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Sample records for residual contaminant concentrations

  1. Zearalenone (ZEN) metabolism and residue concentrations in physiological specimens of dairy cows exposed long-term to ZEN-contaminated diets differing in concentrate feed proportions.

    Science.gov (United States)

    Dänicke, Sven; Keese, Christina; Meyer, Ulrich; Starke, Alexander; Kinoshita, Asako; Rehage, Jürgen

    2014-12-01

    A long-term feeding experiment with dairy cows was performed to investigate the effects of feeding a Fusarium toxin contaminated (FUS) and a background-contaminated control (CON) ration with a mean concentrate feed proportion of 50% during the first 11 weeks after parturition (Groups FUS-50, CON-50, Period 1), and with concentrate feed proportions of 30% or 60% during the remaining 17 weeks (Groups CON-30, CON-60, FUS-30 and FUS-60, Period 2), on zearalenone (ZEN) residue levels in blood serum, milk, urine and bile. ZEN, α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL), zearalanone (ZAL), α-zearalanol (α-ZAL) and β-zearalanol (β-ZAL) were determined by HPLC with fluorescence detection. The ZEN concentrations of the rations fed to Groups CON-50, FUS-50 (Period 1), CON-30, CON-60, FUS-30 and FUS-60 (Period 2) amounted to 53.1, 112.7, 35.0, 24.4, 73.8 and 72.5 µg/kg dry matter, respectively. The concentrations of ZEN, α-ZEL, β-ZEL, ZAN, α-ZAL and β-ZAL in serum, urine and milk were lower than 1, 1, 4, 100, 50 and 200 ng/g, respectively, while ZEN, α-ZEL and β-ZEL were detected in bile. Their levels changed with oral ZEN exposure in the course of the experiment and in a similar direction with concentrate feed proportion (Period 2 only). Thus the proportions of the individual β-ZEL, α-ZEL and ZEN concentrations of their sum varied only in narrow ranges of 68-76%, 6-13% and 12-20%, respectively. Interestingly, the bile concentrations of β-ZEL, α-ZEL and ZEN of Groups CON-60 and FUS-60 amounted to only approximately 50%, 45% and 62%, respectively, of those of Groups CON-30 and FUS-30 despite a similar or even lower ZEN exposure. The results indicate that conversion of ZEN to its detectable metabolites was not changed by different dietary concentrate feed proportions while their absolute levels were decreased. These findings might suggest concentrate feed proportion-dependent and rumen fermentation-mediated alterations in ZEN/metabolite degradation, and

  2. Tetracycline antibiotics transfer from contaminated milk to dairy products and the effect of the skimming step and pasteurisation process on residue concentrations.

    Science.gov (United States)

    Gajda, Anna; Nowacka-Kozak, Ewelina; Gbylik-Sikorska, Malgorzata; Posyniak, Andrzej

    2018-01-01

    The presence of antibiotics in raw milk and milk derivatives poses a threat to human health and can negatively affect the dairy industry. Therefore, the main object of this study was to investigate the transfer of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DC) from raw, experimental milk contaminated with tetracyclines (TCs) to different dairy products: cream, butter, buttermilk, sour milk, whey, curd and cheese. Additionally the effect of the skimming process on TCs concentrations was tested, as well as the influence of low-temperature long-time pasteurisation. The analyses of TCs in milk and dairy products were performed by an LC-MS/MS method. In order to determine TCs residues in dairy products, an analytical method was developed with the same extraction step for all matrices. TCs molecules were inhomogenously distributed between the milk derivative fractions. The highest concentrations were determined in curd and cheese in the ranges 320-482 µg/kg and 280-561 µg/kg, respectively. Low levels of TCs in butter and whey were observed (11.8-41.2 µg/kg). TCs were found in sour milk (66.0-111 µg/kg), cream (85.0-115 µg/kg) and buttermilk (196-221 µg/kg) at much higher levels than in butter and whey, but lower than in curd and cheese. During the skimming process, the highest yield of cream was obtained after the raw milk was held at 2-8°C for 24 h. The differences in concentrations of TCs between whole milk and skimmed milk, expressed as percentages of recovery, were below 19% (recoveries in excess of 81%). The highest content was observed in milk and cream skimmed at 2-8°C. The degradation percentages for TCs during the pasteurisation process (63°C for 30 min) were below 19%.

  3. Earthworm tolerance to residual agricultural pesticide contamination

    DEFF Research Database (Denmark)

    Givaudan, Nicolas; Binet, Françoise; Le Bot, Barbara

    2014-01-01

    This study investigates if acclimatization to residual pesticide contamination in agricultural soils is reflected in detoxification, antioxidant enzyme activities and energy budget of earthworms. Five fields within a joint agricultural area exhibited different chemical and farming histories from...

  4. Contaminant transport at a waste residue deposit

    DEFF Research Database (Denmark)

    Engesgaard, Peter Knudegaard; Traberg, Rikke

    1996-01-01

    Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two-dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code, The code is applied to a column experiment and to the field site...

  5. Contaminant transport at a waste residue deposit

    DEFF Research Database (Denmark)

    Engesgaard, Peter Knudegaard; Traberg, Rikke

    1996-01-01

    Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two-dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code, The code is applied to a column experiment and to the field site...... wells. Contamination was first controlled by transport, and later by transport and ion exchange. In both the column and field site simulations the code is used to identify the controlling transport processes, physical or geochemical (ion exchange and mineral precipitation), and to estimate the Involved...

  6. Artificial Neural Networks and Concentration Residual Augmented ...

    African Journals Online (AJOL)

    Artificial Neural Networks and Concentration Residual Augmented Classical Least Squares for the Simultaneous Determination of Diphenhydramine, Benzonatate, Guaifenesin and Phenylephrine in their Quaternary Mixture.

  7. Hanford tank residual waste - Contaminant source terms and release models

    International Nuclear Information System (INIS)

    Deutsch, William J.; Cantrell, Kirk J.; Krupka, Kenneth M.; Lindberg, Michael L.; Jeffery Serne, R.

    2011-01-01

    Highlights: → Residual waste from five Hanford spent fuel process storage tanks was evaluated. → Gibbsite is a common mineral in tanks with high Al concentrations. → Non-crystalline U-Na-C-O-P ± H phases are common in the U-rich residual. → Iron oxides/hydroxides have been identified in all residual waste samples. → Uranium release is highly dependent on waste and leachant compositions. - Abstract: Residual waste is expected to be left in 177 underground storage tanks after closure at the US Department of Energy's Hanford Site in Washington State, USA. In the long term, the residual wastes may represent a potential source of contamination to the subsurface environment. Residual materials that cannot be completely removed during the tank closure process are being studied to identify and characterize the solid phases and estimate the release of contaminants from these solids to water that might enter the closed tanks in the future. As of the end of 2009, residual waste from five tanks has been evaluated. Residual wastes from adjacent tanks C-202 and C-203 have high U concentrations of 24 and 59 wt.%, respectively, while residual wastes from nearby tanks C-103 and C-106 have low U concentrations of 0.4 and 0.03 wt.%, respectively. Aluminum concentrations are high (8.2-29.1 wt.%) in some tanks (C-103, C-106, and S-112) and relatively low ( 2 -saturated solution, or a CaCO 3 -saturated water. Uranium release concentrations are highly dependent on waste and leachant compositions with dissolved U concentrations one or two orders of magnitude higher in the tests with high U residual wastes, and also higher when leached with the CaCO 3 -saturated solution than with the Ca(OH) 2 -saturated solution. Technetium leachability is not as strongly dependent on the concentration of Tc in the waste, and it appears to be slightly more leachable by the Ca(OH) 2 -saturated solution than by the CaCO 3 -saturated solution. In general, Tc is much less leachable (<10 wt.% of the

  8. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, W.E. Jr.; Peloquin, R.A. (Pacific Northwest Lab., Richland, WA (USA))

    1990-01-01

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs.

  9. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Peloquin, R.A.

    1990-01-01

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs

  10. Residual radioactive contamination at Maralinga and Emu, 1985

    International Nuclear Information System (INIS)

    Lokan, K.H.

    1985-04-01

    An account is provided of residual contamination at Maralinga and Emu, in South Australia, where the United Kingdom Atomic Weapons Research Establishment conducted nuclear weapons development trials between 1953 and 1963. Detailed information is presented about contamination levels at sites on the range where radioactive materials were dispersed. Some of these were associated with trials involving natural uranium or short-lived isotopes which are no longer present. There are four sites where plutonium-239 was dispersed in substantial quantities from minor trials and information is presented about its distribution. Much of this material has been diluted by mixing with local soil, but there is a significant quantity of material present in the form of contaminated fragments, particularly at Taranaki. A considerable quantity of uranium-235 is also present at Taranaki. An assessment is made of the radiological significance of the dispersed plutonium and it is concluded that the material represents a potential long term hazard while it remains in its present form. Residual radioactivity associated with all but one of the seven major trial sites involving nuclear explosions continues to decay in a predictable way and will in the worst case, fall below levels considered safe for continuous occupancy within about fifty years. One site, Tadje, contains significant concentrations of plutonium over a small area and onsidered to be an additional plutonium-contaminated locality. Measurements of beryllium concentrations in soil are presented

  11. Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Miethe, D.; Riis, V.; Stimming, M.

    1996-01-04

    It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen

  12. Residual metallic contamination of transferred chemical vapor deposited graphene.

    Science.gov (United States)

    Lupina, Grzegorz; Kitzmann, Julia; Costina, Ioan; Lukosius, Mindaugas; Wenger, Christian; Wolff, Andre; Vaziri, Sam; Östling, Mikael; Pasternak, Iwona; Krajewska, Aleksandra; Strupinski, Wlodek; Kataria, Satender; Gahoi, Amit; Lemme, Max C; Ruhl, Guenther; Zoth, Guenther; Luxenhofer, Oliver; Mehr, Wolfgang

    2015-05-26

    Integration of graphene with Si microelectronics is very appealing by offering a potentially broad range of new functionalities. New materials to be integrated with the Si platform must conform to stringent purity standards. Here, we investigate graphene layers grown on copper foils by chemical vapor deposition and transferred to silicon wafers by wet etching and electrochemical delamination methods with respect to residual submonolayer metallic contaminations. Regardless of the transfer method and associated cleaning scheme, time-of-flight secondary ion mass spectrometry and total reflection X-ray fluorescence measurements indicate that the graphene sheets are contaminated with residual metals (copper, iron) with a concentration exceeding 10(13) atoms/cm(2). These metal impurities appear to be partially mobile upon thermal treatment, as shown by depth profiling and reduction of the minority charge carrier diffusion length in the silicon substrate. As residual metallic impurities can significantly alter electronic and electrochemical properties of graphene and can severely impede the process of integration with silicon microelectronics, these results reveal that further progress in synthesis, handling, and cleaning of graphene is required to advance electronic and optoelectronic applications.

  13. Food toxicology. Residues and contaminants: Risks and consumer protection; Lebensmitteltoxikologie. Rueckstaende und Kontaminanten: Risiken und Verbraucherschutz

    Energy Technology Data Exchange (ETDEWEB)

    Nau, H. [Tieraerztliche Hochschule Hannover, ZA Lebensmitteltoxikologie (Germany); Steinberg, P. [Potsdam Univ., Inst. fuer Ernaehrungswissenschaft (Germany); Kietzmann, M. (eds.) [Tieraerztliche Hochschule Hannover, Inst. fuer Pharmakologie, Toxikologie/Pharmazie (Germany)

    2003-07-01

    In a detailed introduction, the basic methods of risk assessment for potentially toxic food constituents are presented as well as the analytical methods applied for measuring even very small concentrations of contaminants. The main classes of substances relevant in foods ar represented, i.e. animal drugs, fungicides and herbicides, natural toxins, contaminants, prions from BSE-infested animals and residues of 'new' proteins and 'new' DNA from genetically modified foods. New legislation in Germany and Europe is presented including the National Residue Monitoring Plant which is to enable annual monitoring of residue concentrations in foods derived from animals. (orig.)

  14. Development of irradiation technique on controlling food contamination residue

    International Nuclear Information System (INIS)

    Liu Bin; Xiong Shanbai; Xiong Guangquan; Cheng Wei; Chen Yuxia; Liao Tao; Li Xin; Lin Ruotai

    2010-01-01

    The current state of the researches of irradiation technology on controlling food mycotoxin, pesticide, veterinary drugs and fishery drugs residue was summarized. And the degradation rate, mechanism, products and toxicities of food contamination were expatiated. The free radical from irradiation attack the site of weaker bond, and the less or more toxic substances were produced, which lead to the degradation of the food contamination. The limitations and future application of irradiation technique on controlling food contamination were also analyzed. (authors)

  15. Hanford Site Tank 241-C-108 Residual Waste Contaminant Release Models and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Krupka, Kenneth M.; Geiszler, Keith N.; Arey, Bruce W.; Schaef, Herbert T.

    2010-06-18

    This report presents the results of laboratory characterization, testing, and analysis for a composite sample (designated 20578) of residual waste collected from single-shell tank C-108 during the waste retrieval process after modified sluicing. These studies were completed to characterize concentration and form of contaminant of interest in the residual waste; assess the leachability of contaminants from the solids; and develop release models for contaminants of interest. Because modified sluicing did not achieve 99% removal of the waste, it is expected that additional retrieval processing will take place. As a result, the sample analyzed here is not expected to represent final retrieval sample.

  16. Managing Residual Contaminants Reuse and Isolation Case Studies

    International Nuclear Information System (INIS)

    Kevin M. Kostelnik; James H. Clarke, Ph. D.

    2008-01-01

    Contaminants remaining on sites after regulatory-approved environmental remediation operations are complete represent continued risk to human health and the environment. Many sites require continued management efforts to: (1) protect the integrity of the engineered remedy/control, (2) limit the exposure of individuals to residual contamination by limiting reuse activities, (3) maintain ready access to accurate records/information, and (4) protect against vulnerabilities from intentional threats/actions. This paper presents performance information from selected case studies to provide insight into various management approaches employed for addressing the risks associated with residual contaminants. The case studies involve sites remediated within the U.S. CERCLA framework, and illustrate two prevailing management approaches for addressing the risks. Sacrifice Zones are sites that are purposefully isolated to prevent human access onto the property. Reuse Sites provide limited access for specific use

  17. Contaminated Sites by Residues from Romanian Industry

    International Nuclear Information System (INIS)

    Aurelian, F.; Georgescu, D.; Vacariu, V.; Popescu, M.

    2001-01-01

    Full text: In Romania, the mining industries of ferrous ore, non-ferrous ore, bauxite, coal, chemical fertilisers, the extraction of natural gas and oil, etc. have a considerable weight in economy. The study lets us know that in these industries, in different by-products and waste from the process, some radionuclides come out. The preliminary data, which are determined in these industries, are compared with those data, which are published by the countries from EU. There were determined uranium, radium and thorium from ore and sterile (ferrous, non-ferrous, bauxite, talc, clay, asbestos, barytine, salt, coal and bituminous schist). Also, there have been determined the radium and the uranium content of waters from non-uraniferous mining sites. The level of radioactive noxa has been informative determined in each mine. The level of the concentrations requires a systematic research and an assessment of the risk and the impact against the environment, the workers, and the public. (author)

  18. Residues and contaminants in tea and tea infusions: a review.

    Science.gov (United States)

    Abd El-Aty, A M; Choi, Jeong-Heui; Rahman, Md Musfiqur; Kim, Sung-Woo; Tosun, Alev; Shim, Jae-Han

    2014-01-01

    Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China and Egypt, tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution, whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. This review focuses on green and black tea because they are most commonly consumed. The target was to examine the transfer rate of contaminants - pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides) and plant growth regulators - from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. It is concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits. However, the traditional practice of over-boiling tea leaves should be discouraged as there may be a chance for more transfer of contaminants from the tea to the brew.

