis, Paul; Moncayo, Roy

    2004-02-01

    Tetraamine-[Tyr3]octreotate (Demotate) is a somatostatin (SST) analogue that can be easily labeled with 99mTc at high specific activities and showed promising preclinical properties for SST receptor scintigraphy. This study reports on the first intra-patient comparison of 99mTc-Demotate and another 99mTc-labeled SST analogue, 99mTc-EDDA/HYNIC-TOC (HYNIC-TOC). Five patients with carcinoid tumors (n = 2) and endocrine pancreatic tumors (n = 3) were investigated with both radiopharmaceuticals. 99mTc-Demotate rapidly visualized somatostatin receptor positive tumors as early as 15 minutes post-injection (p.i.) with maximum tumor uptake and tumor/organ ratios already 1 hour p.i. Organs of predominant physiological uptake were the spleen and the kidneys with no intestinal excretion detectable up to 24 hours. 99mTc-Demotate exhibited faster pharmacokinetic properties compared to HYNIC-TOC. Tumor/organ ratios at equivalent time points were higher or comparable for 99mTc-Demotate in three patients with a matching scan result. Equivocal findings were observed in two patients, i.e. comparable uptake behavior in larger lesions with differences in smaller ones. 99mTc-Demotate is a promising agent for somatostatin receptor scintigraphy providing images of excellent quality as early as 1 hour after injection.

  6. The measurement of the charging properties of fine particulate materials in pneumatic suspension

    International Nuclear Information System (INIS)

    Armour-Chelu, D.I.

    1998-11-01

    50%. The tests were also categorised with the sieved particle size ranges of 90 to 106 μm, 63 to 75 μm, and 45 to 53 μm, but the tests at 30 deg. C were only undertaken with the largest of the sieved ranges. The two other particulate materials that were selected for this programme were aluminium oxide and cane sugar, but these were only tested at 19 deg. C and 45% RH and for the sieved range of 90 to 106 μm. However, this has shown that the system can be applied to a number of particulate materials. The charging tendencies of 3 each of these materials has been observed at suspension densities of 1 to 50 mg/m 3 and at superficial conveying air velocities of 16 to 36 m/s. The results have been found to be repeatable and the analysis of this data has led to a technique for estimating tile suspension density for a limited range of flow conditions. (author)

  7. Long-term trend of haze pollution and impact of particulate matter in the Yangtze River Delta, China

    International Nuclear Information System (INIS)

    Cheng, Zhen; Wang, Shuxiao; Jiang, Jingkun; Fu, Qingyan; Chen, Changhong; Xu, Bingye; Yu, Jianqiao; Fu, Xiao; Hao, Jiming

    2013-01-01

    Haze pollution caused by heavy particulate matter (PM) loading brings significant damage in eastern China. Long-term monitoring from 1980 to 2011 and 1-year field measurement in 2011–2012 are used for investigating visibility variation and the impact of PM pollution for the Yangtze River Delta (YRD). It was found that visual range in the YRD endured a sharp reduction from 13.2 km to 10.5 km during 1980–2000. Average mass extinction efficiency (MEE) for inhalable PM (PM 10 ) is 2.25 m 2 /g in 2001–2011, and extinction coefficient due to PM 10 is 207 Mm −1 , accounting for 36.2% of total extinction coefficient. MEE of PM 2.5 and PM 2.5–10 are 4.08 m 2 /g and 0.58 m 2 /g, respectively. Extinction coefficient due to PM 2.5 and PM 2.5–10 is 198 Mm −1 (39.6%) and 20 Mm −1 (4.0%) in 2011–2012. Maximum daily concentration of PM 10 and PM 2.5 is estimated to be 63 μg/m 3 (RH: 73%) and 38 μg/m 3 (RH: 70%) to keep visual range above 10 km. Fine particulate matter is the key factor for haze pollution improvement in the YRD area. -- Highlights: •Long-term visual range variation and its causes in the Yangtze River Delta are analyzed. •Quantitative contribution of particulate matter to haze pollution is estimated. •Mass extinction efficiency of PM 10 , PM 2.5 , and PM 2.5–10 is estimated. -- The long-term variation of haze pollution in the YRD and its cause is investigated and the quantitative contribution of particulate matter to haze pollution is estimated

  8. Casting of particulate Al-base composites

    International Nuclear Information System (INIS)

    Moustafa, S.F.

    1997-01-01

    A molten Al-4 wt.% Cu as well as a Al-13 wt.% Si alloy have been mixed mechanically with particulate of SiC, Al 2 O 3 , or graphite. After the completion of mixing, each mixture was poured into a permanent mould to solidify. To overcome the problem of non-wettability that exists between the investigated particulate and the molten aluminum alloys the particulate was chemically treated by impregnation in a solution containing Na + ions. The loading of SiC or Al 2 O 3 particulate in the produced composites can be as high as 40 wt.%, and for graphite particles it can be 20 wt.%. The mixing time required to introduce and distribute the investigated particles into the molten matrix was as low as five minutes to recluce chemical reactions at the interfaces between them. Processing details and parameters controlling this technique are described. Metallographic examinations as well as tensile tests were carried out to characterize the microstructure, the distribution of the particles and the strength of these composites. The results display that the composites made by this technique have good microstructure and tensile properties. (orig.)

  9. Monitoring of PM10 and PM2.5 around primary particulate anthropogenic emission sources

    Science.gov (United States)

    Querol, Xavier; Alastuey, Andrés; Rodriguez, Sergio; Plana, Felicià; Mantilla, Enrique; Ruiz, Carmen R.

    Investigations on the monitoring of ambient air levels of atmospheric particulates were developed around a large source of primary anthropogenic particulate emissions: the industrial ceramic area in the province of Castelló (Eastern Spain). Although these primary particulate emissions have a coarse grain-size distribution, the atmospheric transport dominated by the breeze circulation accounts for a grain-size segregation, which results in ambient air particles occurring mainly in the 2.5-10 μm range. The chemical composition of the ceramic particulate emissions is very similar to the crustal end-member but the use of high Al, Ti and Fe as tracer elements as well as a peculiar grain-size distribution in the insoluble major phases allow us to identify the ceramic input in the bulk particulate matter. PM2.5 instead of PM10 monitoring may avoid the interference of crustal particles without a major reduction in the secondary anthropogenic load, with the exception of nitrate. However, a methodology based in PM2.5 measurement alone is not adequate for monitoring the impact of primary particulate emissions (such as ceramic emissions) on air quality, since the major ambient air particles derived from these emissions are mainly in the range of 2.5-10 μm. Consequently, in areas characterised by major secondary particulate emissions, PM2.5 monitoring should detect anthropogenic particulate pollutants without crustal particulate interference, whereas PM10 measurements should be used in areas with major primary anthropogenic particulate emissions.

  10. River Export of Dissolved and Particulate Organic Carbon from Permafrost and Peat Deposits across the Siberian Arctic

    Science.gov (United States)

    Wild, B.; Andersson, A.; Bröder, L.; Vonk, J.; Hugelius, G.; McClelland, J. W.; Raymond, P. A.; Gustafsson, O.

    2017-12-01

    Permafrost and peat deposits of northern high latitudes store more than 1300 Pg of organic carbon. This carbon has been preserved for thousands of years by cold and moist conditions, but is now increasingly mobilized as temperatures rise. While part will be degraded to CO2 and CH4 and amplify global warming, part will be exported by rivers to the Arctic Ocean where it can be degraded or re-buried by sedimentation. We here use the four large Siberian rivers Ob, Yenisey, Lena, and Kolyma as natural integrators of carbon mobilization in their catchments. We apply isotope based source apportionments and Markov Chain Monte Carlo Simulations to quantify contributions of organic carbon from permafrost and peat deposits to organic carbon exported by these rivers. More specifically, we compare the 14C signatures of dissolved and particulate organic carbon (DOC, POC) sampled close to the river mouths with those of five potential carbon sources; (1) recent aquatic and (2) terrestrial primary production, (3) the active layer of permafrost soils, (4) deep Holocene deposits (including thermokarst and peat deposits) and (5) Ice Complex Deposits. 14C signatures of these endmembers were constrained based on extensive literature review. We estimate that the four rivers together exported 2.4-4.5 Tg organic carbon from permafrost and peat deposits per year. While total organic carbon export was dominated by DOC (90%), the export of organic carbon from permafrost and peat deposits was more equally distributed between DOC (56%) and POC (44%). Recent models predict that ca. 200 Pg carbon will be lost as CO2 or CH4 by 2100 (RCP8.5) from the circumarctic permafrost area, of which roughly a quarter is drained by the Ob, Yenisey, Lena, and Kolyma rivers. Our comparatively low estimates of river carbon export thus suggest limited transfer of organic carbon from permafrost and peat deposits to high latitude rivers, or its rapid degradation within rivers. Our findings highlight the importance

  11. Characterization of Fine Particulate Matter in Sharjah, United Arab Emirates Using Complementary Experimental Techniques

    Directory of Open Access Journals (Sweden)

    Nasser M. Hamdan

    2018-04-01

    Full Text Available Airborne particulate matter (PM pollutants were sampled from an urban background site in Sharjah, United Arab Emirates. The fine fraction (PM2.5 (particulates with aerodynamic diameters of less than 2.5 μm was collected on 47-mm Teflon filters and analyzed using a combined set of non-destructive techniques in order to provide better understanding of the sources of pollutants and their interaction during transport in the atmosphere. These techniques included gravimetric analysis, equivalent black carbon (EBC, X-ray fluorescence, scanning electron microscopy, and X-ray diffraction. Generally, the PM2.5 concentrations are within the limits set by the World Health Organization (WHO and the United States (US Environmental Protection Agency. The EBC content is in the range of 10–12% of the total PM concentration (2–4 µg m−3, while S (as ammonium sulfate, Ca (as calcite, gypsum, and calcium carbonate, Si (as quartz, Fe, and Al were the major sources of PM pollution. EBC, ammonium sulfate, Zn, V, and Mn originate from anthropogenic sources such as fossil fuel burning, traffic, and industrial emissions. Natural elements such as Ca, Fe, Al, Si, and Ti are due to natural sources such as crustal materials (enhanced during dust episodes and sea salts. The average contribution of natural sources in the total PM2.5 mass concentration over the sampling period is about 40%, and the contribution of the secondary inorganic compounds is about 27% (mainly ammonium sulfate in our case. The remaining 22% is assumed to be secondary organic compounds.

  12. Crude glycerol combustion: Particulate, acrolein, and other volatile organic emissions

    KAUST Repository

    Steinmetz, Scott

    2013-01-01

    Crude glycerol is an abundant by-product of biodiesel production. As volumes of this potential waste grow, there is increasing interest in developing new value added uses. One possible use, as a boiler fuel for process heating, offers added advantages of energy integration and fossil fuel substitution. However, challenges to the use of crude glycerol as a boiler fuel include its low energy density, high viscosity, and high autoignition temperature. We have previously shown that a refractory-lined, high swirl burner can overcome challenges related to flame ignition and stability. However, critical issues related to ash behavior and the possible formation of acrolein remained. The work presented here indicates that the presence of dissolved catalysts used during the esterification and transesterification processes results in extremely large amounts of inorganic species in the crude glycerol. For the fuels examined here, the result is a submicron fly ash comprised primarily of sodium carbonates, phosphates, and sulfates. These particles report to a well-developed accumulation mode (0.3-0.7 μm diameter), indicating extensive ash vaporization and particle formation via nucleation, condensation, and coagulation. Particle mass emissions were between 2 and 4 g/m3. These results indicate that glycerol containing soluble catalyst is not suitable as a boiler fuel. Fortunately, process improvements are currently addressing this issue. Additionally, acrolein is of concern due to its toxicity, and is known to be formed from the low temperature thermal decomposition of glycerol. Currently, there is no known reliable method for measuring acrolein in sources. Acrolein and emissions of other volatile organic compounds were characterized through the use of a SUMMA canister-based sampling method followed by GC-MS analysis designed for ambient measurements. Results indicate crude glycerol combustion produces relatively small amounts of acrolein (∼15 ppbv) and other volatile organic

  13. Distribution of six radionuclides between soluble and particulate phase at the sea-freshwater interface

    International Nuclear Information System (INIS)

    Peres, J.M.

    1984-01-01

    The distribution of the soluble and particulate phases of radionuclides has been studied in water samples of various salinities (0 per mill; 3.8 per mill; 7.6 per mill; 15.2 per mill; 22.8 per mill; 30.4 per mill; 34 per mill). Cesium 137, cobalt 60, manganese 54, zinc 65, chromium 51 and sodium 22 were investigated. The results are expressed as retention percentages or distribution coefficients (Kd). Increased salinities resulted in decreased retention rates varying with the radionuclides; this appeared with the lowest salinities, and the evolution was small beyond 7 per mill. Other parameters were considered beside salinity, viz.: the suspended matter characteristics (mineralogy, particle size distribution); particulate load of water; organic content, whether associated to the soluble or particulate phase; physico-chemical forms of the radionuclides. To determine the particle size spectra of the suspended matter in the experimental samples, a laser granulometer was used [fr

  14. Method and apparatus for removing volatile hydrocarbons from particulate soils

    International Nuclear Information System (INIS)

    Mendenhall, R.L.

    1992-01-01

    This patent describes an apparatus for heating solid particulate mineral compositions. It comprises: a counterflow ratable drum having a first end and an opposite second end, a first portion of the drum extending from the first end for a first length and having a first diameter along the first length, and a second portion of the drum secured to and extending from the first portion to the second end for a second length and having a second diameter along the second length, the second diameter being less than the first diameter, a burner adjacent the first end for introducing and directing hot gases of combustion into the first portion of the drum toward the second end, means for introducing particulate composition into the drum at the second end, means for directing the particulate composition along the drum from the second end toward the first end, and means for recovering composition at the first end, means for removing a gaseous mixture of organic volatiles, gases of combustion and fine particles of the particulate composition adjacent the second drum end, means for separating fine particles of the particulate composition from the gaseous mixture, and means for returning the separated fine particulate composition particles to the first portion of the drum

  15. Exposure of miners to diesel exhaust particulates in underground nonmetal mines.

    Science.gov (United States)

    Cohen, H J; Borak, J; Hall, T; Sirianni, G; Chemerynski, S

    2002-01-01

    A study was initiated to examine worker exposures in seven underground nonmetal mines and to examine the precision of the National Institute for Occupational Safety and Health (NIOSH) 5040 sampling and analytical method for diesel exhaust that has recently been adopted for compliance monitoring by the Mine Safety and Health Administration (MSHA). Approximately 1000 air samples using cyclones were taken on workers and in areas throughout the mines. Results indicated that worker exposures were consistently above the MSHA final limit of 160 micrograms/m3 (time-weighted average; TWA) for total carbon as determined by the NIOSH 5040 method and greater than the proposed American Conference of Governmental Industrial Hygienists TLV limit of 20 micrograms/m3 (TWA) for elemental carbon. A number of difficulties were documented when sampling for diesel exhaust using organic carbon: high and variable blank values from filters, a high variability (+/- 20%) from duplicate punches from the same sampling filter, a consistent positive interference (+26%) when open-faced monitors were sampled side-by-side with cyclones, poor correlation (r 2 = 0.38) to elemental carbon levels, and an interference from limestone that could not be adequately corrected by acid-washing of filters. The sampling and analytical precision (relative standard deviation) was approximately 11% for elemental carbon, 17% for organic carbon, and 11% for total carbon. An hypothesis is presented and supported with data that gaseous organic carbon constituents of diesel exhaust adsorb onto not only the submicron elemental carbon particles found in diesel exhaust, but also mining ore dusts. Such mining dusts are mostly nonrespirable and should not be considered equivalent to submicron diesel particulates in their potential for adverse pulmonary effects. It is recommended that size-selective sampling be employed, rather than open-faced monitoring, when using the NIOSH 5040 method.

  16. Particulate organic matter composition in a semi-enclosed Periantarctic system: the Straits of Magellan

    Directory of Open Access Journals (Sweden)

    M. Fabiano

    1999-12-01

    Full Text Available The elemental and biochemical composition of particulate organic matter (POM was investigated in the Straits of Magellan during February-March 1991. Twenty-two stations were selected in order to identify different areas of the Magellan ecosystem from a trophic point of view. The Strait of Magellan can be divided into three subsystems characterized by different hydrological and geomorphological conditions. Seston concentrations were mostly constrained by physical events, particularly the influence of oceanic and land run-off water inputs and the strong vertical mixing and resuspension events. POM composition displayed quali-quantitative differences between the three areas. In the first subsystem, influenced by Pacific waters, the low seston and POM concentrations and the high POC/Chl-a ratio values indicated the general predominance of the detrital and heterotrophic fractions. In the second subsystem, characterized by superficial stratification, higher seston and organic matter concentrations and lower values of POC/Chl-a ratio were found, indicating that this subsystem was influenced by an active autotrophic component. Shallow waters with intense tidal regime and strong vertical mixing characterized the third subsystem, connected to the Atlantic Ocean, which displayed an increasing importance of the inorganic fraction (values of the POC/TSM ratio lower than in the other systems. Moreover, the third subsystem showed higher values of the RNA/DNA ratio, possibly indicating that resuspension events may enhance the metabolic state of the organic particles mainly dominated by heterotrophic components.

  17. Particulate emission factor: A case study of a palm oil mill boiler

    International Nuclear Information System (INIS)

    Chong, W.C.; Rashid, M.; Ramli, M.; Zainura, Z.N.; NorRuwaida, J.

    2010-01-01

    A study to investigate the particulate emission from a boiler of a palm oil mill plant equipped with a multi-cyclones particulate arrest or was performed and reported in this paper. The particulate emission concentration was measured at the outlet of a 8 mt/ hr capacity water-tube typed boiler of a palm oil mill plant processing 27mt/ hr of fresh fruit bunch (FFB). The particulate sample was collected iso-kinetically using the USEPA method 5 sampling train through a sampling port made at the duct of the exiting flue gas between the boiler and a multi-cyclones unit. Results showed that the particulate emission rates exiting the boiler varied from 0.09 to 0.60 g/s with an average of 0.29 + 0.18 g/ s. While the average particulate emission concentration exiting the boiler was 12.1 + 7.36 g/ Nm 3 (corrected to 7 % oxygen concentration), ranging from 3.62 to 25.3 g/ Nm 3 (at 7 % O 2 ) of the flue gas during the measurement. Based on the 27 mt/ hr FFB processed and the capacity of the boiler of 8mt steam/ hr, the calculated particulate emission factor was 39 g particulate/ mt FFB processed or 131 g particulate/ mt boiler capacity, respectively. In addition, based on the finding and in order to comply with the emission limits of 0.4 g/ Nm 3 , the collection efficiency of any given particulate emission pollution control system to consider for the mill will be from 87 to 98 %, which is not easily achievable with the existing multi-cyclones unit. A considerable amount of efforts are still needed pertaining to the particulate emission control problem in the industry. (author)

  18. Particulate face masks for protection against airborne pathogens - one size does not fit all: an observational study.

    Science.gov (United States)

    Winter, Susan; Thomas, Jane H; Stephens, Dianne P; Davis, Joshua S

    2010-03-01

    To determine the proportion of hospital staff who pass fit tests with each of three commonly used particulate face masks, and factors influencing preference and fit test results. Observational study. 50 healthy hospital staff volunteers in an 18-bed general intensive care unit in an Australian teaching hospital. Participants were administered a questionnaire about mask use and their preferred mask and underwent qualitative fit-testing with each of three different particulate masks: Kimberly-Clark Tecnol FluidShield N95 particulate filter respirator (KC), 3M Flat Fold 9320 particulate respirator and 3M 8822 particulate respirator with exhalation valve. Participants who failed fittesting were trained in correct mask donning, and fittesting was repeated. Proportion of participants who passed the fit test for each mask and the effect of training. The proportion of participants who passed a fit test was low for all three masks tested (KC, 16%; flat fold, 28%; and valved, 34%). Rates improved after training: the first mask tested fitted in 18% of participants pre-training and 40% post-training (P = 0.02). None of the masks fitted for 28% of participants. There were no significant predictors of fit-test results. A large proportion of individuals failed a fit test with any given mask, and we were not able to identify any factors that predicted mask fit in individuals. Training on mask use improved the rates of adequate fit. Hospitals should carry a range of P2 masks, and should conduct systematic P2 mask training and fit-testing programs for all staff potentially exposed to airborne pathogens.

  19. The exposure assessment of airborne particulates matter (PM10 and PM2.5) towards building occupants: A case study at KL Sentral, Kuala Lumpur, Malaysia

    International Nuclear Information System (INIS)

    Mohddin, S A; Aminuddin, N M

    2014-01-01

    Airborne particulates have been recognized as a crucial pollutant of indoor air. These pollutants can contribute towards poor indoor air quality (IAQ), which may affect human health in immediate or long term. This study aims to determine the level of IAQ and the effects of particulate towards occupants of office buildings (the office buildings selected for the case study are SSM, KTMB and MRCB at KL Sentral). The objectives of study are (i) to measure the level of airborne particulates that contribute to the IAQ during working hours, (ii) to compare the level of airborne particulates with the existing guidelines and standards of IAQ in Malaysia and other Asian countries and (iii) to assess the symptoms associated with airborne particulates among the building occupants, which were achieved through primary data collection (case study or site survey, structured interview and questionnaire survey) and supported by literature reviews. The results showed that the mass concentration level of airborne particulates within the areas has exceeded the allowable limit of 0.15mg/m 3 by IAQ Code of Practice, 2005 of the Department of Safety and Health (DOSH), Malaysia and 0.05mg/m 3 by the Department of Environmental (DOE) (outdoor) of 8 hours continuous sampling. Based on the findings, the highest mass concentration values measured is 2.581 mg/m 3 at lobby of SSM building which is the highest recorded 17 times higher from the maximum limit recommended by DOSH than the others. This is due to the nearby construction works and the high numbers of particulates are generated from various types of vehicles for transportation surrounding KL Sentral. Therefore, the development of Malaysian Ambient Air Quality Guidelines on PM 2.5 as one of the crucial parameters is highly recommended

  20. Dynamics of coarse particulate matter in the turbidity maximum zone of the Gironde Estuary

    Science.gov (United States)

    Fuentes-Cid, Ana; Etcheber, Henri; Schmidt, Sabine; Abril, Gwenaël; De-Oliveira, Eric; Lepage, Mario; Sottolichio, Aldo

    2014-01-01

    There is a lack of studies devoted to coarse particulate matter (CPM) in estuaries, although this fraction can disturb activities that filter large volumes of water, such as industrial or fishery activities. In the macrotidal and highly-turbid Gironde Estuary, a monthly sampling of CPM was performed in 2011 and 2013 at two stations in the Turbidity Maximum Zone (TMZ) to understand its seasonal, tidal and hydrological dynamics. Regardless of the season and station, low quantities of CPM (few g m-3) were observed in comparison with suspended particulate matter (several 103 g m-3). The highest concentrations were consistently recorded in bottom waters and at the upstream station. Whereas there is no clear link between the CPM present in the column water and spring or neap tides, an increase in the CPM size has been identified at the two stations after a flood event, fact potentially critical regarding filtering functioning of estuarine activities.

  1. Comparison of particulate matter exposure estimates in young children from personal sampling equipment and a robotic sampler.

    Science.gov (United States)

    Sagona, Jessica A; Shalat, Stuart L; Wang, Zuocheng; Ramagopal, Maya; Black, Kathleen; Hernandez, Marta; Mainelis, Gediminas

    2017-05-01

    Accurate characterization of particulate matter (PM) exposure in young children is difficult, because personal samplers are often too heavy, bulky or impractical to be used. The Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler was developed to help address this problem. In this study, we measured inhalable PM exposures in 2-year-olds via a lightweight personal sampler worn in a small backpack and evaluated the use of a robotic sampler with an identical sampling train for estimating PM exposure in this age group. PM mass concentrations measured by the personal sampler ranged from 100 to almost 1,200 μg/m 3 , with a median value of 331 μg/m 3 . PM concentrations measured by PIPER were considerably lower, ranging from 14 to 513 μg/m 3 with a median value of 56 μg/m 3 . Floor cleaning habits and activity patterns of the 2-year-olds varied widely by home; vigorous play and recent floor cleaning were most associated with higher personal exposure. Our findings highlight the need for additional characterization of children's activity patterns and their effect on personal exposures.

  2. A study of bacteria, fungi and biomass in particulate matter in ambient air of Khorramabad during summer and autumn 2012

    Directory of Open Access Journals (Sweden)

    hatam Godini

    2015-05-01

    Full Text Available Introduction: Particulate matter refers to the combination of atmospheric pollutants that a portion of this particulate is bioaerosol. The aim of this study was the evaluation of bacteria, fungi and biomass in particulate matter in ambient air of Khorramabad during summer and autumn 2012. Materials and Methods: This study was a cross sectional study that conducted in Khorramabad city during summer and fall 2012. Sampling has been done via high-volume sampler. The special cultures were used for cultivation and determination of fungal and Heterotrophic Plate Count (HPC (and Bradford method were used to determine bacteria and protein as biomass indicator, respectively. Relationship between these variables with metrological parameters was evaluated too. Results: The highest PM10 in July (257.18 µg/m3 and lowest in September (92.45 µg/m3 had been recorded. The highest amount of bacteria and fungi were measured as monthly in November (605 No/m3 and December (120 No/m3, respectively. The highest of protein concentration was measured in August, September and December (27-30 µg/m3. With the increase in PM10, biomass concentration in the air showed a meaningful increase. Conclusion: Biomass concentration in the air increased with increasing PM10 but it had no significant effect on the concentration of bacteria and fungi in the air. Meteorological factors such as temperature, humidity, wind speed, solar radiation and the amount of exposure time had a significant impact on bioaerosol concentrations in the air.

  3. Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean

    Science.gov (United States)

    Druffel, E. R. M.; Bauer, J. E.; Griffin, S.

    2005-03-01

    We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC Δ14C results revealed postbomb carbon in river and ocean waters, with slightly higher values at the river mouth. The low DIC δ13C signature of the river end-member (-11‰) demonstrates that about half of the DIC originated from the remineralization of terrestrially derived organic matter. A linear relationship between DIC and salinity indicates that DIC was mixed nearly conservatively in the transition zone from the river mouth to the open ocean, though there was a small amount (≤10%) of organic matter remineralization in the mesohaline region. The POC Δ14C values in the river mouth were markedly lower than those values from the western Amazon region (Hedges et al., 1986). We conclude that the dominant source of POC near the river mouth and in the inner Amazon plume during November 1991 was aged, resuspended material of significant terrestrial character derived from shelf sediments, while the outer plume contained mainly marine-derived POC.

  4. Impact of fugitive sources and meteorological parameters on vertical distribution of particulate matter over the industrial agglomeration.

    Science.gov (United States)

    Štrbová, Kristína; Raclavská, Helena; Bílek, Jiří

    2017-12-01

    The aim of the study was to characterize vertical distribution of particulate matter, in an area well known by highest air pollution levels in Europe. A balloon filled with helium with measuring instrumentation was used for vertical observation of air pollution over the fugitive sources in Moravian-Silesian metropolitan area during spring and summer. Synchronously, selected meteorological parameters were recorded together with particulate matter for exploration its relationship with particulate matter. Concentrations of particulate matter in the vertical profile were significantly higher in the spring than in the summer. Significant effect of fugitive sources was observed up to the altitude ∼255 m (∼45 m above ground) in both seasons. The presence of inversion layer was observed at the altitude ∼350 m (120-135 m above ground) at locations with major source traffic load. Both particulate matter concentrations and number of particles for the selected particle sizes decreased with increasing height. Strong correlation of particulate matter with meteorological parameters was not observed. The study represents the first attempt to assess the vertical profile over the fugitive emission sources - old environmental burdens in industrial region. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Particulate air pollution and mortality in a cohort of Chinese men

    International Nuclear Information System (INIS)

    Zhou, Maigeng; Liu, Yunning; Wang, Lijun; Kuang, Xingya; Xu, Xiaohui; Kan, Haidong

    2014-01-01

    Few prior cohort studies exist in developing countries examining the association of ambient particulate matter (PM) with mortality. We examined the association of particulate air pollution with mortality in a prospective cohort study of 71,431 middle-aged Chinese men. Baseline data were obtained during 1990–1991. The follow-up evaluation was completed in January, 2006. Annual average PM exposure between 1990 and 2005, including TSP and PM 10 , were estimated by linking fixed-site monitoring data with residential communities. We found significant associations between PM 10 and mortality from cardiopulmonary diseases; each 10 μg/m 3 PM 10 was associated with a 1.6% (95%CI: 0.7%, 2.6%), 1.8% (95%CI: 0.8%, 2.9%) and 1.7% (95%CI: 0.3%, 3.2%) increased risk of total, cardiovascular and respiratory mortality, respectively. For TSP, we observed significant associations only for cardiovascular morality. These data contribute to the scientific literature on long-term effects of particulate air pollution for high exposure settings typical in developing countries. -- Highlights: • There have been few air pollution cohort studies in developing countries. • PM 10 was associated with increased cardiorespiratory mortality in 71,431 Chinese men. • PM was not significantly associated with lung cancer mortality. -- PM 10 was associated with increased cardiorespiratory mortality in a cohort of 71,431 Chinese men

  6. Wear behavior of A356/M{sub 7}C{sub 3} and A356/SiC particulate metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Turhan, H. [Univ. of Firat, Dept. of Metallurgy, Elazig (Turkey); Yilmaz, O. [Univ. of Firat, Dept. of Metallurgical Engineering, Elazig (Turkey)

    2002-06-01

    The stability of M{sub 7}C{sub 3} carbides as reinforcement for A356 materials for tribological applications has been investigated. For this purpose, A356/M{sub 7}C{sub 3}, A356/SiC and A356/M{sub 7}C{sub 3}/SiC composites were prepared by powder metallurgy and tested at room temperature against SAE 4620 steel ring and AISI 304 stainless steel counterfaces under loads of 10 - 150 N. For comparison, also unreinforced A356 specimens were processed and tested under the same conditions. The tribological behavior was evaluated by microstructural examination of the wear-effected zones and by weight loss measurements of the specimens and counterfaces. The wear behavior of A356/M{sub 7}C{sub 3} composite gave an excellent result as function of the applied load because the M{sub 7}C{sub 3} particles act as load-bearing elements due to their excellent bonding to the Al matrix, and their interfaces withtood the wear stresses even at the highest applied load. Moreover, the M{sub 7}C{sub 3} particles limited the incorporation of wear debris into the Al matrix and reduced the wear damage occasioned to the steel counterfaces compared to that of A356 Al alloy. (orig.)

  7. Air emission in France. Metropolitan area particulate matter; Emissions dans l'air en France. Metropole poussieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    Substances and index currently in survey are: Particulate matter: Total suspended particulates (TSP), Fine particulates with an equivalent aerodynamic diameter less than 10 {mu}m (PM{sub 10}), 2.5 {mu}m (PM{sub 2.5}) and 1.0 {mu}m (PM{sub 1.0}). Density ratios relating to population, area, gross product, primary energy consumption, etc. Annual emissions are provided for each substance since 1990. Dates corresponding to the maximum and minimum values are also included. Results are provisional for 2001. (author)

  8. PIXE analysis of atmospheric particulate matter in glas fibre filters

    International Nuclear Information System (INIS)

    Tabacniks, M.H.; Orsini, C.Q.; Maenhaut, W.

    1993-01-01

    A 3-step extraction procedure was developed to allow particle-induced X-ray emission (PIXE) analysis of particulate matter in normal glass fibre filter samples. The detection limits, expressed in ng/m 3 of air, for the filter extracts were 5 to 30 times lower than those achieved by PIXE analysis or ordinary Nuclepore polycarbonate filter samples. The concentration results were compared with those obtained from routine atomic absorption spectrometry measurements and with the PIXE data from Nuclepore stacked filter unit samples taken in parallel. (orig.)

  9. Characterization of Fine Particulate Matter and Associated Health Burden in Nanjing

    Science.gov (United States)

    Nie, Dongyang; Chen, Mindong; Ge, Xinlei; Zhang, Kai; Ge, Pengxiang

    2018-01-01

    Particulate matter (PM) air pollution has become a serious environmental problem in Nanjing and poses great health risks to local residents. In this study, characteristics of particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) over Nanjing were analyzed using hourly and daily averaged PM2.5 concentrations and meteorological parameters collected from nine national monitoring sites during the period of March 2014 to February 2017. Then, the integrated exposure-response (IER) model was applied to assess premature mortality, years of life lost (YLL) attributable to PM2.5, and mortality benefits due to PM2.5 reductions. The concentrations of PM2.5 varied among hours, seasons and years, which can be explained by differences in emission sources, secondary formations and meteorological conditions. The decreased ratio of PM2.5 to CO suggested that secondary contributions decreased while the relative contributions of vehicle exhaust increased from increased CO data. According to the values of attributable fractions (AF), stroke was the major cause of death, followed by ischemic heart disease (IHD), lung cancer (LC) and chronic obstructive pulmonary disease (COPD). The estimated total deaths in Nanjing due to PM2.5 were 12,055 and 10,771, leading to 98,802 and 87,647 years of life lost in 2014 and 2015, respectively. The elderly and males had higher health risks than youngsters and females. When the PM2.5 concentrations meet the World Health Organization (WHO) Air Quality Guidelines (AQG) of 10 μg/m3, 84% of the premature deaths would be avoided, indicating that the Nanjing government needs to adopt more stringent measure to reduce PM pollution and enhance the health benefits. PMID:29584626

  10. Characterization of Fine Particulate Matter and Associated Health Burden in Nanjing

    Directory of Open Access Journals (Sweden)

    Dongyang Nie

    2018-03-01

    Full Text Available Particulate matter (PM air pollution has become a serious environmental problem in Nanjing and poses great health risks to local residents. In this study, characteristics of particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5 over Nanjing were analyzed using hourly and daily averaged PM2.5 concentrations and meteorological parameters collected from nine national monitoring sites during the period of March 2014 to February 2017. Then, the integrated exposure-response (IER model was applied to assess premature mortality, years of life lost (YLL attributable to PM2.5, and mortality benefits due to PM2.5 reductions. The concentrations of PM2.5 varied among hours, seasons and years, which can be explained by differences in emission sources, secondary formations and meteorological conditions. The decreased ratio of PM2.5 to CO suggested that secondary contributions decreased while the relative contributions of vehicle exhaust increased from increased CO data. According to the values of attributable fractions (AF, stroke was the major cause of death, followed by ischemic heart disease (IHD, lung cancer (LC and chronic obstructive pulmonary disease (COPD. The estimated total deaths in Nanjing due to PM2.5 were 12,055 and 10,771, leading to 98,802 and 87,647 years of life lost in 2014 and 2015, respectively. The elderly and males had higher health risks than youngsters and females. When the PM2.5 concentrations meet the World Health Organization (WHO Air Quality Guidelines (AQG of 10 μg/m3, 84% of the premature deaths would be avoided, indicating that the Nanjing government needs to adopt more stringent measure to reduce PM pollution and enhance the health benefits.