  19. A method for assessing residual NAPL based on organic chemical concentrations in soil samples

    International Nuclear Information System (INIS)

    Feenstra, S.; Mackay, D.M.; Cherry, J.A.

    1991-01-01

    Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or >10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil chemical analyses indicate the presence of residual NAPL in the subsurface

  20. Contaminant Release from Residual Waste in Single Shell Tanks at the Hanford Site, Washington, USA - 9276

    International Nuclear Information System (INIS)

    Cantrell, Kirk J.; Krupka, Kenneth M.; Deutsch, William J.; Lindberg, Michael J.

    2009-01-01

    Determinations of elemental and solid-phase compositions, and contaminant release studies have been applied in an ongoing study of residual tank wastes (i.e., waste remaining after final retrieval operations) from five of 149 underground single-shell storage tanks (241-C-103, 241-C-106, 241-C-202, 241-C-203, and 241-S-112) at the U.S. Department of Energy's Hanford Site in Washington State. This work is being conducted to support performance assessments that will be required to evaluate long-term health and safety risks associated with tank site closure. The results of studies completed to date show significant variability in the compositions, solid phase properties, and contaminant release characteristics from these residual tank wastes. This variability is the result of differences in waste chemistry/composition of wastes produced from several different spent fuel reprocessing schemes, subsequent waste reprocessing to remove certain target constituents, tank farm operations that concentrated wastes and mixed wastes between tanks, and differences in retrieval processes used to remove the wastes from the tanks. Release models were developed based upon results of chemical characterization of the bulk residual waste, solid-phase characterization (see companion paper 9277 by Krupka et al.), leaching and extraction experiments, and geochemical modeling. In most cases empirical release models were required to describe contaminant release from these wastes. Release of contaminants from residual waste was frequently found to be controlled by the solubility of phases that could not be identified and/or for which thermodynamic data and/or dissolution rates have not been measured. For example, significant fractions of Tc-99, I-129, and Cr appear to be coprecipitated at trace concentrations in metal oxide phases that could not be identified unambiguously. In the case of U release from tank 241-C-103 residual waste, geochemical calculations indicated that leachate

  1. Analysis of Food Contaminants, Residues, and Chemical Constituents of Concern

    Science.gov (United States)

    Ismail, Baraem; Reuhs, Bradley L.; Nielsen, S. Suzanne

    The food chain that starts with farmers and ends with consumers can be complex, involving multiple stages of production and distribution (planting, harvesting, breeding, transporting, storing, importing, processing, packaging, distributing to retail markets, and shelf storing) (Fig. 18.1). Various practices can be employed at each stage in the food chain, which may include pesticide treatment, agricultural bioengineering, veterinary drug administration, environmental and storage conditions, processing applications, economic gain practices, use of food additives, choice of packaging material, etc. Each of these practices can play a major role in food quality and safety, due to the possibility of contamination with or introduction (intentionally and nonintentionally) of hazardous substances or constituents. Legislation and regulation to ensure food quality and safety are in place and continue to develop to protect the stakeholders, namely farmers, consumers, and industry. [Refer to reference (1) for information on regulations of food contaminants and residues.

  2. The behaviour of residual contaminants at a former station site, Antarctica

    International Nuclear Information System (INIS)

    Webster, Jenny; Webster, Kerry; Nelson, Peter; Waterhouse, Emma

    2003-01-01

    Minor contamination by metals, phosphorus, and fuel products were found at a former research station site in Antarctica. - In 1994, New Zealand's only mainland Antarctic base, Vanda Station, was removed from the shores of Lake Vanda, in the McMurdo Dry Valleys region of southern Victoria Land, Antarctica. Residual chemical contamination of the station site has been identified, in the form of discrete fuel spills, locally elevated Pb, Zn, Ag and Cd concentrations in soil and elevated Cu, Ni, Co and phosphate concentrations in suprapermafrost fluids in a gully formerly used for domestic washing water disposal. Pathways for contaminant transfer to Lake Vanda, potential environmental impacts and specific remediation/monitoring options are considered. While some contaminants (particularly Zn) could be selectively leached from flooded soil, during a period of rising lake level, the small area of contaminated soils exposed and low level of contamination suggests that this would not adversely affect either shallow lake water quality or the growth of cyanobacteria. Phosphate-enhanced growth of the latter may, however, be a visible consequence of the minor contamination occurring at this site

  3. Full scale amendment of a contaminated wood impregnation site with iron water treatment residues

    DEFF Research Database (Denmark)

    Nielsen, Sanne Skov; Kjeldsen, Peter; Jakobsen, Rasmus

    2016-01-01

    Iron water treatment residues (Fe-WTR) are a free by-product of the treatment of drinking water with high concentration of iron oxides and potential for arsenic sorption. This paper aims at applying Fe-WTR to a contaminated site, measuring the reduction in contaminant leaching, and discussing...... amendment a 100 m2 test site and a control site (without amendment) were monitored for 14 months. Also soil analysis of Fe to evaluate the degree of soil and Fe-WTR mixing was done. Stabilization with Fe-WTR had a significant effect on leachable contaminants, reducing pore water As by 93%, Cu by 91% and Cr...... by 95% in the upper samplers. Dosage and mixing of Fe-WTR in the soil proved to be difficult in the deeper part of the field, and pore water concentrations of arsenic was generally higher. Despite water logged conditions no increase in dissolved iron or arsenic was observed in the amended soil. Our...

  4. Nicarbazin contamination in feeds as a cause of residues in eggs.

    Science.gov (United States)

    Cannavan, A; Ball, G; Kennedy, D G

    2000-10-01

    A survey was carried out to investigate the prevalence of nicarbazin residues in eggs in Northern Ireland. Nicarbazin, in the form of 4,4'-dinitrocarbanilide (DNC), was detected in 39 of the 190 eggs analysed. An experiment was designed to establish the relationship between nicarbazin-contaminated feed and nicarbazin residues in eggs. The concentrations of both the DNC and 4,6-dimethyl-2-hydroxypyrimidine (DHP) components of the drug in eggs were proportional to feed levels. The maximum feed nicarbazin concentration of 12.1 mg/kg (8.6 mg/kg DNC and 3.5 mg/kg DHP) gave rise to mean maximum whole egg concentrations of 631 micrograms/kg DNC and 51.8 micrograms/kg DHP. After withdrawal of the experimental diet, DNC was undetectable in eggs after 12 days and DHP after 3 days. Feed contaminated with nicarbazin at concentrations greater than about 2 mg/kg gave rise to egg DNC residues at concentrations greater than the Differential Action Limit (DAL) set by the UK (100 micrograms/kg). DNC was contained almost entirely in the yolk of the egg, whereas DHP was distributed between albumen and yolk in a ratio of approximately 3:1.

  5. Critical body residues in the marine amphipod Ampelisca abdita: Sediment exposures with nonionic organic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Fay, A.A.; Brownawell, B.J.; Elskus, A.A.; McElroy, A.E.

    2000-04-01

    Body residues associated with acute toxicity were determined in the marine amphipod Ampelisca abdita exposed to spiked sediments. Nonylphenol and 2,2{prime},4,4{prime}-tetrachlorobiphenyl critical body residues (CBRs, body residue of contaminant at 50% mortality) were 1.1 {micro}mol/g wet tissue and 0.57 {micro}mol/g wet tissue, respectively, values near the low end of the CBR range expected for compounds acting via narcosis. The polycyclic aromatic hydrocarbons tested, benzo[a]pyrene (BaP) and benz[a]anthracene (BaA), were not acutely toxic at exposure concentrations of up to 43 and 1,280 {micro}g/g dry sediment for BaA and BaP respectively, and body burdens up to 1.2 {micro}mol/g wet tissue (for BaP). Neither polycyclic aromatic hydrocarbon (PAH) was significantly metabolized by A. abdita. The microextraction technique employed here allowed residue analysis of samples containing as few as three amphipods (0.33 mg dry wt). The CBR approach avoids confounding factors such as variations in bioavailability and uptake kinetics and could be employed to assess the relative contribution of specific contaminants or contaminant classes in mixtures to effects observed in toxicity tests with Ampelisca and other organisms.

  6. Allowable residual contamination levels for decommissioning. Part 2. A summary of example results

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1985-01-01

    This paper contains a description of the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for decommissioning facilities in the 100 Areas of the Hanford Site. ARCL results are presented both for surface contamination remaining in facilities (in dpm/100 cm 2 ) and for unconfined surface and confined subsurface soil conditions (in pCi/g). Two confined soil conditions are considered: contamination at depths between 1 and 4 m, and contamination at depths greater than or equal to 5 m. A set of worksheets are discussed for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations, to consider the impacts of radioactive decay, and to predict instrument responses. Finally, a comparison is made between the unrestricted release ARCL values for the 100 Area facilities and existing decommissioning and land disposal regulations. For surface contamination, the comparison shows good agreement for a selected annual dose limit. For soil contamination, the comparison shows good agreement if reasonable modification factors are applied to account for the differences in modeling soil contamination and licensed low-level waste. 6 references, 1 figures, 4 tables

  7. Optimal Aquifer Pumping Policy to Reduce Contaminant Concentration

    Directory of Open Access Journals (Sweden)

    Ali Abaei

    2012-01-01

    Full Text Available Different sources of ground water contamination lead to non-uniform distribution of contaminant concentration in the aquifer. If elimination or containment of pollution sources was not possible, the distribution of contaminant concentrations could be modified in order to eliminate peak concentrations using optimal water pumping discharge plan. In the present investigation Visual MODFLOW model was used to simulate the flow and transport in a hypothetic aquifer. Genetic Algorithm (GA also was applied to optimize the location and pumping flow rate of wells in order to reduce contaminants peak concentrations in aquifer.

  8. Contaminant Leach Testing of Hanford Tank 241-C-104 Residual Waste

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-01

    Leach testing of Tank C-104 residual waste was completed using batch and column experiments. Tank C-104 residual waste contains exceptionally high concentrations of uranium (i.e., as high as 115 mg/g or 11.5 wt.%). This study was conducted to provide data to develop contaminant release models for Tank C-104 residual waste and Tank C-104 residual waste that has been treated with lime to transform uranium in the waste to a highly insoluble calcium uranate (CaUO4) or similar phase. Three column leaching cases were investigated. In the first case, C-104 residual waste was leached with deionized water. In the second case, crushed grout was added to the column so that deionized water contacted the grout prior to contacting the waste. In the third case, lime was mixed in with the grout. Results of the column experiments demonstrate that addition of lime dramatically reduces the leachability of uranium from Tank C-104 residual waste. Initial indications suggest that CaUO4 or a similar highly insoluble calcium rich uranium phase forms as a result of the lime addition. Additional work is needed to definitively identify the uranium phases that occur in the as received waste and the waste after the lime treatment.

  9. Application of capillary electrophoresis-mass spectrometry for determining organic food contaminants and residues.

    Science.gov (United States)

    Font, Guillermina; Ruiz, Maria José; Fernández, Monica; Picó, Yolanda

    2008-05-01

    Food contamination continues to be a serious problem around the world. Surveillance of chemical contaminants in foods is important not only for public health but also because of the negative economic impact of contamination. From the analytical perspective, analysis of contaminants in food is an extremely challenging area. There is a wide variety of questions, ranging from the quantification of extremely low levels of individual components to the detailed assessment and evaluation of the analytical technique possibilities. This review considers the applications of CE coupled to MS detection (CE-MS) for the analysis of organic contaminants in food. Analytical information on sample concentration techniques, as well as on the CE separation conditions and recoveries obtained from water and food are provided. Different sections include several fields of application, such as pesticides, drug residues, or toxic formed during food processing in different matrices. A number of tables report a comprehensive listing of CE-MS applications. As a result, this work presents an update overview on the principal application of CE-MS together with a discussion of their main advantages and drawbacks, and an outline of future trends on analysis of organic contaminants.

  10. Remediation of deltamethrin contaminated cotton fields: residual and adsorption assessment

    Directory of Open Access Journals (Sweden)

    Rafique Uzaira

    2016-01-01

    Full Text Available Pakistan occupies a significant global position in the growing of high quality cotton. The extensive application of pesticides on agricultural products leads to environmental risk due to toxic residues in air, water and soil. This study examined the chemodynamic effect of Deltamethrin on cotton fields. Samples were collected from the cotton fields of D.G. Khan, Pakistan and analyzed for heavy metal speciation patterns. Batch experiments were administered in order to study the adsorption of Deltamethrin in cotton fields. The effect of different factors including pH, adsorbate dose, and adsorbent mass on adsorption were studied. It was observed that in general, adsorption increased with increases in the mass of adsorbate, although the trends were irregular. Residual fractions of deltamethrin in the soil and water of cotton fields were analyzed to assess concentrations of xenobiotics bound to soil particles. Results indicated that such residues are significantly higher in soil samples due to high Koc in comparison to water, indicating the former is an efficient degradation agent. Results from the batch experiment resulted in 95% removal with alkaline pH and an adsorbent-adsorbate ratio of 250:1. These results may be used to environment friendly resource management policies.

  11. Preparation and Properties of Agricultural Residuals-Iron Concentrate Pellets

    OpenAIRE

    Liu, Zhulin; Bi, Xuegong; Gao, Zeping; Wang, Yayu

    2017-01-01

    In this paper, carbon-containing pellets were prepared by using crop-derived charcoal made from agricultural residuals and iron ore concentrates, and their pelletizing performance and properties were studied. Experimental results showed that the strengths of pellets were related to the particle size of concentrates and the content of moisture, bentonite, and crop-derived charcoal fines in the pelletizing mixture and the temperature of roasting and reduction. That the granularity of raw materi...

  12. Residual radioactive contamination of the Maralinga range from nuclear weapons tests conducted in 1956 and 1957

    International Nuclear Information System (INIS)

    Cooper, M.B.; Duggleby, J.C.; Kotler, L.H.; Wise, K.N.

    1978-12-01

    Detailed geographical distributions and concentrations of long-lived radionuclides remaining from the major trials of nuclear weapons conducted at Maralinga in 1956 and 1957 are presented. It is shown that residual contamination due to fission products - mainly strontium-90, caesium-137 and europium-155 - are well below levels that could constitute a health hazard to occupants of the area. In the regions near the ground zeroes however, long-lived neutron activation products in soil - mainly cobalt-60 and europium-152 - are present in sufficient abundance to give rise to gamma-radiation dose-rates up to 2 milliroentgen per hour, which exceed maximum recommended dose-rates for continuous occupancy

  13. Residues of sulfadiazine and doxycycline in broiler liver and muscle tissue due to cross-contamination of feed.

    Science.gov (United States)

    Vandenberge, V; Delezie, E; Huyghebaert, G; Delahaut, P; Daeseleire, E; Croubels, S

    2012-01-01

    Veterinary drugs, such as antimicrobial compounds, are widely used in poultry and may lead to the presence of residues in matrices of animal origin, such as muscle and liver tissue. In this study, broilers received an experimental feed containing sulfadiazine or doxycycline at cross-contamination levels of 2.5, 5 and 10% of the therapeutic dose in feed. Breast and thigh muscle and liver samples were collected during treatment and depletion period and analysed via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Concentrations reached a plateau phase 3-5 days after the start of experimental feeding. A rapid depletion of residues was noted after withdrawal of the experimental feed. No significant differences in measured concentrations were observed between the various muscle types. Residue concentrations for some experimental groups; the 10% group of sulfadiazine and the 5 and 10% group of doxycycline, however, exceeded their corresponding maximum residue limits (MRLs).

  14. Complex relationship between groundwater velocity and concentration of radioactive contaminants

    International Nuclear Information System (INIS)

    Kaszeta, F.E.; Bond, F.W.