  11. Airborne particulates. European directives and standardization; Matieres particulaires dans l`air ambiant directives europeennes et normalisation

    Energy Technology Data Exchange (ETDEWEB)

    Houdret, J.L. [Ecole Nationale Superieure des Mines, 59 - Douai (France)

    1996-12-31

    The development of future European directives concerning atmospheric dusts and particulates, organization of the in-charge committee, measurement requirements and limit value determination processes are presented. Various measuring methods and instruments used for particulate and aerosol measurements are reviewed

  12. Molecular composition of organic aerosol over an agricultural site in North China Plain: Contribution of biogenic sources to PM2.5

    Science.gov (United States)

    Li, Xingru; Liu, Yusi; Li, Dong; Wang, Guoan; Bai, Yu; Diao, Heling; Shen, Rongrong; Hu, Bo; Xin, Jinyuan; Liu, Zirui; Wang, Yuesi; Guo, Xueqing; Wang, Lili

    2017-09-01

    Sugars and biogenic secondary organic aerosols (BSOAs) are substantial components of particulate organic matter, which affects regional and global air quality and climate. Fine particulate matter (PM2.5) samples were collected from 20 June to 30 July 2015 on a diurnal/nocturnal cycle in Yucheng, China in the North China Plain. The PM2.5 samples were analyzed for sugars and SOA tracers derived from biogenic volatile organic compounds (BVOCs) and other compounds, such as water soluble ions, element carbon (EC), organic carbon (OC) and water soluble organic carbon (WSOC). The quantified organic components accounted for 4.7% and 0.4% of the OC and PM2.5, respectively. SOA tracer concentrations were weakly higher during the day (101.6 ± 61.7 ng m-3) than at night (90.2 ± 41.5 ng m-3)(t = 0.610, P > 0.05), whereas sugar showed higher concentrations at night (227.0 ± 196.9 ng m-3) than during the day (177.9 ± 145.4 ng m-3)(t = -1.329, P > 0.05). Anhydro sugar (mannosan, galactosan, and levoglucosan) were the main components of the measured sugars and accounted for 58.5% and 75.6% of the daytime and nighttime measurements. The levoglucosan/mannosan ratios were 20.2 ± 12.9 and 17.6 ± 9.1 for the daytime and nighttime samples, respectively, indicating that crop residues, herbaceous plants and hardwood were the dominant types of biomass burned in the Yucheng region. Isoprene SOA tracers exhibited the highest levels among the measured SOA tracers, followed by α-pinene SOA tracers. The concentration of BSOC estimated using the tracer method was 3.9-1817.5 ng C m-3 and accounted for 0.1-26.0% of the OC. A clear negative correlation (r = 0.53) between isoprene-derived SOA and in-situ pH demonstrated that acid-catalyzed heterogeneous reactions can significantly enhance SOA mass. In addition, isoprene-derived SOA increased with the relative humidity (RH) when the RH was lower than 50%, whereas it decreased when the RH was higher than 50%.

  13. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    Science.gov (United States)

    Malloy, Q. G. J.; Qi, Li; Warren, B.; Cocker, D. R., III; Erupe, M. E.; Silva, P. J.

    2009-03-01

    Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine) are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (tested) as detected by an aerosol mass spectrometer (AMS). We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

  14. Secondary organic aerosol formation from primary aliphatic amines with NO3 radical

    Directory of Open Access Journals (Sweden)

    P. J. Silva

    2009-03-01

    Full Text Available Primary aliphatic amines are an important class of nitrogen containing compounds emitted from automobiles, waste treatment facilities and agricultural animal operations. A series of experiments conducted at the UC-Riverside/CE-CERT Environmental Chamber is presented in which oxidation of methylamine, ethylamine, propylamine, and butylamine with O3 and NO3 have been investigated. Very little aerosol formation is observed in the presence of O3 only. However, after addition of NO, and by extension NO3, large aerosol mass yields (~44% for butylamine are seen. Aerosol generated was determined to be organic in nature due to the small fraction of NO and NO2 in the total signal (<1% for all amines tested as detected by an aerosol mass spectrometer (AMS. We propose a reaction mechanism between carbonyl containing species and the parent amine leading to formation of particulate imine products. These findings can have significant impacts on rural communities with elevated nighttime PM loadings, when significant levels of NO3 exist.

  15. Mercury partition in the interface between a contaminated lagoon and the ocean: The role of particulate load and composition

    International Nuclear Information System (INIS)

    Pato, P.; Otero, M.; Valega, M.; Lopes, C.B.; Pereira, M.E.; Duarte, A.C.

    2010-01-01

    After having estimated the patterns of flow to the ocean and found some seasonal and tidal differences, mainly with regard to the relative importance of dissolved and particulate fractions, mercury partitioning at the interface between a contaminated lagoon and the Atlantic Ocean was investigated during four tidal cycles in contrasting season and tidal regimes. Mercury was found to be located predominantely in the particulate fraction throughout the year, contributing to its retention within the system. Seasonal conditions, variations in marine and fluvial signals and processes affecting bed sediment resuspension influenced the character and concentration of suspended particulate matter in the water column. Variation in the nature, levels and partitioning of organic carbon in the particulate fraction affected levels of particulate mercury as well as mercury partitioning. These results highlight the dominant role of suspended particulate matter in the distribution of anthropogenic mercury and reinforce the importance of competitive behavior related to organic carbon in mercury scavenging.

  16. Effects of organic loading rates on reactor performance and microbial community changes during thermophilic aerobic digestion process of high-strength food wastewater.

    Science.gov (United States)

    Jang, Hyun Min; Lee, Jae Won; Ha, Jeong Hyub; Park, Jong Moon

    2013-11-01

    To evaluate the applicability of single-stage thermophilic aerobic digestion (TAD) process treating high-strength food wastewater (FWW), TAD process was operated at four organic loading rates (OLRs) from 9.2 to 37.2 kg COD/m(3)d. The effects of OLRs on microbial community changes were also examined. The highest volumetric removal rate (13.3 kg COD/m(3)d) and the highest thermo-stable protease activity (0.95 unit/mL) were detected at OLR=18.6 kg COD/m(3)d. Denaturing gradient gel electrophoresis (DGGE) profiles and quantitative PCR (qPCR) results showed significant microbial community shifts in response to changes in OLR. In particular, DGGE and phylogenetic analysis demonstrate that the presence of Bacillus sp. (phylum of Firmicutes) was strongly correlated with efficient removal of organic particulates from high-strength food wastewater. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Microwave regenerated particulate trap

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, A.C. Jr.; Yonushonis, T.M. [Cummins Engine Co., Inc., Columbus, IN (United States); Haberkamp, W.C.; Mako, F.; Len, L.K,; Silberglitt, R.; Ahmed, I. [FM Technologies, Inc., Fairfax, VA (United States)

    1997-12-31

    It has been demonstrated that a fibrous particulate filter can extract particulate matter from the diesel exhaust. However, additional engineering efforts remains to achieve the design target of 90%. It has also be shown that with minor modifications magnetrons produced for home ovens can endure a simulated diesel operating environment. Much work remains to develop a robust product ready to complete extensive engine testing and evaluation. These efforts include: (1) additional environmental testing of magnetrons; (2) vibration testing of the filter in the housing; (3) evaluating alternative methods/designs to seal the center bore; and (4) determining the optimum coating thickness that provides sufficient structural integrity while maintaining rapid heating rates.

  18. Optical properties of size fractions of suspended particulate matter in littoral waters of Québec

    Directory of Open Access Journals (Sweden)

    G. Mohammadpour

    2017-11-01

    Full Text Available Mass-specific absorption (ai∗(λ and scattering (bi∗(λ coefficients were derived for four size fractions (i =  0.2–0.4, 0.4–0.7, 0.7–10, and > 10 µm, λ = wavelength in nm of suspended particulate matter (SPM and with samples obtained from surface waters (i.e., 0–2 m depth of the Saint Lawrence Estuary and Saguenay Fjord (SLE-SF during June of 2013. For the visible–near-infrared spectral range (i.e., λ = 400–710 nm, mass-specific absorption coefficients of total SPM (i.e., particulates > 0.2 µm (hereafter aSPM∗ had low values (e.g., < 0.01 m2 g−1 at λ = 440 nm in areas of the lower estuary dominated by particle assemblages with relatively large mean grain size and high particulate organic carbon and chlorophyll a per unit of mass of SPM. Conversely, largest aSPM∗ values (i.e., > 0.05 m2 g−1 at λ = 440 nm corresponded with locations of the upper estuary and SF where particulates were mineral-rich and/or their mean diameter was relatively small. The variability of two optical proxies (the spectral slope of particulate beam attenuation coefficient and the mass-specific particulate absorption coefficient, hereafter γ and Svis, respectively with respect to changes in particle size distribution (PSD and chemical composition was also examined. The slope of the PSD was correlated with bi∗(550 (Spearman rank correlation coefficient ρs up to 0.37 and ai∗(440 estimates (ρs up to 0.32 in a comparable way. Conversely, the contribution of particulate inorganic matter to total mass of SPM (FSPMPIM had a stronger correlation with ai∗ coefficients at a wavelength of 440 nm (ρs up to 0.50. The magnitude of γ was positively related to FSPMi or the contribution of size fraction i to the total mass of SPM (ρs up to 0.53 for i = 0.2–0.4 µm. Also, the relation between γ and FSPMPIM variability was secondary (ρs = −0.34, P > 0.05. Lastly, the magnitude

  19. Hydroxymethane sulfonate as a possible explanation for observed high levels of particulate sulfur during severe winter haze episodes in Beijing, China.

    Science.gov (United States)

    Moch, J.; Jacob, D.; Mickley, L. J.; Cheng, Y.; Li, M.; Munger, J. W.; Wang, Y.

    2017-12-01

    Observed PM2.5 during severe winter haze in Beijing, China, may reach levels as high as 880 μg m-3, with sulfur compounds contributing significantly to PM2.5 composition. Such sulfur has been traditionally assumed to be sulfate, even though models fail to generate such large sulfate enhancements under cold and hazy conditions. We show that particulate sulfur in wintertime Beijing possibly occurs as an S(IV)-HCHO adduct, hydroxymethane sulfonate (HMS), formed by reaction of aqueous-phase HCHO and S(IV) in cloud droplets. We use a 1-D chemistry model extending from the surface through the boundary layer to examine the potential role of HMS during the Beijing haze events of December 2011 and January 2013. Observed and assimilated meteorological fields including cloud liquid water were applied to the model, and we test the sensitivity of HMS formation to cloud pH and ambient SO2 and HCHO. Surface observations from the two haze events show excess ammonium in the aerosol, indicating cloud pH may be relatively high. Model results show that once cloud pH exceeds 4.5, HMS can accumulate rapidly, reaching a few hundred μg m-3 in a few hours. The timing of HMS formation is controlled by the presence of cloud liquid water, with eddy driven diffusion bringing HMS to the surface. The magnitude of HMS peaks is limited by the supply of HCHO. HMS episodes in the model end gradually over 1-3 days as fresh air is entrained into the boundary layer; in observations these episodes typically end when increasing wind speeds destabilize the boundary layer and disperses pollution. We find that consideration of HMS as a source of particulate sulfur significantly improves model match with observations. For example, assuming cloud pH of 5 and average surface SO2 and HCHO levels of 50 ppb and 5.5 ppb, we calculate mean HMS as 43.8 μg m-3 in January 2013, within 7 μg m-3 of observed particulate sulfur. Our 1-D model also captures the timing and magnitude of peak particulate sulfur in January

  20. Some aspects of organic and inorganic particulate transport at Rocky Flats. Final report

    International Nuclear Information System (INIS)

    Nichols, H.

    Findings from the summer 1975 sampling program and the conclusions from the 1975-1976 winter sampling program are summarized. Large radionuclide particles were not found attached to pollen. Sampling the airborne pollen throughout the Rocky Flats area demonstrated that the Rocky Flats air samplers were deficient in their abilities to properly collect large lightweight pollen grains. This may not have serious consequences for the undetected transport of radionuclides by pollen, however, it has implications of sampling inefficiency in some particulate size ranges, and implies that if radionuclides are carried at times by larger particles, then the standard Rocky Flats air samplers are not sampling these materials efficiently. Some initial findings suggested that soil samples from downwind areas associated with winter snow accumulation had abnormally high fissile particle accumulations, and this suggested the need to sample these sites in winter. Areas of preferred particle accumulation such as snow banks had higher concentrations of radionuclide particles than surrounding areas which are more windswept. Any soil sampling program at Rocky Flats which seeks to monitor background radionuclide levels and movement of fissile particles across the site should take account of these topographically and wind-controlled accumulation areas, and not rely solely on a grid pattern of sampling. The snow samples contained radionuclide material in substantial quantities. In terms of fissile particulates smaller than 0.5 microns the snow banks three miles east of the plant site contained as much or more radionuclides than sites close to the Hot Spot contaminated area. The snow samples immediately east of the Hot Spot contained many more large particles (>0.5 m), as did soil samples from the upwind site next to the plant fence. The Hot Spot is clearly implicated again as the source of these materials

  1. Approximation of personal exposure to fine particulate matters (PM2.5) during cooking using solid biomass fuels in the kitchens of rural West Bengal, India.

    Science.gov (United States)

    Nayek, Sukanta; Padhy, Pratap Kumar

    2018-03-27

    More than 85% of the rural Indian households use traditional solid biofuels (SBFs) for daily cooking. Burning of the easily available unprocessed solid fuels in inefficient earthen cooking stoves produce large quantities of particulate matters. Smaller particulates, especially with aerodynamic diameter of 2.5 μm or less (PM 2.5 ), largely generated during cooking, are considered to be health damaging in nature. In the present study, kitchen level exposure of women cooks to fine particulate matters during lunch preparation was assessed considering kitchen openness as surrogate to the ventilation condition. Two-way ANCOVA analysis considering meal quantity as a covariate revealed no significant interaction between the openness and the seasons explaining the variability of the personal exposure to the fine particulate matters in rural kitchen during cooking. Multiple linear regression analysis revealed the openness as the only significant predictor for personal exposure to the fine particulate matters. In the present study, the annual average fine particulate matter exposure concentration was found to be 974 μg m -3 .

  2. Particulate uranium, plutonium and polonium in the biogeochemistries of the coastal zone

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, V F; Koide, M; Goldberg, E D [Scripps Institution of Oceanography, La Jolla, CA (USA)

    1979-01-18

    It is stated that although increasing attention has been paid to the role of inorganic solid phases in the chemistry of seawater, little quantitative data has been available to assess their involvement with living systems. Recent observations are here reported on the uptake of uranium, plutonium and polonium in coastal waters by organisms and submerged surfaces as traced by their isotopes. It is shown that the body burdens of these radioelements in some marine organisms are governed measurably by the uptake of their particulate forms. Furthermore, these elements are associated with different particulate phases, as deduced from the rates at which they deposit on submerged surfaces.

  3. FINE PARTICULATE MATTER (PM) AND ORGANIC SPECIATION OF FIREPLACE EMISSIONS

    Science.gov (United States)

    This paper presents a summary of fireplace particle size and organic speciation data gathered to date in an on-going project. Tests are being conducted in a residential wood combustion (RWC) laboratory on three factory-built fireplaces. RWC wood smoke particles <10?m (PM10) con...

  4. M3 User's Manual. Version 3.0

    International Nuclear Information System (INIS)

    Laaksoharju, Marcus; Skaarman, Erik; Gomez, Javier B.

    2009-11-01

    calculations are relative to the selected reference waters, modelling can only describe changes in terms of mixing and reactions taking place between the reference waters. The results can be used to describe both mathematically and quantitatively the groundwater characteristics, rather than qualitatively as is often the case in a site description of the groundwater chemistry. The M3 method can be used for tracing the evolution, past-present dispersion and water-rock interactions. The outcome from the modelling can be reported in non-hydrochemical terms such as changes in mixing portions or in gain/losses due to mass balance reactions. The comparison with hydrogeological models is easier since the results from the M3 model can be compared to the results from the hydrodynamic models. The effect on the groundwater composition observed from biological reactions such as organic decomposition or sulphate reduction can be traced. In groundwater chemical response modelling such as M3 information concerning fracture mineralogy, thermodynamic data bases or groundwater flow directions are not included. The model concentrates solely on tracing changes in the measured groundwater composition which can be interpreted as a result of mixing and reactions. The validity of the modelling has to be examined carefully using expert knowledge in the areas of hydrochemistry, hydrogeology and alternative modelling together with mathematical validations and verification exercises. The M3 computer program is a standalone program developed in the MATLAB 7.1 computation environment. The M3 toolbox calculates and displays the results both as graphs and numerical data. In addition, it offers the user several ways of examining and interpreting data. Included with the M3 program is an online version of the reference manual, as well as MATLAB libraries required to run the program. The M3 program has been tested on Windows 2000 and XP

  5. Distribution of particulate carbohydrate in the eastern Arabian sea along 15 (degrees) N

    Digital Repository Service at National Institute of Oceanography (India)

    Nandakumar, K.; Bhosle, N.B.; Wagh, A.B.

    The concentration of particulate carbohydrate varied from 38-158 mu g.l-1 and 19-239 mu g.l-1 in shelf and slope waters respectively. At 10 m water column the concentration of particulate carbohydrate increased with the distance from the shore...

  6. Seasonal variation in particulate organic matter and its cnstituent fractions under the ice covered sea near the shelf, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.

    discrete depths. Chl @ia@@ concentration at all the 3 depths varied from 0.026 to 0.253 mu g l@u-1@@ showing minimum values during August-September. POC values varied from 280 to 1058 mu g l@u-1@@ while its constituent fractions such as particulate...

  7. Toxicologically important trace elements and organic compounds investigated in size-fractionated urban particulate matter collected near the Prague highway

    Czech Academy of Sciences Publication Activity Database

    Sysalová, J.; Sýkorová, Ivana; Havelcová, Martina; Száková, J.; Trejtnarová, Hana; Kotlík, B.

    2012-01-01

    Roč. 437, October (2012), s. 127-136 ISSN 0048-9697 R&D Projects: GA ČR GA205/09/1162 Institutional support: RVO:67985891 Keywords : urban particulate matter * grain- size partitioning * grain- size partitioning Subject RIV: DI - Air Pollution ; Quality Impact factor: 3.258, year: 2012

  8. Ambient and laboratory observations of organic ammonium salts in PM1.

    Science.gov (United States)

    Schlag, P; Rubach, F; Mentel, T F; Reimer, D; Canonaco, F; Henzing, J S; Moerman, M; Otjes, R; Prévôt, A S H; Rohrer, F; Rosati, B; Tillmann, R; Weingartner, E; Kiendler-Scharr, A

    2017-08-24

    Ambient measurements of PM 1 aerosol chemical composition at Cabauw, the Netherlands, implicate higher ammonium concentrations than explained by the formation of inorganic ammonium salts. This additional particulate ammonium is called excess ammonium (e NH 4 ). Height profiles over the Cabauw Experimental Site for Atmospheric Research (CESAR) tower, of combined ground based and airborne aerosol mass spectrometric (AMS) measurements on a Zeppelin airship show higher concentrations of e NH 4 at higher altitudes compared to the ground. Through flights across the Netherlands, the Zeppelin based measurements furthermore substantiate e NH 4 as a regional phenomenon in the planetary boundary layer. The excess ammonium correlates with mass spectral signatures of (di-)carboxylic acids, making a heterogeneous acid-base reaction the likely process of NH 3 uptake. We show that this excess ammonium was neutralized by the organic fraction forming particulate organic ammonium salts. We discuss the significance of such organic ammonium salts for atmospheric aerosols and suggest that NH 3 emission control will have benefits for particulate matter control beyond the reduction of inorganic ammonium salts.

  9. On the organ distribution of a selection of 99mTc-tagged tetracyclines

    International Nuclear Information System (INIS)

    Weinhold, S.E.M.

    1983-01-01

    During this study the time course of organ concentrations of 99mTc-tagged tetracycline and of 99mTc-rolitetracycline that had been labeled according to two different methods was investigated with reference to that of two standard preparations, 99mTcO 4 and 3 H-labeled tetracycline, which differ from the test substances in their chemical structures (lipohilia - hydrophilia). As the substances to be investigated here are chemically related, they showed mostly consistent organ concentrations and great vivo stability. The concentrations measured in the organs examined (particularly the lungs) followed the same pattern as the concentrations in the blood and were thus regarded as being primarily the result of convection processes, whereas the concentrations seen in some other organs (especially the kidneys and, to a lesser extent, the liver) rather appeared to be determined by invasion and evasion processes; this held true for 99mTc-labeled tetracyclines as well as for pertechnetate. None of the five substances tested during this study appeared to be able to pass the blood-brain barrier. As regards solubility in water, the 99mTc-labeled tetracyclines occupy an intermediate position between pertechnetate (extremely water-soluble) and 3 H-labeled tetracyclines (extremely lipophil), which can be seen from the moderately high blood concentrations of these preparations. In view of the high organ concentrations that are observed particularly in the kidneys following administration of 99mTc-labeled tetracycline and rolitetracycline, the use of these substances for renal scintiscanning appears worth considering, as only approx. one tenth of the dose of pertechnetate would be required for this purpose. (TRV) [de

  10. Contribution of fungal spores to particulate matter in a tropical rainforest

    International Nuclear Information System (INIS)

    Zhang Ting; Chan Chuenyu; Zhang Yinan; Zhang Zhisheng; Lin Mang; Sang Xuefang; Engling, Guenter; Li, Y D; Li, Yok-Sheung

    2010-01-01

    The polyols arabitol and mannitol, recently proposed as source tracers for fungal spores, were used in this study to estimate fungal contributions to atmospheric aerosol. Airborne particulate matter (PM 2.5 and PM 10 ) was collected at Jianfengling Mountain, a tropical rainforest on Hainan Island situated off the south China coast, during spring and analyzed for arabitol and mannitol by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The average concentrations of arabitol and mannitol exhibited high values with averages of 7.0 and 16.0 ng m -3 respectively in PM 2.5 and 44.0 and 71.0 ng m -3 in PM 10 . The two tracers correlated well with each other, especially in the coarse mode aerosol (PM 2.5-10 ), indicating they were mainly associated with coarse aerosol particles and had common sources. Arabitol and mannitol in PM 10 showed significant positive correlations with relative humidity, as well as positive correlations with average temperature, suggesting a wet emissions mechanism of biogenic aerosol in the form of fungal spores. We made estimations of the contribution of fungal spores to ambient PM mass and to organic carbon, based on the observed ambient concentrations of these two tracers. The relative contributions of fungal spores to the PM 10 mass were estimated to range from 1.6 to 18.2%, with a rather high mean value of 7.9%, and the contribution of fungal spores to organic carbon in PM 10 ranged from 4.64 to 26.1%, with a mean value of 12.1%, implying that biological processes are important sources of atmospheric aerosol.

  11. Particulate COD balance of particulate cod in eletrocuagulation/flotation reactor treating tannery effluent

    Directory of Open Access Journals (Sweden)

    Rodrigo Babora Borri

    2012-04-01

    Full Text Available Mass balance or particulate organic matter was studied in terms of COD, by means of electrocoagulation/flotation (ECF reactor treating tannery effluent. Reactor was operated in fill and draw (batch mode. Operating in hydraulic residence time of 65 minutes, ECF reactor reached 55 % COD removal. Although volatile solids were also removed from liquid phase (removal of 40%, fixed solids concentration, and hence total solids concentration, showed to be higher in withdrawn effluent than in ECF’s influent. This was assigned to NaCl added in order to enhance conductivity in wastewater.

  12. Nutrient variations and isotopic evidences of particulate organic matter provenance in fringing reefs, South China

    International Nuclear Information System (INIS)

    Cao, Di; Cao, Wenzhi; Liang, Ying; Huang, Zheng

    2016-01-01

    Nutrient over-enrichment is considered to be one of the causes of coral decline. Increase in traditional fishing in the Xuwen National Coral Reefs Reserve tract (XW) and tourism around the Sanya National Coral Reefs Reserve tract (SY) are causing this coral decline. This study reviews the current state of knowledge of the nutrient status of coastal fringing reefs in South China and evaluates the primary sources of nutrients using stable isotope method. Surveys of seawater nutrients showed that the seawater remained clean in both the XW and SY coastal coral reef areas. Based on the isotopic differences between anthropogenic sewage and naturally occurring aquatic nutrients, the isotopic values of particulate organic matter (POM) and the C/N ratios were successfully used to identify the presence of anthropogenic nutrients in aquatic environments. The δ"1"3C, δ"1"5N and C/N compositions of POM from XW and SY (− 21.18 ± 2.11‰, 10.30 ± 5.54‰, and 5.35 ± 0.69 and − 20.80 ± 1.34‰, 7.06 ± 3.95‰, and 5.77 ± 2.15, respectively) showed statistically significant variations with the season. The δ"1"3C and δ"1"5N values of POM suggest marine and terrestrial-derived nutrient sources. Organic carbon is a mixture of marine phytoplankton, marine benthic algae and terrestrial-derived plants. The δ"1"5N values suggest terrestrial-derived sewage and upwelling-dominated nitrogen sources. In the presence of natural upwelling and coastal currents, coastal coral reef areas are more vulnerable to the increasing anthropogenic nutrient inputs. Anthropogenic activities might lead to large increases in the nutrient concentrations and could trigger the shift from coral- to macroalgae-dominated ecosystems, which would ultimately result in the degradation of the coastal coral reef ecosystem. These results provide some understanding of the declining coral reef ecosystem and the importance of conservation areas and coastal coral reef resource management. - Highlights: • The

  13. YOGYAKARTA AIR BORNE QUALITY BASED ON THE LEAD PARTICULATE CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Zaenal Abidin

    2010-06-01

    Full Text Available Analysis of Yogyakarta air quality based on concentration of lead particulate using Fast Neutron Activation Analysis (FNAA method has been done. The sample was taken 3 times in 16 strategic locations of Yogyakarta city using Hi-Vol air sampler that equipped with cellulose filter TFA 2133. The sample irradiated for 30 min with 14 MeV fast neutron and then counted using gamma spectroscopy (AccuSpec. The result indicated that concentration of Pb-208 along Diponegoro street up to Janti street respectively are minimally (0.689 - 0.775 mg/m3, and maximally:  (1.598 - 1.785 mg/m3. According to DIY governor decree No. 153/2002 about the limited toxicity ambient on Yogyakarta area it is concentration that Pb. The concentration of Pb-208 are still below the permitted value of 2 mg/m3, but in certain areas, the Pb concentration is almost equal to upper limit of permitted concentration of Pb.   Keywords: air borne, neutron generator, FNAA

  14. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  15. Activation volume and interaction of metal particulate media

    Energy Technology Data Exchange (ETDEWEB)

    Tetsukawa, Hiroki [Sony Corporation, 6-7-35 Kitashinagawa, Shinagawa-ku, Tokyo 141-0001 (Japan)]. E-mail: tetsukaw@arc.sony.co.jp; Kondo, Hirofumi [Sony Corporation, 6-7-35 Kitashinagawa, Shinagawa-ku, Tokyo 141-0001 (Japan)

    2005-09-15

    We have investigated the activation volume (V{sub ac}) and magnetostatic interaction of metal particulate (MP) media. The activation volume of MP media decreases with the decrease of physical volume (V{sub phy}) of metal particles. The activation volume and the ratio of V{sub phy}/V{sub ac} of advanced metal particles are 6x10{sup -24}m{sup 3} and 1.5, respectively. It can be predicted that the physical volume of metal particle is about 3x10{sup -24}m{sup 3} when the physical volume is equal to the activation volume. This value is agreement with the practical lower limit of physical volume of metal particle predicted by Sharrock. The negative interaction (demagnetization effect) in MP media decreases with low saturation magnetization of the metal particles, a thin magnetic layer, a high orientation of MP media, and a low packing fraction of metal particles in the MP media. The activation volume of the MP media decreased as the negative interactions decreased. In advanced MP media with low M{sub r}.t (M{sub r}=remanent magnetization and t=thickness), the influence of interaction on the activation volume is reduced.

  16. Activation volume and interaction of metal particulate media

    International Nuclear Information System (INIS)

    Tetsukawa, Hiroki; Kondo, Hirofumi

    2005-01-01

    We have investigated the activation volume (V ac ) and magnetostatic interaction of metal particulate (MP) media. The activation volume of MP media decreases with the decrease of physical volume (V phy ) of metal particles. The activation volume and the ratio of V phy /V ac of advanced metal particles are 6x10 -24 m 3 and 1.5, respectively. It can be predicted that the physical volume of metal particle is about 3x10 -24 m 3 when the physical volume is equal to the activation volume. This value is agreement with the practical lower limit of physical volume of metal particle predicted by Sharrock. The negative interaction (demagnetization effect) in MP media decreases with low saturation magnetization of the metal particles, a thin magnetic layer, a high orientation of MP media, and a low packing fraction of metal particles in the MP media. The activation volume of the MP media decreased as the negative interactions decreased. In advanced MP media with low M r .t (M r =remanent magnetization and t=thickness), the influence of interaction on the activation volume is reduced

  17. The washout effects of rainfall on atmospheric particulate pollution in two Chinese cities.

    Science.gov (United States)

    Guo, Ling-Chuan; Zhang, Yonghui; Lin, Hualiang; Zeng, Weilin; Liu, Tao; Xiao, Jianpeng; Rutherford, Shannon; You, Jing; Ma, Wenjun

    2016-08-01

    Though rainfall is recognized as one of the main mechanisms to reduce atmospheric particulate pollution, few studies have quantified this effect, particularly the corresponding lag effect and threshold. This study aimed to investigate the association between rainfall and air quality using a distributed lag non-linear model. Daily data on ambient PM2.5 and PM2.5-10 (particulate matter with an aerodynamic diameter less than 2.5 μm and from 2.5 to 10 μm) and meteorological factors were collected in Guangzhou and Xi'an from 2013 to 2014. A better washout effect was found for PM2.5-10 than for PM2.5, and the rainfall thresholds for both particle fractions were 7 mm in Guangzhou and 1 mm in Xi'an. The decrease in PM2.5 levels following rain lasted for 3 and 6 days in Guangzhou and Xi'an, respectively. Rainfall had a better washout effect in Xi'an compared with that in Guangzhou. Findings from this study contribute to a better understanding of the washout effects of rainfall on particulate pollution, which may help to understand the category and sustainability of dust-haze and enforce anthropogenic control measures in time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 1.54 μm Er3+ electroluminescence from an erbium-compound-doped organic light emitting diode with a p-type silicon anode

    International Nuclear Information System (INIS)

    Zhao, W Q; Wang, P F; Ran, G Z; Ma, G L; Zhang, B R; Liu, W M; Wu, S K; Dai, L; Qin, G G

    2006-01-01

    By doping an erbium complex, erbium (III) 2, 4-pentanedionate (Er(acac) 3 ), into the ALQ layer, we fabricate a series of infrared emission organic light emitting diodes (OLED) with structures of p-Si/SiO 2 /NPB/ALQ/ ALQ:Er(acac) 3 /ALQ/Sm/Au, where p-Si is the anode and Sm/Au is the cathode. The 1.54 μm emission from Er 3+ is observed. The impact of doping level of Er(acac) 3 in ALQ on 1.54 μm electroluminescence (EL) intensity is studied, and the best mass ratio of Er(acac) 3 to ALQ is found at 1:60. A competitive EL mechanism from the ALQ and Er(acac) 3 is found and the Er 3+ ions excitations are attributed to energy transfer from the ligands to Er ions

  19. Characteristics of particulate PAHs during a typical haze episode in Guangzhou, China

    Science.gov (United States)

    Tan, Jihua; Guo, Songjun; Ma, Yongliang; Duan, Jingchun; Cheng, Yuan; He, Kebin; Yang, Fumo

    2011-10-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 and TSP were measured in Guangzhou during a typical haze episode. This episode included NH (non-haze, 3 days), HFN (haze when air masses from north and northeast, 6 days) and HFS (haze when air masses from south, 4 days). The air quality in HFN was much worse than that in NH and HFS. The total average concentrations of PAHs in PM 2.5 were 13.25 ng m -3, 59.82 ng m -3 and 13.09 ng m -3 in NH, HFN and HFS, respectively. It indicated PAH pollution had been substantially aggravated by HFN. PAHs(5 + 6) were the most abundant compounds in HFN and HFS, which accounted for 55-75% of total concentration of PAHs, while PAHs(3 + 4) were the most abundant compounds in NH, which accounted for 54-67% of total concentration of PAHs. TEF (Toxic Equivalency Factors)-adjusted concentrations of 13 particulate PAHs were very high in HFN, indicating high health risks to humans for PAH exposure in HFN. The characteristic ratios of PAHs indicated coal combustion and traffic emission were the major contributors to PAHs in HFN and HFS. The concentrations of particulate PAHs in haze episode were strongly affected by wind speed and wind direction. PAHs in NH could be from long-range transport with high north wind speed, while local emission could be the main contributor of particle-associated PAHs in HFN. The transport speed of air masses was found to play an important role on PAH concentrations.

  20. Seasonal distribution of organic matter in mangrove environment of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.

    Water and sediments were studied for the distribution of suspended matter, organic carbon and nitrogen Suspended matter ranged from 3-373 mg.l-1 while particulate organic carbon (POC) from 0.03-9.94 mg.l-1 POC value showed significant correlation...

  1. Airborne particulate matter in spacecraft

    Science.gov (United States)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  2. On the Origin of the 3.3 μ m Unidentified Infrared Emission Feature

    Energy Technology Data Exchange (ETDEWEB)

    Sadjadi, Seyedabdolreza; Zhang, Yong; Kwok, Sun, E-mail: sunkwok@hku.hk [Laboratory for Space Research, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2017-08-20

    The 3.3 μ m unidentified infrared emission feature is commonly attributed to the C–H stretching band of aromatic molecules. Astronomical observations have shown that this feature is composed of two separate bands at 3.28 and 3.30 μ m, and the origin of these two bands is unclear. In this paper, we perform vibrational analyses based on quantum mechanical calculations of 153 organic molecules, including both pure aromatic molecules and molecules with mixed aromatic/olefinic/aliphatic hydridizations. We find that many of the C–H stretching vibrational modes in polycyclic aromatic hydrocarbon (PAH) molecules are coupled. Even considering the uncoupled modes only, the correlation between the band intensity ratios and the structure of the PAH molecule is not observed, and the 3.28 and 3.30 μ m features cannot be directly interpreted in the PAH model. Based on these results, the possible aromatic, olefinic, and aliphatic origins of the 3.3 μ m feature are discussed. We suggest that the 3.28 μ m feature is assigned to aromatic C–H stretch whereas the 3.30 μ m feature is olefinic. From the ratio of these two features, the relative olefinic to aromatic content of the carrier can be determined.

  3. Origin and composition of particulate organic matter in a macrotidal turbid estuary: The Gironde Estuary, France

    Science.gov (United States)

    Savoye, Nicolas; David, Valérie; Morisseau, François; Etcheber, Henri; Abril, Gwenaël; Billy, Isabelle; Charlier, Karine; Oggian, Georges; Derriennic, Hervé; Sautour, Benoît

    2012-08-01

    At the interface between continent and ocean, estuaries receive particles, and especially particulate organic matter (POM) originating from these two reservoirs, but also produce POM, through autochthonous primary production. The origin and composition of surface POM in the Gironde Estuary (SW France) and the environmental forcing of its variability was investigated using the data set produced by the French Coastal Monitoring Network SOMLIT (Service d'Observation en Milieu LITtoral; monthly like sampling during years 2007-2009). This estuary is considered as a model of macrotidal turbid estuaries. Using elemental and isotopic composition of the POM, we estimated that, at the inner estuary space scale and inter-annual time scale, surface particulate organic carbon (POC) was composed of terrestrial POM originated from the turbidity maximum (96.4%; refractory POC) and flood events (1.6%; labile and refractory POC), and of riverine (0.1%), estuarine (0.8%) and marine (1.1%) phytoplankton, i.e. that POC was 98% and 2% of terrestrial and phytoplankton origin, respectively. However, there was a clear spatial gradient: the phytoplankton contribution increases from ca. 1% in the upper and middle estuary to 8.5% in the lower estuary, where light condition is more favourable to plankton growth. The low contribution of phytoplankton to the POC is a characteristic of the Gironde estuary and contrast with other large temperate estuaries. Statistical analysis indicates that salinity, river flow and SPM concentration, and thus associated hydro-dynamic and sedimentary processes, were the only environmental forcings to the composition of surface POC in this system, at intra- and inter-annual time scale. In contrast, temperature and nutrient concentrations, and thus associated processes, do not force this composition of POC. By combining POC fluxes entering the inner estuary (literature data), POC loss as dissolved organic carbon and CO2 and as sediment trapping within the inner

  4. Study of indoor and ambient air fungual bioaerosols and its relation with particulate matters in a hospital of khorramabad

    Directory of Open Access Journals (Sweden)

    Hasan Basiri

    2016-02-01

    Full Text Available Background: The climate change and particulate matter emission contented of bioaerosols is known as an important reason of increasing the allergic interactions especially in patients with defect in immunity system. The aim of this study was to investigate fungal bioaerosol concentrations in relation to particulate matter (PM10, PM2.5 and PM1 in indoor parts and ambient air of the generd educational hospital of Khorramabad city. Materials and Methods: In this descriptive-analytical study, 192 samples (168 for indoor and 24 for outdoor were gathered during 6 months at the seven indoor wards and one outdoor unit using Quick Take-30 method  at an airflow rate of 28.3 L/min and sampling time of 2.5 min on to Sabouraud dextrose agar medium containing chloramphenicol. The sampling of particulate matter was carried out by Monitor Dust-Trak 8520. Also, the relative humidity and temperature were surveyed by TES-1360 digital. Results: The results showed that infectious ward with 101.7 CFU/m3 was as the most contaminated part and operating room with 46.4 CFU/m3 was the cleanest part. Cladosporium with 36.75% and Rodotorolla with 1.3% had higher and lower of fungi rates, respectively. The rate of  I/O<1  illustrate that this contamination had an outdoor source. Conclusion: The surveys demonstrated that the increase of temperature and relative humidity have an effective influence on the pollutant accumulation. In addition, between fungi bioaerosols frequency and particulate matter ther was a significant correlation.

  5. Regional modeling of carbonaceous aerosols over Europe-focus on secondary organic aerosols

    International Nuclear Information System (INIS)

    Bessagnet, B.; Menut, L.; Curci, G.; Hodzic, A.; Guillaume, B.; Liousse, C.; Moukhtar, S.; Pun, B.; Seigneur, C.; Schulz, M.

    2008-01-01

    In this study, an improved and complete secondary organic aerosols (SOA) chemistry scheme was implemented in the CHIMERE model. The implementation of isoprene chemistry for SOA significantly improves agreement between long series of simulated and observed particulate matter concentrations. While simulated organic carbon concentrations are clearly improved at elevated sites by adding the SOA scheme, time correlation are impaired at low level sites in Portugal, Italy and Slovakia. At several sites a clear underestimation by the CHIMERE model is noticed in wintertime possibly due to missing wood burning emissions as shown in previous modeling studies. In Europe, the CHIMERE model gives yearly average SOA concentrations ranging from 0.5 μg m -3 in the Northern Europe to 4 μg m -3 over forested regions in Spain, France, Germany and Italy. In addition, our work suggests that during the highest fire emission periods, fires can be the dominant source of primary organic carbon over the Mediterranean Basin, but the SOA contribution from fire emissions is low. Isoprene chemistry has a strong impact on SOA formation when using current available kinetic schemes. (authors)

  6. Organic carbon deliveries and their flow related dynamics in the Fitzroy estuary

    International Nuclear Information System (INIS)

    Ford, Phillip; Tillman, Pei; Robson, Barbara; Webster, Ian T.

    2005-01-01

    The Fitzroy estuary (Queensland, Australia) receives large, but highly episodic, river flows from a catchment (144,000 km 2 ) which has undergone major land clearing. Large quantities of suspended sediments, and particulate and dissolved organic carbon are delivered. At peak flows, δ 13 C (-21.7 ± 0.8%o) and C/N (14.8 ± 1.3) of the suspended solids indicate that the particulate organic material entering the estuary is principally soil organic carbon. At the lower beginning flows the particulate organic matter comes from in-stream producers (δ 13 C = -26%o). The DOC load is about 10 times the POC load. Using the inverse method, budgets for POC and DOC were constructed for high and low flows. Under high flows, only a small portion of the POC and DOC load is lost in the estuary. Under dry season (low flow) conditions the estuary is a sink for DOC, but remains a source of POC to the coastal waters

  7. Novel mass spectrometric instrument for gaseous and particulate characterization and monitoring

    International Nuclear Information System (INIS)

    Coggiola, M.J.

    1994-02-01

    SRI International will develop a unique new instrument that will be capable of providing real-time (<1 minute), quantitative, chemical characterization of gaseous and particulate pollutants generated from DOE waste cleanup activities. The instrument will be capable of detecting and identifying volatile organic compounds, polynuclear aromatic hydrocarbons, heavy metals, and transuranic species released during waste cleanup activities. The instrument will be unique in its ability to detect and quantify in real-time these diverse pollutants in both vapor and particulate form. The instrument to be developed under this program will consist of several major components: (1) an isokinetic sampler capable of operating over a wide range of temperatures (up to 500 K) and flow rates; (2) a high pressure to low pressure transition and sampling region that efficiently separates particles from vapor-phase components for separate, parallel analyses; (3) two small mass spectrometers, one optimized for organic analysis using a unique field ionization source and one optimized for particulate characterization using thermal pyrolysis and electron-impact ionization (EI); and (4) a powerful personal computer for control and data acquisition. Initially, the instrument will be developed for targeted use in conjunction with the K-1435 Toxic Substances Control Act (TSCA) incinerator at the Oak Ridge National Laboratory K-25 site. Ultimately, the instrument will be designed to operate in the field at any cleanup site, located close to the stack or process vent, providing the plant operations personnel with real-time information and alarm capabilities. In addition, this instrument will be very broadly applicable for cleanup or sampling, for example, any time contaminated soil is moved or disturbed

  8. Bioengineering towards self-assembly of particulate vaccines.

    Science.gov (United States)

    Rehm, Bernd H A

    2017-12-01

    There is an unmet demand for safe and efficient vaccines for prevention of various infectious diseases. Subunit vaccines comprise selected pathogen specific antigens are a safe alternative to whole organism vaccines. However they often lack immunogenicity. Natural and synthetic self-assembling polymers and proteins will be reviewed in view their use to encapsulate and/or display antigens to serve as immunogenic antigen carriers for induction of protective immunity. Recent advances made in in vivo assembly of antigen-displaying polyester inclusions will be a focus. Particulate vaccines are inherently immunogenic due to enhanced uptake by antigen presenting cells which process antigens mediating adaptive immune responses. Bioengineering approaches enable the design of tailor-made particulate vaccines to fine tune immune responses towards protective immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Association of uranium with colloidal and suspended particulate matter in Arabian sea near the west coast of Maharashtra (India)

    International Nuclear Information System (INIS)

    Singhal, R.K.; Joshi, S.N.; Hegde, A.G.

    2004-01-01

    Association of natural uranium in seawater with colloidal and suspended-particulate matter was determined. The separation of suspended particulate material (>0.45 ) and colloidal fraction (as dissolved fractions) in seawater were done by suction and ultra filtration techniques. Seawater samples were collected at 1 km away from the shore and subjected to sequential fractionation in nine stages ranging from 2.7 μm to 1.1 nm. Suspended particulate matter were separated in three different size groups namely >2.7 μm, 0.45 μm and 0.22 μm by suction filtration using cellulose acetate and nitrate membranes filters. To concentrate the solution with colloidal particles <0.22 μm-1.1 nm (0.5 k Nominal Molecular Weight cut-off Limit (NMWL), the solution obtained from filtration through <0.22 μm was passed through stirred ultra-filtration cell. The pH and conductivity at different stages of fractionation (dissolved) showed minor variations. The concentration of uranium was measured in suspended and dissolved fractions by using a pulsed nitrogen laser at 337.1 nm. In order to evaluate the role of mineral colloids in various stages of filtration, concentration of calcium, magnesium, potassium were measured by using ion chromatography and atomic absorption spectrometry. The clay mineral at seawater pH (approximately 8) behave as negative ions and provides binding site for the positively charge species of uranium. Among the dissolved fraction, the maximum concentrations of colloidal uranium was observed about 4 times higher than that compared to average concentration of 6.93 ± 3.10 ppb in other fractions. In the case of suspended particulate matter, the concentration of uranium was below detection limits (<1 ppb). The maximum concentration of Ca, Mg and K in the dissolved fraction were in the <1.1 nm fraction, while for suspended particulate matter, the concentration of Ca, Mg and K decreased with the decrease in size and it is highest in the fraction of 0.22 -0.45 μm.(author)

  10. Ambient particulate matter as a risk factor for suicide.

    Science.gov (United States)

    Kim, Changsoo; Jung, Sang Hyuk; Kang, Dae Ryong; Kim, Hyeon Chang; Moon, Ki Tae; Hur, Nam Wook; Shin, Dong Chun; Suh, Il

    2010-09-01

    The authors assessed the relationship between exposure to ambient particulate matter and suicide in urban settings during a 1-year period. The association between particulate matter and suicide was determined using a time-stratified case-crossover approach in which subjects served as their own controls. All suicide cases (4,341) in 2004 that occurred in seven cities in the Republic of Korea were included. Hourly mean concentrations of particulate matter suicide risk associated with an interquartile range increase in particulate matter was determined by conditional logistic regression analysis after adjusting for national holidays and meteorological factors. Subgroup analysis was performed after stratification by underlying disease (cardiovascular disease, diabetes mellitus, chronic obstructive pulmonary disease, cancer, and psychiatric illness). The largest associations were a 9.0% increase (95% CI=2.4-16.1) and a 10.1% (95% CI=2.0-19.0) increase in suicide risk related to an interquartile range increase in particulate matter suicide) and particulate matter suicide), respectively. Among individuals with cardiovascular disease, a significant association between particulate matter suicide) and suicide was observed (18.9%; 95% CI=3.2-37.0). Conclusions: A transient increase in particulate matter was associated with increased suicide risk, especially for individuals with preexisting cardiovascular disease.

  11. Occupational Exposure to Diesel Particulate Matter in Municipal Household Waste Workers.

    Science.gov (United States)

    Lee, Kyong-Hui; Jung, Hye-Jung; Park, Dong-Uk; Ryu, Seung-Hun; Kim, Boowook; Ha, Kwon-Chul; Kim, Seungwon; Yi, Gwangyong; Yoon, Chungsik

    2015-01-01

    The purposes of this study were to determine the following: 1) the exposure levels of municipal household waste (MHW) workers to diesel particulate matter (DPM) using elemental carbon (EC), organic carbon (OC), total carbon (TC), black carbon (BC), and fine particulate matter (PM 2.5) as indicators; 2) the correlations among the indicators; 3) the optimal indicator for DPM; and 4) factors that influence personal exposure to DPM. A total of 72 workers in five MHW collection companies were assessed over a period of 7 days from June to September 2014. Respirable EC/OC samples were quantified using the thermal optical transmittance method. BC and PM 2.5 were measured using real-time monitors, an aethalometer and a laser photometer. All results were statistically analyzed for occupational and environmental variables to identify the exposure determinants of DPM. The geometric mean of EC, OC, TC, BC and PM 2.5 concentrations were 4.8, 39.6, 44.8, 9.1 and 62.0 μg/m3, respectively. EC concentrations were significantly correlated with the concentrations of OC, TC and BC, but not with those of PM 2.5. The exposures of the MHW collectors to EC, OC, and TC were higher than those of the drivers (pemission standard had higher exposures to EC, OC, TC and PM 2.5 than those working on Euro 4 trucks (pemission standard, and average driving speed were the most influential factors in determining worker exposure. We assessed MHW workers' exposure to DPM using parallel sampling of five possible indicators. Of these five indicators, EC was shown to be the most useful indicator of DPM exposure for MHW workers, and the job task, European emission standard, and average driving speed were the main determinants of EC exposure.

  12. Short term variations in particulate matter in Mahi river estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Rokade, M.A.; Zingde, M.D.

    The particulate matter (PM) collected from Mahi River Estuary was analysed for organic carbon (POC), nitrogen (PON), and chlorophyll a (Chl a). The concentration of PM, POC, PON and Chl a showed short term variations. Average surface concentration...

  13. Time-resolved analysis of particle emissions from residential biomass combustion - Emissions of refractory black carbon, PAHs and organic tracers

    Science.gov (United States)

    Nielsen, Ingeborg E.; Eriksson, Axel C.; Lindgren, Robert; Martinsson, Johan; Nyström, Robin; Nordin, Erik Z.; Sadiktsis, Ioannis; Boman, Christoffer; Nøjgaard, Jacob K.; Pagels, Joakim

    2017-09-01

    Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of

  14. [Exploration of a quantitative methodology to characterize the retention of PM2.5 and other atmospheric particulate matter by plant leaves: taking Populus tomentosa as an example].

    Science.gov (United States)

    Zhang, Zhi-Dan; Xi, Ben-Ye; Cao, Zhi-Guo; Jia, Li-Ming

    2014-08-01

    Taking Populus tomentosa as an example, a methodology called elution-weighing-particle size-analysis (EWPA) was proposed to evaluate quantitatively the ability of retaining fine particulate matter (PM2.5, diameter d ≤ 2.5 μm) and atmospheric particulate matter by plant leaves using laser particle size analyzer and balance. This method achieved a direct, accurate measurement with superior operability about the quality and particle size distribution of atmospheric particulate matter retained by plant leaves. First, a pre-experiment was taken to test the stability of the method. After cleaning, centrifugation and drying, the particulate matter was collected and weighed, and then its particle size distribution was analyzed by laser particle size analyzer. Finally, the mass of particulate matter retained by unit area of leaf and stand was translated from the leaf area and leaf area index. This method was applied to a P. tomentosa stand which had not experienced rain for 27 days in Beijing Olympic Forest Park. The results showed that the average particle size of the atmospheric particulate matter retained by P. tomentosa was 17.8 μm, and the volume percentages of the retained PM2.5, inhalable particulate matter (PM10, d ≤ 10 μm) and total suspended particle (TSP, d ≤ 100 μm) were 13.7%, 47.2%, and 99.9%, respectively. The masses of PM2.5, PM10, TSP and total particulate matter were 8.88 x 10(-6), 30.6 x 10(-6), 64.7 x 10(-6) and 64.8 x 10(-6) g x cm(-2) respectively. The retention quantities of PM2.5, PM10, TSP and total particulate matter by the P. tomentosa stand were 0.963, 3.32, 7.01 and 7.02 kg x hm(-2), respectively.

  15. Analysis of airborne particulate matter

    International Nuclear Information System (INIS)

    Iwatsuki, Masaaki

    2002-01-01

    An airborne particulate matter (APM) consists of many kinds of solid and liquid particles in air. APM analysis methods and the application examples are explained on the basis of paper published after 1998. Books and general remarks, sampling and the measurement of concentration and particle distribution, elemental analysis methods and the present state of analysis of species are introduced. Tapered Element Oscillating Microbalance (TEOM) method can collect continuously the integrating mass, but indicates lower concentration. Cu, Ni, Zn, Co, Fe(2), Mn, Cd, Fe(3) and Pb, the water-soluble elements, are determined by ion-chromatography after ultrasonic extraction of the aqueous solution. The detection limit of them is from 10 to 15 ppb (30 ppb Cd and 60 ppb Pb). The elemental carbon (EC) and organic carbon (OC) are separated by the thermal mass measurement-differential scanning calorimeter by means of keeping at 430degC for 60 min. 11 research organizations compared the results of TC (Total Carbon) and EC by NIOSH method 5040 and the thermal method and obtained agreement of TC. ICP-MS has been developed in order to determine correctly and quickly the trace elements. The determination methods for distinction of chemical forms in the environment were developed. GC/MS, LC/MS and related technologies for determination of organic substances are advanced. Online real-time analysis of APN, an ideal method, is examined. (S.Y.)

  16. Particulate fluxes and transports on the slope between the southern East China Sea and the South Okinawa Trough

    Science.gov (United States)

    Chung, Yu-Chia; Hung, Guo-Wei

    2000-03-01

    This paper presents time-series variations of the particulate fluxes in resolutions of 3-15 d from 10 mooring sites on the continental slope between the southern East China Sea and the South Okinawa Trough, northeast of Taiwan. Three of these sites were located in a canyon cutting across the slope. Temporal and spatial variations in particulate flux in the study area were strongly affected by the bottom topography, the topographically induced eddies, the intensity of tidal currents, the depth and height above bottom where the traps were deployed, and episodic events. The apparent mass fluxes measured at depths from about 300 to 1350 m at different locations varied with time and showed synchronous variations among the traps deployed at the same site for some sites. The time-averaged mass flux for each individual trap deployed at different depth and in different length of mooring time ranged from 0.77 to 53.7 g m -2 d -1. In the canyon the average fluxes were generally greater than 30 g m -2 d -1 with large standard deviations; at other slope sites the average fluxes were generally less than 10 g m -2 d -1, excluding one or two unusually high values which were observed in some individual traps probably reflecting episodic events. The particulate fluxes always increased toward the ocean bottom at each mooring site but the increment was much greater in the canyon. This suggests that the particulates were transported out of the shelf or upper slope area essentially through the canyon where large mass fluxes were observed. The current meter data processed with low-pass filtration and expressed in stick diagrams and progressive vector diagrams showed large temporal and spatial variations which were generally not correlated with those of particulate fluxes. Although strong tidal velocity oscillations in the canyon were found to be associated with high mass fluxes in some instances (Hung and Chung, 1998, Continental Shelf Research 18, 1475-1491), episodic events with very

  17. Mutagenic and recombinagenic activity of airborne particulates, PM10 and TSP, organic extracts in the Drosophila wing-spot test

    International Nuclear Information System (INIS)

    Rodrigues Dihl, Rafael; Grazielli Azevedo da Silva, Carla; Souza do Amaral, Viviane; Reguly, Maria Luiza; Rodrigues de Andrade, Heloisa Helena

    2008-01-01

    The genotoxicity associated with air pollution in the city of Canoas, Rio Grande do Sul (Brazil), was assessed in November (spring) and January (summer). We applied the somatic mutation and recombination test (SMART) in Drosophila melanogaster in its standard version with normal bioactivation (ST) and in its variant with increased cytochrome P450-dependent biotransformation capacity (HB). The data indicated the genotoxicity of TSP and PM10 collected in November, in both ST and HB crosses. The genotoxic activity of the PM10 material in the spring sample was exclusively associated with the induction of mitotic recombination, whereas the TSP genetic toxicity was due to both recombinational as well as point and/or chromosomal mutation events. Considering PM10 collected in January, a positive response-100% (17.10 m 3 /ml) concentration-was observed in the HB cross, which was not detected in the ST cross. - Drosophila Wing-Spot Test can be used for detection of airborne particulates mutagenesis

  18. Mutagenic and recombinagenic activity of airborne particulates, PM10 and TSP, organic extracts in the Drosophila wing-spot test

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Dihl, Rafael [Programa de Pos Graduacao em Genetica e Biologia Molecular (PPGBM), Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Grazielli Azevedo da Silva, Carla [Instituto de Quimica, Departamento de Quimica Organica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Souza do Amaral, Viviane; Reguly, Maria Luiza [Laboratorio de Diagnostico da Toxicidade Genetica (TOXIGEN), Programa de Pos Graduacao em Genetica e Toxicologia Aplicada (PPGGTA), Universidade Luterana do Brasil - ULBRA, Avenida Farroupilha 8001, 92420280 Canoas, RS (Brazil); Rodrigues de Andrade, Heloisa Helena [Laboratorio de Diagnostico da Toxicidade Genetica (TOXIGEN), Programa de Pos Graduacao em Genetica e Toxicologia Aplicada (PPGGTA), Universidade Luterana do Brasil -ULBRA, Avenida Farroupilha 8001, 92420280 Canoas, RS (Brazil)], E-mail: heloisa@ulbra.br

    2008-01-15

    The genotoxicity associated with air pollution in the city of Canoas, Rio Grande do Sul (Brazil), was assessed in November (spring) and January (summer). We applied the somatic mutation and recombination test (SMART) in Drosophila melanogaster in its standard version with normal bioactivation (ST) and in its variant with increased cytochrome P450-dependent biotransformation capacity (HB). The data indicated the genotoxicity of TSP and PM10 collected in November, in both ST and HB crosses. The genotoxic activity of the PM10 material in the spring sample was exclusively associated with the induction of mitotic recombination, whereas the TSP genetic toxicity was due to both recombinational as well as point and/or chromosomal mutation events. Considering PM10 collected in January, a positive response-100% (17.10 m{sup 3}/ml) concentration-was observed in the HB cross, which was not detected in the ST cross. - Drosophila Wing-Spot Test can be used for detection of airborne particulates mutagenesis.

  19. QUANTIFICATION, CHARACTERIZATION AND COMPOSITION PARTICULATE MATTER 2.5, FROM THE USE OF THE COMBARBALITA

    Directory of Open Access Journals (Sweden)

    Ricardo Zamarreño

    2015-12-01

    Full Text Available In this work, the results of the particulate material is PM 2.5 in the city of Combarbala, by exploitation and carving of the "Combarbalita", are shown. The monitoring was conducted between the months of September 2010 and May 2011. Determining PM 2.5 with a suction pump, quantifying the concentration of some metals using atomic absorption spectroscopy. Checking the morphological characteristics of the components, using the technique of immersion microscopy. The average is 22.50 PM 2.5 mg/m3, being under the EPA's recommended values. Items with higher concentrations are iron, copper, lead and zinc, cadmium has the lowest concentration. Particles smaller than 2.5 .mu.m and bordering the 36.11% of total analyzed, which have dimensions of 4 to 10 microns added 50%. Combarbalá has concluded that low levels of particulate pollution PM 2.5.

  20. Variability of particulate organic carbon in inland waters observed from MODIS Aqua imagery

    International Nuclear Information System (INIS)

    Duan, Hongtao; Ma, Ronghua; Zhang, Yuchao; Feng, Lian; Arthur Loiselle, Steven

    2014-01-01

    Surface concentrations of particulate organic carbon (POC) in shallow inland lakes were estimated using MODIS Aqua data. A power regression model of the direct empirical relationship between POC and the atmospherically Rayleigh-corrected MODIS product (R rc,645 -R rc,1240 )/(R rc,859 -R rc,1240 ) was developed (R 2  = 0.72, RMSE = 35.86 μgL −1 , p < 0.0001, N = 47) and validated (RMSE = 44.46 μgL −1 , N = 16) with field data from 56 lakes in the Middle and Lower reaches of the Yangtze River, China. This algorithm was applied to an 11 year series of MODIS data to determine the spatial and temporal distribution of POC in a wide range of lakes with different trophic and optical properties. The results indicate that there is a general increase in minimum POC concentrations in lakes from middle to lower reaches of the Yangtze River. The temporal dynamics of springtime POC in smaller lakes were found to be influenced by local meteorological conditions, in particular precipitation and wind speed, while larger lakes were found to be more sensitive to air temperature. (letter)

  1. Activation of the NLRP3 inflammasome is not a feature of all particulate vaccine adjuvants

    DEFF Research Database (Denmark)

    Neumann, Silke; Burkert, Kristina; Kemp, Roslyn

    2014-01-01

    Particulate vaccine formulations, designed to improve the delivery of antigens to antigen-presenting cells (APCs) and to stimulate an immune response, have been shown to activate the NLRP3 inflammasome. This leads to the processing and secretion of interleukin (IL)-1β, which supports the recruitm...... vaccine formulation.Immunology and Cell Biology advance online publication, 1 April 2014; doi:10.1038/icb.2014.21....

  2. Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

    Science.gov (United States)

    Wang, Liwei; Wang, Xinfeng; Gu, Rongrong; Wang, Hao; Yao, Lan; Wen, Liang; Zhu, Fanping; Wang, Weihao; Xue, Likun; Yang, Lingxiao; Lu, Keding; Chen, Jianmin; Wang, Tao; Zhang, Yuanghang; Wang, Wenxing

    2018-03-01

    Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain) in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m-3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m-3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

  3. Environmentally Persistent Free Radical (EPFRs) - Ambient Air Particulates, Soils and Fate of Some Pollutants

    Science.gov (United States)

    Lomnicki, S. M.

    2017-12-01

    Environmentally Persistent Free Radicals (EPFRs) are relatively recently discovered species that are present on ambient air particulates. Their origin is typically associated with the combustion borne PM, where in the cool zone of the combustion process aromatic precursors react with the metal centers of particulates forming surface-organic complex with radical characteristics. EPFRs have been found to be sufficiently resistant to be emitted from the combustion sources and persist in the ambient air on particulates. Their inhalation has been associated with severe health effects, and potentially are one of the major agents contributing the epidemiological risks of PM exposure. Interestingly, EPFRs can be formed not only at the elevated temperatures but also in ambient conditions, where the contact of precursor molecules with transition metal (but not only) domains can result in adsorbate complexes. In fact, EPFRs have been detected in the contaminated soils, or during the oil spill incidents. It is very likely, that the interaction of some molecules released to the air can result in the formation of EPFRs on the ambient air particulates in atmospheric conditions. These species can be a natural degradation by-products that lead to the formation of oxygenated organics in ambient atmosphere.

  4. Organic and Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Robert

    2016-04-01

    The purpose of this study was to measure the organic carbon (OC) and elemental carbon (EC) fractions of PM2.5 particulate matter at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) sampling site for a 6-month period during the summer of 2013. The site is in a rural location remote from any populated areas, so it would be expected to reflect carbon concentration over long-distance transport patterns. During the same period in 2012, a number of prairie fires in Oklahoma and Texas had produced large plumes of smoke particles, but OC and EC particles had not been quantified. In addition, during the summer months, other wild fires, such as forest fires in the Rocky Mountain states and other areas, can produce carbon aerosols that are transported over long distances. Both of these source types would be expected to contain mixtures of both OC and EC.

  5. Late summer carbon export and remineralisation in the Southern Ocean determined with the combined 234Th and particulate biogenic Ba tracers

    Science.gov (United States)

    Planchon, F.; Cavagna, A.-J.; Cardinal, D.; André, L.; Dehairs, F.

    2012-04-01

    As part of the Bonus-GoodHope expedition (late summer 2008; Feb-March) in the Atlantic sector of the Southern Ocean, we present combined 234Th and biogenic particulate barium (Baxs) results. These data are used to estimate the export of particulate organic carbon (POC) from the upper mixed layer and the impact of twilight zone remineralisation on the carbon export. Total 234Th activity in surface waters is depleted relative to its parent nuclide 238U (234Th/238U ratio ranging from 0.74 to 0.91), while equilibrium is reached at the base of the surface mixed-layer. The export fluxes of 234Th from the 100m horizon, as estimated using steady state (SS) and non steady state (NSS) models, reveal different latitudinal trends. SS 234Th export varies from 496 dpm m-2 d-1 in the subtropical domain of the Cape Basin to 1195 dpm m-2 d-1 close to the Polar Front (PF). NSS export representative for a 15 to 22 day period preceding the cruise, is consistently less than SS export in the sub-Antarctic Zone (SAZ, 150 dpm m-2 d-1) and the Polar Frontal Zone (PFZ, 440 dpm m-2 d-1) but is similar further south in the Antarctic Zone (AZ, 1217 dpm m-2 d-1) and the northern Weddell Gyre (N-WG; 757 dpm m-2 d-1). This reflects temporal variability of export north of the PF, while south of the PF the export system appears to be in steady state during this late summer situation. The POC:Th ratio of large (>53 µm) particles collected below the surface mixed layer increases from 1.7 µmol dpm-1 in the STZ to a maximum of 4.8 µmol dpm-1 at the Southern Antarctic Circumpolar Current Front (SACCF), suggesting a southward increase of the contribution of larger cells, such as diatoms, to sinking material. Using these POC:Th ratios we calculate that the POC SS export from the 100m horizon reaches 0.9-1.7 mmol m-2 d-1 in the STZ and the SAZ, 2.6-4.7 mmol m-2 d-1 in the PFZ, and 3.3 mmol m-2 d-1 in the N-WG. Below the export layer, in the mesopelagic zone (100-600 m), 234Th activities generally reach

  6. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Science.gov (United States)

    Jiang, Huanhuan; Jang, Myoseon; Yu, Zechen

    2017-08-01

    When hydrocarbons (HCs) are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs). These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes) and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs) to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t = 30 min) of dithiothreitol (DTTt), a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2-5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC / NOx ratio from 30 to 5). The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm) was determined over an extended period of reaction time (t = 2 h) to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC / NOx ratio: 5-36 ppbC ppb-1) applied in this study, the amount of organic hydroperoxides was

  7. Characteristics of PCDD/F congener distributions in gas/particulate phases and emissions from two municipal solid waste incinerators in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Kai Hsien; Chang, Moo Been [Graduate Institute of Environmental Engineering, National Central University, Chungli 320 (Taiwan); Chang-Chien, Guo Ping [Department of Chemical Engineering, Cheng-Shiu University, Kaohsiung 833 (Taiwan); Lin, Chieh [Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung 920 (Taiwan)

    2005-07-15

    Partitioning of PCDD/F (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) congeners between gaseous and particulate phases and removal efficiencies of the existing air pollution control devices (APCDs) for PCDD/Fs at two large-scale municipal waste incinerators (MWIs) in Taiwan are evaluated via stack sampling and analysis. Two MWIs investigated are equipped with activated carbon injection (ACI) and selective catalytic reduction system (SCR) as major PCDD/F control devices, respectively. The average PCDD/F concentrations of stack gases are 2.35 and 1.49 ng/N m{sup 3}, and the international toxic equivalent quantity (TEQ) are 0.17 and 0.043 ng TEQ/N m{sup 3} in MWI-A and MWI-B, respectively. The average removal efficiency of PCDD/Fs achieved with ACI+BF (bag filters) reaches 95% (MWI-A) while that achieved with the WS (wet scrubber)+SCR system reaches 99% (MWI-B). The results obtained on gas/particulate partitioning in flue gases indicate that particulate-phase PCDD/Fs accounted for 27.7% and 24.7% of the total PCDD/F concentrations at the outlets of cyclone (CY) and electrostatic precipitator (EP) for MWI-A and MWI-B, respectively. But the gas/particulate partitioning in flue gas after PCDD/Fs control devices is quite different in two MWIs. This study also indicates that total 2,3,7,8-substituted PCDD/F discharges are 142.3 {mu}g TEQ/ton waste for MWI-A and 98.6 {mu}g TEQ/ton waste for MWI-B, respectively.

  8. MONITORING OF PHOSPHORUS CONTENT IN “WATER-PARTICULATE MATERIALS-BOTTOM SEDIMENTS SYSTEM” FOR RIVER PRUT

    Directory of Open Access Journals (Sweden)

    VASILE RUSU

    2011-03-01

    Full Text Available Monitoring of phosphorus content in “water-particulatematerials-bottom sediments system” for river Prut. Seasonal and spatialdynamics of phosphorus forms in water, particulate materials and bottomsediments of river Prut was elucidated. The scheme for determination ofphosphorus forms in water and particulate materials according to World HealthOrganization classification was evaluated. Additionally, this scheme was tested forestimation of phosphorus content in bottom sediments. The supplemented schemeallows the analysis of the phosphorus forms for the entirely system “water –particulate materials – bottom sediments”, extending possibilities for interpretationof phosphorus dynamics in natural waters.

  9. Characterization of airborne and bulk particulate from iron and steel manufacturing facilities.

    Science.gov (United States)

    Machemer, Steven D

    2004-01-15

    Characterization of airborne and bulk particulate material from iron and steel manufacturing facilities, commonly referred to as kish, indicated graphite flakes and graphite flakes associated with spherical iron oxide particles were unique particle characteristics useful in identifying particle emissions from iron and steel manufacturing. Characterization of airborne particulate material collected in receptor areas was consistent with multiple atmospheric release events of kish particles from the local iron and steel facilities into neighboring residential areas. Kish particles deposited in nearby residential areas included an abundance of graphite flakes, tens of micrometers to millimeters in size, and spherical iron oxide particles, submicrometer to tens of micrometers in size. Bulk kish from local iron and steel facilities contained an abundance of similar particles. Approximately 60% of blast furnace kish by volume consisted of spherical iron oxide particles in the respirable size range. Basic oxygen furnace kish contained percent levels of strongly alkaline components such as calcium hydroxide. In addition, concentrations of respirable Mn in airborne particulate in residential areas and at local iron and steel facilities were approximately 1.6 and 53 times the inhalation reference concentration of 0.05 microg/m3 for chronic inhalation exposure of Mn, respectively. Thus, airborne release of kish may pose potential respirable particulate, corrosive, or toxic hazards for human health and/or a corrosive hazard for property and the environment.

  10. Particulate matter mass concentrations produced from pavement surface abrasion

    Directory of Open Access Journals (Sweden)

    Fullova Dasa

    2017-01-01

    Full Text Available According to the latest findings particulate matter belong to the most significant pollutants in Europe together with ground-level ozone O3 and nitrogen dioxide NO2. Road traffic is one of the main sources of particulate matter. Traffic volume has unpleasant impact on longevity of the pavements and also on the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The paper deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The paper offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.

  11. Behavior of secondary particles in particulate matter collected at eastern Kanagawa

    International Nuclear Information System (INIS)

    Nishida, Tomohiro; Kikawada, Yoshikazu; Oi, Takao; Honda, Teruyuki

    2008-01-01

    The suspended particulate matters collected in 100 periods from 2002/10/28 to 2004/10/29 were separated into the water soluble and insoluble components and their main components were analyzed. The characteristics of atmosphere in the east part of Kagawa prefecture and of the secondary particulates were presumed. Therefore, it was considered that in the samples other than Mn the origins of water soluble and insoluble components are different each other from their behavior. The water-soluble part may be mostly ammonium salt (secondary particulate) from the measurement of NH 4 + . Furthermore, it became clear that the evolution of secondary particulate varies largely with season. Then, the variation with season was presumed by the main component analysis using the statistical software, SPSS adding to the correlation coefficient. This method has proved to be effective. (M.H.)

  12. Control strategies for the reduction of airborne particulate nitrate in California's San Joaquin Valley

    Science.gov (United States)

    Kleeman, Michael J.; Ying, Qi; Kaduwela, Ajith

    The effect of NO x, volatile organic compound (VOC), and NH 3 emissions control programs on the formation of particulate ammonium nitrate in the San Joaquin Valley (SJV) was examined under the typical winter conditions that existed on 4-6 January, 1996. The UCD/CIT photochemical transport model was used for this study so that the source origin of primary particulate matter and secondary particulate matter could be identified. When averaged across the entire SJV, the model results predict that 13-18% of the reactive nitrogen (NO y=NO x+reaction products of NO x) emitted from local sources within the SJV was converted to nitrate at the ground level. Each gram of NO x emitted locally within the SJV (expressed as NO 2) produced 0.23-0.31 g of particulate ammonium nitrate (NH 4NO 3), which is much smaller than the maximum theoretical yield of 1.7 g of NH 4NO 3 per gram of NO 2. The fraction of reactive nitrogen converted to nitrate varied strongly as a function of location. Urban regions with large amounts of fresh NO emissions converted little reactive nitrogen to nitrate, while remote areas had up to 70% conversion (equivalent to approximately 1.2 g of NH 4NO 3 per gram of NO 2). The use of a single spatially averaged ratio of NH 4NO 3/NO x as a predictor of how changes to NO x emissions would affect particulate nitrate concentrations would not be accurate at all locations in the SJV under the conditions studied. The largest local sources of particulate nitrate in the SJV were predicted to be diesel engines and catalyst equipped gasoline engines under the conditions experienced on 6 January, 1996. Together, these sources accounted for less than half of the ground-level nitrate aerosol in the SJV. The remaining fraction of the aerosol nitrate originated from reactive nitrogen originally released upwind of the SJV. The majority of this upwind reactive nitrogen was already transformed to nitrate by the time it entered the SJV. The effect of local emissions controls on

  13. Electric charging for preparation of composite particulate materials. Funtai no fukugo zairyoka no tame no kaden sosa

    Energy Technology Data Exchange (ETDEWEB)

    Endo, S [National Institute for Resources and Environment, Tsukuba (Japan)

    1992-11-30

    Explanation was made of problems in interparticulate coagulation mainly in the mixing process of microparticulates which are less than 0.1[mu]m in diameter and about 1[mu]m diameter particulates for the composition in gaseous phase. The utilization of electrostatic interaction was particularly explained together with the recent result of basic experiment. The composition of two-component particulate system in the gaseous phase progresses generally with the Brownian movement and electrostatic interaction of particulates. The interparticulate collision/coagulation rate is evaluated by the coagulation rate function. As for the electric charging operation to make the coagulation more effective, application is made of contact or collision charging and ionic charging, and the latter is further divided into electric field charging and diffusion charging. Experiment was conducted by mixing TiO2 microparticulates which were less than 100nm in diameter and about 1[mu]m diameter PSL (polystyrene latex) particulates for the composition in a mixer. As a result of investigating the coagulation process with a device which could observe the diffused laser beam from the particulates, confirmation could be made of the situation in which the particulate charging effectively contributed to the composition. 20 refs., 10 figs., 2 tabs.

  14. Validation and Intercomparison of Ocean Color Algorithms for Estimating Particulate Organic Carbon in the Oceans

    Directory of Open Access Journals (Sweden)

    Hayley Evers-King

    2017-08-01

    Full Text Available Particulate Organic Carbon (POC plays a vital role in the ocean carbon cycle. Though relatively small compared with other carbon pools, the POC pool is responsible for large fluxes and is linked to many important ocean biogeochemical processes. The satellite ocean-color signal is influenced by particle composition, size, and concentration and provides a way to observe variability in the POC pool at a range of temporal and spatial scales. To provide accurate estimates of POC concentration from satellite ocean color data requires algorithms that are well validated, with uncertainties characterized. Here, a number of algorithms to derive POC using different optical variables are applied to merged satellite ocean color data provided by the Ocean Color Climate Change Initiative (OC-CCI and validated against the largest database of in situ POC measurements currently available. The results of this validation exercise indicate satisfactory levels of performance from several algorithms (highest performance was observed from the algorithms of Loisel et al., 2002; Stramski et al., 2008 and uncertainties that are within the requirements of the user community. Estimates of the standing stock of the POC can be made by applying these algorithms, and yield an estimated mixed-layer integrated global stock of POC between 0.77 and 1.3 Pg C of carbon. Performance of the algorithms vary regionally, suggesting that blending of region-specific algorithms may provide the best way forward for generating global POC products.