    1980-01-01

    This paper uses the results from the Multi-component Mass Transport model to examine the complex interrelationship between groundwater velocity and contaminant dispersion, decay, and retardation with regard to their influence on the contaminant concentration distribution as it travels through the geosphere to the biosphere. The rate of transport of contaminants through the geosphere is governed by groundwater velocity, leach rate, and contaminant retardation. The dominant characteristics of the contaminant concentration distribution are inherited during leaching and modified during transport by dilution, dispersion and decay. For a hypothetical non-decaying, non-dispersing contaminant with no retardation properties, the shape of the source term distribution is governed by the groundwater velocity (dilution) and leach rate. This distribution remains unchanged throughout transport. Under actual conditions, however, dispersion, decay and retardation modify the concentration distribution during both leaching and transport. The amount of dispersion is determined by the distance traveled, but it does have a greater peak-reducing influence on spiked distributions than square-shaped distributions. Decay acts as an overall scaling factor on the concentration distribution. Retardation alters the contaminant travel time and therefore indirectly influences the amount of dilution, dispersion and decay. Simple relationships between individual parameters and groundwater velocity as they influence peak concentration do not exist. For those cases where the source term is not solubility-limited and flow past the waste is independent of regional hydrologic conditions, a threshold concentration occurs at a specific groundwater velocity where the effects of dilution balance those of dispersion and decay

  15. [Research on hyperspectral remote sensing in monitoring snow contamination concentration].

    Science.gov (United States)

    Tang, Xu-guang; Liu, Dian-wei; Zhang, Bai; Du, Jia; Lei, Xiao-chun; Zeng, Li-hong; Wang, Yuan-dong; Song, Kai-shan

    2011-05-01

    Contaminants in the snow can be used to reflect regional and global environmental pollution caused by human activities. However, so far, the research on space-time monitoring of snow contamination concentration for a wide range or areas difficult for human to reach is very scarce. In the present paper, based on the simulated atmospheric deposition experiments, the spectroscopy technique method was applied to analyze the effect of different contamination concentration on the snow reflectance spectra. Then an evaluation of snow contamination concentration (SCC) retrieval methods was conducted using characteristic index method (SDI), principal component analysis (PCA), BP neural network and RBF neural network method, and the estimate effects of four methods were compared. The results showed that the neural network model combined with hyperspectral remote sensing data could estimate the SCC well.

  16. Evaluation of remediation techniques in soils affected by residual contamination with heavy metals and arsenic.

    Science.gov (United States)

    García-Carmona, M; Romero-Freire, A; Sierra Aragón, M; Martínez Garzón, F J; Martín Peinado, F J

    2017-04-15

    Residual soil pollution from the Aznalcóllar mine spill is still a problem in some parts of the affected area, today converted in the Guadiamar Green Corridor. Dispersed spots of polluted soils, identified by the absence of vegetation, are characterized by soil acid pH and high concentrations of As, Pb, Cu and Zn. Ex situ remediation techniques were performed with unrecovered soil samples. Landfarming, Composting and Biopiles techniques were tested in order to immobilize pollutants, to improve soil properties and to promote vegetation recovery. The effectiveness of these techniques was assessed by toxicity bioassays: Lactuca sativa L. root elongation test, Vibrio fischeri bioluminescence reduction test, soil induced respiration test, and Eisenia andrei survival and metal bioaccumulation tests. Landfarming and Composting were not effective techniques, mainly due to the poor improvement of soil properties which maintained high soluble concentrations of Zn and Cu after treatments. Biopile technique, using adjacent recovered soils in the area, was the most effective action in the reduction of soil toxicity; the improvement of soil properties and the reduction in pollutants solubility were key to improve the response of the tested organisms. Therefore, the mixture of recovered soils with polluted soils in the areas affected by residual contamination is considered a more suitable technique to reduce the residual pollution and to promote the complete soil recovery in the Guadiamar Green Corridor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Lead concentration and allocation in vegetable crops grown in a soil contaminated by battery residues Teores e alocação de chumbo em hortaliças cultivadas em solo contaminado por resíduos de baterias

    Directory of Open Access Journals (Sweden)

    Francisco de S Lima

    2009-09-01

    Full Text Available Lead (Pb is a very stable metal in soil and is highly toxic to humans and animals. Exposure to Pb occurs via inhalation of particles from industry and soil, as well as household dust, water, and contaminated food. A greenhouse experiment was carried out to evaluate Pb contents and allocation in vegetable crops grown in a soil contaminated by battery recycling wastes. Eight plant species were studied: tomato, sweet pepper, beet, carrot, cabbage, green collards, eggplant, and okra. The experiment was set up in blocks at random with four replicates. The results showed that carrot, green collards, beet, and okra were the most Pb tolerant species, while the others were very Pb-sensitive, since they did not complete their cycle. The decreasing order for Pb accumulation in the vegetables crops was: carrot > okra > tomato > eggplant > sweet pepper > green collards > cabbage > beet. Taking into account the Pb allocation in plants, the order was: root > stems > leaves > edible parts. Although carrot translocated the lowest Pb amount into the edible part, such level exceeded the legal limit.O chumbo (Pb é um elemento extremamente estável no solo e altamente tóxico para seres humanos e animais. A contaminação com chumbo geralmente ocorre pela exposição decorrente da inalação de partículas oriundas de indústrias ou do solo, ou ainda, pela ingestão de poeira doméstica, água e alimentos de origem animal e vegetal contaminados. O presente trabalho objetivou avaliar os teores e a alocação de Pb em hortaliças cultivadas em solo contaminado com resíduos de reciclagem de baterias. O experimento foi conduzido em casa-de-vegetação com delineamento experimental em blocos casualizados, com quatro repetições. Os tratamentos corresponderam a oito hortaliças: tomate, pimentão, beterraba, cenoura, repolho, couve manteiga, berinjela e quiabo. Os resultados mostraram que as espécies mais tolerantes ao Pb foram cenoura, couve-manteiga, beterraba e

  18. Pesticide residues and microbial contamination of water resources in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    Cheah Uan Boh; Lum Keng Yeang

    2002-01-01

    Studies on the water resources of the Muda rice growing areas revealed evidence of pesticide residues in the agroecosystem. While the cyclodiene endosulfan was found as a ubiquitous contaminant, the occurrence of other organochlorine insecticides was sporadic. The presence of 2,4-D, paraquat and molinate residues was also evident but the occurrence of these herbicides was seasonal. Residue levels of molinate were generally higher than those from the other herbicides. The problem of thiobencarb and carbofuran residues was not encountered. Analyses for microbial contamination revealed that the water resources were unfit for drinking; coliform counts were higher during certain periods of the year than others. (Author)

  19. Spacecraft maximum allowable concentrations for selected airborne contaminants, volume 1

    Science.gov (United States)

    As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMAC's) for contaminants, and to review SMAC's for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to NASA's request, the NRC organized the Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants within the Committee on Toxicology (COT). In the first phase of its work, the subcommittee developed the criteria and methods for preparing SMAC's for spacecraft contaminants. The subcommittee's report, entitled Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants, was published in 1992. The executive summary of that report is reprinted as Appendix A of this volume. In the second phase of the study, the Subcommittee on Spacecraft Maximum Allowable Concentrations reviewed reports prepared by NASA scientists and contractors recommending SMAC's for 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the first 11 SMAC reports that have been reviewed for their application of the guidelines developed in the first phase of this activity and approved by the subcommittee.

  20. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units.

    Science.gov (United States)

    Smith, Gordon Wg; Goldie, Frank; Long, Steven; Lappin, David F; Ramage, Gordon; Smith, Andrew J

    2011-01-10

    The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Residual protein was detected on 72% (n = 136) of instruments reprocessed centrally and 90% (n = 170) of instruments reprocessed locally. Significantly less protein (p podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  1. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units

    Directory of Open Access Journals (Sweden)

    Ramage Gordon

    2011-01-01

    Full Text Available Abstract Background The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. Methods The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Results Residual protein was detected on 72% (n = 136 of instruments reprocessed centrally and 90% (n = 170 of instruments reprocessed locally. Significantly less protein (p Conclusions Overall, the results show the superiority of central reprocessing for complex podiatry instruments when protein contamination is considered, though no significant difference was found in residual protein between local decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency.

  2. Concentration of plutonium in desert plants from contaminated area

    International Nuclear Information System (INIS)

    Xu Hui; Jin Yuren; Tian Mei; Li Weiping; Zeng Ke; Wang Yaoqin; Wang Yu

    2012-01-01

    The investigation of plutonium in desert plants from contaminated sites contributes to the evaluation of its pollution situation and to the survey of plutonium hyper accumulator. The concentration of 239 Pu in desert plants collected from a contaminated site was determined, and the influence factors were studied. The concentration of 239 Pu in plants was (1.8±4.9) Bq/kg in dry weight, and it means that the plants were contaminated, moreover, the resuspension results in dramatic plutonium pollution of plant surface. The concentration of plutonium in plants depends on species, live stages and the content of plutonium in the rhizosphere soil. The concentration of plutonium in herbage is higher than that in woody plant, and for the seven species of desert plants investigated, it decreases in the order of Hexinia polydichotoma, Phragmites australis, Halostashys caspica, Halogeton arachnoideus, Lycium ruthenicum, Tamarix hispida and Calligonum aphyllum. (authors)

  3. Residual contamination from Cs-137 in the Sondrio area (Lombardy - Italy)

    International Nuclear Information System (INIS)

    Rimoldi, E.M.; Leonardi, L.; Cavallone, E.; Bignazzi, R.; Galimberti, A.

    2000-01-01

    The authors conducted the investigations on the contamination by Cs-137, resulting from Chernobyl's Accident, in the Sondrio area (Lombardy, Italy). Analyses were performed with NaI (T1) spectrometer. 130 samples collected from superficial earth layer (up to 15 cm) and deep earth layer (from 15 to 30 cm) of woods and meadows, pond's mud, mosses, mushrooms, wild wood fruits, forages, striated muscle from deer, chamois and roe deer, goat's and cow's milk, and running and stagnant water, were studied. Superficial earth samples always showed a higher Cs-137 concentration compared to deep earth samples, their mean activities being 68 Bq/kg (sup. wood) and 18 Bq/kg (sup. meadow). In 1 sample from superficial wood earth in Val Belsivo, the concentration was 1109 Bq/kg. The mud samples had a mean Cs-137 concentration of 96 Bq/kg. Cs-137 was always present in mosses with a mean activity of 234 Bq/kg, whereas in mushrooms contamination was continuous (mean, 63 Bq/kg). Cs-137 was absent in wild wood fruits and in forages except for one sample of bilberry (12 Bq/Kg) and one sample of forage (54 Bq/Kg). In the striated muscle samples from wild animals, chamois always showed high Cs-137 concentration (29 Bq/kg), but was intermediate in roe deer (18 Bq/kg) and lowest in deer (5 Bq/kg). In 4 deer and 4 roe deer, contamination was undetectable. Running and stagnant waters, and cow's milk were not contaminated whereas some Cs-137 activities were detected in goat milk samples (18 Bq/kg). It is concluded that residual contamination from Chernobyl's accident in the investigated areas has by now just become a scientific interest and no longer a sanitary issue, as the contamination levels detected in all the samples are clearly below the maximal admissible levels established by the European Gazettes. However, it is interesting to note that the recycling of Cs-137 is more present in wood, confirming the delicate environmental balance of this ecosystem. The routine radio

  4. Control levels for residual contamination in materials considered for recycle and reuse

    International Nuclear Information System (INIS)

    Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

    1993-09-01

    Pacific Northwest Laboratory (PNL) is collecting data and conducting technical analyses to support joint efforts by the U.S. Department of Energy (DOE), Office of Environmental Guidance, Air, Water and Radiation Division (DOE/EH-232); by the U.S. Environmental Protection Agency (EPA); and by the U.S. Nuclear Regulatory Commission (NRC) to develop radiological control criteria for the recycle and reuse of scrap materials and equipment that contain residual radioactive contamination. The initial radiological control levels are the concentrations in or on materials considered for recycle or reuse that meet the individual (human) or industrial (electronics/film) dose criteria. The analysis identifies relevant radionuclides, potential mechanisms of exposure, and methods to determine possible non-health-related impacts from residual radioactive contamination in materials considered for recycle or reuse. The generic methodology and scenarios described here provide a basic framework for numerically deriving radiological control criteria for recycle or reuse. These will be adequately conservative for most situations

  5. Forecasting device for air contamination concentration of in working environment

    International Nuclear Information System (INIS)

    Kimura, Kiichi; Mikajiri, Motohiko.

    1992-01-01

    The device of the present invention forecasts contamination concentration of air in working environment, as one of information of radiation environment required upon planning of radiation management for operations under radiation such as periodical inspection in a nuclear power plant. That is, values of the actual result of each of the contamination concentration of air determined from past operation experiences such as periodical inspections are stored together with accompanying factors in a data bank of the device of the present invention. When the air contamination concentration of newly planned operation is estimated, information relevant to factors giving an effect on the air contamination concentration and evaluation of information are inputted. An estimation engine extracts the data coincident with inputted information from a data bank. All of extracted data are processed statistically to forecast the value of air contamination concentration at the objective operation. In the present invention, if the quantity of data stored in the data bank is increased, the application range is enlarged, and a forecast of high reliability can be conducted. (I.S.)

  6. Allowable Residual Contamination Levels in soil for decommissioning the Shippingport Atomic Power Station site

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.; Soldat, J.K.

    1983-09-01

    As part of decommissioning the Shippingport Atomic Power Station, a fundamental concern is the determination of Allowable Residual Contamination Levels (ARCL) for radionuclides in the soil at the site. The ARCL method described in this report is based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for unrestricted use of the land after decommissioning. In addition to naturally occurring radionuclides and fallout from weapons testing, soil contamination could potentially come from five other sources. These include operation of the Shippingport Station as a pressurized water reactor, operations of the Shippingport Station as a light-water breeder, operation of the nearby Beaver Valley reactors, releases during decommissioning, and operation of other nearby industries, including the Bruce-Mansfield coal-fired power plants. ARCL values are presented for 29 individual radionculides and a worksheet is provided so that ARCL values can be determined for any mixture of the individual radionuclides for any annual dose limit selected. In addition, a worksheet is provided for calculating present time soil concentration value that will decay to the ARCL values after any selected period of time, such as would occur during a period of restricted access. The ARCL results are presented for both unconfined (surface) and confined (subsurface) soil contamination. The ARCL method and results described in this report provide a flexible means of determining unrestricted-use site release conditions after decommissioning the Shippingport Atomic Power Station

  7. Methodology for determining acceptable residual radioactive contamination levels at decommissioned nuclear facilities/sites

    International Nuclear Information System (INIS)

    Watson, E.C.; Kennedy, W.E. Jr.; Hoenes, G.R.; Waite, D.A.

    1979-01-01

    The ultimate disposition of decommissioned nuclear facilities and their surrrounding sites depends upon the degree and type of residual contamination. Examination of existing guidelines and regulations has led to the conclusion that there is a need for a general method to derive residual radioactive contamination levels that are acceptable for public use of any decommissioned nuclear facility or site. This paper describes a methodology for determining acceptable residual radioactive contamination levels based on the concept of limiting the annual dose to members of the public. It is not the purpose of this paper to recommend or even propose dose limits for the exposure of the public to residual radioactive contamination left at decommissioned nuclear facilities or sites. Unrestricted release of facilities and/or land is based on the premise that the potential annual dose to any member of the public using this property from all possible exposure pathways will not exceed appropriate limits as may be defined by Federal regulatory agencies. For decommissioned land areas, consideration should be given to people living directly on previously contaminated areas, growing crops, grazing food animals and using well water. Mixtures of radionuclides in the residual contamination representative of fuel reprocessing plants, light water reactors and their respective sites are presented. These mixtures are then used to demonstrate the methodology. Example acceptable residual radioactive contamination levels, based on an assumed maximum annual dose of one millirem, are calculated for several selected times following shutdown of a facility. It is concluded that the methodology presented in this paper results in defensible acceptable residual contamination levels that are directly relatable to risk assessment with the proviso that an acceptable limit to the maximum annual dose will be established. (author)

  8. Protein concentrate production from the biomass contaminated with radionuclides

    International Nuclear Information System (INIS)

    Nizhko, V.F.; Shinkarenko, M.P.; Polozhaj, V.V.; Krivchik, O.V.