  15. Effects of dietary particulate limestone, vitamin K3 and fluoride and photostimulation on skeletal morphology and osteoporosis in laying hens.

    Science.gov (United States)

    Fleming, R H; McCormack, H A; McTeir, L; Whitehead, C C

    2003-12-01

    1. Female chicks of a White Leghorn strain were fed three different diets from one day old: control, additional vitamin K3 (10 mg/kg), and a diet containing a combination of additional vitamin K3, sodium fluoride (10 mg/kg) and limestone in particulate rather than powdered form. At 16 weeks photoperiod was increased for half the birds from 8:16 L:D to 16:8 L:D immediately or by one hour per week to the same ultimate photoperiod for the other half. 2. Age at first egg was lower by 4.0 d for birds on the fast lighting regime but there were no overall effects of lighting on bone quality at either 25 or 70 weeks. 3. Additional vitamin K3 resulted in higher proximal tarsometatarsus cancellous bone volumes at 15 weeks and throughout the laying period compared with controls. Plasma osteocalcin concentrations were unaffected by vitamin K3 supplementation during growth. 4. The combination diet resulted in beneficial responses of 12 to 20% in most bone characteristics in hens at 70 weeks. The magnitude of these effects was similar to a previous study involving a particulate calcium source alone (Fleming et al., Poultry Science, 39: 434-440, 1998b). We conclude that the beneficial effects of the combined treatment over the lifetime of the hens were attributable mainly to the presence in the diet of a calcium source in particulate form.

  16. Particulate air pollution and vascular reactivity: the bus stop study.

    Science.gov (United States)

    Dales, Robert; Liu, Ling; Szyszkowicz, Mietek; Dalipaj, Mary; Willey, Jeff; Kulka, Ryan; Ruddy, Terrence D

    2007-11-01

    Particulate air pollution is associated with cardiovascular morbidity but mechanisms are not well understood. We tested the effects on vascular reactivity of exposure to fine particulates matter mass (PM(2.5)), number of particles bus stops. Flow-mediated vasodilation (FMD) of the brachial artery was then measured by ultrasound and expressed as: (maximum artery diameter after release of a blood pressure cuff inflated above systolic pressure-baseline resting diameter)/baseline resting diameter. A 30 microg/m(3) increase in PM(2.5) exposure corresponded to a 0.48% reduction in FMD, P=0.05 representing a 5% relative change in the maximum ability to dilate. Results were consistent between the two bus stops and not sensitive to type of analysis. No significant association was found between FMD and NO(2), PM(1.0) or traffic density. PM(2.5) may reduce the capacity to vasodilate, a potential explanation for the documented association with cardiovascular morbidity.

  17. Miniaturized inertial impactor for personal airborne particulate monitoring: Prototyping

    Science.gov (United States)

    Pasini, Silvia; Bianchi, Elena; Dubini, Gabriele; Cortelezzi, Luca

    2017-11-01

    Computational fluid dynamic (CFD) simulations allowed us to conceive and design a miniaturized inertial impactor able to collect fine airborne particulate matter (PM10, PM2.5 and PM1). We created, by 3D printing, a prototype of the impactor. We first performed a set of experiments by applying a suction pump to the outlets and sampling the airborne particulate of our laboratory. The analysis of the slide showed a collection of a large number of particles, spanning a wide range of sizes, organized in a narrow band located below the exit of the nozzle. In order to show that our miniaturized inertial impactor can be truly used as a personal air-quality monitor, we performed a second set of experiments where the suction needed to produce the airflow through the impactor is generated by a human being inhaling through the outlets of the prototype. To guarantee a number of particles sufficient to perform a quantitative characterization, we collected particles performing ten consecutive deep inhalations. Finally, the potentiality for realistic applications of our miniaturized inertial impactor used in combination with a miniaturized single-particle detector will be discussed. CARIPLO Fundation - project MINUTE (Grant No. 2011-2118).

  18. Trimethylsilyl derivatives of organic compounds in source samples and in atmospheric fine particulate matter.

    Science.gov (United States)

    Nolte, Christopher G; Schauer, James J; Cass, Glen R; Simoneit, Bernd R T

    2002-10-15

    Source sample extracts of vegetative detritus, motor vehicle exhaust, tire dust paved road dust, and cigarette smoke have been silylated and analyzed by GC-MS to identify polar organic compounds that may serve as tracers for those specific emission sources of atmospheric fine particulate matter. Candidate molecular tracers were also identified in atmospheric fine particle samples collected in the San Joaquin Valley of California. A series of normal primary alkanols, dominated by even carbon-numbered homologues from C26 to C32, the secondary alcohol 10-nonacosanol, and some phytosterols are prominent polar compounds in the vegetative detritus source sample. No new polar organic compounds are found in the motor vehicle exhaust samples. Several hydrogenated resin acids are present in the tire dust sample, which might serve as useful tracers for those sources in areas that are heavily impacted by motor vehicle traffic. Finally, the alcohol and sterol emission profiles developed for all the source samples examined in this project are scaled according to the ambient fine particle mass concentrations attributed to those sources by a chemical mass balance receptor model that was previously applied to the San Joaquin Valley to compute the predicted atmospheric concentrations of individual alcohols and sterols. The resulting underprediction of alkanol concentrations at the urban sites suggests that alkanols may be more sensitive tracers for natural background from vegetative emissions (i.e., waxes) than the high molecular weight alkanes, which have been the best previously available tracers for that source.

  19. Cervical transforaminal epidural steroid injection for the management of cervical radiculopathy: a comparative study of particulate versus non-particulate steroids

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Woo; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Gyeonggi-Do (Korea); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Gyeonggi-Do (Korea); Chung, Sang-Ki; Kim, Ki-Jeong; Kim, Hyun-Jib [Seoul National University Bundang Hospital, Department of Neurosurgery, Gyeonggi-do (Korea)

    2009-11-15

    To determine if a particulate steroid which has a risk for embolic infarct would be more effective than a non-particulate steroid for transforaminal epidural steroid injection (TFESI). The purpose of this study was (1) to compare the effect of cervical TFESI using particulate (e.g., triamcinolone) and non-particulate (e.g., dexamethasone) steroids and (2) to evaluate the effectiveness of cervical TFESI in general. From January 2006 to August 2008, 159 consecutive patients [male:female (M:F) 89:70; mean age 53 years, range 33-75 years] who underwent cervical TFESI were included in this non-randomized study. For cervical TFESI, triamcinolone was injected into 97 patients and dexamethasone into 62 patients. Short-term follow-up was conducted within 1 month. The outcome was classified as effective or ineffective. Fisher's exact test was used to analyze the difference of outcome according to the injected steroid (triamcinolone vs dexamethasone). Other possible outcome predictors, such as age, gender, duration of radiculopathy, predominant symptom, attack of radiculopathy, cause of radiculopathy, number of nerve root compression levels, previous operation, and failure of previous interlaminar epidural injection, were also analyzed. Cervical TFESI using triamcinolone (78/97, 80.4%) was slightly more effective than that using dexamethasone (43/62, 69.4%), which was not significant (P = 0.129). In general, cervical TFESIs were effective in 121 of 159 patients (76.1%) at short-term follow-up. The only significant outcome predictor was whether the patient had had a previous operation (6/13, 46/2%) or not (115/146, 78.8%) (P = 0.015). There was no significant difference between particulate or non-particulate steroid for the effect of cervical TFESI. Cervical TFESI was effective in managing cervical radiculopathy in general. (orig.)

  20. Cervical transforaminal epidural steroid injection for the management of cervical radiculopathy: a comparative study of particulate versus non-particulate steroids

    International Nuclear Information System (INIS)

    Lee, Joon Woo; Kang, Heung Sik; Park, Kun Woo; Yeom, Jin S.; Chung, Sang-Ki; Kim, Ki-Jeong; Kim, Hyun-Jib

    2009-01-01

    To determine if a particulate steroid which has a risk for embolic infarct would be more effective than a non-particulate steroid for transforaminal epidural steroid injection (TFESI). The purpose of this study was (1) to compare the effect of cervical TFESI using particulate (e.g., triamcinolone) and non-particulate (e.g., dexamethasone) steroids and (2) to evaluate the effectiveness of cervical TFESI in general. From January 2006 to August 2008, 159 consecutive patients [male:female (M:F) 89:70; mean age 53 years, range 33-75 years] who underwent cervical TFESI were included in this non-randomized study. For cervical TFESI, triamcinolone was injected into 97 patients and dexamethasone into 62 patients. Short-term follow-up was conducted within 1 month. The outcome was classified as effective or ineffective. Fisher's exact test was used to analyze the difference of outcome according to the injected steroid (triamcinolone vs dexamethasone). Other possible outcome predictors, such as age, gender, duration of radiculopathy, predominant symptom, attack of radiculopathy, cause of radiculopathy, number of nerve root compression levels, previous operation, and failure of previous interlaminar epidural injection, were also analyzed. Cervical TFESI using triamcinolone (78/97, 80.4%) was slightly more effective than that using dexamethasone (43/62, 69.4%), which was not significant (P = 0.129). In general, cervical TFESIs were effective in 121 of 159 patients (76.1%) at short-term follow-up. The only significant outcome predictor was whether the patient had had a previous operation (6/13, 46/2%) or not (115/146, 78.8%) (P = 0.015). There was no significant difference between particulate or non-particulate steroid for the effect of cervical TFESI. Cervical TFESI was effective in managing cervical radiculopathy in general. (orig.)

  1. Electrical diesel particulate filter (DPF) regeneration

    Science.gov (United States)

    Gonze, Eugene V; Ament, Frank

    2013-12-31

    An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

  2. Feasibility of plasma aftertreatment for simultaneous control of NOx and particulates

    International Nuclear Information System (INIS)

    Brusasco, R M; Merritt, B T; Penetrante, B; Pitz, W J; Vogtlin, G E

    1999-01-01

    Plasma reactors can be operated as a particulate trap or as a NOx converter. Particulate trapping in a plasma reactor can be accomplished by electrostatic precipitation. The soluble organic fraction of the trapped particulates can be utilized for the hydrocarbon-enhanced oxidation of NO to NO2 . The NO2 can then be used to non-thermally oxidize the carbon fraction of the particulates. The oxidation of the carbon fraction by NO2 can lead to reduction of NOx or backconversion of NO2 to NO. This paper examines the hydrocarbon and electrical energy density requirements in a plasma for maximum NOx conversion in both heavy-duty and light-duty diesel engine exhaust. The energy density required for complete oxidation of hydrocarbons is also examined and shown to be much greater than that required for maximum NOx conversion. The reaction of NO2 with carbon is shown to lead mainly to backconversion of NO2 to NO. These results suggest that the combination of the plasma with a catalyst will be required to reduce the NOx and oxidize the hydrocarbons. The plasma reactor can be operated occasionally in the arc mode to thermally oxidize the carbon fraction of the particulates

  3. Potential effects of particulate matter from combustion during services on human health and on works of art in medieval churches in Cyprus

    International Nuclear Information System (INIS)

    Loupa, Glykeria; Karageorgos, Evangelos; Rapsomanikis, Spyridon

    2010-01-01

    Indoor and outdoor particulate matter (PM 0.3-10 ) number concentrations were established in two medieval churches in Cyprus. In both churches incense was burnt occasionally during Mass. The highest indoor PM 0.5-1 concentrations compared with outdoors (10.7 times higher) were observed in the church that burning of candles indoors was allowed. Peak indoor black carbon concentration was 6.8 μg m -3 in the instances that incense was burning and 13.4 μg m -3 in the instances that the candles were burning (outdoor levels ranged between 0.6 and 1.3 μg m -3 ). From the water soluble inorganic components determined in PM 10 , calcium prevailed in all samples indoors or outdoors, whilst high potassium concentration indoors were a clear marker of combustion. Indoor sources of PM were clearly identified and their emission strengths were estimated via modeling of the results. Indoor estimated PM 0.3-10 mass concentrations exceeded air quality standards for human health protection and for the preservation of works of art. - Particulate matter in medieval churches of Cyprus.

  4. Rapid prediction of particulate, humus and resistant fractions of soil organic carbon in reforested lands using infrared spectroscopy.

    Science.gov (United States)

    Madhavan, Dinesh B; Baldock, Jeff A; Read, Zoe J; Murphy, Simon C; Cunningham, Shaun C; Perring, Michael P; Herrmann, Tim; Lewis, Tom; Cavagnaro, Timothy R; England, Jacqueline R; Paul, Keryn I; Weston, Christopher J; Baker, Thomas G

    2017-05-15

    Reforestation of agricultural lands with mixed-species environmental plantings can effectively sequester C. While accurate and efficient methods for predicting soil organic C content and composition have recently been developed for soils under agricultural land uses, such methods under forested land uses are currently lacking. This study aimed to develop a method using infrared spectroscopy for accurately predicting total organic C (TOC) and its fractions (particulate, POC; humus, HOC; and resistant, ROC organic C) in soils under environmental plantings. Soils were collected from 117 paired agricultural-reforestation sites across Australia. TOC fractions were determined in a subset of 38 reforested soils using physical fractionation by automated wet-sieving and 13 C nuclear magnetic resonance (NMR) spectroscopy. Mid- and near-infrared spectra (MNIRS, 6000-450 cm -1 ) were acquired from finely-ground soils from environmental plantings and agricultural land. Satisfactory prediction models based on MNIRS and partial least squares regression (PLSR) were developed for TOC and its fractions. Leave-one-out cross-validations of MNIRS-PLSR models indicated accurate predictions (R 2  > 0.90, negligible bias, ratio of performance to deviation > 3) and fraction-specific functional group contributions to beta coefficients in the models. TOC and its fractions were predicted using the cross-validated models and soil spectra for 3109 reforested and agricultural soils. The reliability of predictions determined using k-nearest neighbour score distance indicated that >80% of predictions were within the satisfactory inlier limit. The study demonstrated the utility of infrared spectroscopy (MNIRS-PLSR) to rapidly and economically determine TOC and its fractions and thereby accurately describe the effects of land use change such as reforestation on agricultural soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Membrane Characteristics for Removing Particulates in PFC Wastes

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin; Park, Jin Ho

    2005-01-01

    Pc (Per fluorocarbon) decontamination process is one of best methods to remove hot particulate adhered at inside surface of hot cell and surface of equipment in hot cell. It was necessary to develop a particulate filtration equipment to reuse Pc solution used on Pc decontamination due to its high cost and to minimize the volume of second wastewater. Contamination characteristics of hot particulate were investigated and then a filtration process was presented to remove hot particulate in Pc solution generated through Pc decontamination process. The removal efficiency of Pvdf (Poly vinylidene fluoride), Pp (Polypropylene), Ceramic (Al 2 O 3 ) filter showed more than 95%. The removal efficiency of Pvdf filter was a little lower than those of other kiters at same pressure (3 psi). A ceramic filter showed a higher removal efficiency with other filters, while a little lower flux rate than other filters. Due to inorganic composition, a ceramic filter was highly stable against radio nuclides in comparison with Pvdf and Pp membrane, which generate H 2 gas in α-radioactivity atmosphere. Therefore, the adoption of ceramic filter is estimated to be suitable for the real nitration process.

  6. Airborne particulate matter from livestock production systems: A review of an air pollution problem

    International Nuclear Information System (INIS)

    Cambra-Lopez, Maria; Aarnink, Andre J.A.; Zhao Yang; Calvet, Salvador; Torres, Antonio G.

    2010-01-01

    Livestock housing is an important source of emissions of particulate matter (PM). High concentrations of PM can threaten the environment, as well as the health and welfare of humans and animals. Particulate matter in livestock houses is mainly coarse, primary in origin, and organic; it can adsorb and contain gases, odorous compounds, and micro-organisms, which can enhance its biological effect. Levels of PM in livestock houses are high, influenced by kind of housing and feeding, animal type, and environmental factors. Improved knowledge on particle morphology, primarily size, composition, levels, and the factors influencing these can be useful to identify and quantify sources of PM more accurately, to evaluate their effects, and to propose adequate abatement strategies in livestock houses. This paper reviews the state-of-the-art of PM in and from livestock production systems. Future research to characterize and control PM in livestock houses is discussed. - Control of particulate matter emissions, a major challenge to modern livestock production.

  7. Y{sub 3}Fe{sub 5}O{sub 12}/Na,Bi,Sr-doped PZT particulate magnetoelectric composites

    Energy Technology Data Exchange (ETDEWEB)

    Lisnevskaya, I.V., E-mail: liv@sfedu.ru; Bobrova, I.A.; Lupeiko, T.G.; Agamirzoeva, M.R.; Myagkaya, K.V.

    2016-05-01

    Magnetoelectric (ME) composites of Na, Bi, Sr substituted lead zirconate titanate (PZT) and yttrium iron garnet having representative formula (100−x) wt% Na,Bi,Sr-doped PZT (PZTNB-1)+x wt% Y{sub 3}Fe{sub 5}O{sub 12} (YIG) with x=10–90 were manufactured using powdered components obtained through sol–gel processes. It is shown that the decrease in sintering temperature provided by the use of finely dispersed PZTNB-1 and YIG powders allows to significantly reduce content of fluorite-like foreign phase based on zirconium oxide, which forms due to the interfacial interaction during heat treatment and becomes stabilized by yttrium oxide. Connectivity has considerable effect on the value of ME coefficient of composite ceramics. With the same x value, ΔE/ΔH characteristic decreases when changing from 0–3-type structured composites (PZT grains embedded in ferrite matrix) to 3-3-(interpenetrating network of two phases) and especially 3-0-type samples (YIG grains embedded in PZT matrix); in the last case this can be attributed to the substrate clamping effect when ferrite grains are clamped with piezoelectric matrix. ΔE/ΔH value of 0–3 composites with x=40–60 wt% was found to be ∼1.6 mV/(cm Oe). - Highlights: • Y{sub 3}Fe{sub 5}O{sub 12}/Na,Bi,Sr-doped PZT particulate magnetoelectric composites were prepared. • The decrease in sintering temperature reduces the content of foreign phase of ZrO{sub 2}. • Connectivity pattern is important factor for magnetoelectric response. • The value of ME coefficient reaches ~1,6 mV/(cm Oe) in 0–3 composites.

  8. Origin, composition and quality of suspended particulate organic matter in relation to freshwater inflow in a South Texas estuary

    Science.gov (United States)

    Lebreton, Benoit; Beseres Pollack, Jennifer; Blomberg, Brittany; Palmer, Terence A.; Adams, Leslie; Guillou, Gaël; Montagna, Paul A.

    2016-03-01

    South Texas has a semi-arid climate with a large interannual variability of freshwater inflows. This study sought to define how changes in freshwater inflow affect the composition, quantity and quality of suspended particulate organic matter (SPOM) in a South Texas estuary: the Mission-Aransas estuary. The study was implemented 1.5 months after a large rain event in September 2010 and continued for 10 months of drought conditions. The composition of SPOM originating from rivers, the Gulf of Mexico and the estuary were determined using stable isotopes (δ13C, δ15N and δ34S). The quantity and quality of SPOM were assessed using organic carbon content, chlorophyll a concentrations and C/chl a ratios. Our results demonstrated that autochthonous phytoplankton was the dominant component of SPOM in the Mission-Aransas estuary during droughts. Benthic organic matter from local primary producers (i.e., seagrass, salt marsh plants, benthic microalgae) did not influence SPOM composition, either as fresh material or as detritus. A comparison with a positive estuary (i.e., Sabine-Neches estuary, TX) indicates that decreases in freshwater inflow may lead to decreases of terrestrial organic matter inputs and to increase the ratio of autochtonous phytoplanktonic material in SPOM.

  9. Formation of Particulate Matter from the Oxidation of Evaporated Wastewater from Hydraulic Fracturing Activity

    Science.gov (United States)

    Hildebrandt Ruiz, L.; Bean, J. K.; Bilotto, A.

    2017-12-01

    The use of hydraulic fracturing for production of petroleum and natural gas has increased dramatically in the last decade, but the environmental impacts of this technology remain unclear. Experiments were conducted to quantify airborne emissions from twelve samples of hydraulic fracturing flowback wastewater collected in the Permian Basin, as well as the photochemical processing of these emissions leading to the formation of particulate matter. The concentration of total volatile carbon (TVC, hydrocarbons evaporating at room temperature) averaged 29 milligrams of carbon per liter (mgC/L) and the TVC evaporation rate averaged 1357 mgC/L-m2-min. After photochemical oxidation under high NOx conditions the amount of organic particulate matter formed per milliliter of wastewater evaporated averaged 24 micrograms (µg); the amount of ammonium nitrate formed averaged 262 µg. In the state of Texas, the potential formation of PM from evaporated flowback wastewater is similar to the estimated PM emissions from diesel engines used in oil rigs, emphasizing the need to quantify wastewater evaporation and atmospheric processing of these emissions.

  10. Occupational Exposure to Diesel Particulate Matter in Municipal Household Waste Workers.

    Directory of Open Access Journals (Sweden)

    Kyong-Hui Lee

    Full Text Available The purposes of this study were to determine the following: 1 the exposure levels of municipal household waste (MHW workers to diesel particulate matter (DPM using elemental carbon (EC, organic carbon (OC, total carbon (TC, black carbon (BC, and fine particulate matter (PM 2.5 as indicators; 2 the correlations among the indicators; 3 the optimal indicator for DPM; and 4 factors that influence personal exposure to DPM.A total of 72 workers in five MHW collection companies were assessed over a period of 7 days from June to September 2014. Respirable EC/OC samples were quantified using the thermal optical transmittance method. BC and PM 2.5 were measured using real-time monitors, an aethalometer and a laser photometer. All results were statistically analyzed for occupational and environmental variables to identify the exposure determinants of DPM.The geometric mean of EC, OC, TC, BC and PM 2.5 concentrations were 4.8, 39.6, 44.8, 9.1 and 62.0 μg/m3, respectively. EC concentrations were significantly correlated with the concentrations of OC, TC and BC, but not with those of PM 2.5. The exposures of the MHW collectors to EC, OC, and TC were higher than those of the drivers (p<0.05. Workers of trucks meeting Euro 3 emission standard had higher exposures to EC, OC, TC and PM 2.5 than those working on Euro 4 trucks (p<0.05. Multiple regression analysis revealed that the job task, European engine emission standard, and average driving speed were the most influential factors in determining worker exposure.We assessed MHW workers' exposure to DPM using parallel sampling of five possible indicators. Of these five indicators, EC was shown to be the most useful indicator of DPM exposure for MHW workers, and the job task, European emission standard, and average driving speed were the main determinants of EC exposure.

  11. Predicting ambient aerosol Thermal Optical Reflectance (TOR) measurements from infrared spectra: organic carbon

    Science.gov (United States)

    Dillner, A. M.; Takahama, S.

    2014-11-01

    Organic carbon (OC) can constitute 50% or more of the mass of atmospheric particulate matter. Typically, the organic carbon concentration is measured using thermal methods such as Thermal-Optical Reflectance (TOR) from quartz fiber filters. Here, methods are presented whereby Fourier Transform Infrared (FT-IR) absorbance spectra from polytetrafluoroethylene (PTFE or Teflon) filters are used to accurately predict TOR OC. Transmittance FT-IR analysis is rapid, inexpensive, and non-destructive to the PTFE filters. To develop and test the method, FT-IR absorbance spectra are obtained from 794 samples from seven Interagency Monitoring of PROtected Visual Environment (IMPROVE) sites sampled during 2011. Partial least squares regression is used to calibrate sample FT-IR absorbance spectra to artifact-corrected TOR OC. The FTIR spectra are divided into calibration and test sets by sampling site and date which leads to precise and accurate OC predictions by FT-IR as indicated by high coefficient of determination (R2; 0.96), low bias (0.02 μg m-3, all μg m-3 values based on the nominal IMPROVE sample volume of 32.8 m-3), low error (0.08 μg m-3) and low normalized error (11%). These performance metrics can be achieved with various degrees of spectral pretreatment (e.g., including or excluding substrate contributions to the absorbances) and are comparable in precision and accuracy to collocated TOR measurements. FT-IR spectra are also divided into calibration and test sets by OC mass and by OM / OC which reflects the organic composition of the particulate matter and is obtained from organic functional group composition; this division also leads to precise and accurate OC predictions. Low OC concentrations have higher bias and normalized error due to TOR analytical errors and artifact correction errors, not due to the range of OC mass of the samples in the calibration set. However, samples with low OC mass can be used to predict samples with high OC mass indicating that the

  12. CHARACTERISTIC OF AIRBORNE PARTICULATE MATTER SAMPLES COLLECTED FROM TWO SEMI INDUSTRIAL SITES IN BANDUNG, INDONESIA

    Directory of Open Access Journals (Sweden)

    Diah Dwiana Lestiani

    2013-12-01

    Full Text Available Air particulate matter concentrations, black carbon as well as elemental concentrations in two semi industrial sites were investigated as a preliminary study for evaluation of air quality in these areas. Sampling of airborne particulate matter was conducted in July 2009 using a Gent stacked filter unit sampler and a total of 18 pairs of samples were collected. Black carbon was determined by reflectance measurement and elemental analysis was performed using particle induced X-ray emission (PIXE. Elements Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn and As were detected. Twenty four hour PM2.5 concentration at semi industrial sites Kiaracondong and Holis ranged from 4.0 to 22.2 µg m-3, while the PM10 concentration ranged from 24.5 to 77.1 µg m-3. High concentration of crustal elements, sulphur and zinc were identified in fine and coarse fractions for both sites. The fine fraction data from both sites were analyzed using a multivariate principal component analysis and for Kiaracondong site, identified factors are attributed to sea-salt with soil dust, vehicular emissions and biomass burning, non ferrous smelter, and iron/steel work industry, while for Holis site identified factors are attributed to soil dust, industrial emissions, vehicular emissions with biomass burning, and sea-salt. Although particulate samples were collected from semi industrial sites, vehicular emissions constituted with S, Zn and BC were identified in both sites.

  13. Electrically heated particulate filter restart strategy

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-07-12

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

  14. Polycyclic aromatic hydrocarbons in the urban atmospheric particulate matter in the city of Naples (Italy)

    Science.gov (United States)

    Caricchia, Anna Maria; Chiavarini, Salvatore; Pezza, Massimo

    An investigation on PAH in the atmospheric particulate matter of the city of Naples has been carried out. Urban atmospheric particulate matter was sampled in three sampling sites (West, East and central areas of the city), whose characteristics were representative of the prevailing conditions. In each site, 24 h samplings for 7 consecutive days were performed during three sampling campaigns, in 1996-1997. The results were comparable with those reported in literature for similar investigations. Total PAH were in the range 2-130 ng m -3, with a seasonal variation (autumn/winter vs. summer) in the range 1.5-4.5. The relative contribution of diesel engines vs. gasoline fuelled engines was evidenced.

  15. Volatile and semivolatile organic compounds in laboratory peat fire emissions

    Data.gov (United States)

    U.S. Environmental Protection Agency — Supporting information Tables S3 and S4 list emission factors in g/kg of speciated volatile and particulate organic compounds emitted from peat burning. Peat samples...

  16. Preliminary Characterization of Organic Geochemistry in the Fly-Strickland River System, Papua New Guinea

    Science.gov (United States)

    Alin, S. R.; Aalto, R.; Remington, S. M.; Richey, J. E.

    2003-12-01

    The Fly-Strickland fluvial dispersal system comprises one of the largest river basins in tropical Oceania, ranking among the top 20 rivers in the world for water and sediment discharge. From the New Guinea highlands, these rivers flow >1000 km across lowland tropical floodplains to the Gulf of Papua, with an average annual depth of runoff 100 times that of the Amazon. Within the system, the Strickland has greater sediment discharge and a steeper gradient than the Fly, providing an opportunity to investigate biogeochemical differences associated with particulate flux. For eight lowland sites across the Fly-Strickland river system, we analyzed water and suspended sediment (SS) samples for an initial survey of various carbon cycle parameters. Both the Fly and Strickland Rivers were strongly supersaturated with carbon dioxide (2008-10,479 uatm CO2) and undersaturated with oxygen (1.10-5.48 mg/l O2), with the Fly having higher CO2 and lower O2 concentrations than the Strickland River. These pCO2 and O2 concentrations are comparable to and lower than (respectively) typical values in the Amazon. Measured Fly-Strickland alkalinity values fell in the range of 0.893-1.888 meq, and pH measurements were neutral to slightly alkaline (6.916-7.852). In a sample from a sediment-impoverished tributary from Lake Murray to the Strickland (Herbert R.), pH was neutral (7.060), and alkalinity and pCO2 had their lowest observed values at 0.234 meq and 1407 uatm, respectively. Nutrient concentrations were generally higher in the Strickland ([NO3]=3.36+/-0.69 uM, [PO4]=0.09+/-0.10 uM, and [Si(OH)4]=176.6+/-41.7 uM) than in the Fly River ([NO3]=1.09+/-0.04 uM, [PO4]=0.01+/-0.01 uM, and [Si(OH)4]=110.6+/-4.8 uM). NO3 and PO4 concentrations in the Fly-Strickland river system were lower than in the Amazon, and silicate was comparable. SS concentrations were higher in the Strickland than in the Fly (49.4-231.1 mg/l vs. 19.5-59.6 mg/l). Coarse particulates were organic-poor in the Fly and

  17. On the Impact of Particulate Matter Distribution on Pressure Drop of Wall-Flow Particulate Filters

    Directory of Open Access Journals (Sweden)

    Vicente Bermúdez

    2017-03-01

    Full Text Available Wall-flow particulate filters are a required exhaust aftertreatment system to abate particulate matter emissions and meet current and incoming regulations applying worldwide to new generations of diesel and gasoline internal combustion engines. Despite the high filtration efficiency covering the whole range of emitted particle sizes, the porous substrate constitutes a flow restriction especially relevant as particulate matter, both soot and ash, is collected. The dependence of the resulting pressure drop, and hence the fuel consumption penalty, on the particulate matter distribution along the inlet channels is discussed in this paper taking as reference experimental data obtained in water injection tests before the particulate filter. This technique is demonstrated to reduce the particulate filter pressure drop without negative effects on filtration performance. In order to justify these experimental data, the characteristics of the particulate layer are diagnosed applying modeling techniques. Different soot mass distributions along the inlet channels are analyzed combined with porosity change to assess the new properties after water injection. Their influence on the subsequent soot loading process and regeneration is assessed. The results evidence the main mechanisms of the water injection at the filter inlet to reduce pressure drop and boost the interest for control strategies able to force the re-entrainment of most of the particulate matter towards the inlet channels’ end.

  18. Characterization of the particulate air pollution in contrasted mega cities

    International Nuclear Information System (INIS)

    Favez, O.

    2008-02-01

    This work aims at characterizing the physics and the chemistry that govern particulate air pollution in two mega cities (Paris and Cairo) for which the size distribution and the chemical composition of airborne particles were poorly documented. Seasonal variations of the main aerosol sources and transformation processes are investigated in these two urban centres, with a particular attention to semi-volatile material and secondary organic aerosols. Short-term health effects of Paris size-segregated aerosols, as well as particulate pollution during the Cairo 'Black Cloud' season, are also emphasized here. Finally, the comparison of results obtained for the two mega cities and for another one (Beijing) allows investigating main factors responsible for particulate air pollution in urban centres with contrasted climatic conditions and development levels. Notably, this work also allows the build-up of an experimental dataset which is now available for the modelling of urban air quality and of environmental impacts of mega city air pollution. (author)

  19. Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

    Science.gov (United States)

    Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-04-01

    Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

  20. Les particules et leurs symétries

    CERN Document Server

    Chanfray, Guy

    1997-01-01

    Les particules élémentaires, initialement au nombre de trois (proton, neutron, électron) se sont rapidement révélées plus nombreuses, notamment grâce aux expériences menées dans des accélérateurs de plus en plus puissants. L'interprétation théorique des données a permis de fonder une classification qui permet aujourd'hui de parler des " vrais " constituants fondamentaux : les quards et les leptons. Ce livre expose la manière dont les lois de symétrie, externes et internes, déterminent les propriétés des particules élémentaires. Il montre comment ces symétries mènent aux lois de conservation, comment le formalisme canonique de la théorie des champs permet de retrouver les diagrammes de Feynman et comment la compréhension des symétries SU(2) et SU (3)F détermine la classification des hadrons en multiples. La deuxième partie de l'ouvrage est consacrée aux grandes théories de jauge, la chromodynamique quantique et la théorie électrofaible. La QCD permet aujourd'hui de comprendre la...

  1. Measurement and analysis of ambient atmospheric particulate matter in urban and remote environments

    Science.gov (United States)

    Hagler, Gayle S. W.

    Atmospheric particulate matter pollution is a challenging environmental concern in both urban and remote locations worldwide. It is intrinsically difficult to control, given numerous anthropogenic and natural sources (e.g. fossil fuel combustion, biomass burning, dust, and seaspray) and atmospheric transport up to thousands of kilometers after production. In urban regions, fine particulate matter (particles with diameters under 2.5 mum) is of special concern for its ability to penetrate the human respiratory system and threaten cardiopulmonary health. A second major impact area is climate, with particulate matter altering Earth's radiative balance through scattering and absorbing solar radiation, modifying cloud properties, and reducing surface reflectivity after deposition in snow-covered regions. While atmospheric particulate matter has been generally well-characterized in populated areas of developed countries, particulate pollution in developing nations and remote regions is relatively unexplored. This thesis characterizes atmospheric particulate matter in locations that represent the extreme ends of the spectrum in terms of air pollution-the rapidly-developing and heavily populated Pearl River Delta Region of China, the pristine and climate-sensitive Greenland Ice Sheet, and a remote site in the Colorado Rocky Mountains. In China, fine particles were studied through a year-long field campaign at seven sites surrounding the Pearl River Delta. Fine particulate matter was analyzed for chemical composition, regional variation, and meteorological impacts. On the Greenland Ice Sheet and in the Colorado Rocky Mountains, the carbonaceous fraction (organic and elemental carbon) of particulate matter was studied in the atmosphere and snow pack. Analyses included quantifying particulate chemical and optical properties, assessing atmospheric transport, and evaluating post-depositional processing of carbonaceous species in snow.

  2. Metabarcoding-based fungal diversity on coarse and fine particulate organic matter in a first-order stream in Nova Scotia, Canada [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Christian Wurzbacher

    2016-02-01

    Full Text Available Most streams receive substantial inputs of allochthonous organic material in the form of leaves and twigs (CPOM, coarse particulate organic matter. Mechanical and biological processing converts this into fine particulate organic matter (FPOM. Other sources of particles include flocculated dissolved matter and soil particles. Fungi are known to play a role in the CPOM conversion process, but the taxonomic affiliations of these fungi remain poorly studied. The present study seeks to shed light on the composition of fungal communities on FPOM and CPOM as assessed in a natural stream in Nova Scotia, Canada. Maple leaves were exposed in a stream for four weeks and their fungal community evaluated through pyrosequencing. Over the same period, four FPOM size fractions were collected by filtration and assessed. Particles had much lower ergosterol contents than leaves, suggesting major differences in the extent of fungal colonization. Pyrosequencing documented a total of 821 fungal operational taxonomic units (OTU, of which 726 were exclusive to particles and 47 to leaf samples. Most fungal phyla were represented, including yeast lineages (e.g., Taphrinaceae and Saccharomycotina, Basidiomycota, Chytridiomycota and Cryptomycota, but several classes of Pezizomycontina (Ascomycota dominated. Cluster dendrograms clearly separated fungal communities from leaves and from particles. Characterizing fungal communities may shed some light on the processing pathways of fine particles in streams and broadens our view of the phylogenetic composition of fungi in freshwater ecosystems.

  3. Particulate organic carbon mass distribution at the Bermuda Atlantic Time-series Study (BATS) site

    Science.gov (United States)

    Gundersen, Kjell; Orcutt, Karen M.; Purdie, Duncan A.; Michaels, Anthony F.; Knap, Anthony H.

    Errors in total particulate organic carbon (total POC) measurements caused by particles settling in Niskin water samplers, loss of bacterial cells during filtration and undersampling of rare particles such as the diazotrophic cyanobacterium Trichodesmium spp. were investigated at the Bermuda Atlantic Time-series Study (BATS) site. Regular core samples of temperature, primary production, bacterial abundance, chlorophyll- a (Chl- a) and POC were collected at monthly intervals from 1991 to 1996. During this period of time, shorter investigations of particles settling in water samples (1991-1992), bacterial cells lost during filtration (1992-1993), and Trichodesmium abundance (1995-1996) were performed at the BATS site. The BATS site shows striking seasonal patterns in hydrography and phytoplankton primary productivity, with a strong maximum immediately following the deep winter mixing of the water column. Following the peak in primary production, bacterial abundance showed only slightly elevated levels in spring. Maxima of Chl- a and POC also were associated with the primary production peaks, but these particle concentrations became less pronounced through summer and fall. An average of 26% of total POC collected in Niskin water bottles settled below the spigot before it could be sampled. An average of 47% of all bacterial cells passed the nominal pore size of a Whatman GF/F filter, and total POC measurements generated from GF/F filtered seawater samples had to be corrected for this loss. The average integrated stocks of total POC in the upper 65 m of the water column was 32% pigmented phytoplankton, 15% microheterotrophs, 54% other detrital matter (32 : 15 : 54). Phytoplankton C equaled bacterial C in the 65-135 m depth range (16 : 19 : 65), but phytoplankton C was virtually non-existent deeper than 135 m (2 : 14 : 74). Bacterial C biomass was higher than phytoplankton in surface waters outside the spring bloom period, but carbon not accounted for by phytoplankton

  4. [H2en]2{La2M(SO4)6(H2O)2} (M=Co, Ni): First organically templated 3d-4f mixed metal sulfates

    International Nuclear Information System (INIS)

    Yuan Yanping; Wang Ruiyao; Kong Deyuan; Mao Jianggao; Clearfield, Abraham

    2005-01-01

    The first organically templated 3d-4f mixed metal sulfates, [H 2 en] 2 {La 2 M(SO 4 ) 6 (H 2 O) 2 } (M=Co 1, Ni 2) have been synthesized and structurally determined from non-merohedrally twinned crystals. The two compounds are isostructural and their structures feature a three-dimensional anionic network formed by the lanthanum(III) and nickel(II) ions bridged by sulfate anions. The La(III) ions in both compounds are 10-coordinated by four sulfate anions in bidentate chelating fashion, and two sulfate anions in a unidentate fashion. The transition metal(II) ion is octahedrally coordinated by six oxygens from four sulfate anions and two aqua ligands. The doubly protonated enthylenediamine cations are located at the tunnels formed by 8-membered rings (four La and four sulfate anions)

  5. Carbon Composition of Particulate Organic Carbon in the Gulf of Mexico

    Science.gov (United States)

    Rogers, K.; Montoya, J. P.; Weber, S.; Bosman, S.; Chanton, J.

    2016-02-01

    The Deepwater Horizon blowout released 5.0x1011 g C from gaseous hydrocarbons and up to 6.0x1011g C from oil into the water column. Another carbon source, adding daily to the water column, leaks from the natural hydrocarbon seeps that pepper the seafloor of the Gulf of Mexico. How much of this carbon from the DWH and natural seeps is assimilated into particulate organic carbon (POC) in the water column? We filtered seawater collected in 2010, 2012, and 2013 from seep and non-seep sites, collecting POC on 0.7µm glass microfiber filters and analyzing the POC for stable and radiocarbon isotopes. Mixing models based on carbon isotopic endmembers of methane, oil, and modern production were used to estimate the percentage of hydrocarbon incorporated into POC. Significant differences were seen between POC from shallow and deep waters and between POC collected from seep, non-seep, and blowout sites; however yearly differences were not as evident suggesting the GOM has a consistent supply of depleted carbon. Stable carbon isotopes signatures of POC in the Gulf averaged -23.7±2.5‰ for shallow samples and -26.65±2.9‰ for deep POC samples, while radiocarbon signatures averaged -100.4±146.1‰ for shallow and -394.6±197‰ for deep samples. POC in the northern Gulf are composed of 23-91% modern carbon, 2-21% methane, and 0-71% oil. Oil plays a major role in the POC composition of the GOM, especially at the natural seep GC600.

  6. Identification of amines in wintertime ambient particulate material using high resolution aerosol mass spectrometry

    Science.gov (United States)

    Bottenus, Courtney L. H.; Massoli, Paola; Sueper, Donna; Canagaratna, Manjula R.; VanderSchelden, Graham; Jobson, B. Thomas; VanReken, Timothy M.

    2018-05-01

    Significant amounts of amines were detected in fine particulate matter (PM) during ambient wintertime conditions in Yakima, WA, using a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Positive matrix factorization (PMF) of the organic aerosol (OA) signal resulted in a six-factor solution that included two previously unreported amine OA factors. The contributions of the amine factors were strongly episodic, but the concentration of the combined amine factors was as high as 10-15 μg m-3 (2-min average) during those episodes. In one occasion, the Amine-II component was 45% of total OA signal. The Amine-I factor was dominated by spectral peaks at m/z 86 (C5H12N+) and m/z 100 (C6H14N+), while the Amine-II factor was dominated by spectral peaks at m/z 58 (C3H8N+ and C2H6N2+) and m/z 72 (C4H10N+ and C3H8N2+). The ions dominating each amine factor showed distinct time traces, suggesting different sources or formation processes. Investigation into the chemistry of the amine factors suggests a correlation with inorganic anions for Amine-I, but no evidence that the Amine-II was being neutralized by the same inorganic ions. We also excluded the presence of organonitrates (ON) in the OA. The presence of C2H4O2+ at m/z 60 (a levoglucosan fragment) in the Amine-I spectrum suggests some influence of biomass burning emissions (more specifically residential wood combustion) in this PMF factor, but wind direction suggested that the most likely sources of these amines were agricultural activities and feedlots to the S-SW of the site.

  7. Air quality in terms of particulate matter (PM10) and element components in Antananarivo city

    International Nuclear Information System (INIS)

    Raoelina Andriambololona; Rakotondramanana, H.T.; Rasoazanany, E.O.; Randriamanivo, L.V.; Rasolofonirina, M.; Razafy Andrianarivo, R.

    2001-01-01

    The main objective of this research was to study the size distribution of toxic elements, undesirables ones and PM10 in the aerosols of Antananarivo urban areas using Total reflection X-ray Fluorescence. This work was carried out in the framework of Co-ordinated Research Program organised by the IAEA in 1998. The air sampler DICHOTOMOUS was used for sampling, with which two types of aerosols could be obtained: respirable aerosols or fine particles (aerodynamic diameter below 2.5 μm PM-2 ,5 ) and inhalable or coarse particles (aerodynamic diameter from 2.5 μm to 10μm PM 10 ). Samples were taken from six sampling sites, namely Ambohidahy tunnel, Ambanidia tunnel, Andravoahangy, Soarano, Mahamasina and Ankorondrano. Then, they were digested with acid digestion bomb. The results showed the presence of elements such as sulfur (S), chlorine (Cl), kalium (K), calcium (Ca), titanium (Ti), lead (Pb) in the aerosols. Their concentrations are higher in respirable particles. For classical air pollutant components, particularly lead and PM10, the 1.8 μg.m -3 mean concentration value of lead is largely higher than 0.5μg. m -3 , which is the WHO (World Health organization) adopted value, and above the USEPA (United States Environmental Protection Agency) maximum admissible one (1.5 μg.m -3 ) as well. Regarding the size distribution of lead, the results showed that the small particles were mainly enriched in lead. The same observation can also be stated for PM10 with a 240 μg.m -3 mean concentration value , higher than 150 μg.m - 3 , adopted by the two above-mentioned organizations. Therefore, the Antananarivo urban area is classified as saturated zone for both parameters (lead and particulate matter). In addition, the results of Mason enrichment factors showed that the elements such as sulfur (S), chromium (Cr), copper (Cu), zinc (Zn), bromine (Br), and lead (Pb) are from both natural and anthropogenic sources. The elements such as kalium (K), chlorine (Cl), calcium (Ca

  8. Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Pope III, C.A.; Burnett, R.T.; Thun, M.J.; Calle, E.E.; Krewski, D.; Ito, K.; Thurston, G.D. [Brigham Young University, Provo, UT (United States)

    2003-03-06

    A study was conducted to the relationship between long-term exposure to fine particulate air pollution and all-cause, lung cancer, and cardiopulmonary mortality. Vital status and cause of death data were collected by the American Cancer Society as part of the Cancer Prevention II study, an ongoing prospective mortality study, which enrolled approximately 1.2 million adults in 1982. Participants completed a questionnaire detailing individual risk factor data (age, sex, race, weight, height, smoking history, education, marital status, diet, alcohol consumption, and occupational exposures). The risk factor data for approximately 500 000 adults were linked with air pollution data for metropolitan areas throughout the United States and combined with vital status and cause of death data through December 31, 1998. Fine particulate and sulfur oxide-related pollution were found to be associated with all-cause, lung cancer, and cardiopulmonary mortality. Each 10-{mu}g/m{sup 3} elevation in fine particulate air pollution was associated with approximately a 4%, 6%, and 8% increased risk of all-cause, cardiopulmonary, and lung cancer mortality, respectively. Measures of coarse particle fraction and total suspended particles were not consistently associated with mortality. It was concluded that long-term exposure to combustion-related fine particulate air pollution is an important environmental risk factor for cardiopulmonary and lung cancer mortality. 31 refs., 5 figs., 2 tabs.

  9. Particulate waste outflow from fish-farming cages. How much is uneaten feed?

    Science.gov (United States)

    Ballester-Moltó, M; Sanchez-Jerez, P; Cerezo-Valverde, J; Aguado-Giménez, F

    2017-06-15

    Particulate wastes drive benthic organic enrichment from cage fish farming. Differentiation between faeces and uneaten feed estimates at cage level are of great value to both economize the feeding process and reduce waste. This study estimates the particulate waste outflowing cages at different depths and orientations, and the wasted feed component by combining in situ measurements and modelling. Particulate matter flux (PMF) was greater vertically through the cage bottoms (60.89%), but lateral outflow was also substantial (39.11%). PMF occurs all around the cages, and the influence of the mainstream current was low. Wasted feed was greatly variable, reaching high values (about 50% of supplied feed. The self-application of feed wastage monitoring and estimates by fish farmers is recommended to improve sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Demonstration of radionuclides removal at the 105-N basin using the 3M system

    International Nuclear Information System (INIS)

    Hobart, S.A.; Hyman, M.

    1996-03-01

    A field demonstration of the Minnesota Mining and Manufacturing Company (3M) innovative Cs- and Sr-removal technology was undertaken to support deactivation of the Hanford Site's N Reactor. The field demonstration and laboratory studies performed by Pacific Northwest National Laboratory are documented in this report. The deactivation of N Reactor includes an aggressive schedule for removing water from the reactor's original fuel storage pool, known as N Basin. The plan for treating N Basin water involves particulate filtration, followed by further treatment at the Hanford Site's Effluent Treatment Facility (ETF) before the water is discharged to a permitted soil column. Prudence calls for developing a backup treatment plan in the event that ETF is not available to support the N Basin critical path schedule. The 3M technique uses membrane filters that are impregnated with chemical species to remove specific ions from water by ion exchange or selective reaction. Sodium titanate is used to remove Sr by ion exchange, and potassium-cobalt hexacyanoferrate (COHEX) is used to remove Cs by formation of cesium-cobalt ferrocyanide. As a result of this field test, the following recommendations are made: 3M technology should not be considered for removing Sr from N Basin water, although the technology merits consideration for Sr removal in waters that have relatively low Cs content; application of 3M technology by recirculation of basin water through 3M adsorption cartridges for removal of Cs-137 should be considered since it efficiently removes Cs and may be cost effective; additional pilot-scale tests should be performed to determine the capacity of COHEX for Cs-137 removal, if full-scale application is desired

  11. Characteristics of differently stabilised soil organic carbon fractions in relation to long-term fertilisation in Brown Earth of Northeast China.

    Science.gov (United States)

    Xu, Xiangru; Zhang, Wenju; Xu, Minggang; Li, Shuangyi; An, Tingting; Pei, Jiubo; Xiao, Jing; Xie, Hongtu; Wang, Jingkuan

    2016-12-01

    Long-term use of artificial fertiliser has a significant impact on soil organic carbon (SOC). We used physical-chemical fractionation methods to assess the impact of long-term (26years) fertilisation in a maize cropping system developed on Brown Earth in Northeast China. Plot treatments consisted of control (CK); nitrogen (N) fertiliser (N2); low-level organic manure combined with inorganic N and phosphorus (P) fertiliser (M1N1P1); medium-level organic manure combined with inorganic N fertiliser (M2N2); and high-level organic manure combined with inorganic N and P fertiliser (M4N2P1). Our objectives were to (1) determine the contents of and variations in the SOC fractions; (2) explore the relationship between total SOC and its fractions. In treatments involving organic manure (M1N1P1, M2N2, and M4N2P1), total SOC and physically protected microaggregate (μagg) and μagg occluded particulate organic carbon (iPOC) contents increased by 9.9-58.9%, 1.3-34.7%, 29.5-127.9% relative to control, respectively. But there no significant differences (P>0.05) were detected for the chemically, physically-chemically, and physically-biochemically protected fractions among the M1N1P1, M2N2, and M4N2P1 treatments. Regression analysis revealed that there was a linear positive correlation between SOC and the unprotected coarse particulate organic carbon (cPOC), physically protected μagg, and iPOC fractions (Pfractions responded negatively to SOC content. The highest rate of C accumulation among the SOC fractions occurred in the cPOC fraction, which accounted for as much as 32% of C accumulation as total SOC increased, suggesting that cPOC may be the most sensitive fraction to fertiliser application. We found that treatments had no effect on C levels in H-μsilt and NH-μsilt, indicating that the microaggregated silt C-fractions may have reached a steady state in terms of C saturation in the Brown Earth of Northeast China. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Effect of particulate matter less than 10μm (PM10 on mortality in Bogota, Colombia: a time-series analysis, 1998-2006

    Directory of Open Access Journals (Sweden)

    Luis Camilo Blanco-Becerra

    2014-07-01

    Full Text Available Objective. To analyze the association between daily mortality from different causes and acute exposure to particulate matter less than 10 microns in aerodynamic diameter (PM10, in Bogota, Colombia. Materials and methods. A time-series ecological study was conducted from 1998 to 2006. The association between mortality (due to different causes and exposure was analyzed using single and distributed lag models and adjusting for potential confounders. Results. For all ages, the cumulative effect of acute mortality from all causes and respiratory causes increased 0.71% (95%CI 0.46-0.96 and 1.43% (95%CI 0.85-2.00, respectively, per 10μg/m3 increment in daily average PM10 with a lag of three days before death. Cumulative effect of mortality from cardiovascular causes was -0.03% (95%CI -0.49-0.44% with the same lag. Conclusions. The results suggest an association between an increase in PM10 concentrations and acute mortality from all causes and respiratory causes.

  13. Overview of surface measurements and spatial characterization of submicrometer particulate matter during the DISCOVER-AQ 2013 campaign in Houston, TX.

    Science.gov (United States)

    Leong, Y J; Sanchez, N P; Wallace, H W; Karakurt Cevik, B; Hernandez, C S; Han, Y; Flynn, J H; Massoli, P; Floerchinger, C; Fortner, E C; Herndon, S; Bean, J K; Hildebrandt Ruiz, L; Jeon, W; Choi, Y; Lefer, B; Griffin, R J

    2017-08-01

    The sources of submicrometer particulate matter (PM 1 ) remain poorly characterized in the industrialized city of Houston, TX. A mobile sampling approach was used to characterize PM 1 composition and concentration across Houston based on high-time-resolution measurements of nonrefractory PM 1 and trace gases during the DISCOVER-AQ Texas 2013 campaign. Two pollution zones with marked differences in PM 1 levels, character, and dynamics were established based on cluster analysis of organic aerosol mass loadings sampled at 16 sites. The highest PM 1 mass concentrations (average 11.6 ± 5.7 µg/m 3 ) were observed to the northwest of Houston (zone 1), dominated by secondary organic aerosol (SOA) mass likely driven by nighttime biogenic organonitrate formation. Zone 2, an industrial/urban area south/east of Houston, exhibited lower concentrations of PM 1 (average 4.4 ± 3.3 µg/m 3 ), significant organic aerosol (OA) aging, and evidence of primary sulfate emissions. Diurnal patterns and backward-trajectory analyses enable the classification of airmass clusters characterized by distinct PM sources: biogenic SOA, photochemical aged SOA, and primary sulfate emissions from the Houston Ship Channel. Principal component analysis (PCA) indicates that secondary biogenic organonitrates primarily related with monoterpenes are predominant in zone 1 (accounting for 34% of the variability in the data set). The relevance of photochemical processes and industrial and traffic emission sources in zone 2 also is highlighted by PCA, which identifies three factors related with these processes/sources (~50% of the aerosol/trace gas concentration variability). PCA reveals a relatively minor contribution of isoprene to SOA formation in zone 1 and the absence of isoprene-derived aerosol in zone 2. The relevance of industrial amine emissions and the likely contribution of chloride-displaced sea salt aerosol to the observed variability in pollution levels in zone 2 also are captured by PCA. This

  14. Regional modeling of carbonaceous aerosols over Europe-focus on secondary organic aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bessagnet, B. [INERIS, Inst Nat Env Indust Risques, F-60550 Verneuil en Halatte, (France); Menut, L. [Ecole Poltechnique, Inst Pierre Simon Laplace, Lab Meteorol Dyn, F-91128 Palaiseau, (France); Curci, G. [Univ degli Studi dell' Aquila, CETEMPS, 67010 Coppito - L' Aquila, (Italy); Hodzic, A. [NCAR, Nat Center for Atmosph Research, Boulder, 80301, CO, (United States); Guillaume, B.; Liousse, C. [LA/OMP, Lab Aerol/Observ Midi-Pyrenees, F-31400 Toulouse, (France); Moukhtar, S. [York Univ, Centre Atmosph Chem, Toronto, (Italy); Pun, B.; Seigneur, C. [Atmosph and Environ Research, San Ramon, CA 94583, (United States); Schulz, M. [CEA-CNRS-UVSQ, IPSL, Lab Sciences Climat et Environm, F-91191 Gif sur Yvette, (France)

    2008-07-01

    In this study, an improved and complete secondary organic aerosols (SOA) chemistry scheme was implemented in the CHIMERE model. The implementation of isoprene chemistry for SOA significantly improves agreement between long series of simulated and observed particulate matter concentrations. While simulated organic carbon concentrations are clearly improved at elevated sites by adding the SOA scheme, time correlation are impaired at low level sites in Portugal, Italy and Slovakia. At several sites a clear underestimation by the CHIMERE model is noticed in wintertime possibly due to missing wood burning emissions as shown in previous modeling studies. In Europe, the CHIMERE model gives yearly average SOA concentrations ranging from 0.5 {mu}g m{sup -3} in the Northern Europe to 4 {mu}g m{sup -3} over forested regions in Spain, France, Germany and Italy. In addition, our work suggests that during the highest fire emission periods, fires can be the dominant source of primary organic carbon over the Mediterranean Basin, but the SOA contribution from fire emissions is low. Isoprene chemistry has a strong impact on SOA formation when using current available kinetic schemes. (authors)

  15. [Impact of atmospheric total suspended particulate pollution on photosynthetic parameters of street mango trees in Xiamen City].

    Science.gov (United States)

    Yu, Yu-xian; Chen, Jin-sheng; Ren, Yin; Li, Fang-yi; Cui, Sheng-hui

    2010-05-01

    With the development of urbanization, total suspended particulate (TSP) pollution is getting serious, and the normal physiological processes of urban vegetation are profoundly affected while adsorbing and purifying the particulates. In this study, four areas were selected, i.e., Tingxi reservoir (clean control area), Xiamen University (cultural and educational area), Xianyue (business area), and Haicang (industrial area), with their atmospheric TSP concentrations and the photosynthetic parameters of street Mango (Mangifera indica) trees monitored in April and May, 2009. The daily average concentration of TSP in Tingxi, Xiamen University, Xianyue, and Haicang was 0.061, 0.113, 0.120 and 0.205 mg x m(-3), respectively, and the impact of TSP stress on M. indica was in the sequence of Haicang > Xianyue > Xiamen University > Tingxi. TSP pollution negatively affected the net photosynthetic rate, stomatal conductance, and transpiration rate of M. indica, and induced intercellular CO2 concentration changed significantly. High TSP concentration could cause the decline of net photosynthetic rate via stomatal limitation.

  16. Bio-derived fuels may ease the regeneration of diesel particulate traps

    Energy Technology Data Exchange (ETDEWEB)

    E. Coda Zabetta; M. Hupa; S. Niemi [Aabo Akademi Process Chemistry Centre, Turku (Finland)

    2006-12-15

    Particulate is the most problematic emission from diesel engines. To comply with environmental regulations, these engines are often equipped with particulate traps, which must be regenerated frequently for the sake of efficiency. The regeneration is commonly achieved by rising the temperature in the trap till the particulate self-ignites. However, this method implies energy losses and thermal shocks in the trap. Alternatively, catalysts and additives have been recently considered for reducing the ignition temperature of particulate, but these techniques suffer from poisoning and undesirable byproducts. The present experimental study shows that the ignition temperature of particulate from seed-derived oils (SO) and from blends of SO with diesel fuel oil (DO) can be lower than that of particulate from neat DO. If substantiated by more extensive studies, such finding could have noteworthy implications on the future of fuels and traps. Short communication. 8 refs., 3 figs., 2 tabs.

  17. Enhancement of photocurrents due to the oxidation of water and organic compounds at BiZn2VO6 particulate thin film electrodes by treatment with a TiCl4 solution

    International Nuclear Information System (INIS)

    Liu Haimei; Imanishi, Akihito; Yang Wensheng; Nakato, Yoshihiro

    2010-01-01

    Photocurrents due to water oxidation at BiZn 2 VO 6 (E g 2.4 eV) particulate thin film electrodes were largely enhanced by pre-treatment with an aqueous TiCl 4 solution. Photocurrents for BiZn 2 VO 6 electrodes with no TiCl 4 treatment were also enhanced by the addition of organic compounds such as methanol and trimethyl amine to the aqueous electrolyte. Interestingly, such enhanced photocurrents by organic compounds were further enhanced by the TiCl 4 pre-treatment. EDAX and SEM investigations showed the formation of a flock-like TiO 2 overlayer on BiZn 2 VO 6 particles after the TiCl 4 treatment. The photocurrent enhancement by the TiCl 4 pre-treatment is thus mainly attributed to the necking effect of the flock-like TiO 2 overlayer, which facilitates the transport of photogenerated electrons within the BiZn 2 VO 6 particulate thin film electrode.

  18. Organic nitrogen and carbon in atmospheric dry and wet depositions in the southern East China Sea: its implication for new production in coastal region

    Science.gov (United States)

    Chen, H. Y.; Yeh, J. X.; Lin, C. T.

    2016-02-01

    We collected 11 sets of size-segregated particulate aerosol (include coarse and fine particles) and 53 rain samples from January to December 2014 at a coastal city (Keelung) on the southern East China Sea. Here we present measurements of water-soluble inorganic/organic nitrogen and carbon (WSIN/WSON and WSIC/WSOC, respectively) in aerosol samples and dissolved inorganic/organic nitrogen and carbon (DIN/DON and DIC/DOC, respectively) in rain samples. In addition, 4-d back trajectories of air masses arriving daily at the sampling site were calculated to determine the potential aerosol source regions. The concentrations of water-soluble species in particulate aerosols were relatively high in March (WSON: 223±48 nmol m-3; WSOC: 203±51 nmol m-3) and dissolved species in rain samples were high in December (DON: 157±69 μM; DOC: 294±168 μM), which occur frequently during the spring and winter. The monsoon system of East Asia play a key role on the atmospheric composition of nitrogen and carbon, with higher loadings in northerly (winter to spring) than southerly (summer to autumn) monsoon periods, owing to strong emissions from the East Asian continent. Our results indicate that biomass burning and dust events yielded the largest concentrations of ON and OC not only on particulate aerosols but also in precipitations. For aerosols, the amounts of WSON and WSOC accounted for 42±8% and 80±7% of the water-soluble total nitrogen (WSTN) and carbon (WSTC), respectively. Additionally, the concentrations of DON and DOC accounted for 40±5% and 75±3% of total dissolved nitrogen (TDN) and carbon (TDC), respectively, for precipitations. By using dry and wet deposition flux estimations, we estimated that the fluxes of WSTN/TDN and WSTC/TDC were 47.1±24.4 / 266±20 mmol m-2 yr-1 and 23±9 / 153±3 mmol m-2 yr-1, respectively. These results suggest that atmospheric deposition contributed approximately 25-34% of the annual biological new production in the southern East China Sea.

  19. INAA at the top of the world: Elemental characterization and analysis of airborne particulate matter collected in the Himalayas at 5,100 m high

    International Nuclear Information System (INIS)

    Giaveri, G.; Bergamaschi, L.; Rizzio, E.; Brandone, A.; Profumo, A.; Gallorini, M.; Zambelli, G.; Baudo, R.; Tartari, G.

    2005-01-01

    In 1990, following an agreement with the Royal Nepal Academy of Science, the Italian National Research Council (CNR) installed a scientific laboratory (Pyramid) at 5,050 m (s.l.) in the Himalayan region. Among the environmental related researches, the task project RATEAP (Remote Areas Trace Elements Atmospheric Pollution), started in 2001, aims at obtaining information about the chemical composition of the high altitude airborne particulate matter. During the period of March-April 2002 series of samplings have been carried out by pump aspiration. Samples of total suspended particles (TSP) as well as of the particles size fraction PM10 and PM 2.5 have been collected and submitted to INAA for the determination of more than 30 elements present, at nanogram levels, in few micrograms of air dust. Data quality assurance has been performed by the analysis of different NIST SRMs and, in particular, the SRM 2783 Air particulate on Filter Media. (author)

  20. High secondary aerosol contribution to particulate pollution during haze events in China

    Science.gov (United States)

    Huang, Ru-Jin; Zhang, Yanlin; Bozzetti, Carlo; Ho, Kin-Fai; Cao, Jun-Ji; Han, Yongming; Daellenbach, Kaspar R.; Slowik, Jay G.; Platt, Stephen M.; Canonaco, Francesco; Zotter, Peter; Wolf, Robert; Pieber, Simone M.; Bruns, Emily A.; Crippa, Monica; Ciarelli, Giancarlo; Piazzalunga, Andrea; Schwikowski, Margit; Abbaszade, Gülcin; Schnelle-Kreis, Jürgen; Zimmermann, Ralf; An, Zhisheng; Szidat, Sönke; Baltensperger, Urs; Haddad, Imad El; Prévôt, André S. H.

    2014-10-01

    Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.

  1. High Efficiency Particulate Air (HEPA) Filter Generation, Characterization, and Disposal Experiences at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Coffey, D. E.

    2002-01-01

    High Efficiency Particulate Air filtration is an essential component of the containment and ventilation systems supporting the research and development activities at the Oak Ridge National Laboratory. High Efficiency Particulate Air filters range in size from 7.6cm (3 inch) by 10.2 cm (4 inch) cylindrical shape filters to filter array assemblies up to 2.1 m (7 feet) high by 1.5 m (5 feet) wide. Spent filters are grouped by contaminates trapped in the filter media and become one of the components in the respective waste stream. Waste minimization and pollution prevention efforts are applied for both radiological and non-radiological applications. Radiological applications include laboratory hoods, glove boxes, and hot cells. High Efficiency Particulate Air filters also are generated from intake or pre-filtering applications, decontamination activities, and asbestos abatement applications. The disposal avenues include sanitary/industrial waste, Resource Conservation and Recovery Act and Toxic Substance Control Act, regulated waste, solid low-level waste, contact handled transuranic, and remote handled transuranic waste. This paper discusses characterization and operational experiences associated with the disposal of the spent filters across multiple applications

  2. Is there a difference in treatment outcomes between epidural injections with particulate versus non-particulate steroids?

    Energy Technology Data Exchange (ETDEWEB)

    Bensler, Susanne; Sutter, Reto; Pfirrmann, Christian W.A.; Peterson, Cynthia K. [Orthopedic University Hospital Balgrist, Department of Radiology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland)

    2017-04-15

    To compare the outcomes of patients after interlaminar computed tomography (CT)-guided epidural injections of the lumbar spine with particulate vs. non-particulate steroids. 531 consecutive patients were treated with CT-guided lumbar interlaminar epidural injections with steroids and local anaesthetics. 411 patients received a particulate steroid and 120 patients received a non-particulate steroid. Pain levels were assessed using the 11-point numerical rating scale (NRS) and overall reported 'improvement' was assessed using the Patients Global Impression of Change (PGIC) at 1 day, 1 week and 1 month post-injection. Descriptive and inferential statistics were applied. Patients receiving particulate steroids had statistically significantly higher NRS change scores (p = 0.0001 at 1 week; p = 0.0001 at 1 month). A significantly higher proportion of patients receiving particulate steroids reported relevant improvement (PGIC) at both 1 week and 1 month post injection (p = 0.0001) and they were significantly less likely to report worsening at 1 week (p = 0.0001) and 1 month (p = 0.017). Patients treated with particulate steroids had significantly greater pain relief and were much more likely to report clinically relevant overall 'improvement' at 1 week and 1 month compared to the patients treated with non-particulate steroids. (orig.)

  3. Is there a difference in treatment outcomes between epidural injections with particulate versus non-particulate steroids?

    International Nuclear Information System (INIS)

    Bensler, Susanne; Sutter, Reto; Pfirrmann, Christian W.A.; Peterson, Cynthia K.

    2017-01-01

    To compare the outcomes of patients after interlaminar computed tomography (CT)-guided epidural injections of the lumbar spine with particulate vs. non-particulate steroids. 531 consecutive patients were treated with CT-guided lumbar interlaminar epidural injections with steroids and local anaesthetics. 411 patients received a particulate steroid and 120 patients received a non-particulate steroid. Pain levels were assessed using the 11-point numerical rating scale (NRS) and overall reported 'improvement' was assessed using the Patients Global Impression of Change (PGIC) at 1 day, 1 week and 1 month post-injection. Descriptive and inferential statistics were applied. Patients receiving particulate steroids had statistically significantly higher NRS change scores (p = 0.0001 at 1 week; p = 0.0001 at 1 month). A significantly higher proportion of patients receiving particulate steroids reported relevant improvement (PGIC) at both 1 week and 1 month post injection (p = 0.0001) and they were significantly less likely to report worsening at 1 week (p = 0.0001) and 1 month (p = 0.017). Patients treated with particulate steroids had significantly greater pain relief and were much more likely to report clinically relevant overall 'improvement' at 1 week and 1 month compared to the patients treated with non-particulate steroids. (orig.)

  4. Measurements and Analysis of Chemical Composition of Particulate Matter during High Pollution Events at Guanzhong Plain, China

    Science.gov (United States)

    Junji, C.

    2017-12-01

    Particulate matter pollution is a serious environmental problem which influencing air quality, regional and global climates, and human health. PM2.5 samples were collected at Guanzhong Plain with six sampling sites atdifferent cities in the year scale from 2012 to 2014. All of the six sites exhibited highest organic carbon (OC)and elemental carbon (EC) values in winter and lowest values in summer. OC correlates well with EC indicating similar emission sources. The contributions of secondary species SO42-, NO3- and NH4+ in total ions were greatest, and the high concentrations in winter were mainly due to emissions from coal combustion and biomass burning.During autumn the haze days were severest in Xi'an city with similar tendency of PM2.5 variations, and it was proved that biomass burning may be the main emission source of the regional pollution. In winter pollution episodes, the pollution patterns in Guanzhong Plain were similar which was resulted from strong secondary reactions and coal burning.Source apportionment using a positive matrix factorizationreceptor model indicates that on average secondary aerosol was the main source of PM2.5 (39.3%), followed by coal burning (17.3%), motor vehicle/industrial emissions (15.7%), fugitive dust (14.9%), and biomass burning (12.8%). The online, in situ measurement airborne species, especially the chemical composition of non-refectory submicron aerosol, during a heavyhaze-fog event, was analyzed in detailed.The formation of secondary sulfate and organic aerosol were observed during the event. The sulfur oxidation ratio (SOR), defined as sulfate/(SO2+sulfate) were mostly over 0.10, with a maximum of 0.30, when relative humidity > 80%. The aging product of organic aerosol (OA) were also observed in the event. The wet scattering coefficient was influenced by secondary sulfate, in the form of (NH4)2SO4, with contribution of 48.9% of wet particulate phase scattering. Thus decreased the visibility dramatically with a minimum of

  5. Physique des particules introduction aux concepts et au formalisme du modèle standard

    CERN Document Server

    Clément, Benoit

    2017-01-01

    Cet ouvrage propose une introduction à la physique des particules pour tout étudiant de niveau M1, qu'il se destine à la physique théorique ou non. Il présente la physique des particules de manière abordable sans occulter les concepts formels sur lesquels elle repose. Les rappels de mécanique relativiste et du formalisme de Lagrange permettent de comprendre la nature et le comportement des particules à très haute énergie. Enfin, les règles de Feynman offrent une description simple de leurs interactions. Chaque chapitre est complété par des exercices corrigés. Dans cette seconde édition, actualisée, le chapitre sur les champs classiques et quantiques libres a été entièrement refondu pour aborder les problématiques liées à la mécanique relativiste, et de nouveaux exercices ont été ajoutés.

  6. [Temperature modifies the acute effect of particulate air pollution on mortality in Jiang'an district of Wuhan].

    Science.gov (United States)

    Zhu, Y H; Wu, R; Zhong, P R; Zhu, C H; Ma, L

    2016-06-01

    To analyze the temperature modification effect on acute mortality due to particulate air pollution. Daily non-accidental mortality, cardiovascular mortality, and respiratory mortality data were obtained from Jiang'an District Center for Disease Control and Prevention. Daily meteorological data on mean temperature and relative humidity were collected from China Meteorological Data Sharing Service System. The daily concentration of particulate matter was collected from Wuhan Environmental Monitoring center. By using the stratified time-series models, we analyzed effects of particulate air pollution on mortality under different temperature zone from 2002 to 2010, meanwhile comparing the difference of age, gender and educational level, in Wuhan city of China. High temperature (daily average temperature > 33.4 ℃) obviously enhanced the effect of PM10 on mortality. With 10 μg/m(3) increase in PM10 concentrations, non-accidental, cardiovascular, and respiratory mortality increased 2.95% (95%CI: 1.68%-4.24%), 3.58% (95%CI: 1.72%-5.49%), and 5.07% (95%CI: 2.03%-9.51%) respectively. However, low temperature (daily average temperature respiratory mortality with 3.31% (95% CI: 0.07%-6.64%) increase. At high temperature, PM10 had significantly stronger effect on non-accidental mortality of female aged over 65 and people with high educational level groups. With an increase of 10 μg/m(3), daily non-accidental mortality increased 4.27% (95% CI:2.45%-6.12%), 3.38% (95% CI:1.93%-4.86%) and 3.47% (95% CI:1.79%-5.18%), respectively. Whereas people with low educational level were more susceptible to low temperature. A 10 μg/m(3) increase in PM10 was associated with 2.11% (95% CI: 0.20%-4.04%) for non-accidental mortality. Temperature factor can modify the association between the PM10 level and cause-specific mortality. Moreover, the differences were apparent after considering the age, gender and education groups.

  7. Study of the combustion of aluminium and magnesium particulates: influence of the composition of the gaseous mixture and of pressure; Etude de la combustion de particules d'aluminium et de magnesium: influence de la composition du melange gazeux et de la pression

    Energy Technology Data Exchange (ETDEWEB)

    Legrand, B.