    1992-01-01

    Coefficients of radionuclides accumulation are determined for traditional and rare forage crops grown on contaminated soils. It is shown that with low concentration of radionuclides in soil minimal level of contamination were found in the biomass of lupine (Lupinus luteus L.) and sainfoin (Onobrychis hybridus L.). Relatively high levels of contamination were found in comfrey (Symphytum asperum Lepech.) and bistort (Polygonum divaricatum L.). Comparatively low accumulation coefficients in case of higher density of soil contamination were observed for white and yellow sweetclovers (Melilotus albus Medik. and M. officinalis (L.) Desr.), while higher values of coefficients were found for bird's-foot trefoil (Lotus corniculatus L.), white clover (Trifolium repens L.) and alsike clover (t. hybridum L.). Biomass of white sweet-clover and alsike clover has been processed to produce leaf protein concentrate. It is shown that with biomass contamination of 1 kBq/kg and above conventional technology based on thermal precipitation of the protein does not provide production of pure product. More purified protein concentrates are obtained after two-stage processing of the biomass

  9. Quantitative analysis of residual protein contamination of podiatry instruments reprocessed through local and central decontamination units

    Science.gov (United States)

    2011-01-01

    Background The cleaning stage of the instrument decontamination process has come under increased scrutiny due to the increasing complexity of surgical instruments and the adverse affects of residual protein contamination on surgical instruments. Instruments used in the podiatry field have a complex surface topography and are exposed to a wide range of biological contamination. Currently, podiatry instruments are reprocessed locally within surgeries while national strategies are favouring a move toward reprocessing in central facilities. The aim of this study was to determine the efficacy of local and central reprocessing on podiatry instruments by measuring residual protein contamination of instruments reprocessed by both methods. Methods The residual protein of 189 instruments reprocessed centrally and 189 instruments reprocessed locally was determined using a fluorescent assay based on the reaction of proteins with o-phthaldialdehyde/sodium 2-mercaptoethanesulfonate. Results Residual protein was detected on 72% (n = 136) of instruments reprocessed centrally and 90% (n = 170) of instruments reprocessed locally. Significantly less protein (p decontamination unit and central decontamination unit processes for Blacks files. Further research is needed to undertake qualitative identification of protein contamination to identify any cross contamination risks and a standard for acceptable residual protein contamination applicable to different instruments and specialities should be considered as a matter of urgency. PMID:21219613

  10. Residual waste from Hanford tanks 241-C-203 and 241-C-204. 2. Contaminant release model.

    Science.gov (United States)

    Cantrell, Kirk J; Krupka, Kenneth M; Deutsch, William J; Lindberg, Michael J

    2006-06-15

    Release of U and 99Tc from residual sludge in Hanford waste tanks 241-C-203 and 241-C-204 atthe U.S. Department of Energy's (DOE) Hanford Site in southeastern Washington state was quantified by water-leaching, selective extractions, empirical solubility measurements, and thermodynamic modeling. A contaminant release model was developed based on these experimental results and solid-phase characterization results presented elsewhere. Uranium release was determined to be controlled by two phases and occurred in three stages. In the first stage, U release is controlled by the solubility of tejkaite, which is suppressed by high concentrations of sodium released from the dissolution of NaNO3 in the residual sludges. Equilibrium solubility calculations indicate the U released during this stage will have a maximum concentration of 0.021 M. When all the NaNO3 has dissolved from the sludge, the solubility of the remaining cejkaite will increase to 0.28 M. After cejkaite has completely dissolved, the majority of the remaining U is in the form of poorly crystalline Na2U2O7 [or clarkeite Na[(UO2)O(OH)](H20)0-1]. In contact with Hanford groundwater this phase is not stable, and becquerelite becomes the U solubility controlling phase, with a calculated equilibrium concentration of 1.2 x 10(-4) M. For Tc, a significant fraction of its concentration in the residual sludge was determined to be relatively insoluble (20 wt % for C-203 and 80 wt % for C-204). Because of the low concentrations of Tc in these sludge materials, the characterization studies did not identify any discrete Tc solids phases. Release of the soluble fraction of Tc was found to occur concomitantly with NO3-. It was postulated that a NaNO3-NaTcO4 solid solution could be responsible for this behavior. The Tc release concentrations for the soluble fraction were estimated to be 2.4 x 10-6 M for C-203 and 2.7 x 10(-5) M for C-204. Selective extraction results indicated that the recalcitrant fraction of Tc was

  11. Preparation and Properties of Agricultural Residuals-Iron Concentrate Pellets

    Directory of Open Access Journals (Sweden)

    Zhulin Liu

    2017-01-01

    Full Text Available In this paper, carbon-containing pellets were prepared by using crop-derived charcoal made from agricultural residuals and iron ore concentrates, and their pelletizing performance and properties were studied. Experimental results showed that the strengths of pellets were related to the particle size of concentrates and the content of moisture, bentonite, and crop-derived charcoal fines in the pelletizing mixture and the temperature of roasting and reduction. That the granularity of raw materials was fine and the bentonite content increased was beneficial to the improvement of pellet strengths. The suitable molar ratio of carbon to oxygen was 1.0 and the proper proportioning ratios of moisture and binder were 8.0% and 6.5%, respectively. The pellet strengths increased accordingly with increasing the reduction temperature, and when the temperature reached 1200°C, accompanied by the fast reduction of iron and the formation of crystal stock, the dropping strength of product pellets was 15 times and the compressive strength was 1650 N; this may be improved by grinding of the concentrate, leading to acceptable strength for the blast furnace.

  12. Removal of metal ions from contaminated water using agricultural residues

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    As the world population grows, there is a growing awareness that our environment is getting more polluted. Clean water is becoming a critical issue for many parts of the world for human, animal and agricultural use. Filtration systems to clean our air and water are a growing industry. There are many approaches to removing contaminates from our water supply ranging from...

  13. Assessment of pesticide residues and trace element contamination ...

    African Journals Online (AJOL)

    ajl10

    Kara River to an electric power plant whose waste oils are dumped in the river. The accumulation of lead (9.53 mg/kg for B. oleracea var. capitata) at the high altitude of. Danyi may be explained by a probable geological origin. This contamination could also be due to the application of agrochemicals to cocoa and coffee ...

  14. The Behavior of Mercury in Coal Combustion Residue-Contaminated Sediments

    Science.gov (United States)

    Gofstein, T.; Heyes, A.

    2014-12-01

    Coal combustion residues (CCRs), the products of coal combustion, contain high concentrations of heavy metals such as mercury. Recent structural failures of on-site containment ponds and leaching of CCRs has potentially endangered the health of adjacent water bodies. This study examines the influence of CCR enrichment of river sediments through the study of mercury, an abundant constituent of CCRs, and the concomitant production of methylmercury. We hypothesized that CCR contamination increases the exposure to mercury for aquatic life through leaching and resuspension mechanisms. Resuspension experiments were conducted using CCR-contaminated sediments from the Dan River and uncontaminated sediments enriched with 0%, 10%, and 30% CCRs in the laboratory. Sediments were sieved to obtain the silt-clay fraction, which was then resuspended in solution with a dispersant to obtain the separate silt and clay fractions and then analyzed for total mercury concentrations. We found that CCR particles and the mercury they contain are present primarily in the silt and clay fractions of sediment and there is a direct relationship between CCR concentrations and total mercury concentrations. These findings have implications for both the bioavailability of mercury to methylating bacteria, higher organisms prone to direct ingestion of fine particles, CCR spill event remediation, current industrial waste disposal practices, and further research required in this field. Our seven day incubations of river sediment cores enriched with CCRs did not increase methylmercury in porewater above controls, suggesting that there is no immediate risk of increased methylmercury bioaccumulation, however this does not necessarily reflect the long-term effects of CCRs on river ecology, which requires further research.

  15. Averaging of diffusing contaminant concentrations in atmosphere surface layer

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Ramzina, T.V.

    1985-01-01

    Calculations permitting to average concentration fields of diffusing radioactive contaminant coming from the NPP exhaust stack in the atmospheric surface layer are given. Formulae of contaminant concentration field calculation are presented; it depends on the average wind direction value (THETA) for time(T) and stability of this direction (σsub(tgTHETA) or σsub(THETA)). Probability of wind direction deviation from the average value for time T is satisfactory described by the Gauss law. With instability increase in the atmosphere σ increases, when wind velocity increasing the values of σ decreases for all types of temperature gradients. Nonuniformity of σ value dependence on averaging time T is underlined, that requires accurate choice of σsub(tgTHETA) and σsub(THETA) parameters in calculations

  16. Contaminant interferences with SIMS analyses of microparticle impactor residues on LDEF surfaces

    International Nuclear Information System (INIS)

    Simon, C.G.; Batchelor, D.; Griffis, D.P.; Hunter, J.L.; Misra, V.; Ricks, D.A.; Wortman, J.J.

    1992-01-01

    Elemental analyses of impactor residues on high purity surface exposed to the low earth orbit (LEO) environment for 5.8 years on Long Duration Exposure Facility (LDEF) has revealed several probable sources for microparticles at this altitude, including natural micrometeorites and manmade debris ranging from paint pigments to bits of stainless steel. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences included pre-, post-, and in-flight deposited particulate surface contaminants, as well as indigenous heterogeneous material contaminants. Non-flight contaminants traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF and proximity to active electrical fields. In-flight deposited (low velocity) contaminants included urine droplets and bits of metal film from eroded thermal blankets

  17. Flow of microemulsion through soil columns contaminated with asphaltic residue; Fluxo de microemulsoes atraves do solo contaminado com residuos asfalticos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcia C.K.; Oliveira, Jose F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Oliveira, Roberto C.G.; Gonzalez, Gazpar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2004-07-01

    Nowadays, soil contamination with nonaqueous phase liquids (NAPLs) such as petroleum hydrocarbons is a major environmental problem. Significant efforts have been devoted to the development of processes to remediate sites contaminated with NAPLs. Unfortunately, most of the developed processes proved to be inefficient to remove the organic heavy fraction present in the NAPLs. Nevertheless, in our preliminary bench scale tests it was observed that, due to their high solubilization capacity and stability, microemulsions are able to remove organic heavy fractions like asphaltenes and resins, typically present in crude oils. The present work was dimensioned to evaluate, under up-flow condition, the performance of different microemulsions specially designed to remove asphaltenes fractions from soils using a column test set-up. The contaminant residual concentration was quantified by UV spectroscopy and the microemulsion efficiency determined using mass balance. The results showed that the microemulsions tested have a high capacity for removing asphaltenes fractions from contaminated soils. It was also observed that the predominant removal mechanism, solubilization or mobilization, depends essentially on the microemulsion's chemical formulation. Finally it was verified that microemulsion's formulations based on natural solvents compounds are also efficient for removing asphaltic residues. (author)

  18. Geotechnical behavior of a tropical residual soil contaminated with gasoline

    Directory of Open Access Journals (Sweden)

    Óscar Echeverri-Ramírez

    2015-01-01

    Full Text Available La infraestructura para transporte de hidrocarburos ha crecido de manera importante debido a la necesidad de abastecer la mayo r cantidad de poblaciones; sin embargo por pro blemas en las redes de sumin istro, se presentan derrames accidentales que contaminan los su elos bajo los cuales se apoyan estas estructuras. Los suelos contaminados , en este caso particular con gasolina, son la motivación del p resente artículo, el cual pretende analizar los cambios que ocurren en un suelo d e origen residual tropical al ser contaminado con éste; mediant e pruebas de laboratorio específicos para caracterizar este tipo de suelos (Clasificación Miniatura Compactado Tropical, Succión, Pinhole Test, Índice de Colapso, Difracción de rayos “X”, Microscopía Electrónica de Barrido, determinación de pH y de ensayos tradicionales (hume dad natural, gravedad específica, granulometría, límites de Atterbe rg, corte directo, etc, tanto con muestras en estado natural c omo contaminadas que permitan percibir las posibles variaciones en las características mecánicas del material.

  19. Urban groundwater contamination by residues of UV filters.

    Science.gov (United States)

    Jurado, Anna; Gago-Ferrero, Pablo; Vàzquez-Suñé, Enric; Carrera, Jesus; Pujades, Estanislao; Díaz-Cruz, M Silvia; Barceló, Damià

    2014-04-30

    The occurrence and fate of UV filters (UV F) in an urban aquifer in correlation with (1) the spatial distribution of UV F in Barcelona's groundwater, (2) the depth of the groundwater sample, (3) the physicochemical properties of the target compounds, (4) the recharge sources, and (5) the redox conditions of the Barcelona aquifers, were studied for the first time. The highest groundwater concentrations and the largest number of detected UV F were observed in an aquifer recharged by a polluted river (around 55 ng/L in SAP-4). In contrast, the urbanized areas had lower concentrations (around 20 ng/L in MPSP-1). Two pathways can be identified for UV F to enter the aquifers: (1) leakage of row sewage from the sewage network in urbanized areas and (2) wastewater treatment plant (WWTP) effluents discharged into the river. Measured concentrations of UV F were significantly much lower than those estimated from the waste water proportion in groundwater samples suggesting that UV F might undergo transformation processes in both reducing and oxidizing conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

    Directory of Open Access Journals (Sweden)

    Dana Védy

    2009-04-01

    Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

  1. Contamination of food with residues of antibiotics in the sulphonamide class, risk can be avoided

    Directory of Open Access Journals (Sweden)

    Carmen Lidia Chitescu,

    2010-12-01

    Full Text Available Sulfadimethoxine, sulfamethoxazole, sulfaquinoxaline and sulfadiazine are the most common usedsulfonamides in veterinary practice. The recommended withdrawal periods if not observed before slaughteringof the medicated animals, the products may obtain from such animals may be contaminated with residue. Theinterest in having reliable methods able to detect low amounts of sulfonamides in food is very actual. In thisstudy, a multiresidue analysis was performed to simultaneously determine those four sulfonamides in chickenmuscle tissue by the Waters LC.Criteria of validation: specificity, accuracy, precision, limit of detection, limit of quantification, and linearity,according to the European Commission Decision 2002/657/EC, show that the method can detect differentkinds of sulfonamides within one run, without mass spectrometry analyses, or Fluor metric derivatization ofanalyts.The method is accurate, simple, economical in both time and cost, capable of detecting sulfonamidesresidues below the maximum residue limits (MRL and easy to perform to routine samples, in normal conditionof laboratory.The sulfonamides were extracted with acetonitrile and acetone and dichloromethane. N-hexane wasadded for defeating the sample. Separation was carried out on a Zorbax SB- C18 analytical column, using asmobile phase a mixture of 75:25 = di-natrium-hydrogenphosphat solution 6 g/1000 ml (pH = 8.5 : methanol.The detection wavelength was set at: 254 nm Calibration graphs were linear with very good correlationcoefficients in the concentration range from 0.320 to 1.5μg /mL. The limits of quantification (LOQ for thesulfonamides were in the range of 6.6–0.34 μg /kg. The recovery for spiked chicken muscle with 50–150 μg/kg ranged more than 70%. The relative standard deviation (Reds of the sulfonamides for six measurementsat 50 go/kg, 100 μg /kg and 150 μg /kg was less then 15%.The applicability of the method to the analysis of chicken muscle tissue was

  2. Utilization of air pollution control residues for the stabilization/solidification of trace element contaminated soil.

    Science.gov (United States)

    Travar, I; Kihl, A; Kumpiene, J

    2015-12-01

    The aim of this study was to evaluate the stabilization/solidification (S/S) of trace element-contaminated soil using air pollution control residues (APCRs) prior to disposal in landfill sites. Two soil samples (with low and moderate concentrations of organic matter) were stabilized using three APCRs that originated from the incineration of municipal solid waste, bio-fuels and a mixture of coal and crushed olive kernels. Two APCR/soil mixtures were tested: 30% APCR/70% soil and 50% APCR/50% soil. A batch leaching test was used to study immobilization of As and co-occurring metals Cr, Cu, Pb and Zn. Solidification was evaluated by measuring the unconfined compression strength (UCS). Leaching of As was reduced by 39-93% in APCR/soil mixtures and decreased with increased amounts of added APCR. Immobilization of As positively correlated with the amount of Ca in the APCR and negatively with the amount of soil organic matter. According to geochemical modelling, the precipitation of calcium arsenate (Ca3(AsO4)2/4H2O) and incorporation of As in ettringite (Ca6Al2(SO4)3(OH)12 · 26H2O) in soil/APCR mixtures might explain the reduced leaching of As. A negative effect of the treatment was an increased leaching of Cu, Cr and dissolved organic carbon. Solidification of APCR/soil was considerably weakened by soil organic matter.

  3. Rapid determination of radionuclide activity concentrations in contaminated drinking water

    International Nuclear Information System (INIS)

    Medley, P.; Ryan, B.; Bollhofer, A.; Martin, P.; International Atomic Energy Agency, Vienna

    2007-01-01

    As a result of an incident at the Ranger Uranium mine in which drinking water was contaminated with process water, it was necessary to perform quick analysis for naturally occurring uranium and thorium series radionuclide activity concentrations, including 226Ra, 210Pb, 210Po, U and Th isotopes. The methods which were subsequently used are presented here. The techniques used were high-resolution gamma spectrometry, Inductively Coupled Plasma Mass Spectrometry (ICPMS) and high-resolution alpha spectrometry. Routine methods were modified to allow for rapid analyses on priority samples in 1-2 days, with some results for highest priority samples available in less than 1 day. Comparison of initial results obtained through standard procedures, is discussed. An emphasis is placed on high-resolution alpha spectrometry of major alpha-emitting nuclides, specifically 226Ra, 230Th and 238U. The range of uranium concentrations in the samples investigated was from background levels to 6.6ppm. Implications for radiological dose assessment in contamination incidents involving process water are presented. The worst-case scenario for the incident at Ranger Uranium Mine indicates that the maximum committed effective dose to workers was well below the ICRP limit for worker-related dose and below the dose limit for a member of the public, with 230Th being the highest contributor

  4. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Juhasz, Albert L., E-mail: albert.juhasz@unisa.edu.a [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Smith, Euan [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia); Waller, Natasha [CSIRO Land and Water, Glen Osmond, SA 5064 (Australia); Stewart, Richard [Remediate, Kent Town, SA 5067 (Australia); Weber, John [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, SA 5095 (Australia)

    2010-02-15

    The impact of residual PAHs (2250 +- 71 mug total PAHs g{sup -1}) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +- 1286 mug total PAHs g{sup -1}) was assessed using a variety of ecological assays. Microtox{sup TM} results for aqueous soil extracts indicated that there was no significant difference in EC{sub 50} values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  5. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil

    International Nuclear Information System (INIS)

    Juhasz, Albert L.; Smith, Euan; Waller, Natasha; Stewart, Richard; Weber, John

    2010-01-01

    The impact of residual PAHs (2250 ± 71 μg total PAHs g -1 ) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 ± 1286 μg total PAHs g -1 ) was assessed using a variety of ecological assays. Microtox TM results for aqueous soil extracts indicated that there was no significant difference in EC 50 values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. - Residual PAHs in creosote-contaminated soil following enhanced natural attenuation impacted negatively on ecological receptors.

  6. Dispersal and attenuation of trace contaminants downstream of the Ajka bauxite residue (red mud) depository failure, Hungary.

    Science.gov (United States)

    Mayes, William M; Jarvis, Adam P; Burke, Ian T; Walton, Melanie; Feigl, Viktória; Klebercz, Orsolya; Gruiz, Katalin

    2011-06-15

    This paper identifies the spatial extent of bauxite processing residue (red mud)-derived contaminants and modes of transport within the Marcal and Rába river systems after the dike failure at Ajka, western Hungary. The geochemical signature of the red mud is apparent throughout the 3076 km² Marcal system principally with elevated Al, V, As, and Mo. Elevated concentrations of Cr, Ga, and Ni are also observed within 2 km of the source areas in aqueous and particulate phases where hyperalkalinity (pH extraction suggests the bulk of the As, Cr, Ni, and V are associated with residual (aqua-regia/HF digest) phases and unlikely to be mobile in the environment. However, at some depositional hotspots, association of As, Cr, and V with weak acid-extractable phases is observed.

  7. Trophic ecology drives contaminant concentrations within a tropical seabird community.

    Science.gov (United States)

    Sebastiano, Manrico; Bustamante, Paco; Eulaers, Igor; Malarvannan, Govindan; Mendez-Fernandez, Paula; Churlaud, Carine; Blévin, Pierre; Hauselmann, Antoine; Covaci, Adrian; Eens, Marcel; Costantini, David; Chastel, Olivier

    2017-08-01

    To support environmental management programs, there is an urgent need to know about the presence and understand the dynamics of major contaminants in seabird communities of key marine ecosystems. In this study, we investigated the concentrations and trophodynamics of trace elements in six seabird species and persistent organic pollutants (POPs) in three seabird species breeding on Grand Connétable Island (French Guiana), an area where the increase in human population and mining activities has raised concerns in recent years. Red blood cell Hg concentrations in adults were the highest in Magnificent frigatebirds Fregata magnificens (median: 5.6 μg g -1 dw; range: 3.8-7.8 μg g -1 dw) and lowest in Sooty terns Onychoprion fuscatus (median: 0.9 μg g -1 dw; range: 0.6-1.1 μg g -1 dw). Among POPs, dichlorodiphenyldichloroethylene (p,p'-DDE) was the most abundant compound in plasma of Cayenne terns Thalasseus sandvicensis (median: 1100 pg g -1 ww; range: 160 ± 5100 pg g -1 ww), while polychlorinated biphenyls (PCBs) were the most abundant compound class in plasma of Magnificent frigatebirds (median: 640 pg g -1 ww; range 330 ± 2700 pg g -1 ww). While low intensity of POP exposure does not appear to pose a health threat to this seabird community, Hg concentration in several adults Laughing gulls Leucophaeus atricilla and Royal terns Thalasseus maximus, and in all Magnificent frigatebirds was similar or higher than that of high contaminated seabird populations. Furthermore, nestling red blood cells also contained Hg concentrations of concern, and further studies should investigate its potential health impact in this seabird community. Differences in adult trophic ecology of the six species explained interspecific variation in exposure to trace element and POPs, while nestling trophic ecology provides indications about the diverse feeding strategies adopted by the six species, with the consequent variation in exposure to contaminants. Copyright

  8. JUSTIFICATION FOR THE RADIOLOGICAL CRITERIA FOR THE USE OF AREAS WITH RESIDUAL RADIOACTIVE CONTAMINATION BASED ON THE DOSE APPROACH

    Directory of Open Access Journals (Sweden)

    V. Yu. Golikov

    2017-01-01

    Full Text Available The article presents a methodology for assessing the radiological criteria for the use of the territory (a land plot with buildings with residual radioactive contamination from the so-called “green area”, i.e., complete release from radiation control until a number of restrictions are imposed on the use of the territory. In accordance with the further use of the territory, a range of scenarios and pathways for the exposure of the population was considered. A set of models and their parameters, corresponding to the number of the considered pathways of exposure, was defined. Assuming a uniform distribution of a radionuclide with a unit concentration in the source zone, the distribution of effective doses for the population living in the territory with the residual radioactive contamination for different irradiation scenarios was calculated by stochastic modeling, 95% of the quantile of which was attributed to the dose in the representatives of the critical population group. Next, the value of radiological criteria, depending on the implemented scenario, was determined as the ratio of the dose constraint EL = 0,3 mSv/yr and 95% quantile in the distribution of the effective dose from a unit contamination. The numerical values of radiological criteria for the presence of radionuclides in the soil are presented, both for the radiation scenarios that correspond to the permanent residence of the population in the contaminated territory and for recreational use. A further consideration is given to the so-called worker scenario, which corresponds to the limited time spent on the contaminated territory and the simultaneous effects of radionuclides contained both in the soil and in the construction of the buildings. A comparison of the results of the own calculations with the data of other authors was carried out.

  9. Enhanced bioremediation of PAH-contaminated soil by immobilized bacteria with plant residue and biochar as carriers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baoliang; Yuan, Miaoxin; Qian, Linbo [Zhejiang Univ., Hangzhou (China). Dept. of Environmental Science; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou (China)

    2012-10-15

    Polycyclic aromatic hydrocarbons (PAHs) are largely accumulated in soils in China. The immobilized-microorganism technique (IMT) is a potential approach for abating soil contamination with PAHs. However, few studies about the application of IMT to contaminated soil remediation were reported. Due to recalcitrance to decomposition, biochar application to soil may enhance soil carbon sequestration, but few studies on the application of biochars to remediation of contaminated soil were reported. In this study, we illustrated enhanced bioremediation of soil having a long history of PAH contamination by IMT using plant residues and biochars as carriers. Two PAH-degrading bacteria, Pseudomonas putida and an unidentified indigenous bacterium, were selected for IMT. The extractability and biodegradation of 15 PAHs in solution and an actual PAH-contaminated soil amended with immobilized-bacteria materials were investigated under different incubation periods. The effects of carriers and the molecular weight of PAHs on bioremediation efficiency were determined to illustrate their different bio-dissipation mechanisms of PAHs in soil. The IMT can considerably enhance the removal of PAHs. Carriers impose different effects on PAH bio-dissipation by amended soil with immobilized-bacteria, which can directly degrade the carrier-associated PAHs. The removal of PAHs from soil depended on PAH molecular weight and carrier types. Enhanced bio-dissipation by IMT was much stronger for 4- and 5-ring PAHs than for 3- and 6-ring ones in soil. Only P400 biochar-immobilized bacteria enhanced bio-dissipation of all PAHs in contaminated soil after a 90-day incubation. Biochar can promote bioremediation of contaminated soil as microbial carriers of IMT. It is vital to select an appropriate biochar as an immobilized carrier to stimulate biodegradation. It is feasible to use adsorption carriers with high sorptive capabilities to concentrate PAHs as well as microorganisms and thereby enhance

  10. Concentrations of selected contaminants in cabin air of airbus aircrafts.

    Science.gov (United States)

    Dechow, M; Sohn, H; Steinhanses, J

    1997-07-01

    The concentrations of selected air quality parameters in aircraft cabins were investigated including particle numbers in cabin air compared to fresh air and recirculation air, the microbiological contamination and the concentration of volatile organic compounds (VOC). The Airbus types A310 of Swissair and A340 of Lufthansa were used for measurements. The particles were found to be mainly emitted by the passengers, especially by smokers. Depending on recirculation filter efficiency the recirculation air contained a lower or equal amount of particles compared to the fresh air, whereas the amount of bacteria exceeded reported concentrations within other indoor spaces. The detected species were mainly non-pathogenic, with droplet infection over short distances identified as the only health risk. The concentration of volatile organic compounds (VOC) were well below threshold values. Ethanol was identified as the compound with the highest amount in cabin air. Further organics were emitted by the passengers--as metabolic products or by smoking--and on ground as engine exhaust (bad airport air quality). Cleaning agents may be the source of further compounds.

  11. Stabilization of Rocky Flats combustible residues contaminated with plutonium metal and organic solvents

    International Nuclear Information System (INIS)

    Bowen, S.M.; Cisneros, M.R.; Jacobson, L.L.; Schroeder, N.C.; Ames, R.L.

    1998-01-01

    This report describes tests on a proposed flowsheet designed to stabilize combustible residues that were generated at the Rocky Flats Environmental Technology Site (RFETS) during the machining of plutonium metal. Combustible residues are essentially laboratory trash contaminated with halogenated organic solvents and plutonium metal. The proposed flowsheet, designed by RFETS, follows a glovebox procedure that includes (1) the sorting and shredding of materials, (2) a low temperature thermal desorption of solvents from the combustible materials, (3) an oxidation of plutonium metal with steam, and (4) packaging of the stabilized residues. The role of Los Alamos National Laboratory (LANL) in this study was to determine parameters for the low temperature thermal desorption and steam oxidation steps. Thermal desorption of carbon tetrachloride (CCl 4 ) was examined using a heated air stream on a Rocky Flats combustible residue surrogate contaminated with CCl 4 . Three types of plutonium metal were oxidized with steam in a LANL glovebox to determine the effectiveness of this procedure for residue stabilization. The results from these LANL experiments are used to recommend parameters for the proposed RFETS stabilization flowsheet

  12. Mechanized recovery of olive pruning residues: ash contamination and harvesting losses

    Directory of Open Access Journals (Sweden)

    A. Assirelli

    2013-09-01

    Full Text Available Agricultural residues represent an important source of biomass for energy. Among the available biomass suitable for energy and available in Italy, pruning represents about the 20% of the total. About 1.184 million of hectares are planted with olive trees; the pruning residues coming from these plantations represent a wide source of biomass at National level. The authors tested six commercial pruning harvesters to determine harvesting losses and product contamination when recovering pruning residues. All harvesters used a mechanical pick-up to collect the residues and a shredder to reduce them into chips. Three different pick-up settings were tested and namely: 1 cm above ground level, manufacturer’s specification and 3 cm above ground level. Ash content in the shredded material was taken as a measure of contamination: the uncontaminated branch material collected directly from the trees had a value of 3.5%, whereas in shredded residues varied between 4.5% and over 5.5%, for the shortest and the longest distance between the pick-up and the soil surface, respectively. Harvesting losses were slightly, but significantly, related to pick-up setting, and mainly depended on machine type. Both machines have shown a good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

  13. Persistent organochlorine residues in foodstuffs from Australia, Papua New Guinea and the Solomon Islands: contamination levels and human dietary exposure.

    Science.gov (United States)

    Kannan, K; Tanabe, S; Williams, R J; Tatsukawa, R

    1994-08-15

    Concentrations of polychlorinated biphenyls (PCBs), DDT and its metabolites (DDTs), HCH isomers (HCHs), chlordane compounds (CHLs), aldrin, dieldrin, heptachlor, heptachlor epoxide and HCB were determined in a wide variety of foodstuffs collected from different locations in Australia, Papua New Guinea and the Solomon Islands. Elevated levels of PCBs, CHLs, DDTs and dieldrin were detected in most of the foodstuffs of animal origin. Fish samples collected near the coast of Sydney recorded noticeable concentrations of PCBs, CHLs and DDTs. PCB contamination was generally prominent in samples collected in urban areas, whereas organochlorine pesticides were distributed uniformly throughout Australia. The widespread usage of CHLs was evident from the composition of its compounds in various foods while HCHs and DDTs were found to have been used sporadically in space and time. For the most part, residue levels of organochlorines in foodstuffs were below the tolerance limits established by national and international health organizations. The exception was CHLs in some fish samples, which exceeded the maximum residue limits recommended by the National Health and Medical Research Council of the Australian government. Although the number of samples analysed in each class of foods is small for the purpose of estimating human dietary exposure, we tentatively conclude that the dietary intake of PCBs in Australia was higher than those observed in most developed and developing nations, whereas the intake of organochlorine pesticides was higher than in developed nations but lower than in developing countries. Meat products contributed to the higher dietary intakes of most of the organochlorines. The contamination pattern and the residual concentrations of organochlorines in foodstuffs of Papua New Guinea and the Solomon Islands resembled those observed in Australia.