    2000-07-01

    The combustion of metal particulates has a major interest in the domain of space propulsion. Aluminium is today used as doping material in the solid propellant of Ariane 5 rocket engines. Magnesium represents a possible fuel for propellers allowing a come back from Mars. An electrostatic levitation device has been used to study the combustion in controlled environment of particulates having a size representative of those encountered in propellers. The particulates are ignited with a laser and observed by fast cinematography. The inhibitive property of hydrogen chloride, an important constituent of the propellant atmosphere, on the combustion of aluminium particulates has been evidenced. These results have been compared with those obtained with a kinetic model in gaseous phase. The combustion of magnesium particulates in carbon dioxide has been studied for 53-63 {mu}m and 1-2 mm particulates. It is shown that the ignition of small particulates is controlled by the chemical kinetics and that the limit ignition pressure is reversely proportional to the particulates size. A study on big samples, performed in normal gravity but also in reduced gravity to get rid of the natural convection phenomena, has permitted to show a pulsed combustion regime linked with the presence of heterogenous reactions. The measurement of the combustion durations for the different sizes of particulates has permitted to propose a correlation between these two parameters for the particulate diameters comprised between 50 {mu}m and 2 mm. (J.S.)

  8. High-Latitude Wintertime Urban Pollution: Particulate Matter Composition and Temporal Trends in Fairbanks, Alaska

    Science.gov (United States)

    Simpson, W. R.; Nattinger, K.; Hooper, M.

    2017-12-01

    High latitude cities often experience severe pollution episodes during wintertime exacerbated by thermal inversion trapping of pollutant emissions. Fairbanks, Alaska is an extreme example of this problem, currently being classified by the US Environmental Protection Agency (EPA) as a "serious" non-attainment area for fine particulate matter (PM2.5). For this reason, we have studied the chemical composition of PM2.5 at multiple EPA monitoring sites in the non-attainment area from 2006 to the present. The chemical composition is dominated by organic carbon with lesser amounts of black carbon and inorganic ionic species such as ammonium, sulfate, and nitrate. We find large spatial differences in composition and amount of PM2.5 that indicate a different mix of sources in residential areas as compared to the city center. Specifically, the difference in composition is consistent with increased wood smoke source in the residential areas. The extent to which organic matter could be secondary (formed through conversion of emitted gases) is also an area needing study. Ammonium sulfate is responsible for about a fifth to a quarter of the particles mass during the darkest months, possibly indicating a non-photochemical source of sulfate, but the chemical mechanism for this possible transformation is unclear. Therefore, we quantified the relationship between particulate sulfate concentrations and gas-phase sulfur dioxide concentrations along with particulate metals and inferred particulate acidity with the hopes that these data can assist in elucidation of the mechanism of particulate sulfate formation. We also analyze temporal trends in PM2.5 composition in an attempt to understand how the problem is changing over time and find most trends are small despite regulatory changes. Improving mechanistic understanding of particulate formation under cold and dark conditions could assist in reducing air-quality-related health effects.

  9. Vertical transport of suspended particulate trace elements in the North Atlantic Ocean

    International Nuclear Information System (INIS)

    Kuss, J.; Kremling, K.; Scholten, J.

    1999-01-01

    Suspended marine particles play a key role in the exchange processes between rapidly sinking particles and seawater because of their large surface area and long residence times. They are involved in the transport processes of rapidly sinking particles (∼ 100 m/day) through aggregation and disaggregation. This mechanism results in a net downward transport of suspended particulate trace elements (TE). To provide more information to these processes TE in suspended particulate material (SPM) have been measured on three cruises from 1995 to 1997 along 20 deg. W using a large volume in situ filtration between 25 m and 4150 m depth in addition to particle flux measurements with sediment traps. These studies were performed under the framework of German JGOFS

  10. PARTICULATE MATTER AND HUMAN HEALTH: USING HUMAN STUDIES TO UNDERSTAND SUSCEPTIBILITY

    Science.gov (United States)

    The potential for experiencing adverse health effects from air pollution particulate matter (PM) exposure is an important public health issue. The World Health Organization has estimated that PM contributes to the deaths of 500,000 people world-wide each year. Epidemiologic stu...

  11. Review of plants to mitigate particulate matter, ozone as well as nitrogen dioxide air pollutants and applicable recommendations for green roofs in Montreal, Quebec.

    Science.gov (United States)

    Gourdji, Shannon

    2018-05-28

    In urbanized regions with expansive impervious surfaces and often low vegetation cover, air pollution due to motor vehicles and other combustion sources, is a problem. The poor air quality days in Montreal, Quebec are mainly due to fine particulate matter and ozone. Businesses using wood ovens are a source of particulates. Careful vegetation selection and increased green roof usage can improve air quality. This paper reviews different green roofs and the capability of plants in particulate matter (PM), ozone (O 3 ) as well as nitrogen dioxide (NO 2 ) level reductions. Both the recommended green roof category and plants to reduce these pollutants in Montreal's zone 5 hardiness region are provided. Green roofs with larger vegetation including shrubs and trees, or intensive green roofs, remove air pollutants to a greater extent and are advisable to implement on existing, retrofitted or new buildings. PM is most effectively captured by pines. The small Pinus strobus 'Nana', Pinus mugho var. pumilio, Pinus mugho 'Slowmound' and Pinus pumila 'Dwarf Blue' are good candidates for intensive green roofs. Drought tolerant, deciduous broadleaved trees with low biogenic volatile organic compound emissions including Japanese Maple or Acer palmatum 'Shaina' and 'Mikawa-Yatsubusa' are options to reduce O 3 levels. Magnolias are tolerant to NO 2 and it is important in their metabolic pathways. The small cold-tolerant Magnolia 'Genie' is a good option to remove NO 2 in urban settings and to indirectly reduce O 3 formation. Given the emissions by Montreal businesses' wood ovens, calculations performed based on their respective complex roof areas obtained via Google Earth Pro indicates 88% Pinus mugho var. pumilio roof coverage can annually remove 92.37 kg of PM 10 of which 35.10 kg is PM 2.5 . The removal rates are 4.00 g/m 2 and 1.52 g/m 2 for PM 10 and PM 2.5 , respectively. This paper provides insight to addressing air pollution through urban rooftop greening. Copyright

  12. Spatiotemporal analysis of particulate air pollution and ischemic heart disease mortality in Beijing, China.

    Science.gov (United States)

    Xu, Meimei; Guo, Yuming; Zhang, Yajuan; Westerdahl, Dane; Mo, Yunzheng; Liang, Fengchao; Pan, Xiaochuan

    2014-12-12

    Few studies have used spatially resolved ambient particulate matter with an aerodynamic diameter of <10 μm (PM10) to examine the impact of PM10 on ischemic heart disease (IHD) mortality in China. The aim of our study is to evaluate the short-term effects of PM10 concentrations on IHD mortality by means of spatiotemporal analysis approach. We collected daily data on air pollution, weather conditions and IHD mortality in Beijing, China during 2008 and 2009. Ordinary kriging (OK) was used to interpolate daily PM10 concentrations at the centroid of 287 township-level areas based on 27 monitoring sites covering the whole city. A generalized additive mixed model was used to estimate quantitatively the impact of spatially resolved PM10 on the IHD mortality. The co-effects of the seasons, gender and age were studied in a stratified analysis. Generalized additive model was used to evaluate the effects of averaged PM10 concentration as well. The averaged spatially resolved PM10 concentration at 287 township-level areas was 120.3 ± 78.1 μg/m3. Ambient PM10 concentration was associated with IHD mortality in spatiotemporal analysis and the strongest effects were identified for the 2-day average. A 10 μg/m3 increase in PM10 was associated with an increase of 0.33% (95% confidence intervals: 0.13%, 0.52%) in daily IHD mortality. The effect estimates using spatially resolved PM10 were larger than that using averaged PM10. The seasonal stratification analysis showed that PM10 had the statistically stronger effects on IHD mortality in summer than that in the other seasons. Males and older people demonstrated the larger response to PM10 exposure. Our results suggest that short-term exposure to particulate air pollution is associated with increased IHD mortality. Spatial variation should be considered for assessing the impacts of particulate air pollution on mortality.

  13. Study of poly hydrocarbons compounds (PAH) in air particulates and their variations in several periods of the year in Damascus city

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Al-Kharfan, K.; Mahzia, Y.; Ibrahim, S.

    2012-01-01

    A study of poly aromatic hydrocarbons (PAH) associated with suspended particulate and their variations in several periods of the year in several sites locations in Damascus City during the period of 2008-2009 was carried out. The studied sites were Zablatani (Ahdaasharea), Mohafaza square, Roken Eddin (Shamdine square) and Mezh (near AlAkram mosque), in addition to Soja as a reference site. The average concentrations of PAH associated with total particulates ranged between 0.97-70.11 ng/m3, which are higher than the average concentrations in the reference site (0.0013-0.75 ng/m3). Also, results have showed that the concentrations were maximal in the dry period comparing with the wet period, while they increased in the day period by 42% in comparison with the night period and decreased in the holidays, which indicates the impact of the traffic. In addition, the highest concentrations were recorded in Zablatani location in all study stages. On the other hand, the results of distribution study of the PAHs according to particle size showed that 81.65-93.51% of the total concentration of these compounds were associated with respiratory particulates (PM10). (author)

  14. Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    D. A. Thornhill

    2008-06-01

    Full Text Available As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO study in the Mexico City Metropolitan Area in March 2006, we measured particulate polycyclic aromatic hydrocarbons (PAHs and other gaseous species and particulate properties, including light absorbing carbon or effective black carbon (BC, at six locations throughout the city. The measurements were intended to support the following objectives: to describe spatial and temporal patterns in PAH concentrations, to gain insight into sources and transformations of PAHs and BC, and to quantify the relationships between PAHs and other pollutants. Total particulate PAHs at the Instituto Mexicano del Petróleo (T0 supersite located near downtown averaged 50 ng m3, and aerosol active surface area averaged 80 mm2 m3. PAHs were also measured on board the Aerodyne Mobile Laboratory, which visited six sites encompassing a mixture of different land uses and a range of ages of air parcels transported from the city core. A combination of analyses of time series, back trajectories, concentration fields, pollutant ratios, and correlation coefficients supports the concept of T0 as an urban source site, T1 as a receptor site with strong local sources, Pedregal and PEMEX as intermediate sites, Pico Tres Padres as a vertical receptor site, and Santa Ana as a downwind receptor site. Weak intersite correlations suggest that local sources are important and variable and that exposure to PAHs and BC cannot be represented by a single regional-scale value. The relationships between PAHs and other pollutants suggest that a variety of sources and ages of particles are present. Among carbon monoxide, nitrogen oxides (NOx, and carbon dioxide, particulate PAHs are most strongly correlated with NOx. Mexico City's PAH/BC mass ratio of 0.01 is similar to that found on a freeway loop in the Los Angeles area and approximately 8–30

  15. Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexico City

    Science.gov (United States)

    Thornhill, D. A.; de Foy, B.; Herndon, S. C.; Onasch, T. B.; Wood, E. C.; Zavala, M.; Molina, L. T.; Gaffney, J. S.; Marley, N. A.; Marr, L. C.

    2008-06-01

    As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) study in the Mexico City Metropolitan Area in March 2006, we measured particulate polycyclic aromatic hydrocarbons (PAHs) and other gaseous species and particulate properties, including light absorbing carbon or effective black carbon (BC), at six locations throughout the city. The measurements were intended to support the following objectives: to describe spatial and temporal patterns in PAH concentrations, to gain insight into sources and transformations of PAHs and BC, and to quantify the relationships between PAHs and other pollutants. Total particulate PAHs at the Instituto Mexicano del Petróleo (T0 supersite) located near downtown averaged 50 ng m-3, and aerosol active surface area averaged 80 mm2 m-3. PAHs were also measured on board the Aerodyne Mobile Laboratory, which visited six sites encompassing a mixture of different land uses and a range of ages of air parcels transported from the city core. A combination of analyses of time series, back trajectories, concentration fields, pollutant ratios, and correlation coefficients supports the concept of T0 as an urban source site, T1 as a receptor site with strong local sources, Pedregal and PEMEX as intermediate sites, Pico Tres Padres as a vertical receptor site, and Santa Ana as a downwind receptor site. Weak intersite correlations suggest that local sources are important and variable and that exposure to PAHs and BC cannot be represented by a single regional-scale value. The relationships between PAHs and other pollutants suggest that a variety of sources and ages of particles are present. Among carbon monoxide, nitrogen oxides (NOx), and carbon dioxide, particulate PAHs are most strongly correlated with NOx. Mexico City's PAH/BC mass ratio of 0.01 is similar to that found on a freeway loop in the Los Angeles area and approximately 8 30 times higher than that found in other cities. Evidence also suggests that primary

  16. Ferruginous compounds in the airborne particulate matter of the metropolitan area of Belo Horizonte, Minas Gerais, Brazil.

    Science.gov (United States)

    Tavares, Fernanda Vasconcelos Fonseca; Ardisson, José Domingos; Rodrigues, Paulo César Horta; Fabris, José Domingos; Fernandez-Outon, Luis Eugenio; Feliciano, Vanusa Maria Delage

    2017-08-01

    Samples of soil, iron ore, and airborne particulate matter (size airborne particulate matter in the metropolitan area of Belo Horizonte, Minas Gerais, Brazil, are either from natural origin, as, for instance, re-suspension of particles from soil, or due to anthropogenic activities, meaning that it would be originated from the many iron ore minings surrounding the metropolitan area. Numerical simulations were used to model the atmospheric dispersion of the airborne particulate matter emitted by iron mining located at the Iron Quadrangle geodomain, Minas Gerais. Results from these numerical simulations supported identifying the sites with the highest concentrations of airborne particulate matter in the metropolitan area. Samples of these suspended materials were collected at the selected sites by using high-volume air samplers. The physicochemical features of the solid materials were assessed by X-ray fluorescence, X-ray diffraction, magnetometry, and 57 Fe Mössbauer spectroscopy. The soil materials were found to be rich in quartz, aluminum, organic matter, and low contents of iron, mainly as low crystalline iron oxides. The samples of the iron ores, on the other hand, contain high concentration of iron, dominantly as relatively pure and crystalline hematite (α-Fe 2 O 3 ). The samples of the airborne particulate matter are rich in iron, mainly as hematite, but contained also quartz, aluminum, and calcium. Mössbauer spectroscopy was used to evaluate the hyperfine structure of 57 Fe of the hematite both from the iron ore and the soil samples. The structural characteristics of the hematite of these particulate materials were further explored. The direct influence of the iron ore mining on the composition of the airborne particulate matter was clearly evidenced based on the trace ability of hematite to its source of emission. Even the atmospheric air on regions relatively far away from the mining activities is also significantly influenced.

  17. Caught in a net: Retention efficiency of microplankton ≥ 10 and < 50 μm collected on mesh netting

    Science.gov (United States)

    Molina, Vanessa; Robbins-Wamsley, Stephanie H.; Riley, Scott C.; First, Matthew R.; Drake, Lisa A.

    2018-03-01

    Living organisms ≥ 10 μm and loss of organisms that, in turn, may underestimate the concentration of organisms within samples. To address this loss, the retention efficiency (RE) was determined for six filtration approaches using laboratory cultures of microalgae and ambient marine organisms. The approaches employed a membrane filter or mesh nettings of different compositions (nylon, stainless steel, polyester, and polycarbonate), nominal pore sizes (5, 7, and 10 μm), and filtering sequences (e.g., pre-filtering water through a coarse filter). Additionally, in trials with polycarbonate track etched (PCTE) membrane filters, water was amended with particulate material to increase turbidity. Organisms ≥ 10 μm were counted in the material retained on the filter (the filtrand), the material passing through the filter (the filtrate), and the whole water (i.e., unfiltered water). In addition, variable fluorescence fluorometry was used to gauge the relative photochemical yield of phytoplankton-a proximal measurement of the physiological status of phytoplankton-in the size fractions. Further, the mesh types and filters were examined using scanning electron microscopy, which showed irregular openings. The RE of cultured organisms-calculated as the concentration in the filtrand relative to combined concentration in the filtrand and the filtrate-was high for all filtration approaches when laboratory cultures were assessed (> 93%), but RE ranged from 66 to 98% when mixed assemblages of ambient organisms were evaluated. Although PCTE membrane filters had the highest RE (98%), it was not significantly higher than the efficiencies of the 7-μm polyester, Double 7-μm polyester, and Dual 35-μm and 7-μm polyester approaches, but it was significantly higher than the 5-μm nylon and 5-μm stainless steel techniques. This result suggests that PCTE membrane filters perform comparably to 7-μm polyester meshes, so that any of these approaches could be used for concentrating

  18. Identification of organic nitrates in the NO3 radical initiated oxidation of alpha-pinene by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Perraud, Véronique; Bruns, Emily A; Ezell, Michael J; Johnson, Stanley N; Greaves, John; Finlayson-Pitts, Barbara J

    2010-08-01

    The gas-phase reactions of nitrate radicals (NO3) with biogenic organic compounds are a major sink for these organics during night-time. These reactions form secondary organic aerosols, including organic nitrates that can undergo long-range transport, releasing NOx downwind. We report here studies of the reaction of NO3 with alpha-pinene at 1 atm in dry synthetic air (relative humidity approximately 3%) and at 298 K using atmospheric pressure chemical ionization triple quadrupole mass spectrometry (APCI-MS) to identify gaseous and particulate products. The emphasis is on the identification of individual organic nitrates in the particle phase that were obtained by passing the product mixture through a denuder to remove gas-phase reactants and products prior to entering the source region of the mass spectrometer. Filter extracts were also analyzed by GC-MS and by APCI time-of-flight mass spectrometry (APCI-ToF-MS) with methanol as the proton source. In addition to pinonaldehyde and pinonic acid, five organic nitrates were identified in the particles as well as in the gas phase: 3-oxopinane-2-nitrate, 2-hydroxypinane-3-nitrate, pinonaldehyde-PAN, norpinonaldehyde-PAN, and (3-acetyl-2,2-dimethyl-3-nitrooxycyclobutyl)acetaldehyde. Furthermore, there was an additional first-generation organic nitrate product tentatively identified as a carbonyl hydroxynitrate with a molecular mass of 229. These studies suggest that a variety of organic nitrates would partition between the gas phase and particles in the atmosphere, and serve as a reservoir for NOx.

  19. Particulate matter levels in a South American megacity: the metropolitan area of Lima-Callao, Peru.

    Science.gov (United States)

    Silva, Jose; Rojas, Jhojan; Norabuena, Magdalena; Molina, Carolina; Toro, Richard A; Leiva-Guzmán, Manuel A

    2017-11-13

    The temporal and spatial trends in the variability of PM 10 and PM 2.5 from 2010 to 2015 in the metropolitan area of Lima-Callao, Peru, are studied and interpreted in this work. The mean annual concentrations of PM 10 and PM 2.5 have ranges (averages) of 133-45 μg m -3 (84 μg m -3 ) and 35-16 μg m -3 (26 μg m -3 ) for the monitoring sites under study. In general, the highest annual concentrations are observed in the eastern part of the city, which is a result of the pattern of persistent local winds entering from the coast in a south-southwest direction. Seasonal fluctuations in the particulate matter (PM) concentrations are observed; these can be explained by subsidence thermal inversion. There is also a daytime pattern that corresponds to the peak traffic of a total of 9 million trips a day. The PM 2.5 value is approximately 40% of the PM 10 value. This proportion can be explained by PM 10 re-suspension due to weather conditions. The long-term trends based on the Theil-Sen estimator reveal decreasing PM 10 concentrations on the order of -4.3 and -5.3% year -1 at two stations. For the other stations, no significant trend is observed. The metropolitan area of Lima-Callao is ranked 12th and 16th in terms of PM 10 and PM 2.5 , respectively, out of 39 megacities. The annual World Health Organization thresholds and national air quality standards are exceeded. A large fraction of the Lima population is exposed to PM concentrations that exceed protection thresholds. Hence, the development of pollution control and reduction measures is paramount.

  20. Environmental studies in two communes of Santiago de Chile by the analysis of magnetic properties of particulate matter deposited on leaves of roadside trees

    Science.gov (United States)

    Muñoz, David; Aguilar, Bertha; Fuentealba, Raúl; Préndez, Margarita

    2017-03-01

    Emissions from motor vehicles are considered to be one of the main sources of airborne particulate matter in Santiago. International researchers have shown that particulate matter contains metal oxides and magnetic particles, both of which are emitted mainly from vehicles exhaust pipes. On the other hand, trees are effective in reducing such contamination, so that they act as passive collectors of particulate matter. This work presents the results obtained from the first magnetic study of the particulate matter collected in two areas of the city of Santiago de Chile. Magnetic susceptibility and Saturation Isothermic Remanent Magnetization (SIRM) were determined in leaves from abundant urban trees and from urban dust samples. Results indicate that most of the samples contain ferromagnetic minerals with magnetite (Fe3O4) as the main carrier. Values of magnetic susceptibility (SI ×10-6 m3/kg) in the range 0.04-0.24 for leaves and in the range 10-45 for urban dust were determinated. In one of the city areas studied, significant correlation between the particulate matter deposited on leaves of Platanus orientalis and measured traffic flows was obtained. In addition, it was possible to estimate that the species Platanus orientalis and Acer negundo have a better ability to capture particulate matter than the species Robinia pseudoacacia.

  1. Airborne particulate discriminator

    Science.gov (United States)

    Creek, Kathryn Louise [San Diego, CA; Castro, Alonso [Santa Fe, NM; Gray, Perry Clayton [Los Alamos, NM

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  2. Dry deposition of gaseous radioiodine and particulate radiocaesium onto leafy vegetables

    International Nuclear Information System (INIS)

    Tschiersch, Jochen; Shinonaga, Taeko; Heuberger, Heidi

    2009-01-01

    Radionuclides released to the atmosphere during dry weather (e.g. after a nuclear accident) may contaminate vegetable foods and cause exposure to humans via the food chain. To obtain experimental data for an appropriate assessment of this exposure path, dry deposition of radionuclides to leafy vegetables was studied under homogeneous and controlled greenhouse conditions. Gaseous 131 I-tracer in predominant elemental form and particulate 134 Cs-tracer at about 1 μm diameter were used to identify susceptible vegetable species with regard to contamination by these radionuclides. The persistence was examined by washing the harvested product with water. The vegetables tested were spinach (Spinacia oleracea), butterhead lettuce (Lactuca sativa var. capitata), endive (Cichorium endivia), leaf lettuce (Lactuca sativa var. crispa), curly kale (Brassica oleracea convar. acephala) and white cabbage (Brassica oleracea convar. capitata). The variation of radionuclides deposited onto each vegetable was evaluated statistically using the non-parametric Kruskal-Wallis Test and the U-test of Mann-Whitney. Significant differences in deposited 131 I and 134 Cs activity concentration were found among the vegetable species. For 131 I, the deposition velocity to spinach normalized to the biomass of the vegetation was 0.5-0.9 cm 3 g -1 s -1 which was the highest among all species. The particulate 134 Cs deposition velocity of 0.09 cm 3 g -1 s -1 was the highest for curly kale, which has rough and structured leaves. The lowest deposition velocity was onto white cabbage: 0.02 cm 3 g -1 s -1 (iodine) and 0.003 cm 3 g -1 s -1 (caesium). For all species, the gaseous iodine deposition was significantly higher compared to the particulate caesium deposition. The deposition depends on the sensitive parameters leaf area, stomatal aperture, and plant morphology. Decontamination by washing with water was very limited for iodine but up to a factor of two for caesium.

  3. Particulate matter and carbon monoxide multiple regression models using environmental characteristics in a high diesel-use area of Baguio City, Philippines

    International Nuclear Information System (INIS)

    Cassidy, Brandon E.; Naeher, Luke P.; Alabanza-Akers, Mary Anne; Akers, Timothy A.; Hall, Daniel B.; Ryan, P. Barry; Bayer, Charlene W.

    2007-01-01

    In Baguio City, Philippines, a mountainous city of 252,386 people where 61% of motor vehicles use diesel fuel, ambient particulate matter 2.5 ) and 10 ) in aerodynamic diameter and carbon monoxide (CO) were measured at 30 street-level locations for 15 min apiece during the early morning (4:50-6:30 am), morning rush hour (6:30-9:10 am) and afternoon rush hour (3:40-5:40 pm) in December 2004. Environmental observations (e.g. traffic-related variables, building/roadway designs, wind speed and direction, etc.) at each location were noted during each monitoring event. Multiple regression models were formulated to determine which pollution sources and environmental factors significantly affect ground-level PM 2.5 , PM 10 and CO concentrations. The models showed statistically significant relationships between traffic and early morning particulate air pollution [(PM 2.5 p = 0.021) and PM 10 (p = 0.048)], traffic and morning rush hour CO (p = 0.048), traffic and afternoon rush hour CO (p = 0.034) and wind and early morning CO (p 0.044). The mean early morning, street-level PM 2.5 (110 ± 8 μg/m 3 ; mean ± 1 standard error) was not significantly different (p-value > 0.05) from either rush hour PM 2.5 concentration (morning = 98 ± 7 μg/m 3 ; afternoon = 107 ± 5 μg/m 3 ) due to nocturnal inversions in spite of a 100% increase in automotive density during rush hours. Early morning street-level CO (3.0 ± 1.7 ppm) differed from morning rush hour (4.1 ± 2.3 ppm) (p 0.039) and afternoon rush hour (4.5 ±2.2 ppm) (p = 0.007). Additionally, PM 2.5 , PM 10 , CO, nitrogen dioxide (NO 2 ) and select volatile organic compounds were continuously measured at a downtown, third-story monitoring station along a busy roadway for 11 days. Twenty-four-hour average ambient concentrations were: PM 2.5 = 72.9 ± 21 μg/m 3 ; CO = 2.61 ± 0.6 ppm; NO 2 = 27.7 ± 1.6 ppb; benzene = 8.4 ± 1.4 μg/m 3 ; ethylbenzene = 4.6 ± 2.0 μg/m 3 ; p-xylene = 4.4 ± 1.9 μg/m 3 ; m-xylene = 10.2 ± 4

  4. Modelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxes

    Directory of Open Access Journals (Sweden)

    D. Brigolin

    2018-03-01

    Full Text Available This work presents the result of a study carried out in the north-western Adriatic Sea, by combining two different types of biogeochemical models with field sampling efforts. A longline mussel farm was taken as a local source of perturbation to the natural particulate organic carbon (POC downward flux. This flux was first quantified by means of a pelagic model of POC deposition coupled to sediment trap data, and its effects on sediment bioirrigation capacity and organic matter (OM degradation pathways were investigated constraining an early diagenesis model by using original data collected in sediment porewater. The measurements were performed at stations located inside and outside the area affected by mussel farm deposition. Model-predicted POC fluxes showed marked spatial and temporal variability, which was mostly associated with the dynamics of the farming cycle. Sediment trap data at the two sampled stations (inside and outside of the mussel farm showed average POC background flux of 20.0–24.2 mmol C m−2 d−1. The difference of organic carbon (OC fluxes between the two stations was in agreement with model results, ranging between 3.3 and 14.2 mmol C m−2 d−1, and was primarily associated with mussel physiological conditions. Although restricted, these changes in POC fluxes induced visible effects on sediment biogeochemistry. Observed oxygen microprofiles presented a 50 % decrease in oxygen penetration depth (from 2.3 to 1.4 mm, accompanied by an increase in the O2 influx at the station below the mussel farm (19–31 versus 10–12 mmol O2 m−2 d−1 characterised by higher POC flux. Dissolved inorganic carbon (DIC and NH4+ concentrations showed similar behaviour, with a more evident effect of bioirrigation underneath the farm. This was confirmed through constraining the early diagenesis model, of which calibration leads to an estimation of enhanced and shallower bioirrigation underneath the farm

  5. Dithiothreitol activity by particulate oxidizers of SOA produced from photooxidation of hydrocarbons under varied NOx levels

    Directory of Open Access Journals (Sweden)

    H. Jiang

    2017-08-01

    Full Text Available When hydrocarbons (HCs are atmospherically oxidized, they form particulate oxidizers, including quinones, organic hydroperoxides, and peroxyacyl nitrates (PANs. These particulate oxidizers can modify cellular materials (e.g., proteins and enzymes and adversely modulate cell functions. In this study, the contribution of particulate oxidizers in secondary organic aerosols (SOAs to the oxidative potential was investigated. SOAs were generated from the photooxidation of toluene, 1,3,5-trimethylbenzene, isoprene, and α-pinene under varied NOx levels. Oxidative potential was determined from the typical mass-normalized consumption rate (reaction time t =  30 min of dithiothreitol (DTTt, a surrogate for biological reducing agents. Under high-NOx conditions, the DTTt of toluene SOA was 2–5 times higher than that of the other types of SOA. Isoprene DTTt significantly decreased with increasing NOx (up to 69 % reduction by changing the HC ∕ NOx ratio from 30 to 5. The DTTt of 1,3,5-trimethylbenzene and α-pinene SOA was insensitive to NOx under the experimental conditions of this study. The significance of quinones to the oxidative potential of SOA was tested through the enhancement of DTT consumption in the presence of 2,4-dimethylimidazole, a co-catalyst for the redox cycling of quinones; however, no significant effect of 2,4-dimethylimidazole on modulation of DTT consumption was observed for all SOA, suggesting that a negligible amount of quinones was present in the SOA of this study. For toluene and isoprene, mass-normalized DTT consumption (DTTm was determined over an extended period of reaction time (t =  2 h to quantify their maximum capacity to consume DTT. The total quantities of PANs and organic hydroperoxides in toluene SOA and isoprene SOA were also measured using the Griess assay and the 4-nitrophenylboronic acid assay, respectively. Under the NOx conditions (HC ∕ NOx ratio: 5–36 ppbC ppb−1 applied in

  6. Creating breakthroughs at 3M.

    Science.gov (United States)

    von Hippel, E; Thomke, S; Sonnack, M

    1999-01-01

    Most senior managers want their product development teams to create break-throughs--new products that will allow their companies to grow rapidly and maintain high margins. But more often they get incremental improvements to existing products. That's partly because companies must compete in the short term. Searching for breakthroughs is expensive and time consuming; line extensions can help the bottom line immediately. In addition, developers simply don't know how to achieve breakthroughs, and there is usually no system in place to guide them. By the mid-1990s, the lack of such a system was a problem even for an innovative company like 3M. Then a project team in 3M's Medical-Surgical Markets Division became acquainted with a method for developing breakthrough products: the lead user process. The process is based on the fact that many commercially important products are initially thought of and even prototyped by "lead users"--companies, organizations, or individuals that are well ahead of market trends. Their needs are so far beyond those of the average user that lead users create innovations on their own that may later contribute to commercially attractive breakthroughs. The lead user process transforms the job of inventing breakthroughs into a systematic task of identifying lead users and learning from them. The authors explain the process and how the 3M project team successfully navigated through it. In the end, the team proposed three major new product lines and a change in the division's strategy that has led to the development of breakthrough products. And now several more divisions are using the process to break away from incrementalism.

  7. Characterization and sources of air particulate matter at Kwabenya, near Accra, Ghana

    International Nuclear Information System (INIS)

    Aboh, I. J. K.

    2009-01-01

    Gravimetric, reflectometric and elemental analyses have been carried out on airborne particulate matter sampled in a semi-rural area of Kwabenya, near Accra-Ghana. The PM 10 aerosols were sampled using a Gent sampler, size segregating the aerosol into coarse (PM 10-2.5 ) and fine (PM 1.5 ) fractions. The data and derived information were generated from 216 days of sampling spanning a period of about 14 months, 28 th December 2005 to 12 th February 2007. The particulate matter (PM) at Kwabenya was dominated by the coarse particulates and showed low levels during the Rainy season and high levels during the Harmattan period. The levels measured during the 2006/07 Harmattan were very high. The mass concentration for the measuring period were in the following ranges; coarse (PM 10-2.5 ) fraction (0.16 - 1794.01 µg/m 3 ); PM 2.5 (fine) fraction (0.50 - 430.23 µg/m 3 ) and PM 10 (0.87 µg/m 3 to 2064.89 µg/m 3 ). Additional information about the ambient air was obtained through the subsequent determination of elemental concentration using energy dispersive x-ray fluorescence (EDXRF) analysis and black carbon (BC) concentration through the b lack smoke method . The elements identified and quantified with the Quantitative X-ray Analysis System (QXAS) package software were: AI, Si, S, CI, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb in the coarse fraction. The following elements were identified and quantified in the fine fraction: AI, Si, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr and Pb. Validation of the quantitative methods with the standard reference filter SRM2783 gave very good agreement (within ± 15%) for most elements analysed except for Ni (±43%)which was very close to the detection limit. The elemental concentrations in the two fractions vary from season to season. Using simple correlation analysis some elements correlate, the elemental correlations also vary from season to season, for example during the Harmattan S, CI, V, Br and Sr correlated very

  8. A five-year study of particulate matter (PM2.5) and cerebrovascular diseases

    International Nuclear Information System (INIS)

    Leiva G, Manuel A.; Santibañez, Daniela A.; Ibarra E, Sergio; Matus C, Patricia; Seguel, Rodrigo

    2013-01-01

    Cerebrovascular accidents, or strokes, are the second leading cause of mortality and the leading cause of morbidity in both Chile and the rest of the world. However, the relationship between particulate matter pollution and strokes is not well characterized. The association between fine particle concentration and stroke admissions was studied. Data on hospital admissions due to cerebrovascular accidents were collected from the Ministry of Health. Air quality and meteorological data were taken from the Air Quality database of the Santiago Metropolitan Area. Santiago reported 33,624 stroke admissions between January 1, 2002 and December 30, 2006. PM2.5 concentration was markedly seasonal, increasing during the winter. This study found an association between PM2.5 exposure and hospital admissions for stroke; for every PM2.5 concentration increase of 10 μg m3 , the risk of emergency hospital admissions for cerebrovascular causes increased by 1.29% (95% CI 0.552%–2.03%). Highlights: •Particulate matter pollution – cerebrovascular diseases relationship is not well known. •Cerebrovascular diseases are the second leading cause of mortality and the leading cause of morbidity. •PM2.5 increase 10 μg/m 3 the risk of hospital admissions for stroke causes increases by 1.29%. •The results are similar to that of other cities worldwide. -- Relationship between PM pollution and strokes is not well characterized. In Santiago the risk of the stroke increased by 1.29%; for every increase of 10 μg m3 in PM2.5

  9. The spectral optical properties and relative radiant heating contribution of dissolved and particulate matter in the surface waters across the Fram Strait

    DEFF Research Database (Denmark)

    Pavlov, A.K.; Granskog, M.A.; Stedmon, Colin

    autumns of 2009 and 2010 comprehensive observations were performed on transects along 79 N across the Fram Strait. Samples for chromophoric dissolved organic matter (CDOM) and particulate absorption were collected and analyzed together with distribution of temperature and salinity in surface waters (0......-100 m). Large spatial variations in the distribution of CDOM and particulate matter as well as in their relative contributions to total absorption were apparent, with high contrast between waters of Arctic and Atlantic origin. In addition, estimates of underwater light profiles and radiant heating rate...... (RHR) of the upper layer were obtained using a simplistic exponential RHR model. This is one of the first detailed overviews of sea water optical properties across the northern Fram Strait, and might have potential implications for biological, biogeochemical and physical processes in the region...

  10. Magnetoelectric effect in lead free piezoelectric Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}–modified CFO based magnetostrictive (Co{sub 0.6}Zn{sub 0.4}Fe{sub 1.7} Mn{sub 0.3}O{sub 4}) particulate nanocomposite prepared by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Megha [Nanotechnology Research Laboratory, Desh Bhagat University, Mandi Govindgarh 147330, Punjab (India); Sharma, Puneet [School of Physics & Materials Science, Thapar University, Patiala 147004, Punjab (India); Kumari, Mukesh; Singh, Anoop Pratap [Magnetics & Advanced ceramics laboratory, Department of Physics, Indian Institute of Technology, Delhi 110016 (India); Tyagi, Mintu, E-mail: mintutyagi@deshbhagatuniversity.in [Nanotechnology Research Laboratory, Desh Bhagat University, Mandi Govindgarh 147330, Punjab (India)

    2017-03-15

    Lead free magnetoelectric composites that comprise Co{sub 0.6}Zn{sub 0.4}Fe{sub 1.7}Mn{sub 0.3}O{sub 4} (CZFMO) and Bi{sub 1/2}Na{sub 1/2}TiO{sub 3} (BNT) were synthesized using sol-gel method and it's structural, dielectric, magnetic, ferroelectric and magnetoelectric (ME) properties were studied. The X-ray diffraction displayed the single phase formation of parent phases and the presence of two phases in the composites. The temperature dependent dielectric spectra of samples indicates two anomalies at ~220 °C and ~320 °C were ascribed to ferroelectric to antiferroelectric, and anti-ferroelectric to paraelectric phase transitions respectively. Room temperature (RT) magnetic measurements show that composites are soft magnetic. The composite with x=0.2, showed the large value of ME voltage coefficient (α{sub E})~58 mV/cmOe. Moreover, these ME composites provide a great opportunity as potential lead free systems for multifunctional devices. - Highlights: • In this work, Modified CFO based lead free particulate nanocomposites with significantly high value of ME coupling coefficient α{sub E} ~52 mV/cmOe have been prepared. • This sufficient high value of α{sub E} in such composites is obtained by manipulating/improving the piezomagnetic component. • The studies on BNT based particulate ME composites are very scarce in literature. However, no report is available in on the modified CFO based lead free particulate composites.