  14. Contaminant transport at a waste residue deposit: 1. Inverse flow and non-reactive transport modelling

    DEFF Research Database (Denmark)

    Sonnenborg, Torben Obel; Engesgaard, Peter Knudegaard; Rosbjerg, Dan

    1996-01-01

    to steady state versus transient flow conditions and to the amount of hydraulic and solute data used is investigated. The flow parameters, transmissivity and leakage factor, are estimated simultaneously with the transport parameters: source strength, porosity, and longitudinal dispersivity. This paper...... is the first in a two-paper series describing contaminant transport at a waste residue site. III the second paper, reactive transport at the site is investigated....

  15. Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2005-06-03

    CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOE's Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL.

  16. Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2005-01-01

    CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOE's Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL

  17. Sex differences in contaminant concentrations of fish: a synthesis

    Science.gov (United States)

    Madenjian, Charles P.; Rediske, Richard R.; Krabbenhoft, David P.; Stapanian, Martin A.; Chernyak, Sergei M.; O'Keefe, James P.

    2016-01-01

    Comparison of whole-fish polychlorinated biphenyl (PCB) and total mercury (Hg) concentrations in mature males with those in mature females may provide insights into sex differences in behavior, metabolism, and other physiological processes. In eight species of fish, we observed that males exceeded females in whole-fish PCB concentration by 17 to 43%. Based on results from hypothesis testing, we concluded that these sex differences were most likely primarily driven by a higher rate of energy expenditure, stemming from higher resting metabolic rate (or standard metabolic rate (SMR)) and higher swimming activity, in males compared with females. A higher rate of energy expenditure led to a higher rate of food consumption, which, in turn, resulted in a higher rate of PCB accumulation. For two fish species, the growth dilution effect also made a substantial contribution to the sex difference in PCB concentrations, although the higher energy expenditure rate for males was still the primary driver. Hg concentration data were available for five of the eight species. For four of these five species, the ratio of PCB concentration in males to PCB concentration in females was substantially greater than the ratio of Hg concentration in males to Hg concentration in females. In sea lamprey (Petromyzon marinus), a very primitive fish, the two ratios were nearly identical. The most plausible explanation for this pattern was that certain androgens, such as testosterone and 11-ketotestosterone, enhanced Hg-elimination rate in males. In contrast, long-term elimination of PCBs is negligible for both sexes. According to this explanation, males ingest Hg at a higher rate than females, but also eliminate Hg at a higher rate than females, in fish species other than sea lamprey. Male sea lamprey do not possess either of the above-specified androgens. These apparent sex differences in SMRs, activities, and Hg-elimination rates in teleost fishes may also apply, to some degree, to higher

  18. Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site

    International Nuclear Information System (INIS)

    Merry-Libby, P.

    1985-01-01

    About 11,000 m 3 of uranium ore residues and 180,000 m 3 of slightly contaminated soils (wastes) are consolidated within a diked containment area at the Niagara Falls Storage Site located about 30 km north of Buffalo, New York. The residues account for less than 6% of the total volume of contaminated materials but almost 99% of the radioactivity. The average radium-226 concentration in the residues is 67,000 pCi/g. The US Department of Energy is considering several alternatives for long-term management of the wastes and residues, including: improvement of the containment at NFSS, modification of the form of the residues, management of the residues separately from the wastes, management of the wastes and residues at another humid site (Oak Ridge, Tennessee) or an arid site (Hanford, Washington), and dispersal of the wastes in the ocean. Potential radiological risks associated with implementation of any of the alternatives are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant radiological risk to humans. The residues and wastes will remain hazardous for thousands of years. After controls cease, the radioactive materials will eventually be dispersed in the environment. Loss of the earthen covers over the buried materials is predicted to occur from several hundred to more than two million years, depending primarily on the use of the land surface. Groundwater will eventually be contaminated in all alternatives; however, the groundwater pathway is relatively insignificant with respect to radiological risks to the general population. 2 references, 2 figures, 6 tables

  19. Minimizing residual aluminum concentration in treated water by tailoring properties of polyaluminum coagulants.

    Science.gov (United States)

    Kimura, Masaoki; Matsui, Yoshihiko; Kondo, Kenta; Ishikawa, Tairyo B; Matsushita, Taku; Shirasaki, Nobutaka

    2013-04-15

    Aluminum coagulants are widely used in water treatment plants to remove turbidity and dissolved substances. However, because high aluminum concentrations in treated water are associated with increased turbidity and because aluminum exerts undeniable human health effects, its concentration should be controlled in water treatment plants, especially in plants that use aluminum coagulants. In this study, the effect of polyaluminum chloride (PACl) coagulant characteristics on dissolved residual aluminum concentrations after coagulation and filtration was investigated. The dissolved residual aluminum concentrations at a given coagulation pH differed among the PACls tested. Very-high-basicity PACl yielded low dissolved residual aluminum concentrations and higher natural organic matter (NOM) removal. The low residual aluminum concentrations were related to the low content of monomeric aluminum (Ala) in the PACl. Polymeric (Alb)/colloidal (Alc) ratio in PACl did not greatly influence residual aluminum concentration. The presence of sulfate in PACl contributed to lower residual aluminum concentration only when coagulation was performed at around pH 6.5 or lower. At a wide pH range (6.5-8.5), residual aluminum concentrations residual aluminum concentrations did not increase with increasing the dosage of high-basicity PACl, but did increase with increasing the dosage of normal-basicity PACl. We inferred that increasing the basicity of PACl afforded lower dissolved residual aluminum concentrations partly because the high-basicity PACls could have a small percentage of Ala, which tends to form soluble aluminum-NOM complexes with molecular weights of 100 kDa-0.45 μm. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Rapid detection of chlorpyrifos pesticide residue concentration in agro-product using Raman spectroscopy

    Science.gov (United States)

    Dhakal, Sagar; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei; Zhang, Leilei; Xu, Tianfeng

    2014-05-01

    Different chemicals are sprayed in fruits and vegetables before and after harvest for better yield and longer shelf-life of crops. Cases of pesticide poisoning to human health are regularly reported due to excessive application of such chemicals for greater economic benefit. Different analytical technologies exist to detect trace amount of pesticides in fruits and vegetables, but are expensive, sample destructive, and require longer processing time. This study explores the application of Raman spectroscopy for rapid and non-destructive detection of pesticide residue in agricultural products. Raman spectroscopy with laser module of 785 nm was used to collect Raman spectral information from the surface of Gala apples contaminated with different concentrations of commercially available organophosphorous (48% chlorpyrifos) pesticide. Apples within 15 days of harvest from same orchard were used in this study. The Raman spectral signal was processed by Savitzky-Golay (SG) filter for noise removal, Multiplicative Scatter Correction (MSC) for drift removal and finally polynomial fitting was used to eliminate the fluorescence background. The Raman spectral peak at 677 cm-1 was recognized as Raman fingerprint of chlorpyrifos. Presence of Raman peak at 677 cm-1 after fluorescence background removal was used to develop classification model (presence and absence of pesticide). The peak intensity was correlated with actual pesticide concentration obtained using Gas Chromatography and MLR prediction model was developed with correlation coefficient of calibration and validation of 0.86 and 0.81 respectively. Result shows that Raman spectroscopy is a promising tool for rapid, real-time and non-destructive detection of pesticide residue in agro-products.

  1. Multivariate concentration determination using principal component regression with residual analysis.

    Science.gov (United States)

    Keithley, Richard B; Heien, Michael L; Wightman, R Mark

    2009-10-01

    Data analysis is an essential tenet of analytical chemistry, extending the possible information obtained from the measurement of chemical phenomena. Chemometric methods have grown considerably in recent years, but their wide use is hindered because some still consider them too complicated. The purpose of this review is to describe a multivariate chemometric method, principal component regression, in a simple manner from the point of view of an analytical chemist, to demonstrate the need for proper quality-control (QC) measures in multivariate analysis and to advocate the use of residuals as a proper QC method.

  2. Contaminant transport at a waste residue deposit: 1. Inverse flow and non-reactive transport modelling

    DEFF Research Database (Denmark)

    Sonnenborg, Torben Obel; Engesgaard, Peter Knudegaard; Rosbjerg, Dan

    1996-01-01

    An application of an inverse flow and transport model to a contaminated aquifer is presented. The objective of the study is to identify physical and nonreactive flow and transport parameters through an optimization approach. The approach can be classified as a statistical procedure, where a flow ...... is the first in a two-paper series describing contaminant transport at a waste residue site. III the second paper, reactive transport at the site is investigated.......An application of an inverse flow and transport model to a contaminated aquifer is presented. The objective of the study is to identify physical and nonreactive flow and transport parameters through an optimization approach. The approach can be classified as a statistical procedure, where a flow...

  3. Estimation of human body concentrations of DDT from indoor residual spraying for malaria control

    International Nuclear Information System (INIS)

    Gyalpo, Tenzing; Fritsche, Lukas; Bouwman, Henk; Bornman, Riana; Scheringer, Martin; Hungerbühler, Konrad

    2012-01-01

    Inhabitants of dwellings treated with DDT for indoor residual spraying show high DDT levels in blood and breast milk. This is of concern since mothers transfer lipid-soluble contaminants such as DDT via breastfeeding to their children. Focusing on DDT use in South Africa, we employ a pharmacokinetic model to estimate DDT levels in human lipid tissue over the lifetime of an individual to determine the amount of DDT transferred to children during breastfeeding, and to identify the dominant DDT uptake routes. In particular, the effects of breastfeeding duration, parity, and mother's age on DDT concentrations of mother and infant are investigated. Model results show that primiparous mothers have greater DDT concentrations than multiparous mothers, which causes higher DDT exposure of first-born children. DDT in the body mainly originates from diet. Generally, our modeled DDT levels reproduce levels found in South African biomonitoring data within a factor of 3. - Highlights: ► Comparison of one-compartment pharmacokinetic model with biomonitoring data. ► Pre- and postnatal exposure of infants depends on breastfeeding duration and parity. ► Dietary exposure of DDT is the dominant uptake route in South Africa. ► Elimination half-lives of DDT and DDE are shorter in children than in adults. - Model predictions of a one-compartment pharmacokinetic model confirm the trends of DDT found in human samples of inhabitants living in DDT-treated dwellings.

  4. The assessment of melamine and cyanuric acid residues in eggs from laying hens exposed to contaminated feed

    Directory of Open Access Journals (Sweden)

    Pavel Novák

    2012-01-01

    Full Text Available The aim of this study was to monitor the carry-over of melamine and its metabolite cyanuric acid from melamine-contaminated feed administered to layers into eggs. Ten experimental Isa Brown layers (36 week of age were fed melamine-contaminated feed containing 100 mg of melamine per kg of feed. The duration of the experiment was 6 weeks. Eggs were collected during whole experiment. Analysis of eggs was done by a simple extraction of melamine and cyanuric acid residues, using a water-acetonitrile mixture and analysed by gas chromatography - triple quadrupole mass spectrometry. Melamine and cyanuric acid residues were detected in all eggs collected from the experimental layers, immediately after the first administration of melamine-contaminated feed. The mean concentrations of melamine in the egg yolk and egg white recalculated on a dry matter basis were 1.90 mg·kg-1 ± 0.158 and 10.84 mg·kg-1 ± 3.951 (P ≤ 0.01; the cyanuric acid contents were 6.54 mg·kg-1 ± 0.2.466 and 4.07 mg·kg-1 ± 0.909, respectively. Melamine and cyanuric acid were not detected in eggs from control layers. Concentrations of melamine and cyanuric acid in eggs decreased quickly after melamine feeding was stopped. Our results indicate that melamine undergoes biotransformation to cyanuric acid in the layer’s body that also passed into the eggs. The results verified the presence of distribution metabolic pathway of melamine and its easiest transfer into egg yolk. Moreover, the biotransformation of melamine into cyanuric acid in eggs of layers was confirmed.

  5. Assessment of concentration in contaminated soil by potentially toxic elements using electrical properties.

    Science.gov (United States)

    Son, Younghwan

    2011-05-01

    Soils contaminated by potentially toxic elements (PTEs) which affect human health, such as zinc, lead, mercury, cadmium, and arsenic, were applied. The aims of this study are to judge contamination of soil and also to evaluate concentration of contaminated soil using electrical properties such as electrical resistivity and permittivity. The frequency was applied in the experiment ranged from 100 Hz to 10 MHz. As a result, the values of electrical resistivity and permittivity of each soil contaminated by PTEs could be presented as a function related to frequency and could determine whether the soil was contaminated. Also, results indicated that electrical properties give a reliable estimation of concentrations of PTEs contamination in soil.

  6. Citric-acid preacidification enhanced electrokinetic remediation for removal of chromium from chromium-residue-contaminated soil.

    Science.gov (United States)

    Meng, Fansheng; Xue, Hao; Wang, Yeyao; Zheng, Binghui; Wang, Juling

    2018-02-01

    Electrokinetic experiments were conducted on chromium-residue-contaminated soils collected from a chemical plant in China. Acidification-electrokinetic remediation technology was proposed in order to solve the problem of removing inefficient with ordinary electrokinetic. The results showed that electrokinetic remediation removal efficiency of chromium from chromium-contaminated soil was significantly enhanced with acidizing pretreatment. The total chromium [Cr(T)] and hexavalent chromium [Cr(VI)] removal rate of the group acidized by citric acid (0.9 mol/L) for 5 days was increased from 6.23% and 19.01% in the acid-free experiments to 26.97% and 77.66% in the acidification-treated experiments, respectively. In addition, part of chromium with the state of carbonate-combined will be converted into water-soluble state through acidification to improve the removal efficiency. Within the appropriate concentration range, the higher concentration of acid was, the more chromium was released. So the removal efficiency of chromium depended on the acid concentration. The citric acid is also a kind of complexing agent, which produced complexation with Cr that was released by the electrokinetic treatment and then enhanced the removal efficiency. The major speciation of chromium that was removed from soils by acidification-electrokinetics remediation was acid-soluble speciation, revivification speciation and oxidation speciation, which reduced biological availability of chromium.

  7. Biogas from Agricultural Residues as Energy Source in Hybrid Concentrated Solar Power

    NARCIS (Netherlands)

    Corré, W.J.; Conijn, J.G.

    2016-01-01

    This paper explores the possibilities of sustainable biogas use for hybridisation of Concentrated Solar Power (HCSP) in Europe. The optimal system for the use of biogas from agricultural residues (manure and crop residues) in HCSP involves anaerobic digestion with upgrading of biogas to

  8. Bioavailability of residual polycyclic aromatic hydrocarbons following enhanced natural attenuation of creosote-contaminated soil.