  11. Potential effects of particulate matter from combustion during services on human health and on works of art in medieval churches in Cyprus

    Energy Technology Data Exchange (ETDEWEB)

    Loupa, Glykeria, E-mail: gloupa@env.duth.g [Laboratory of Atmospheric Pollution and Pollution Control Engineering, Faculty of Engineering, Department of Environmental Engineering, Democritus University of Thrace, P.O. Box 447, Xanthi 67100 (Greece); Karageorgos, Evangelos, E-mail: vkarageo@env.duth.g [Laboratory of Atmospheric Pollution and Pollution Control Engineering, Faculty of Engineering, Department of Environmental Engineering, Democritus University of Thrace, P.O. Box 447, Xanthi 67100 (Greece); Rapsomanikis, Spyridon, E-mail: rapso@env.duth.g [Laboratory of Atmospheric Pollution and Pollution Control Engineering, Faculty of Engineering, Department of Environmental Engineering, Democritus University of Thrace, P.O. Box 447, Xanthi 67100 (Greece)

    2010-09-15

    Indoor and outdoor particulate matter (PM{sub 0.3-10}) number concentrations were established in two medieval churches in Cyprus. In both churches incense was burnt occasionally during Mass. The highest indoor PM{sub 0.5-1} concentrations compared with outdoors (10.7 times higher) were observed in the church that burning of candles indoors was allowed. Peak indoor black carbon concentration was 6.8 {mu}g m{sup -3} in the instances that incense was burning and 13.4 {mu}g m{sup -3} in the instances that the candles were burning (outdoor levels ranged between 0.6 and 1.3 {mu}g m{sup -3}). From the water soluble inorganic components determined in PM{sub 10}, calcium prevailed in all samples indoors or outdoors, whilst high potassium concentration indoors were a clear marker of combustion. Indoor sources of PM were clearly identified and their emission strengths were estimated via modeling of the results. Indoor estimated PM{sub 0.3-10} mass concentrations exceeded air quality standards for human health protection and for the preservation of works of art. - Particulate matter in medieval churches of Cyprus.

  12. Particulate emission characteristics of a port-fuel-injected SI engine

    International Nuclear Information System (INIS)

    Gupta, S.; Poola, R.; Lee, K. O.; Sekar, R.

    2000-01-01

    Particulate emissions from spark-ignited (SI) engines have come under close scrutiny as they tend to be smaller than 50 nm, are composed mainly of volatile organic compounds, and are emitted in significant numbers. To assess the impact of such emissions, measurements were performed in the exhaust of a current-technology port-fuel-injected SI engine, which was operated at various steady-state conditions. To gain further insights into the particulate formation mechanisms, measurements were also performed upstream of the catalytic converter. At all engine speeds, a general trend was observed in the number densities and mass concentrations: a moderate increase at low loads followed by a decrease at mid-range loads, which was followed by a steep increase at high loads. Within reasonable bounds, one could attribute such a trend to three different mechanisms. An unidentified mechanism at low loads results in particulate emissions monotonically increasing with load. At medium loads, wherein the engine operates close to stoichiometric conditions, high exhaust temperatures lead to particulate oxidation. At high loads, combustion occurs mostly under fuel-rich conditions, and the contribution from combustion soot becomes significant. Estimates of the number of particles emitted per kilometer by a vehicle carrying the current test engine were found to be lower than those from a comparable diesel vehicle by three orders of magnitude. Similar estimates for mass emissions (grams of particulates emitted per kilometer) were found to be two orders of magnitude lower than the future regulated emission value of 0.006 (g/km) for light-duty diesel vehicles. Moreover, considering the fact that these particles have typical lifetimes of 15 min, the health hazard from particulate emissions from SI engines appears to be low

  13. Establishment of a Practical Approach for Characterizing the Source of Particulates in Water Distribution Systems

    Directory of Open Access Journals (Sweden)

    Seon-Ha Chae

    2016-02-01

    Full Text Available Water quality complaints related to particulate matter and discolored water can be troublesome for water utilities in terms of follow-up investigations and implementation of appropriate actions because particulate matter can enter from a variety of sources; moreover, physicochemical processes can affect the water quality during the purification and transportation processes. The origin of particulates can be attributed to sources such as background organic/inorganic materials from water sources, water treatment plants, water distribution pipelines that have deteriorated, and rehabilitation activities in the water distribution systems. In this study, a practical method is proposed for tracing particulate sources. The method entails collecting information related to hydraulic, water quality, and structural conditions, employing a network flow-path model, and establishing a database of physicochemical properties for tubercles and slimes. The proposed method was implemented within two city water distribution systems that were located in Korea. These applications were conducted to demonstrate the practical applicability of the method for providing solutions to customer complaints. The results of the field studies indicated that the proposed method would be feasible for investigating the sources of particulates and for preparing appropriate action plans for complaints related to particulate matter.

  14. Dynamics of particulate and dissolved organic and inorganic phosphorus during the peak and declining phase of an iron-induced phytoplankton bloom in the eastern subarctic Pacific

    Science.gov (United States)

    Yoshimura, Takeshi; Nishioka, Jun; Ogawa, Hiroshi; Tsuda, Atsushi

    2018-01-01

    Phosphorus (P) is an essential element for all organisms and thus the P cycle plays a key role in determining the dynamics of lower trophic levels in marine ecosystems. P in seawater occurs conceptually in particulate and dissolved organic and inorganic (POP, PIP, DOP, and DIP, respectively) pools and clarification of the dynamics in these P pools is the basis to assess the biogeochemical cycle of P. Despite its importance, behaviors of each P pool with phytoplankton dynamics have not been fully examined. We measured the four operationally defined P pools (POPop, PIPop, DOPop, and SRP) during an iron-induced phytoplankton bloom (as part of the subarctic ecosystem response to iron enrichment study (SERIES)) in the eastern subarctic Pacific in summer 2002. During our observations of the iron-enriched patch from day 15 to day 26 after the iron infusion, chlorophyll-a concentration in the surface layer decreased from 6.3 to 1.2 μg L- 1, indicating the peak through decline phase of the phytoplankton bloom. At the bloom peak, P was partitioned into POPop, PIPop, and DOPop in proportions of 60, 27, and 13%, respectively. While chlorophyll-a and POPop showed similar temporal variations during the declining phase, PIPop showed a different peak timing with a 2 day delay compared to POPop, resulting in a rapid change in the relative proportion of PIPop to total particulate P (TPP = POPop + PIPop) at the peak (25%) and during the declining phase of the bloom (50%). A part of POPop was replaced by PIPop just after slowing down of phytoplankton growth. This process may have a significant role in the subsequent regeneration of P. We conclude that measurement of TPP alone is insufficient to show the interaction between P and phytoplankton dynamics and fractionation of TPP into POPop and PIPop provides useful insights to clarify the biogeochemical cycle of P.

  15. Waste Gas And Particulate Control Measures For Laser Cutters In The Automotive Cloth Industry

    Science.gov (United States)

    Ball, R. D.; Kulik, B. F.; Stoncel, R. J.; Tan, S. L.

    1986-11-01

    Demands for greater flexibility and accuracy in the manufacture of automobile trim parts has made single-ply laser cutting an attractive proposition. Lasers are able to cut a large variety of cloth types, from vinyls to velours. Unlike mechanically cut parts, which in the case of velours produce rough edges and dust problems, laster cutting of parts produces smooth edges, fumes and fine particulate. A detailed study of the nature of the laser effluent from a cross section of typical synthetic cloth found in an automotive trim plant was undertaken. Most samples were cut by a fast axial flow, 500 Watt, continuous wave CO2 laser. A 254 mm (10-inch) focussing optics package was used. The width of the kerf varied with the material, and values were determined at between 0.2 and 0.7 mm. Particle size distribution analysis and rates of particulate emission for each cloth were determined. Gases were collected in gas sample bags and analyzed using Fourier transform infrared analysis. Low boiling point organics were collected on activated charcoal tubes, identified on a gas chromatograph mass spectrometer, and quantified on a gas chromatograph. Inorganic contaminants were collected on filter paper and analysed on an inductively coupled plasma atomic emission spectrometer. A number of different effluent control systems were evaluated. Due to the very fine and sticky nature of the particulate, filters capable of removing particulate sizes in the 10 μm or lower range, tend to clog rapidly. Laboratory scale models of wet scrubbers, and electrostatic precipitators were built and tested. The most effective dust and effluent gas control was given by a wet electrostatic precipitator. This system, in conjunction with a scrubber, should maintain emission levels within environmental standards.

  16. M3 User's Manual. Version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Skaarman, Erik (Abscondo Utveckling, Bromma (Sweden)); Gomez, Javier B. (Univ. of Zaragoza (Spain). Geochemical modelling Group); Gurban, Ioana (3D Terra (Canada))

    2006-07-15

    . Since the calculations are relative to the selected reference waters, modelling can only describe changes in terms of mixing and reactions taking place between the reference waters. The results can be used to describe both mathematically and quantitatively the groundwater characteristics, rather than qualitatively as is often the case in a site description of the groundwater chemistry. The M3 method can be used for tracing the evolution, past-present dispersion and water-rock interactions. The outcome from the modelling can be reported in non-hydrochemical terms such as changes in mixing portions or in gain/losses due to mass balance reactions. The comparison with hydrogeological models is easier since the results from the M3 model can be compared to the results from the hydrodynamic models. The effect on the groundwater composition observed from biological reactions such as organic decomposition or sulphate reduction can be traced.

  17. Standard Practice for Sampling for Particulate Contamination by Tape Lift

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers procedures for sampling surfaces to determine the presence of particulate contamination, 5 m and larger. The practice consists of the application of a pressure-sensitive tape to the surface followed by the removal of particulate contamination with the removal of the tape. The tape with the adhering particles is then mounted on counting slides. Counting and measuring of particles is done by standard techniques. 1.2 This practice describes the materials and equipment required to perform sampling of surfaces for particle counting and sizing. 1.3 The criteria for acceptance or rejection of a part for conformance to surface cleanliness level requirements shall be determined by the user and are not included in this practice. 1.4 This practice is for use on surfaces that are not damaged by the application of adhesive tape. The use of this practice on any surface of any material not previously tested or for which the susceptibility to damage is unknown is not recommended. In general, metal...

  18. Application of Natural Radioisotopes as Tracers of Particulate Organic Carbon Transport, Export and Burial Processes in Chukchi Sea, Arctic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yu; Jianhua, He [Key Lab of Global Change and Marine-Atmosphere Chemistry, State Oceanic Administration, Xiamen (China)

    2013-07-15

    To evaluate the efficiency of the biological pump and carbon sequestration content on the Arctic shelf, estimations of POC export fluxes derived from 234Th/238U disequilibrium and organic carbon burial rate from 210Pbex chronology in sediment core were made during the 3rd Chinese National Arctic Research Expedition (CHINARE-3), Jul 12-Sep 22, 2008. Great deficits of {sup 234}Th to {sup 238}U were observed widely over the Chukchi shelf, with an average {sup 234}Th/{sup 238}U of 0.64{+-}0.28, resulting from intense particle scavenging. The average POC export fluxes in the entire study area, shelf and slope area were 24.9 {+-} 23.3, 29.5 {+-} 23.0 and 2.1 {+-} 0.5 mmol C/m{sup 2}d, respectively, i.e. 21% of the primary production on average was exported to the benthos. An organic carbon burial rate of 517 mmol C/m{sup 2}a were estimated, accounting for 6% of the average primary production. The efficient biological pump led to 11.6{+-}9.0 T g C exported to benthos and 3.4 T g C buried permanently in the sediment per year, accounting for 0.3% of total POC export amount and 2.1% of total organic carbon burial amount of the global ocean. (author)

  19. Investigation on magnetoelectric behavior of (80Bi0.5Na0.5TiO3-20Bi0.5K0.5TiO3)-CoFe2O4 particulate composites

    Science.gov (United States)

    Liu, Sheng; Yan, Shuoqing; Yao, Lingling; He, Jun; He, Longhui; Hu, Zhaowen; Huang, Shengxiang; Deng, Lianwen

    2017-12-01

    Particulate magnetoelectric (ME) ceramics constituted by (1-x)(80Bi0.5Na0.5TiO3-20Bi0.5K0.5TiO3)-xCoFe2O4 [(1-x)BNKT-xCFO] (x = 0, 0.1, 0.2, 0.3, 0.4 and 1.0) were synthesized by an powder-in-sol precursor hybrid processing method and their structure, magnetic, ferroelectric, magnetodielectric (MD) and ME properties have been investigated. Results showed that the ceramics consisted of only two chemically separated phases and had homogeneous microstructure. The introduction of CFO into BNKT matrix led to the weakening of ferroelectric and dielectric properties whereas the strengthening magnetic and MD properties. The observation of the MD effect revealed the evidence of the strain-induced ME coupling and the MD value is well scaled with M2. A maximum value of ME output of 25.07 mV/cm·Oe was achieved for the 0.7BNKT-0.3CFO composite. The improved ME response together with the linear MD effect makes the ceramics promise for use in magnetic field controllable devices or magneto-electric transducers.

  20. Omega-3 Fatty Acid Attenuates Cardiovascular Effects in Healthy Older Volunteers Exposed to Concentrated Ambient Fine and UltrafineParticulate Matter

    Science.gov (United States)

    Rationale: Ambient particulate matter (PM) exposure has been associated with adverse cardiovascular effects. A recent epidemiology study reported that omega-3 polyunsaturated fatty acid (fish oil) supplementation blunted the response of study participants to PM. Our study was des...

  1. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    International Nuclear Information System (INIS)

    Turner, Andrew; Mawji, Edward

    2005-01-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D ow , ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant ( 3.3 -10 5.3 ml g -1 . The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating trace metals in natural waters

  2. Source apportionment of fine organic aerosols in Beijing

    Directory of Open Access Journals (Sweden)

    S. Guo

    2009-11-01

    Full Text Available Fine particles (PM2.5, i.e., particles with an aerodynamic diameter of ≤2.5 μm were collected from the air in August 2005, August–September 2006, and January–February 2007, in Beijing, China. The chemical compositions of particulate organic matter in the ambient samples were quantified by gas chromatography/mass spectrometry. The dominant compounds identified in summertime were n-alkanoic acids, followed by dicarboxylic acids and sugars, while sugars became the most abundant species in winter, followed by polycyclic aromatic hydrocarbons, n-alkanes, and n-alkanoic acids. The contributions of seven emission sources (i.e., gasoline/diesel vehicles, coal burning, wood/straw burning, cooking, and vegetative detritus to particulate organic matter in PM2.5 were estimated using a chemical mass balance receptor model. The model results present the seasonal trends of source contributions to organic aerosols. Biomass burning (straw and wood had the highest contribution in winter, followed by coal burning, vehicle exhaust, and cooking. The contribution of cooking was the highest in summer, followed by vehicle exhaust and biomass burning, while coal smoke showed only a minor contribution to ambient organic carbon.

  3. Secondary organic aerosol from sesquiterpene and monoterpene emissions in the United States.

    Science.gov (United States)

    Sakulyanontvittaya, Tanarit; Guenther, Alex; Helmig, Detlev; Milford, Jana; Wiedinmyer, Christine

    2008-12-01

    Emissions of volatile organic compounds (VOC) from vegetation are believed to be a major source of secondary organic aerosol (SOA), which in turn comprises a large fraction of fine particulate matter in many areas. Sesquiterpenes are a class of biogenic VOC with high chemical reactivity and SOA yields. Sesquiterpenes have only recently been quantified in emissions from a wide variety of plants. In this study, a new sesquiterpene emission inventory is used to provide input to the Models-3 Community Multiscale Air Quality (CMAQ) model. CMAQ is used to estimate the contribution of sesquiterpenes and monoterpenes to SOA concentrations over the contiguous United States. The gas-particle partitioning module of CMAQ was modified to include condensable products of sesquiterpene oxidation and to update values of the enthalpy of vaporization. The resulting model predicts July monthly average surface concentrations of total SOA in the eastern U.S. ranging from about 0.2-0.8 microg m(-3). This is roughly double the amount of SOA produced in this region when sesquiterpenes are not included. Even with sesquiterpenes included, however, the model significantly underpredicts surface concentrations of particle-phase organic matter compared to observed values. Treating all SOA as capable of undergoing polymerization increases predicted monthly average surface concentrations in July to 0.4-1.2 microg m(-3), in closer agreement with observations. Using the original enthalpy of vaporization value in CMAQ in place of the values estimated from the recent literature results in predicted SOA concentrations of about 0.3-1.3 microg m(-3).

  4. Radiant zone heated particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  5. Investigations on Mechanical Behaviour of Micro Graphite Particulates Reinforced Al-7Si Alloy Composites

    Science.gov (United States)

    Nagaraj, N.; Mahendra, K. V.; Nagaral, Madeva

    2018-02-01

    Micro particulates reinforced metal matrix composites are finding wide range of applications in automotive and sports equipment manufacturing industries. In the present study, an attempt has been made to develop Al-7Si-micro graphite particulates reinforced composites by using liquid melt method. 3 and 6 wt. % of micro graphite particulates were added to the Al-7Si base matrix. Microstructural characterization was done by using scanning electron microscope and energy dispersive spectroscope. Mechanical behaviour of Al-7Si-3 and 6 wt. % composites were evaluated as per ASTM standards. Scanning electron micrographs revealed the uniform distribution of micro graphite particulates in the Al-7Si alloy matrix. EDS analysis confirmed the presence of B and C elements in graphite reinforced composites. Further, it was noted that ultimate tensile and yield strength of Al-7Si alloy increased with the addition of 3 and 6wt. % of graphite particulates. Hardness of graphite reinforced composites was lesser than the base matrix.

  6. On the Redox Activity of Urban Aerosol Particles: Implications for Size Distribution and Relationships with Organic Aerosol Components

    Directory of Open Access Journals (Sweden)

    Constantini Samara

    2017-10-01

    Full Text Available This article presents the distribution of the dithiothreitol-based (DTT redox activity of water-soluble airborne particulate matter (PM from two urban sites in the city of Thessaloniki, northern Greece in four size ranges (<0.49, 0.49–0.97, 0.97–3.0 and >3 μm. Seasonal and spatial variations are examined. The correlations of the mass-normalized DTT activity with the content of PM in water-soluble organic carbon (WSOC and non-water-soluble carbonaceous species, such as organic and elemental carbon, as well as with solvent-extractable trace organic compounds (polycyclic aromatic hydrocarbons and nitro-derivatives, polychlorinated biphenyls, organochlorines, polybrominated biphenyl ethers and polar organic markers (dicarboxylic acids and levoglucosan, are investigated. Our study provides new and additional insights into the ambient size distribution of the DTT activity of the water-soluble fraction of airborne PM at urban sites and its associations with organic PM components.

  7. Brand Cigarillos: Low Price but High Particulate Matter Levels-Is Their Favorable Taxation in the European Union Justified?

    Science.gov (United States)

    Wasel, Julia; Boll, Michael; Schulze, Michaela; Mueller, Daniel; Bundschuh, Matthias; Groneberg, David A; Gerber, Alexander

    2015-08-06

    Second hand smoke (ETS)-associated particulate matter (PM) contributes considerably to indoor air contamination and constitutes a health risk for passive smokers. Easy to measure, PM is a useful parameter to estimate the dosage of ETS that passive smokers are exposed to. Apart from its suitability as a surrogate parameter for ETS-exposure, PM itself affects human morbidity and mortality in a dose-dependent manner. We think that ETS-associated PM should be considered an independent hazard factor, separately from the many other known harmful compounds of ETS. We believe that brand-specific and tobacco-product-specific differences in the release of PM matter and that these differences are of public interest. To generate ETS of cigarettes and cigarillos as standardized and reproducible as possible, an automatic second hand smoke emitter (AETSE) was developed and placed in a glass chamber. L&M cigarettes ("without additives", "red label", "blue label"), L&M filtered cigarillos ("red") and 3R4F standard research cigarettes (as reference) were smoked automatically according to a self-developed, standardized protocol until the tobacco product was smoked down to 8 mm distance from the tipping paper of the filter. Mean concentration (Cmean) and area under the curve (AUC) in a plot of PM2.5 against time were measured, and compared. CmeanPM2.5 were found to be 518 μg/m(3) for 3R4F cigarettes, 576 μg/m(3) for L&M "without additives" ("red"), 448 μg/m(3) for L&M "blue label", 547 μg/m(3) for L&M "red label", and 755 μg/m(3) for L&M filtered cigarillos ("red"). AUCPM2.5-values were 208,214 μg/m(3)·s for 3R4F reference cigarettes, 204,629 μg/m(3)·s for L&M "without additives" ("red"), 152,718 μg/m(3)·s for L&M "blue label", 238,098 μg/m(3)·s for L&M "red label" and 796,909 μg/m(3)·s for L&M filtered cigarillos ("red"). Considering the large and significant differences in particulate matter emissions between cigarettes and cigarillos, we think that a favorable

  8. Organic particulate matter formation at varying relative humidity using surrogate secondary and primary organic compounds with activity corrections in the condensed phase obtained using a method based on the Wilson equation

    Directory of Open Access Journals (Sweden)

    E. I. Chang

    2010-06-01

    Full Text Available Secondary organic aerosol (SOA formation in the atmosphere is currently often modeled using a multiple lumped "two-product" (N·2p approach. The N·2p approach neglects: 1 variation of activity coefficient (ζi values and mean molecular weight MW in the particulate matter (PM phase; 2 water uptake into the PM; and 3 the possibility of phase separation in the PM. This study considers these effects by adopting an (N·2pζpMW,ζ approach (θ is a phase index. Specific chemical structures are assigned to 25 lumped SOA compounds and to 15 representative primary organic aerosol (POA compounds to allow calculation of ζi and MW values. The SOA structure assignments are based on chamber-derived 2p gas/particle partition coefficient values coupled with known effects of structure on vapor pressure pL,io (atm. To facilitate adoption of the (N·2pζpMW,θ approach in large-scale models, this study also develops CP-Wilson.1 (Chang-Pankow-Wilson.1, a group-contribution ζi-prediction method that is more computationally economical than the UNIFAC model of Fredenslund et al. (1975. Group parameter values required by CP-Wilson.1 are obtained by fitting ζi values to predictions from UNIFAC. The (N·2pζpMW,θ approach is applied (using CP-Wilson.1 to several real α-pinene/O3 chamber cases for high reacted hydrocarbon levels (ΔHC≈400 to 1000 μg m3 when relative humidity (RH ≈50%. Good agreement between the chamber and predicted results is

  9. 210Pb and Mass Flux Imbalance Between the Settling Particulates and Sediments at a Sediment Trap

    Science.gov (United States)

    Wu, C.; Chung, Y.; Hung, G.

    2005-05-01

    In order to evaluate the mass balance problems between the settling particulates and the underlying sediments, sediment traps were deployed at M1 site (21o32¡¦N, 119o28¡¦E; 2948m) where a box core was taken recently. The sediment trap results were previously published (Chung et al., 2004: Continental Shelf Research). We report here the 210Pb profile measured on this box core by determining its daughter, 210Po, with alpha spectrometry, assuming the paired nuclides are in radioactive equilibrium. The box core (33 cm long, taken in June, 2004) was analyzed for the distributions of its water content, loss on ignition (LOI), and 210Pb. The water content decreases with depth and averages about 55 percent; the LOI as a measure of the total organic matter (TOM) is fairly constant at about 12 percent. The 210Pb profile shows a general exponential decrease with depth, yielding a maximum sedimentation rate of 0.26cm/y, applying a constant flux and constant sedimentation rate model. This rate translates to a mass flux of 0.31g/cm2/y or about 8.5g/m2/d with a dry bulk density of 1.2g/cm3. Based on the excess 210Pb inventory integrated over the core length, the 210Pb flux is estimated at about 19.2dpm/cm2/y or 526dpm/cm2/d assuming at steady state. The 210Pb and mass fluxes obtained from the deepest trap at M1 were only 129dpm/m2/d and 0.55g/m2/d, respectively. The large ¡excess¡" of the 210Pb and mass fluxes in the sediments over those measured from the sediment trap (4 times in 210Pb flux and 14 times in mass flux) suggests either the sedimentation rate was overestimated due to neglect of the mixing effect, and/or large additional particulates, as resuspended sediments which contain less 210Pb, have been transported laterally near the bottom from elsewhere.

  10. Particulate Matter Mass Concentration in Residential Prefabricated Buildings Related to Temperature and Moisture

    Science.gov (United States)

    Kraus, Michal; Juhásová Šenitková, Ingrid

    2017-10-01

    Building environmental audit and the assessment of indoor air quality (IAQ) in typical residential buildings is necessary process to ensure users’ health and well-being. The paper deals with the concentrations on indoor dust particles (PM10) in the context of hygrothermal microclimate in indoor environment. The indoor temperature, relative humidity and air movement are basic significant factors determining the PM10 concentration [μg/m3]. The experimental measurements in this contribution represent the impact of indoor physical parameters on the concentration of particulate matter mass concentration. The occurrence of dust particles is typical for the almost two-thirds of interiors of the buildings. Other parameters indoor environment, such as air change rate, volume of the room, roughness and porosity of the building material surfaces, static electricity, light ions and others, were set constant and they are not taken into account in this study. The mass concentration of PM10 is measured during summer season in apartment of residential prefabricated building. The values of global temperature [°C] and relative humidity of indoor air [%] are also monitored. The quantity of particulate mass matter is determined gravimetrically by weighing according to CSN EN 12 341 (2014). The obtained results show that the temperature difference of the internal environment does not have a significant effect on the concentration PM10. Vice versa, the difference of relative humidity exhibits a difference of the concentration of dust particles. Higher levels of indoor particulates are observed for low values of relative humidity. The decreasing of relative air humidity about 10% caused 10µg/m3 of PM10 concentration increasing. The hygienic limit value of PM10 concentration is not exceeded at any point of experimental measurement.

  11. Composition and Sources of Particulate Matter Measured near Houston, TX: Anthropogenic-Biogenic Interactions

    Directory of Open Access Journals (Sweden)

    Jeffrey K. Bean

    2016-05-01

    Full Text Available Particulate matter was measured in Conroe, Texas (~60 km north of downtown Houston, Texas during the September 2013 DISCOVER-AQ campaign to determine the sources of particulate matter in the region. The measurement site is influenced by high biogenic emission rates as well as transport of anthropogenic pollutants from the Houston metropolitan area and is therefore an ideal location to study anthropogenic-biogenic interactions. Data from an Aerosol Chemical Speciation Monitor (ACSM suggest that on average 64 percent of non-refractory PM1 was organic material, including a high fraction (27%–41% of organic nitrates. There was little diurnal variation in the concentrations of ammonium sulfate; however, concentrations of organic and organic nitrate aerosol were consistently higher at night than during the day. Potential explanations for the higher organic aerosol loadings at night include changing boundary layer height, increased partitioning to the particle phase at lower temperatures, and differences between daytime and nighttime chemical processes such as nitrate radical chemistry. Positive matrix factorization was applied to the organic aerosol mass spectra measured by the ACSM and three factors were resolved—two factors representing oxygenated organic aerosol and one factor representing hydrocarbon-like organic aerosol. The factors suggest that the measured aerosol was well mixed and highly processed, consistent with the distance from the site to major aerosol sources, as well as the high photochemical activity.

  12. River inputs and organic matter fluxes in the northern Bay of Bengal: Fatty acids

    Digital Repository Service at National Institute of Oceanography (India)

    Reemtsma, T.; Ittekkot, V.; Bartsch, M.; Nair, R.R

    ) 55-71 55 Elsevier Science Publishers B.V., Amsterdam \\[RA\\] River inputs and organic matter fluxes in the northern Bay of Bengal: fatty acids T. Reemtsma a, V. Ittekkot a, M. Bartsch a and R.R. Nair b alnstitut fiir Biogeochemie und Meereschemie..., R.R., 1993. River inputs and organic matter fluxes in the northern Bay of Bengal: fatty acids. Chem. Geol., 103: 55-71. Total particulate matter flux and organic carbon and fatty acid fluxes associated with settling particles collected during...

  13. 5 CFR 1303.3 - Organization.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Organization. 1303.3 Section 1303.3... OF THE ADMINISTRATIVE PROCEDURES ACT Organization § 1303.3 Organization. (a) The brief description of the central organization of the Office of Management and Budget follows: (1) The Director's Office...

  14. Photochemical Reactions of Particulate Organic Matter: Deciphering the Role of Direct and Indirect Processes

    Science.gov (United States)

    Carrasquillo, A. J.; Gelfond, C. E.; Kocar, B. D.

    2016-12-01

    Photochemical reactions of natural organic matter (NOM) represent potentially important pathways for biologically recalcitrant material to be chemically altered in aquatic systems. Irradiation can alter the physical state of organic matter by facilitating the cycling between the particulate (POM) and dissolved (DOM) pools, however, a molecular level understanding of this chemically dynamic system is currently lacking. Photochemical reactions of a target molecule proceed by the direct absorption of a photon, or through reaction with a second photolytically generated species (i.e. the hydroxyl radical, singlet oxygen, excited triplet state NOM, hydrogen peroxide, etc.). Here, we isolate the major direct and indirect photochemical reactions of a lignocellulose-rich POM material (Phragmites australis) to determine their relative importance in changing the the chemical structure of the parent POM, and in the production of DOM. We measured POM molecular structure using a combination of NMR and FTIR for bulk analyses and scanning transmission x-ray microscopy (STXM) for spatially resolved chemistry, while the chemical composition of photo-produced DOM was measured using ultra-high resolution mass spectrometry. Results are discussed in the context of the differences in chemical composition of both NOM pools resulting from the isolated photochemical pathways. All treatments result in an increase in DOM with reaction time, indicating that the larger POM matrix is likely fragmenting into smaller more soluble species. Spectroscopic measurements, on the other hand, point to functionalization reactions which increase the abundance of alcohol, acid, and carbonyl moieties in both carbon pools. This unique dataset provides new insight into how photochemical reactions alter the chemical composition of NOM while highlighting the relative importance of indirect pathways.

  15. Contributions of biomass/biofuel burning to organic aerosols and particulate matter in Tanzania, East Africa, based on analyses of ionic species, organic and elemental carbon, levoglucosan and mannosan

    Directory of Open Access Journals (Sweden)

    S. L. Mkoma

    2013-10-01

    Full Text Available Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania, East Africa, in 2011 during wet and dry seasons and were analysed for carbonaceous components, levoglucosan, mannosan and water-soluble inorganic ions. The contributions of biomass/biofuel burning to the organic carbon (OC and particulate matter (PM mass were estimated to be 46–52% and 87–13%, respectively. The mean mass concentrations of PM2.5 and PM10 were 28 ± 6 μg m−3 and 47 ± 8 μg m−3 in wet season, and 39 ± 10 μg m−3 and 61 ± 19 μg m−3 in dry season, respectively. Total carbon (TC accounted for 16–19% of the PM2.5 mass and 13–15% of the PM10 mass. On average, 86 to 89% of TC in PM2.5 and 87 to 90% of TC in PM10 was OC, of which 67–72% and 63% was found to be water-soluble organic carbon (WSOC in PM2.5 and PM10, respectively. We found that concentrations of levoglucosan and mannosan (specific organic tracers of pyrolysis of cellulose well correlated with non-sea-salt potassium (nss-K+ (r2 = 0.56–0.75, OC (r2 = 0.75–0.96 and WSOC (r2 = 0.52–0.78. The K+ / OC ratios varied from 0.06 to 0.36 in PM2.5 and from 0.03 to 0.36 in PM10 with slightly higher ratios in dry season. Mean percent ratios of levoglucosan and mannosan to OC were found to be 3–4% for PM2.5 and PM10 in both seasons. We found lower levoglucosan / K+ ratios and higher K+ / EC (elemental carbon ratios in the biomass-burning aerosols from Tanzania than those reported from other regions. This feature is consistent with the high levels of potassium reported in the soils of Morogoro, Tanzania, suggesting an importance of direct emission of potassium by soil resuspension although K+ is present mostly in fine particles. It is also likely that biomass burning of vegetation of Tanzania emits high levels of potassium that may be enriched in plant tissues. The present study demonstrates that emissions from mixed biomass- and biofuel-burning activities largely

  16. Volatile Organic Compounds from Logwood Combustion: Emissions and Transformation under Dark and Photochemical Aging Conditions in a Smog Chamber.

    Science.gov (United States)

    Hartikainen, Anni; Yli-Pirilä, Pasi; Tiitta, Petri; Leskinen, Ari; Kortelainen, Miika; Orasche, Jürgen; Schnelle-Kreis, Jürgen; Lehtinen, Kari E J; Zimmermann, Ralf; Jokiniemi, Jorma; Sippula, Olli

    2018-04-17

    Residential wood combustion (RWC) emits high amounts of volatile organic compounds (VOCs) into ambient air, leading to formation of secondary organic aerosol (SOA), and various health and climate effects. In this study, the emission factors of VOCs from a logwood-fired modern masonry heater were measured using a Proton-Transfer-Reactor Time-of-Flight Mass Spectrometer. Next, the VOCs were aged in a 29 m 3 Teflon chamber equipped with UV black lights, where dark and photochemical atmospheric conditions were simulated. The main constituents of the VOC emissions were carbonyls and aromatic compounds, which accounted for 50%-52% and 30%-46% of the detected VOC emission, respectively. Emissions were highly susceptible to different combustion conditions, which caused a 2.4-fold variation in emission factors. The overall VOC concentrations declined considerably during both dark and photochemical aging, with simultaneous increase in particulate organic aerosol mass. Especially furanoic and phenolic compounds decreased, and they are suggested to be the major precursors of RWC-originated SOA in all aging conditions. On the other hand, dark aging produced relatively high amounts of nitrogen-containing organic compounds in both gas and particulate phase, while photochemical aging increased especially the concentrations of certain gaseous carbonyls, particularly acid anhydrides.