    Science.gov (United States)

    Juhasz, Albert L; Smith, Euan; Waller, Natasha; Stewart, Richard; Weber, John

    2010-02-01

    The impact of residual PAHs (2250 +/- 71 microg total PAHs g(-1)) following enhanced natural attenuation (ENA) of creosote-contaminated soil (7767 +/- 1286 microg total PAHs g(-1)) was assessed using a variety of ecological assays. Microtox results for aqueous soil extracts indicated that there was no significant difference in EC(50) values for uncontaminated, pre- and post-remediated soil. However, in studies conducted with Eisenia fetida, PAH bioaccumulation was reduced by up to 6.5-fold as a result of ENA. Similarly, Beta vulgaris L. biomass yields were increased 2.1-fold following ENA of creosote-contaminated soil. While earthworm and plant assays indicated that PAH bioavailability was reduced following ENA, the residual PAH fraction still exerted toxicological impacts on both receptors. Results from this study highlight that residual PAHs following ENA (presumably non-bioavailable to bioremediation) may still be bioavailable to important receptor organisms such as earthworms and plants. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  9. Uranium Concentration of Contaminated Zone due to the Cover Depth for Self-Disposal

    International Nuclear Information System (INIS)

    Koo, Dae Seo; Sung, Hyun Hee; Kim, Gye Nam; Kim, Seung Soo; Kim, Il Gook; Han, Gyu Seong; Choi, Jong Won

    2016-01-01

    To acquire radiation dose under self disposal from them, the study on decontamination of some uranium contaminated soil and concrete wastes was performed using electrokinetic-electrodialytic. In this study, we evaluated radiation dose due to cover depth on contaminated zone such as uranium contaminated soil and concrete wastes under radiation dose limit using RESRAD Version 6.5. At first, the calculation of the radiation dose on the contaminated zone are carried out. The second, the uranium concentration of contaminated zone due to the cover depth are also analyzed. The uranium contaminated soil and concrete wastes under radiation dose limit by decontaminating them have application to self-disposal of contaminated zone. The area of contaminated zone is 1,500 m 2 . The thickness of contaminated zone is 2 m. The length parallel to aquifer flow is 43.702m. The age of the residents on contaminated zone is 15 years old. The period of evaluation on the contaminated zone is from regulation exemption of uranium contaminated soil and concrete wastes till 1,000 years. The calculation of the radiation dose on contaminated zone are carried out. The uranium concentration of contaminated zone due to the cover depth was also analyzed. as the cover depth increases, the uranium concentration has an increasing trend. As the cover depth increases, radiation dose of a person has a decreasing trend. As the cover depth increases, the radiation dose of residents has also a decreasing trend.

  10. Hanford Tank 241-C-106: Impact of Cement Reactions on Release of Contaminants from Residual Waste

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2006-09-01

    The CH2M HILL Hanford Group, Inc. (CH2M HILL) is producing risk/performance assessments to support the closure of single-shell tanks at the U.S. Department of Energy's Hanford Site. As part of this effort, staff at Pacific Northwest National Laboratory were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. Initial work to produce release models was conducted on residual tank sludge using pure water as the leaching agent. The results were reported in an earlier report. The decision has now been made to close the tanks after waste retrieval with a cementitious grout to minimize infiltration and maintain the physical integrity of the tanks. This report describes testing of the residual waste with a leaching solution that simulates the composition of water passing through the grout and contacting the residual waste at the bottom of the tank.

  11. Hanford Tank 241-C-106: Impact of Cement Reactions on Release of Contaminants from Residual Waste

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2006-01-01

    The CH2M HILL Hanford Group, Inc. (CH2M HILL) is producing risk/performance assessments to support the closure of single-shell tanks at the U.S. Department of Energy's Hanford Site. As part of this effort, staff at Pacific Northwest National Laboratory were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. Initial work to produce release models was conducted on residual tank sludge using pure water as the leaching agent. The results were reported in an earlier report. The decision has now been made to close the tanks after waste retrieval with a cementitious grout to minimize infiltration and maintain the physical integrity of the tanks. This report describes testing of the residual waste with a leaching solution that simulates the composition of water passing through the grout and contacting the residual waste at the bottom of the tank.

  12. Evaluation of residual uranium contamination in the dirt floor of an abandoned metal rolling mill.

    Science.gov (United States)

    Glassford, Eric; Spitz, Henry; Lobaugh, Megan; Spitler, Grant; Succop, Paul; Rice, Carol

    2013-02-01

    A single, large, bulk sample of uranium-contaminated material from the dirt floor of an abandoned metal rolling mill was separated into different types and sizes of aliquots to simulate samples that would be collected during site remediation. The facility rolled approximately 11,000 tons of hot-forged ingots of uranium metal approximately 60 y ago, and it has not been used since that time. Thirty small mass (≈ 0.7 g) and 15 large mass (≈ 70 g) samples were prepared from the heterogeneously contaminated bulk material to determine how measurements of the uranium contamination vary with sample size. Aliquots of bulk material were also resuspended in an exposure chamber to produce six samples of respirable particles that were obtained using a cascade impactor. Samples of removable surface contamination were collected by wiping 100 cm of the interior surfaces of the exposure chamber with 47-mm-diameter fiber filters. Uranium contamination in each of the samples was measured directly using high-resolution gamma ray spectrometry. As expected, results for isotopic uranium (i.e., U and U) measured with the large-mass and small-mass samples are significantly different (p uranium isotopic concentrations measured in the air and on the wipe samples were not significantly different and were also not significantly different (p > 0.05) from results for the large- or small-mass samples. Large-mass samples are more reliable for characterizing heterogeneously distributed radiological contamination than small-mass samples since they exhibit the least variation compared to the mean. Thus, samples should be sufficiently large in mass to insure that the results are truly representative of the heterogeneously distributed uranium contamination present at the facility. Monitoring exposure of workers and the public as a result of uranium contamination resuspended during site remediation should be evaluated using samples of sufficient size and type to accommodate the heterogeneous

  13. A survey of the Maralinga atomic weapons testing range for residual plutonium contamination

    International Nuclear Information System (INIS)

    Ellis, W.R.

    1979-06-01

    Residual plutonium levels in soil, flora, fauna and the air of the Maralinga (South Australia) Atomic Weapons Testing Range are presented and discussed. It is shown that only on rare occasions (and possibly never) would the plutonium concentration in air from wind resuspended dust exceed the maximum allowable concentration for continuous exposure of the general public. In the case of artificially resuspended dust, this maximum concentration could be exceeded for short periods, but the accompanying dust level would be such that working conditions would be uncomfortable, if not intolerable. Potential hazards from other possible exposure routes are so low that they are of no consequence

  14. Histopathology and contaminant concentrations in fish from Kuwait's marine environment.

    Science.gov (United States)

    Al-Zaidan, A S; Al-Sarawi, H A; Massoud, M S; Al-Enezi, M; Smith, A J; Bignell, J P; Green, M J; Askem, C; Bolam, T P C; Barber, J L; Bersuder, P; Lyons, B P

    2015-11-30

    Kuwait has witnessed major socioeconomic and industrial development in recent decades. Consequently, a variety of contaminants related to these activities have been discharged directly into the marine environment. This paper describes the application of a histopathology baseline survey in two potential sentinel species, the Giant sea catfish (Arius thalassinus) and the Fourlined terapon (Pelates quadrilineatus) to assess the health of biota inhabiting Kuwait's marine environment. Histological analysis revealed several lesion types in both species, although the prevalence was generally considered low with no discernible differences between sampling locations. The analysis of contaminant burdens (metals, PCBs, PBDEs, HBCDD) in A. thalassinus, along with the analysis of bile for PAH metabolites in both species, indicated that levels of contaminant exposure was low. Overall the data show that both species appear to be susceptible to pathologies associated with environmental contaminants and therefore suitable for further investigation as sentinel organisms for biological effects monitoring. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. The effects of toothpastes on the residual microbial contamination of toothbrushes.

    Science.gov (United States)

    Warren, D P; Goldschmidt, M C; Thompson, M B; Adler-Storthz, K; Keene, H J

    2001-09-01

    Contaminated toothbrushes have been shown to harbor and transmit viruses and bacteria. The authors conducted a study to evaluate the effect of a triclosan-containing toothpaste on the residual anaerobic microbial contamination of toothbrushes. Twenty patients who had Type III or Type IV periodontitis participated in this study. One side of each of their mouths served as a control (no toothpaste). The teeth on the other side were brushed with a regular toothpaste or a triclosan-containing toothpaste. After the toothbrushes were allowed to dry in air for four hours, the authors placed the toothbrush heads in solution, dislodged the microbes from the brushes by vortexing and plated them in culture dishes. The authors anerobically incubated the culture dishes and determined the presence or absence of Prevotella species or Ps; Porphyromonas gingivalis, or Pg; and Actinobacillus actinomycetemcomitans, or Aa. The authors detected Aa and Pg on the control toothbrushes more frequently than they did Ps. This variation in isolation frequency was statistically significant by chi 2 analysis (P frequency of the three test organisms between the control and regular-toothpaste groups, between the control and triclosan-containing--toothpaste groups, and between the triclosan-containing--toothpaste and regular-toothpaste groups. They found no significant intergroup differences in the isolation frequencies after using chi 2 analysis. Toothpaste use reduced the residual microbial contamination for two of three test organisms, but the lower isolation frequencies were not statistically significant. Further study in this area is indicated. Dental professionals should advise patients who have systemic, localized or oral inflammatory diseases to disinfect or frequently replace their toothbrushes.

  16. Dietary exposure to pesticide residues from commodities alleged to contain the highest contamination levels.

    Science.gov (United States)

    Winter, Carl K; Katz, Josh M

    2011-01-01

    Probabilistic techniques were used to characterize dietary exposure of consumers to pesticides found in twelve commodities implicated as having the greatest potential for pesticide residue contamination by a United States-based environmental advocacy group. Estimates of exposures were derived for the ten most frequently detected pesticide residues on each of the twelve commodities based upon residue findings from the United States Department of Agriculture's Pesticide Data Program. All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8 percent) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse Effect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD. It is concluded that (1) exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers, (2) substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks, and (3) the methodology used by the environmental advocacy group to rank commodities with respect to pesticide risks lacks scientific credibility.

  17. A method for determining allowable residual contamination levels of radionuclide mixtures in soil

    International Nuclear Information System (INIS)

    Napier, B.A.

    1982-05-01

    An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches

  18. A Nitrogen-concentrated Phase in IA Iron Meteorite Acid Residue

    Science.gov (United States)

    Hashizume, K.; Sugiura, N.

    1993-07-01

    portion of nitrogen is released at 500 degrees C and 600 degrees C temperature fractions. Total nitrogen amounts and average delta^l5N values of the two acid residues are described in Table 1. Discussion and Summary: Sample "Can-1bn" is 3-4 times concentrated in nitrogen than "Call-2b," although its delta^15N value is within terrestrial range (0 < delta^15N < +20 per mil). Presently, we cannot deny the possibility that nitrogen in "Can-1bn" is dominated by terrestrial nitrogen, which may have been acquired during the acid treatment. Nevertheless, nitrogen isotope data of "Can-2b" suggests that indigenous nitrogen is indeed concentrated in the acid residue of Canyon Diablo. Bulk nitrogen isotope data of Canyon Diablo is reported to be delta^15N= -61.8 +- 10.4 per mil, N= 38.0 +- 155 ppm [2]. Therefore, delta^15N values of "Can-2b" can be resulted by a mixing of indigenous nitrogen and contaminating nitrogen. However, distinct delta^15N values of these two samples may indicate, in turn, that nitrogen isotopes in inclusions of Canyon Diablo are truly heterogeneous because carbon isotopes of graphite inclusions in IA iron meteorites seem to be heterogeneous [7]. Acknowledgments: We thank Dr. J.-I. Matsuda of Osaka University for providing samples and information on these samples. References: [1] Scott E. R. D. and Wasson J. T. (1975) Rev. Geophys. Space Sci., 13, 527-546. [2] Prombo C. A. and Clayton R. N. (1983) Meteoritics, 18, 377-379. [3] Franchi I. A. et al. (1988) Meteoritics, 22, 379-380. [4] Hashizume K. (1993) Doctor Thesis. [5] Murty S. V. S. et al. (1983) GCA, 47, 1061-1068. [6] Ogata Y. et al. (1990) In Abstract of the 1990 Annual Meeting of the Geochemical Society of Japan, 57. [7] Deines P. and Wickman F. E. (1973) GCA, 37, 1295-1319. Table 1 appears here in the hard copy.

  19. Removal of low concentration contaminant species using photocatalysis

    DEFF Research Database (Denmark)

    Nielsen, Morten Godtfred; Vesborg, Peter Christian Kjærgaard; Hansen, Ole

    2015-01-01

    A photocatalytic model reactor system has been devised to assess the capacity and feasibility of a photocatalytic unit for the removal of trace amounts of organic contaminants in air. Realistic operating conditions are applied, and a mathematical model based on Langmuir–Hinselwood adsorbtion...

  20. Detection of Pb, Ba, and Sb in Blowfly Larvae of Porcine Tissue Contaminated with Gunshot Residue by ICP OES

    Directory of Open Access Journals (Sweden)

    Larissa C. Motta

    2015-01-01

    Full Text Available Lead (Pb, barium (Ba, and antimony (Sb concentrations were monitored in flies larvae (immature Chrysomya albiceps contaminated with gunshot residue (GSR from .40 caliber Taurus pistols during the period of 2 to 12 days after the death of a female pig in decomposition, during the winter, under the influence of rain and high relative humidity. The samples were also analyzed by the colorimetric test using sodium rhodizonate (Feigl-Suter reaction. It was possible to detect and quantify the three metals of interest by inductively coupled plasma-optical emission spectrometry (ICP OES, where the concentrations of all three elements kept practically constant during the putrefaction stage. Minimum ([Pb] = 382.26 μg L−1; [Ba] = 140.50 μg L−1; [Sb] = 39.18 μg L−1 and maximum ([Pb] = 522.66 μg L−1; [Ba] = 190.30 μg L−1; [Sb] = 56.14 μg L−1 concentrations were found during the third and fifth days after death, respectively. ICP OES presented higher sensitivity in metals determination when compared to the conventional colorimetric test, which showed negative result for the GSR extracts obtained from the immature Chrysomya albiceps.

  1. Retrospective: Adjusting contaminant concentrations in bird eggs to account for moisture and lipid Loss during their incubation

    Science.gov (United States)

    Rattner, Barnett A.; Wiemeyer, Stanley N.; Blus, Lawrence J.

    2016-01-01

    By the 1960s, research and monitoring efforts on chlorinated pesticide residues in tissues of wildlife were well underway in North America and Europe. Conservationists and natural resource managers were attempting to resolve whether pesticide exposure and accumulated residues were related to population declines in several species of predatory and scavenging birds (e.g., bald eagle Haliaeetus leucocephalus, peregrine falcon Falco peregrinus, brown pelican Pelecanus occidentalis and osprey Pandion haliaetus). The avian egg was a favored sampling matrix even before the realization that eggshell thinning was linked to population declines (Ratcliffe 1967; Hickey and Anderson 1968) and that the concentration of p,p’-DDE in an egg was associated with the shell thinning phenomenon (e.g., Blus et al. 1972; Wiemeyer et al. 1988). The necessity for making wet-weight concentration adjustments to account for natural moisture loss during incubation of viable eggs was realized. Correction for the more dramatic moisture loss in non-viable decaying eggs was recognized as being paramount. For example, the ∑DDT residues in osprey eggs were reported to vary by as much as eightfold without accounting for moisture loss adjustments (Stickel et al. 1965). In the absence of adjusting concentrations to the fresh wet-weight that was present at the time of egg laying, the uncorrected values exaggerated contaminant concentrations, yielding artifactual results and ultimately incorrect conclusions. The adjustment to fresh wet-weight concentration is equally important for many other persistent contaminants including PCBs, dioxins, furans, and brominated diphenyl ethers.

  2. Forecasting contaminant concentrations: Spills in the White Oak Creek Basin

    International Nuclear Information System (INIS)

    Borders, D.M.; Hyndman, D.W.; Huff, D.D.