  17. ) m /SrVO3 ( m = 5, 6) Superlattices

    KAUST Repository

    Dai, Qingqing; Lü ders, Ulrike; Fré sard, Raymond; Eckern, Ulrich; Schwingenschlö gl, Udo

    2018-01-01

    The (LaV3+O3)m/SrV4+O3 (m = 5, 6) superlattices are investigated by first principles calculations. While bulk LaVO3 is a C‐type antiferromagnetic semiconductor and bulk SrVO3 is a paramagnetic metal, semiconducting A‐type antiferromagnetic states

  18. Strong interaction scattering of a spin-zero particle by a 1/2 spin particle; Diffusion par interaction forte d'une particule de spin zero par une particule de spin 1/2

    Energy Technology Data Exchange (ETDEWEB)

    Derem, Andre [Commissariat a l' Energie Atomique - CEA, Centre d' Etudes Nucleaires de Saclay, Departement de Physique des Particules Elementaires (France)

    1969-03-15

    This paper gather kinematic formulas that are commonly used to describe the scattering, with conservation of parity, 0{sup -} + 1{sup +}/2 → 0{sup -} + 1{sup +}/2 (in the notation S{sup P}, S being the spin and P the parity). The two particles 0{sup -} will be two mesons M and M', the two particles 1{sup +}/2 two baryons B and B'. The authors assume that the masses of these four particles are all different. The notations and the definitions are introduced in chapter 1. Chapter 2 recalls essential notions concerning the Dirac equation. The relativistic invariant differential cross-section is calculated in chapter 3, as a function of the invariant amplitudes A'(s,t) and B(s,t). Pauli's usual formalism in the center of mass system is given in chapter 4, as well as the means of passing f(θ) and g(θ) amplitudes to A' and B amplitudes. Chapter 5 is concerned with elastic scattering [French] Nous rassemblons ici un certain nombre de formules cinematiques qui sont utilisees couramment lorsqu'on veut decrire la diffusion, avec conservation de la parite, 0{sup -} + 1{sup +}/2 → 0{sup -} + 1{sup +}/2 (dans la notation S{sup P}, S etant le spin et P la parite). Les deux particules 0{sup -} seront deux mesons M et M', les deux particules 1{sup +}/2 deux baryons B et B'. Nous supposerons que les masses de ces quatre particules sont toutes differentes. Les notations et les definitions sont introduites au chapitre 1. Dans le chapitre 2 sont reprises les notions essentielles concernant l'equation de Dirac. La section efficace differentielle, invariante relativiste, est calculee au chapitre 3 en fonction des amplitudes invariantes A'(s,t) et B(s,t). Le formalisme habituel de Pauli dans le systeme du centre de masse est donne au chapitre 4, de meme que le moyen de passer des amplitudes f(θ) et g(θ) aux amplitudes A' et B. Le chapitre 5 concerne la diffusion elastique. Les formules sont numerotees independamment dans chaque paragraphe. Lorsque les renvois se font d

  19. Spatial and temporal distribution of metals in suspended particulate matter of the Kali estuary, India

    Science.gov (United States)

    Suja, S.; Kessarkar, Pratima M.; Fernandes, Lina L.; Kurian, Siby; Tomer, Arti

    2017-09-01

    Major (Al, Fe, Mn, Ti, Mg) and trace (Cu, Zn, Pb, Cr, Ni, Co, Zr, Rb, Sr, Ba, Li, Be, Sc, V, Ga, Nb, Mo, Sn, Sb, Cs, Hf, Ta, Bi, Th, U) elements and particulate organic carbon (POC) concentrations in surface suspended particulate matter (SPM) of the Kali estuary, (central west coast of India) were studied during the pre-monsoon, monsoon and post monsoon seasons to infer estuarine processes, source of SPM and Geoaccumulation Index (Igeo) assigned pollutionIgeo levels. Distribution of SPM indicates the presence of the estuarine turbidity maximum (ETM) during all three seasons near the river mouth and a second ETM during the post monsoon time in the upstream associated with salinities gradient. The SPM during the monsoon is finer grained (avg. 53 μm), characterized by uniformly low normalized elemental concentration, whereas the post and pre monsoon are characterized by high normalized elemental concentration with coarser grain size (avg. 202 μm and 173 μm respectively) with highest ratios in the upstream estuary. The elemental composition and principal component analysis for the upstream estuary SPM support more contribution from the upstream catchment area rocks during the monsoon season; there is additional contribution from the downstream catchment area during the pre and post monsoon period due to the tidal effect. The Kali estuarine SPM has higher Al, Fe, Mn, Ti, Mg, Ni, Co, Ba, Li and V with respect to Average World River SPM (WRSPM). Igeo values for the SPM indicate Kali Estuary to be severely enriched with Mn and moderately enriched with Cu, Zn, Ni, Co, U and Mo in the upstream estuary during pre and post monsoon seasons. Seasonal changes in salinity gradient (reduced freshwater flow due to closing of the dam gates), reduced velocity at meandering region of the estuary and POC of 1.6-2.3% resulted in co-precipitation of trace elements that were further fortified by flocculation and coagulation throughout the water column resulting in metal trapping in the

  20. Particulate filtration in nuclear facilities

    International Nuclear Information System (INIS)

    1991-01-01

    The removal of particulate radioactive material from exhaust air or gases is an essential feature of virtually all nuclear facilities. Recent IAEA publications have covered the broad designs of off-gas and air cleaning systems for the range of nuclear power plants and other facilities. This report is a complementary guidebook that examines in detail the latest developments in the design, operation, maintenance and testing of fibrous air filters. The original draft of the report was prepared by three consultants, M.W. First, of the School of Public Health, Harvard University, United States of America, K.S. Robinson, from the UKAEA Harwell Laboratory, United Kingdom, and H.G. Dillmann, of the Kernforschungzentrum, Karlsruhe, Germany. The Technical Committee Meeting (TCM), at which the report was reviewed and much additional information contributed, was attended by 11 experts and was held in Vienna, from 30 May to 3 June 1988. 64 refs, 41 figs, 10 tabs

  1. Particulate matter and carbon monoxide multiple regression models using environmental characteristics in a high diesel-use area of Baguio City, Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Cassidy, Brandon E.; Naeher, Luke P. [The University of Georgia (UGA), College of Public Health, Department of Environmental Health Science, Athens, Georgia, GA 30602-2102 (United States); Alabanza-Akers, Mary Anne [UGA, College of Environment and Design, Athens, Georgia (United States); Akers, Timothy A. [Kennesaw State University, WellStar College of Health and Human Services, Kennesaw, Georgia (United States); Hall, Daniel B. [UGA, Franklin College of Arts and Sciences, Department of Statistics, Athens, Georgia (United States); Ryan, P. Barry [Emory University, Rollins School of Public Health, Atlanta, Georgia (United States); Bayer, Charlene W. [Georgia Tech Research Institute, Atlanta, Georgia (United States)

    2007-08-01

    In Baguio City, Philippines, a mountainous city of 252,386 people where 61% of motor vehicles use diesel fuel, ambient particulate matter < 2.5 {mu}m (PM{sub 2.5}) and < 10 {mu}m (PM{sub 10}) in aerodynamic diameter and carbon monoxide (CO) were measured at 30 street-level locations for 15 min apiece during the early morning (4:50-6:30 am), morning rush hour (6:30-9:10 am) and afternoon rush hour (3:40-5:40 pm) in December 2004. Environmental observations (e.g. traffic-related variables, building/roadway designs, wind speed and direction, etc.) at each location were noted during each monitoring event. Multiple regression models were formulated to determine which pollution sources and environmental factors significantly affect ground-level PM{sub 2.5}, PM{sub 10} and CO concentrations. The models showed statistically significant relationships between traffic and early morning particulate air pollution [(PM{sub 2.5}p = 0.021) and PM{sub 10} (p = 0.048)], traffic and morning rush hour CO (p = 0.048), traffic and afternoon rush hour CO (p = 0.034) and wind and early morning CO (p 0.044). The mean early morning, street-level PM{sub 2.5} (110 {+-} 8 {mu}g/m{sup 3}; mean {+-} 1 standard error) was not significantly different (p-value > 0.05) from either rush hour PM{sub 2.5} concentration (morning = 98 {+-} 7 {mu}g/m{sup 3}; afternoon = 107 {+-} 5 {mu}g/m{sup 3}) due to nocturnal inversions in spite of a 100% increase in automotive density during rush hours. Early morning street-level CO (3.0 {+-} 1.7 ppm) differed from morning rush hour (4.1 {+-} 2.3 ppm) (p 0.039) and afternoon rush hour (4.5 {+-}2.2 ppm) (p = 0.007). Additionally, PM{sub 2.5}, PM{sub 10}, CO, nitrogen dioxide (NO{sub 2}) and select volatile organic compounds were continuously measured at a downtown, third-story monitoring station along a busy roadway for 11 days. Twenty-four-hour average ambient concentrations were: PM{sub 2.5} = 72.9 {+-} 21 {mu}g/m{sup 3}; CO = 2.61 {+-} 0.6 ppm; NO{sub 2} = 27

  2. ) m /SrVO3 ( m = 5, 6) Superlattices

    KAUST Repository

    Dai, Qingqing

    2018-05-04

    The (LaV3+O3)m/SrV4+O3 (m = 5, 6) superlattices are investigated by first principles calculations. While bulk LaVO3 is a C‐type antiferromagnetic semiconductor and bulk SrVO3 is a paramagnetic metal, semiconducting A‐type antiferromagnetic states for both superlattices are found due to epitaxial strain. At the interfaces, however, the V spins couple antiferromagnetically for m = 5 and ferromagnetically for m = 6 (m‐dependence of the magnetization). Electronic reconstruction in form of charge ordering is predicted to occur with V3+ and V4+ states arranged in a checkerboard pattern on both sides of the SrO layer. As compared to bulk LaVO3, the presence of V4+ ions introduces in‐gap states that strongly reduce the bandgap and influence the orbital occupation and ordering.

  3. Sources and export of particle-borne organic matter during a monsoon flood in a catchment of northern Laos

    Science.gov (United States)

    Gourdin, E.; Huon, S.; Evrard, O.; Ribolzi, O.; Bariac, T.; Sengtaheuanghoung, O.; Ayrault, S.

    2015-02-01

    The yields of the tropical rivers of Southeast Asia supply large quantities of carbon to the ocean. The origin and dynamics of particulate organic matter were studied in the Houay Xon River catchment located in northern Laos during the first erosive flood of the rainy season in May 2012. This cultivated catchment is equipped with three successive gauging stations draining areas ranging between 0.2 and 11.6 km2 on the main stem of the permanent stream, and two additional stations draining 0.6 ha hillslopes. In addition, the sequential monitoring of rainwater, overland flow and suspended organic matter compositions was conducted at the 1 m2 plot scale during a storm. The composition of particulate organic matter (total organic carbon and total nitrogen concentrations, δ13C and δ15N) was determined for suspended sediment, soil surface (top 2 cm) and soil subsurface (gullies and riverbanks) samples collected in the catchment (n = 57, 65 and 11, respectively). Hydrograph separation of event water was achieved using water electric conductivity and δ18O measurements for rainfall, overland flow and river water base flow (n = 9, 30 and 57, respectively). The composition of particulate organic matter indicates that upstream suspended sediments mainly originated from cultivated soils labelled by their C3 vegetation cover (upland rice, fallow vegetation and teak plantations). In contrast, channel banks characterized by C4 vegetation (Napier grass) supplied significant quantities of sediment to the river during the flood rising stage at the upstream station as well as in downstream river sections. The highest runoff coefficient (11.7%), sediment specific yield (433 kg ha-1), total organic carbon specific yield (8.3 kg C ha-1) and overland flow contribution (78-100%) were found downstream of reforested areas planted with teaks. Swamps located along the main stream acted as sediment filters and controlled the composition of suspended organic matter. Total organic carbon

  4. Punicalagin and (-)-Epigallocatechin-3-Gallate Rescue Cell Viability and Attenuate Inflammatory Responses of Human Epidermal Keratinocytes Exposed to Airborne Particulate Matter PM10.

    Science.gov (United States)

    Seok, Jin Kyung; Lee, Jeong-Won; Kim, Young Mi; Boo, Yong Chool

    2018-01-01

    Airborne particulate matter with a diameter of < 10 µm (PM10) causes oxidative damage, inflammation, and premature skin aging. In this study, we evaluated whether polyphenolic antioxidants attenuate the inflammatory responses of PM10-exposed keratinocytes. Primary human epidermal keratinocytes were exposed in vitro to PM10 in the absence or presence of punicalagin and (-)-epigallocatechin-3-gallate (EGCG), which are the major polyphenolic antioxidants found in pomegranate and green tea, respectively. Assays were performed to determine cell viability, production of reactive oxygen species (ROS), and expression of NADPH oxidases (NOX), proinflammatory cytokines, and matrix metalloproteinase (MMP)-1. PM10 decreased cell viability and increased ROS production in a dose-dependent manner. It also increased the expression levels of NOX-1, NOX-2, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, IL-8, and MMP-1. Punicalagin was not cytotoxic up to 300 μM, and (-)-EGCG was cytotoxic above 30 μM, respectively. Further, punicalagin (3-30 μM) and EGCG (3-10 μM) rescued the viability of PM10-exposed cells. They also attenuated ROS production and the expression of NOX-1, NOX-2, TNF-α, IL-1β, IL-6, IL-8, and MMP-1 stimulated by PM10. This study demonstrates that polyphenolic antioxidants, such as punicalagin and (-)-EGCG, rescue keratinocyte viability and attenuate the inflammatory responses of these cells due to airborne particles. © 2018 S. Karger AG, Basel.

  5. Model-based comparison of maternal and foetal organ doses from 99mTc pertechnetate, DMSA, DTPA, HDP, MAA and MAG3 diagnostic intakes during pregnancy

    International Nuclear Information System (INIS)

    Saunders, Margaret; Palmer, Maria; Preece, Alan; Millard, Roger

    2002-01-01

    Organ residence times were calculated for diagnostic intakes of 99m Tc pertechnetate, 2,3-dimercaptosuccinic acid (DMSA), diethylene triamine penta-acetic acid (DTPA), hydroxymethylene diphosphonate (HDP), macroaggregated albumin (MAA) and mercapto-acetyltriglycine (MAG 3 ) during the 1st and 3rd stages of pregnancy and used with the MIRDOSE3 pregnant female phantoms for generation of dose estimates. At stage 3 individual foetal organ doses were estimated via a surrogate phantom based on that for the new-born but with mean dose/cumulated activity (S) values scaled for compatibility with foetal whole body S. Stage 1 or 3 whole foetus doses ranged from 5.2 to 0.77 μGy MBq -1 respectively, analogous to current ICRP estimates for these agents using similar in vivo biodistribution model databases. Most stage 3 maternal and foetal organ doses were similar within a factor of 3, being higher in the foetus than the mother with pertechnetate, DTPA and MAG 3 , and lower with DMSA, HDP and MAA. Doses were more uniformly distributed among foetal organs than in the mother. Placental transfer was greatest with pertechnetate, where dose to the stage 3 foetal thyroid was 60-140 μGy MBq -1 . With each agent there was more placental transfer in stage 3 than in stage 1, but doses to stage 1 whole foetus were always higher, with the contribution from the mother dominant. For DMSA, HDP and MAG 3 the maternal contribution to total foetal body dose exceeded 93% for both stages. (orig.)

  6. Cashew nut roasting: Chemical characterization of particulate matter and genotocixity analysis

    International Nuclear Information System (INIS)

    Oliveira Galvão, Marcos Felipe de; Melo Cabral, Thiago de; André, Paulo Afonso de; Fátima Andrade, Maria de; Miranda, Regina Maura de; Saldiva, Paulo Hilário Nascimento; Castro Vasconcellos, Pérola de; Batistuzzo de Medeiros, Silvia Regina

    2014-01-01

    Background: Particulate matter (PM) is potentially harmful to health and related to genotoxic events, an increase in the number of hospitalizations and mortality from respiratory and cardiovascular diseases. The present study conducted the first characterization of elemental composition and polycyclic aromatic hydrocarbon (PAH) analysis of PM, as well as the biomonitoring of genotoxic activity associated to artisanal cashew nut roasting, an important economic and social activity worldwide. Methods: The levels of PM 2.5 and black carbon were also measured by gravimetric analysis and light reflectance. The elemental composition was determined using X-ray fluorescence spectrometry and PAH analysis was carried out by gas chromatography–mass spectrometry. Genotoxic activity was measured by the Tradescantia pallida micronucleus bioassay (Trad-MCN). Other biomarkers of DNA damage, such as nucleoplasmic bridges and nuclear fragments, were also quantified. Results: The mean amount of PM 2.5 accumulated in the filters (January 2124.2 µg/m 3 ; May 1022.2 µg/m 3 ; September 1291.9 µg/m 3 ), black carbon (January 363.6 µg/m 3 ; May 70 µg/m 3 ; September 69.4 µg/m 3 ) and concentrations of Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb were significantly higher than the non-exposed area. Biomass burning tracers K, Cl, and S were the major inorganic compounds found. Benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, benzo[ghi]perylene, phenanthrene and benzo[b]fluoranthene were the most abundant PAHs. Mean benzo[a]pyrene-equivalent carcinogenic power values showed a significant cancer risk. The Trad-MCN bioassay revealed an increase in micronucleus frequency, 2–7 times higher than the negative control and significantly higher in all the months analyzed, possibly related to the mutagenic PAHs found. Conclusions: This study demonstrated that artisanal cashew nut roasting is a serious occupational problem, with harmful effects on workers' health. Those

  7. Collection of size fractionated particulate matter sample for neutron activation analysis in Japan

    International Nuclear Information System (INIS)

    Otoshi, Tsunehiko; Nakamatsu, Hiroaki; Oura, Yasuji; Ebihara, Mitsuru

    2004-01-01

    According to the decision of the 2001 Workshop on Utilization of Research Reactor (Neutron Activation Analysis (NAA) Section), size fractionated particulate matter collection for NAA was started from 2002 at two sites in Japan. The two monitoring sites, ''Tokyo'' and ''Sakata'', were classified into ''urban'' and ''rural''. In each site, two size fractions, namely PM 2-10 '' and PM 2 '' particles (aerodynamic particle size between 2 to 10 micrometer and less than 2 micrometer, respectively) were collected every month on polycarbonate membrane filters. Average concentrations of PM 10 (sum of PM 2-10 and PM 2 samples) during the common sampling period of August to November 2002 in each site were 0.031mg/m 3 in Tokyo, and 0.022mg/m 3 in Sakata. (author)

  8. Historical performance of particulate settleable in a municipality located in the ceramic cluster of Castellón (Spain)

    Science.gov (United States)

    Pardo, P.; Sanfeliu, Teófilo; Soriano, A.; Pallarés, S.; Vicente, A. B.

    2010-05-01

    Air pollution can be defined as: "the introduction into the atmosphere by man, directly or indirectly, of substances or energy with have effects deleterious of such a nature that endangers human health, causing damage to biological resources and to ecosystems, which impair material goods and to harm or interfere with amenities and other legitimate uses of the environment". One of the main pollutants in air is the particulate matter. This material particulate includes settleable, particles larger than 10 μm that remain airborne for relatively short periods of time. For what its effects are most pronounced in the vicinity of the emitting sources. The study area is located in the city of Alcora. This population is located in the region eastern of the province of Castellon (Spain). The municipality of Alcora has a high industrial density, highlighting framed companies in chemical industry and non-metallic mineral products. The area has a high traffic density due to the proximity of population to various roads. These two factors point peaks rise high concentration of atmospheric particulate pollutants. The purpose of this paper is conducting a retrospective view of the evolution of settleable particulate concentrations. Settleable particulate samples were collected with a sensor BRITISH STANDARD PS particles during the period between January 2000 and December 2005. REFERENCES Gómez E.T.; Sanfeliu T.; Rius J.; Jordán M.M. (2005) "Evolution, sources and distribution of mineral particles and amorphous phase of atmospheric aerosol in an industrial and Mediterranean coastal area" Water, air and Soil Pollution 167:311-330. Sanfeliu T.; Gómez E.T.; Hernánde D.;Martín J.D.; Ovejero M.; Jordán M.M. (2002). "Avaluation of the particulate atmospheric aerosol in the urban area on Castellón, Spain". Protecction and conservation of the cultural heritage of the Mediterranean cities. Eds. Galán and Zezza Ed. Swets&Zeitlinger, Lisse pp:61-64. Sanfeliu T.; Jordán M.M.; Gómez E

  9. PIXE analysis of vehicle exhaust particulate

    International Nuclear Information System (INIS)

    Shi Xianfeng; Yao Huiying; Liu Bo; Sun Minde; Xu Huawei; Mi Yong; Shen Hao

    2001-01-01

    PIXE technique on the analysis of vehicle exhaust particulate is introduced. The clement composition and concentration of particulate are obtained. Some elements which are related to environmental pollution such as sulfur lead, silicon and manganese, were analyzed and discussed in detail by PIXE technique Nowadays although unleaded gasoline is widely used, the lead concentration is still very high in exhaust particulate. The concentrations of silicon and manganese in exhaust particulate from different model vehicles are also quite high from measurements. It shows that an evidence for exhaust pollution control could be provided from this work

  10. Characteristics of fine particulate matter and its sources in an industrialized coastal city, Ningbo, Yangtze River Delta, China

    Science.gov (United States)

    Wang, Weifeng; Yu, Jie; Cui, Yang; He, Jun; Xue, Peng; Cao, Wan; Ying, Hongmei; Gao, Wenkang; Yan, Yingchao; Hu, Bo; Xin, Jinyuan; Wang, Lili; Liu, Zirui; Sun, Yang; Ji, Dongsheng; Wang, Yuesi

    2018-05-01

    Chemical information is essential in understanding the characteristics of airborne particles, and effectively controlling airborne particulate matter pollution, but it remains unclear in some regions due to the scarcity of measurement data. In the present study, 92 daily PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm) samples as well as historical observation data of air pollutants were collected in urban Ningbo, one of important industrial cities in the coastal area of the Yangtze River Delta, China in autumn and winter (from Nov. 2014 to Feb. 2015). Various chemical species in PM2.5 were determined including water soluble ions, organic and elemental carbon and elements. Positive matrix factorization model, cluster analysis of back trajectories, potential source contribution function (PSCF) model and concentration-weighted trajectory (CWT) model were used for identifying sources, apportioning contributions from each source and tracking potential areas of sources. The results showed the PM2.5 concentration has been reducing; nonetheless, the concentrations of PM2.5 are still much higher than the World Health Organization guideline with high PM2.5 concentrations observed in autumn and winter for the past few years. During the sampling period, the average PM2.5 mass concentration was 77 μg/m3 with the major components of OC, NO3-, SO42 -, NH4+ and EC, accounting for 24.7, 18.8, 14.5, 11.8 and 6.4% in the total mass concentration, respectively. When the aerosol pollution got worse during the sampling period, the NO3-, SO42 - and NH4+ concentrations increased accordingly and NO3- appeared to increase at fastest rate. SO42 - transported from industrial areas led to slight difference in spatial distribution of SO42 - in Ningbo. More secondary organic carbon was formed and the enrichment factor values of Cu, Ag, Cd, Sn and Pb increased with the degradation of air quality. Ten types of sources were identified for PM2.5 in the autumn and winter of

  11. Collection and Characterization of Particulate from the Tore Supra Tokamak (Dec. 1999 Vent)

    International Nuclear Information System (INIS)

    Sharpe, John Phillip

    2002-01-01

    Particulate generated during the operation of a fusion device contributes to the radiological source term associated with accident scenarios in the device. Understanding the mechanisms generating the particulate and correctly describing its physical and chemical behavior is essential for safety analyses of future fusion devices. Knowledge of these mechanisms is gained by collecting and characterizing particulate matter from operating fusion facilities. Tokamak dust, the particulate matter generated during the operation of a tokamak fusion device, was collected from Tore Supra in December 1999, during the initial phase of the scheduled shutdown for installation of advanced plasma facing components. Tore Supra, located at CEA Cadarache, France, is presently the third largest operating tokamak with the capability of long-pulse operation. Eighteen super-conducting coils produce the 4.5 T magnetic field inside a vessel 2.4 m in major radius and 1.2 m in minor radius. Limiter and divertor regimes of operation are possible. In the divertor regime, the circular magnetic configuration is ergodized by six outboard resonant divertor modules that are covered with 12 m2 of carbon fiber composite (CFC) tiles. In addition, some field lines are diverted to actively cooled neutralizing plates made of CuCrZr bars covered with B4C. In the limiter regime, the plasma leans on the actively cooled inboard first wall or on a set of inertially cooled pumped limiters. The first wall area of 12 m2 is covered with both polycrystalline graphite tiles (83%) and CFC tiles (17%). The single outboard limiter is constructed of pyrolitic graphite, and the four toroidally symmetric bottom limiters are constructed of CFC. Figure 1.1 displays the relative location of plasma facing components within the plasma chamber of Tore Supra. In this report, we present in Section 2 the methods used to collect and analyze this dust and describe the selection of sampling locations. Section 3 includes a discussion

  12. Evolution of the Lunar Receiving Laboratory to the Astromaterial Sample Curation Facility: Technical Tensions Between Containment and Cleanliness, Between Particulate and Organic Cleanliness

    Science.gov (United States)

    Allton, J. H.; Zeigler, R. A.; Calaway, M. J.

    2016-01-01

    The Lunar Receiving Laboratory (LRL) was planned and constructed in the 1960s to support the Apollo program in the context of landing on the Moon and safely returning humans. The enduring science return from that effort is a result of careful curation of planetary materials. Technical decisions for the first facility included sample handling environment (vacuum vs inert gas), and instruments for making basic sample assessment, but the most difficult decision, and most visible, was stringent biosafety vs ultra-clean sample handling. Biosafety required handling of samples in negative pressure gloveboxes and rooms for containment and use of sterilizing protocols and animal/plant models for hazard assessment. Ultra-clean sample handling worked best in positive pressure nitrogen environment gloveboxes in positive pressure rooms, using cleanable tools of tightly controlled composition. The requirements for these two objectives were so different, that the solution was to design and build a new facility for specific purpose of preserving the scientific integrity of the samples. The resulting Lunar Curatorial Facility was designed and constructed, from 1972-1979, with advice and oversight by a very active committee comprised of lunar sample scientists. The high precision analyses required for planetary science are enabled by stringent contamination control of trace elements in the materials and protocols of construction (e.g., trace element screening for paint and flooring materials) and the equipment used in sample handling and storage. As other astromaterials, especially small particles and atoms, were added to the collections curated, the technical tension between particulate cleanliness and organic cleanliness was addressed in more detail. Techniques for minimizing particulate contamination in sample handling environments use high efficiency air filtering techniques typically requiring organic sealants which offgas. Protocols for reducing adventitious carbon on sample

  13. Airborne lead and particulate levels in Semarang, Indonesia and potential health impacts.

    Science.gov (United States)

    Browne, D R; Husni, A; Risk, M J

    1999-03-09

    Spatial and temporal variation in airborne lead and total suspended particulates was examined in the city of Semarang, Indonesia, and surrounding area. Both airborne lead and TSP varied significantly with the type of urban development. Mean urban airborne lead levels were 0.35 microgram/m3 in the highway zone, 0.95 microgram/m3 in the residential zone, and 0.99 microgram/m3 in the commercial zone. Airborne lead levels in the industrial zone were significantly higher than all other areas, with a mean of 8.41 micrograms/m3. Airborne lead concentrations of this magnitude have not been reported in Indonesia previously. Mean TSP levels ranged from 115.5 micrograms/m3 to 165.8 micrograms/m3 in urban areas. Increased levels of TSP were associated with areas adjacent to major transportation routes. On a seasonal basis, TSP levels were significantly lower during the rainy season, while mean airborne lead levels did not show a significant seasonal trend. Observed ambient pollution levels were translated into potential heath impacts based on previously established relationships. Increased levels of TSP pollution near major roads was estimated to result in a 1.6% increase in mortality for all causes of death and a 7.9% increase in mortality due to respiratory disease. Estimated child blood lead levels indicated possible lead toxicity among Semarang children.

  14. Theoretical descriptions of novel triplet germylenes M1-Ge-M2-M3 (M1 = H, Li, Na, K; M2 = Be, Mg, Ca; M3 = H, F, Cl, Br).

    Science.gov (United States)

    Kassaee, Mohamad Zaman; Ashenagar, Samaneh

    2018-02-06

    In a quest to identify new ground-state triplet germylenes, the stabilities (singlet-triplet energy differences, ΔE S-T ) of 96 singlet (s) and triplet (t) M 1 -Ge-M 2 -M 3 species were compared and contrasted at the B3LYP/6-311++G**, QCISD(T)/6-311++G**, and CCSD(T)/6-311++G** levels of theory (M 1  = H, Li, Na, K; M 2  = Be, Mg, Ca; M 3  = H, F, Cl, Br). Interestingly, F-substituent triplet germylenes (M 3  = F) appear to be more stable and linear than the corresponding Cl- or Br-substituent triplet germylenes (M 3  = Cl or Br). Triplets with M 1  = K (i.e., the K-Ge-M 2 -M 3 series) seem to be more stable than the corresponding triplets with M 1  = H, Li, or Na. This can be attributed to the higher electropositivity of potassium. Triplet species with M 3  = Cl behave similarly to those with M 3  = Br. Conversely, triplets with M 3  = H show similar stabilities and linearities to those with M 3  = F. Singlet species of formulae K-Ge-Ca-Cl and K-Ge-Ca-Br form unexpected cyclic structures. Finally, the triplet germylenes M 1 -Ge-M 2 -M 3 become more stable as the electropositivities of the α-substituents (M 1 and M 2 ) and the electronegativity of the β-substituent (M 3 ) increase.

  15. Fractionation of airborne particulate-bound elements in haze-fog episode and associated health risks in a megacity of southeast China.

    Science.gov (United States)

    Li, Huiming; Wang, Qin'geng; Shao, Min; Wang, Jinhua; Wang, Cheng; Sun, Yixuan; Qian, Xin; Wu, Hongfei; Yang, Meng; Li, Fengying

    2016-01-01

    Haze caused by high particulate matter loadings is an important environmental issue. PM2.5 was collected in Nanjing, China, during a severe haze-fog event and clear periods. The particulate-bound elements were chemically fractionated using sequential extractions. The average PM2.5 concentration was 3.4 times higher during haze-fog (96-518 μg/m(3)) than non-haze fog periods (49-142 μg/m(3)). Nearly all elements showed significantly higher concentrations during haze-fog than non-haze fog periods. Zn, As, Pb, Cd, Mo and Cu were considered to have higher bioavailability and enrichment degree in the atmosphere. Highly bioavailable fractions of elements were associated with high temperatures. The integrated carcinogenic risk for two possible scenarios to individuals exposed to metals was higher than the accepted criterion of 10(-6), whereas noncarcinogenic risk was lower than the safe level of 1. Residents of a city burdened with haze will incur health risks caused by exposure to airborne metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Two new two-dimensional organically templated phosphite compounds: (C6H16N2)0.5[M(HPO3)F], M=Fe(II) and Co(II): Solvothermal synthesis, crystal structures, thermal, spectroscopic, and magnetic properties

    International Nuclear Information System (INIS)

    Fernandez-Armas, Sergio; Mesa, Jose L.; Pizarro, Jose L.; Chung, U-Chan; Arriortua, Maria I.; Rojo, Teofilo

    2005-01-01

    The organically templated (C 6 H 16 N 2 ) 0.5 [M(HPO 3 )F] [M(II)=Fe (1) and Co (2)] compounds have been synthesized by using mild hydrothermal conditions under autogeneous pressure. The crystal structures have been determined from X-ray single-crystal diffraction data. The compounds are isostructural and crystallize in the C2/c monoclinic space group. The unit-cell parameters are a=5.607(1), b=21.276(4), c=11.652(1)A, β=93.74(1) deg. for the iron phase and a=5.5822(7), b=21.325(3), c=11.4910(1)A, β=93.464(9) o for the cobalt compound with Z=4. The crystal structure of these compounds consists of [M(HPO 3 )F] - anionic sheets. The layers are constructed from chains which contain [M 2 O 6 F 3 ] dimeric units linked by fluoride ions. The trans-1,4-diaminocyclohexane cations are placed in the interlayer space. The IR and Raman spectra show the bands corresponding to the phosphite oxoanion and organic dication. The Dq and Racah (B and C) parameters have been calculated from the diffuse reflectance spectra in the visible region. Dq parameter is 790cm -1 for compound (1). For phase (2) the Dq value is 725cm -1 and B and C are 930 and 4100cm -1 , respectively. The thermal evolution of the molar magnetic susceptibilities of these compounds show maxima at 20.0 and 6.0K for the iron(II) and cobalt(II) phases, respectively. These results indicate the existence of antiferromagnetic interactions in both compounds

  17. A Simplified Method for Laboratory Preparation of Organ Specific Indium 113m Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Adatepe, M H; Potchen, E James [Washington University School of Medicine, St. Louis (United States)

    1969-03-15

    Generator systems producing short lived nuclides from longer lived parents have distinct clinical advantages. They are more economical, result in a lower radiation dose, and can make short lived scanning readily available even in areas remote from rapid radiopharmaceutical delivery services. The {sup 113}Sn-{sup 113m}In generator has the additional advantage that, as a transition metal, Indium can be readily complexed into organ specific preparations. 113Sn, a reactor produced nuclide with a 118 day half life, is absorbed on a zirconium or silica gel column. the generator is eluded with 5 to 8 ml of 0.05 N HCL solution at pH 1.3-1.4. The daughter nuclide, {sup 113m}In, has a half life of 1.7 hours and emits a 393 Kev monoenergetic gamma ray. Previous methods for labeling organ specific complexes with {sup 113m}In required terminal autoclaving before injection. With the recent introduction of sterile, apyrogenic {sup 113}Sn-{sup 113m}In generators, we have developed a simplified technique for the laboratory preparation of Indium labeled compounds. This method eliminates autoclaving and titration enabling us to pre-prepare organ specific complexes for blood pool, liver, spleen, brain, kidney and lung scanning.

  18. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)]. E-mail: aturner@plymouth.ac.uk; Mawji, Edward [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D{sub ow}, ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (<1%) to octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10{sup 3.3}-10{sup 5.3} ml g{sup -1}. The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision. - New approaches are presented for fractionating

  19. Octanol-solubility of dissolved and particulate trace metals in contaminated rivers: implications for metal reactivity and availability.

    Science.gov (United States)

    Turner, Andrew; Mawji, Edward

    2005-05-01

    The lipid-like, amphiphilic solvent, n-octanol, has been used to determine a hydrophobic fraction of dissolved and particulate trace metals (Al, Cd, Co, Cu, Mn, Ni, Pb, Zn) in contaminated rivers. In a sample from the River Clyde, southwest Scotland, octanol-solubility was detected for all dissolved metals except Co, with conditional octanol-water partition coefficients, D(ow), ranging from about 0.2 (Al and Cu) to 1.25 (Pb). In a sample taken from the River Mersey, northwest England, octanol-solubility was detected for dissolved Al and Pb, but only after sample aliquots had been spiked with individual ionic metal standards and equilibrated. Spiking of the River Clyde sample revealed competition among different metals for hydrophobic ligands. Metal displacement from hydrophobic complexes was generally most significant following the addition of ionic Al or Pb, although the addition of either of these metals had little effect on the octanol-solubility of the other. In both river water samples hydrophobic metals were detected on the suspended particles retained by filtration following their extraction in n-octanol. In general, particulate Cu and Zn (up to 40%) were most available, and Al, Co and Pb most resistant (octanol extraction. Distribution coefficients defining the concentration ratio of octanol-soluble particle-bound metal to octanol-soluble dissolved metal were in the range 10(3.3)-10(5.3)mlg(-1). The presence of hydrophobic dissolved and particulate metal species has implications for our understanding of the biogeochemical behaviour of metals in aquatic environments. Specifically, such species are predicted to exhibit characteristics of non-polar organic contaminants, including the potential to penetrate the lipid bilayer. Current strategies for assessing the bioavailability and toxicity of dissolved and particulate trace metals in natural waters may, therefore, require revision.

  20. Nutrient variations and isotopic evidences of particulate organic matter provenance in fringing reefs, South China

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Di; Cao, Wenzhi, E-mail: wzcao@xmu.edu.cn; Liang, Ying; Huang, Zheng

    2016-10-01

    Nutrient over-enrichment is considered to be one of the causes of coral decline. Increase in traditional fishing in the Xuwen National Coral Reefs Reserve tract (XW) and tourism around the Sanya National Coral Reefs Reserve tract (SY) are causing this coral decline. This study reviews the current state of knowledge of the nutrient status of coastal fringing reefs in South China and evaluates the primary sources of nutrients using stable isotope method. Surveys of seawater nutrients showed that the seawater remained clean in both the XW and SY coastal coral reef areas. Based on the isotopic differences between anthropogenic sewage and naturally occurring aquatic nutrients, the isotopic values of particulate organic matter (POM) and the C/N ratios were successfully used to identify the presence of anthropogenic nutrients in aquatic environments. The δ{sup 13}C, δ{sup 15}N and C/N compositions of POM from XW and SY (− 21.18 ± 2.11‰, 10.30 ± 5.54‰, and 5.35 ± 0.69 and − 20.80 ± 1.34‰, 7.06 ± 3.95‰, and 5.77 ± 2.15, respectively) showed statistically significant variations with the season. The δ{sup 13}C and δ{sup 15}N values of POM suggest marine and terrestrial-derived nutrient sources. Organic carbon is a mixture of marine phytoplankton, marine benthic algae and terrestrial-derived plants. The δ{sup 15}N values suggest terrestrial-derived sewage and upwelling-dominated nitrogen sources. In the presence of natural upwelling and coastal currents, coastal coral reef areas are more vulnerable to the increasing anthropogenic nutrient inputs. Anthropogenic activities might lead to large increases in the nutrient concentrations and could trigger the shift from coral- to macroalgae-dominated ecosystems, which would ultimately result in the degradation of the coastal coral reef ecosystem. These results provide some understanding of the declining coral reef ecosystem and the importance of conservation areas and coastal coral reef resource management