    1987-01-01

    The Streamflow Synthesis and Reservoir Regulation (SSARR) model has been installed and sufficiently calibrated for use in managing accidental release of contaminants in surface waters of the White Oak Creek (WOC) watershed at ORNL. The model employs existing watershed conditions, hydrologic parameters representing basin response to precipitation, and a Quantitative Precipitation Forecast (QPF) to predict variable flow conditions throughout the basin. Natural runoff from each of the hydrologically distinct subbasins is simulated and added to specified plant and process water discharges. The resulting flows are then routed through stream reaches and eventually to White Oak Lake (WOL), which is the outlet from the WOC drainage basin. In addition, the SSARR model is being used to simulate change in storage volumes and pool levels in WOL, and most recently, routing characteristics of contaminant spills through WOC and WOL. 10 figs

  3. Nanofiber Enabled, Multi - Target Passive Sampling Device for Determination of the Freely Dissolved Sediment Pore Water Concentrations of Organic Contaminants

    Science.gov (United States)

    2016-06-01

    Concentrations of Organic Contaminants SERDP Project ER-2543 JUNE 2016 Dr. Andres Martinez Dr. David M. Cwiertny The University of Iowa...Soil Preparation and Uptake Experiments ................................................................................ 15 Contaminated Sediment...38 Contaminated Sediment Systems .......................................................................................... 41 Conclusions and

  4. Leaching and soil/groundwater transport of contaminants from coal combustion residues

    International Nuclear Information System (INIS)

    Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

    1992-01-01

    In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

  5. Increased concentrations of potassium in heartwood of trees in response to groundwater contamination

    Science.gov (United States)

    Vroblesky, D.A.; Yanosky, T.M.; Siegel, F.R.

    1992-01-01

    The wood of tuliptrees (Liriodendron tulipifera L.) growing above groundwater contamination from a hazardous-waste landfill in Maryland contained elevated concentrations of potassium (K). The groundwater contamination also contained elevated concentrations of dissolved K, as well as arsenic (As), cadmium (Cd), chloride (Cl), iron (Fe), manganese (Mn), zinc (Zn), and organic solvents. The dissolved K is derived from disposed smoke munitions. The excess K in the tuliptrees is concentrated in the heartwood, the part of the xylem most depleted in K in trees growing outside of the contamination. These data show that the uptake and translocation of K by tuliptrees can be strongly influenced by the availability of K in groundwater contamination and suggest the utility of this species as an areal indicator of groundwater contamination. ?? 1992 Springer-Verlag New York Inc.

  6. Minimizing residual aluminum concentration in treated water by tailoring properties of polyaluminum coagulants

    OpenAIRE

    Kimura, Masaoki; Matsui, Yoshihiko; Kondo, Kenta; Ishikawa, Tairyo B.; Matsushita, Taku; Shirasaki, Nobutaka

    2013-01-01

    Aluminum coagulants are widely used in water treatment plants to remove turbidity and dissolved substances. However, because high aluminum concentrations in treated water are associated with increased turbidity and because aluminum exerts undeniable human health effects, its concentration should be controlled in water treatment plants, especially in plants that use aluminum coagulants. In this study, the effect of polyaluminum chloride (PACl) coagulant characteristics on dissolved residual al...

  7. Residual radioactive contamination of the test site at Emu from nuclear weapons tests conducted in 1953

    International Nuclear Information System (INIS)

    Maclagan, D.S.; Cooper, M.B.; Duggleby, J.C.

    1979-08-01

    The detailed distributions and soil concentrations of long-lived radionuclides remaining from nuclear weapons trials conducted at Emu in October 1953, are presented. Significant radiation levels due to long-lived neutron activation products in soil, 60 Co and 152 Eu, occur only in the immediate vicinity of the ground zeros of TOTEM 1 and TOTEM 2. It is shown that the levels of contamination due to fallout products in the soil are well below those which would constitute a health hazard to occupants of the area

  8. Performance of passive samplers for monitoring estuarine water column concentrations: 2. Emerging contaminants.

    Science.gov (United States)

    Perron, Monique M; Burgess, Robert M; Suuberg, Eric M; Cantwell, Mark G; Pennell, Kelly G

    2013-10-01

    Measuring dissolved concentrations of emerging contaminants, such as polybrominated diphenyl ethers (PBDEs) and triclosan, can be challenging due to their physicochemical properties resulting in low aqueous solubilities and association with particles. Passive sampling methods have been applied to assess dissolved concentrations in water and sediments primarily for legacy contaminants. Although the technology is applicable to some emerging contaminants, the use of passive samplers with emerging contaminants is limited. In the present study, the performance of 3 common passive samplers was evaluated for sampling PBDEs and triclosan. Passive sampling polymers included low-density polyethylene (PE) and polyoxymethylene (POM) sheets, and polydimethylsiloxane (PDMS)-coated solid-phase microextraction (SPME) fibers. Dissolved concentrations were calculated using measured sampler concentrations and laboratory-derived partition coefficients. Dissolved tri-, tetra-, and pentabrominated PBDE congeners were detected at several of the study sites at very low pg/L concentrations using PE and POM. Calculated dissolved water concentrations of triclosan ranged from 1.7 ng/L to 18 ng/L for POM and 8.8 ng/L to 13 ng/L for PE using performance reference compound equilibrium adjustments. Concentrations in SPME were not reported due to lack of detectable chemical in the PDMS polymer deployed. Although both PE and POM were found to effectively accumulate emerging contaminants from the water column, further research is needed to determine their utility as passive sampling devices for emerging contaminants. © 2013 SETAC.

  9. Phytostabilization of semiarid soils residually contaminated with trace elements using by-products: Sustainability and risks

    International Nuclear Information System (INIS)

    Perez-de-Mora, Alfredo; Madejon, Paula; Burgos, Pilar; Cabrera, Francisco; Lepp, Nicholas W.; Madejon, Engracia

    2011-01-01

    We investigated the efficiency of various by-products (sugarbeet lime, biosolid compost and leonardite), based on single or repeated applications to field plots, on the establishment of a vegetation cover compatible with a stabilization strategy on a multi-element (As, Cd, Cu, Pb and Zn) contaminated soil 4-6 years after initial amendment applications. Results indicate that the need for re-treatment is amendment- and element-dependent; in some cases, a single application may reduce trace element concentrations in above-ground biomass and enhance the establishment of a healthy vegetation cover. Amendment performance as evaluated by % cover, biomass and number of colonizing taxa differs; however, changes in plant community composition are not necessarily amendment-specific. Although the translocation of trace elements to the plant biotic compartment is greater in re-vegetated areas, overall loss of trace elements due to soil erosion and plant uptake is usually smaller compared to that in bare soil. - Highlights: → By-products enhance vegetation dynamics in contaminated semiarid soils. → Depending on the situation single or repeated incorporations may be required. → The structure of the plant community established is not amendment-dependent. → Phytostabilization reduces overall loss of trace elements in semiarid soils. - Phytostabilization using by-products as amendments is a suitable approach for long-term immobilization of various trace elements in semiarid contaminated soils.

  10. Phytostabilization of semiarid soils residually contaminated with trace elements using by-products: Sustainability and risks

    Energy Technology Data Exchange (ETDEWEB)

    Perez-de-Mora, Alfredo, E-mail: perezdemora@gmail.com [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain); Madejon, Paula; Burgos, Pilar; Cabrera, Francisco [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain); Lepp, Nicholas W. [35, Victoria Road, Formby, Liverpool L37 7DH (United Kingdom); Madejon, Engracia [Instituto de Recursos Naturales y Agrobiologia de Sevilla (IRNAS), CSIC, PO Box 1052, 41080 Sevilla (Spain)

    2011-10-15

    We investigated the efficiency of various by-products (sugarbeet lime, biosolid compost and leonardite), based on single or repeated applications to field plots, on the establishment of a vegetation cover compatible with a stabilization strategy on a multi-element (As, Cd, Cu, Pb and Zn) contaminated soil 4-6 years after initial amendment applications. Results indicate that the need for re-treatment is amendment- and element-dependent; in some cases, a single application may reduce trace element concentrations in above-ground biomass and enhance the establishment of a healthy vegetation cover. Amendment performance as evaluated by % cover, biomass and number of colonizing taxa differs; however, changes in plant community composition are not necessarily amendment-specific. Although the translocation of trace elements to the plant biotic compartment is greater in re-vegetated areas, overall loss of trace elements due to soil erosion and plant uptake is usually smaller compared to that in bare soil. - Highlights: > By-products enhance vegetation dynamics in contaminated semiarid soils. > Depending on the situation single or repeated incorporations may be required. > The structure of the plant community established is not amendment-dependent. > Phytostabilization reduces overall loss of trace elements in semiarid soils. - Phytostabilization using by-products as amendments is a suitable approach for long-term immobilization of various trace elements in semiarid contaminated soils.

  11. Measurement methodology of vegetable samples from an area affected by residual contamination due to uranium mining sterile

    International Nuclear Information System (INIS)

    Navarro, N.; Suarez, J. A.; Yague, L.; Ortiz Gandia, M. I.; Marijuan, M. J.; Garcia, E.; Ortiz, T.; Alvarez, A.

    2013-01-01

    This paper presents the methodology established for radiological characterization of plant material generated during the first stage of the realization of a movement of land in an area of land affected by residual contamination due to the burial of sterile of uranium mining. (Author)

  12. Determination of residual ractopamine concentrations by enzyme immunoassay in treated pig's tissues on days after withdrawal.

    Science.gov (United States)

    Pleadin, Jelka; Perši, Nina; Vulić, Ana; Milić, Dinka; Vahčić, Nada

    2012-03-01

    The objective of this study was to measure residual ractopamine concentrations in tissues of pigs as experimental animals after treatment with dietary ractopamine for 28 consecutive days. Ractopamine was administered orally to the experimental group (n=9) in a dose of 0.1mg/kg body mass per day, whereas control animals (n=3) were left untreated. Treated pigs (60kg) were sacrificed on days 1, 3 and 8 of treatment discontinuation and residues were determined in kidney, liver, muscle, brain and heart tissues using previously validated enzyme-linked immunosorbent assay (ELISA) as a quantitative screening method. Validation showed good mean recoveries (approx. 70-90%) with acceptable inter- and intra-day relative standard deviations (RSDractopamine tissue concentrations. The highest ractopamine concentration on day 1 (24h) after the last exposure was recorded in the kidney (12.49±7.96ng/g), followed by the liver (7.21±2.73ng/g), heart (1.26±0.12ng/g) and brain (0.63±0.05ng/g); at this time of withdrawal, residues were not detected in the muscle. Ractopamine was depleted rapidly from all study tissues, with mostly no detectable residues on day 8 of withdrawal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. The residual C concentration control for low temperature growth p-type GaN

    International Nuclear Information System (INIS)

    Liu Shuang-Tao; Zhao De-Gang; Yang Jing; Jiang De-Sheng; Liang Feng; Chen Ping; Zhu Jian-Jun; Liu Zong-Shun; Li Xiang; Liu Wei; Xing Yao; Zhang Li-Qun

    2017-01-01

    In this work, the influence of C concentration to the performance of low temperature growth p-GaN is studied. Through analyses, we have confirmed that the C impurity has a compensation effect to p-GaN. At the same time we have found that several growth and annealing parameters have influences on the residual C concentration: (i) the C concentration decreases with the increase of growth pressure; (ii) we have found there exists a Ga memory effect when changing the Cp 2 Mg flow which will lead the growth rate and C concentration increase along the increase of Cp 2 Mg flow; (iii) annealing outside of metal–organic chemical vapor deposition (MOCVD) could decrease the C concentration while in situ annealing in MOCVD has an immobilization role to C concentration. (paper)

  14. Residual viral and bacterial contamination of surfaces after cleaning and disinfection

    NARCIS (Netherlands)

    Tuladhar, E.; Hazeleger, W.C.; Koopmans, M.; Zwietering, M.H.; Beumer, R.R.; Duizer, E.

    2012-01-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses,

  15. Transfer of heavy metals to biota after remediation of contaminated soils with calcareous residues.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martínez-Sánchez, Maria Jose; Agudo, Ines; Gonzalez, Eva; Perez-Espinosa, Victor; Belen Martínez, Lucia; Hernández, Carmen; García-Fernandez, Antonio Juan; Bech, Jaime

    2013-04-01

    A study was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (broccoli, lettuce and leek), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). Five consecutive crops of each vegetable were obtained in greenhouse. In a second stage, experiments were carried out with rabbits fed with such vegetables. The plants were cultivated in four types of soil. The first one was contaminated by heavy metals (S1), the second was a uncontaminated soil (blank soil) (S2), the third was the material obtained by mixing S1 with residues coming from demolition and construction activities (S3); while the fourth was the result of remediating S1 with lime residues coming from quarries (S4). The total metal content (As, Pb, Cd and Zn) of the soil samples, rizosphere, leached water and vegetable samples, were measured, and both the translocation and bioconcentration factors (TF and BCF, respectively) were calculated. In the second stage, the effect caused in rabbits fed with the vegetables was monitorized using both external observation and the analysis of blood, urine, and the levels of metals in muscles, liver and kidney. The statistical analysis of the results obtained showed that there were no significant differences in the heavy metal levels for the vegetables cultivated in S2, S3 and S4. The results for soil sample S1 did not have a normal distribution since the growing of the vegetables were not homogeneous and also strongly dependent on the type of vegetal. As regards the effect caused in rabbits, significant differences were observed for the animals fed with plants cultivated in S1 compared with the others.

  16. Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

    International Nuclear Information System (INIS)

    Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

    2017-01-01

    Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

  17. Role of quantitative mineralogical analysis in the investigation of sites contaminated by chromite ore processing residue.

    Science.gov (United States)

    Hillier, S; Roe, M J; Geelhoed, J S; Fraser, A R; Farmer, J G; Paterson, E

    2003-06-01

    A range of techniques, normally associated with mineralogical studies of soils and sediments, has been used to characterise the solid materials found on sites contaminated with chromite ore processing residue (COPR). The results show that a wide range of minerals are present, many of which are found extensively in high-temperature synthetic systems such as cements and clinkers and their low temperature hydration products. Thus, the minerals in COPR can be divided into three main categories: unreacted feedstock ore (chromite); high temperature phases produced during chromium extraction (brownmillerite, periclase and larnite); and finally, minerals formed under ambient weathering conditions on the disposal sites (brucite, calcite, aragonite, ettringite, hydrocalumite, hydrogarnet). Apart from chromite, chromium occurs in brownmillerite, ettringite, hydrocalumite and hydrogarnet. Detailed study of the chemistry and stoichiometry of chromium-bearing phases in conjunction with phase abundance provides a quantitative description of the solid state speciation of Cr(III) and Cr(VI) in and amongst these minerals and in the COPR as a whole. Of the total chromium present in the samples most, approximately 60-70% is present as Cr(III) in chromite, whilst brownmillerite also represents a significant reservoir of Cr(III) which is approximately 15% of the total. The remaining chromium, between 20 and 25%, is present as Cr(VI) and resides mainly in hydrogarnet, and to a slightly lesser extent in hydrocalumite. In the latter, it is present principally in an exchangeable anionic form. Chromium (VI) is also present in ettringite, but quantitatively ettringite is a much less important reservoir of Cr(VI), accounting for approximately 3% of total chromium in one sample, but less than 1% in the other two. This description provides insight into the processes likely to control the retention and release of Cr(VI) from COPR-contaminated sites. Such information is of particular value in

  18. Uncertainty of pesticide residue concentration determined from ordinary and weighted linear regression curve.

    Science.gov (United States)

    Yolci Omeroglu, Perihan; Ambrus, Árpad; Boyacioglu, Dilek

    2018-03-28

    Determination of pesticide residues is based on calibration curves constructed for each batch of analysis. Calibration standard solutions are prepared from a known amount of reference material at different concentration levels covering the concentration range of the analyte in the analysed samples. In the scope of this study, the applicability of both ordinary linear and weighted linear regression (OLR and WLR) for pesticide residue analysis was investigated. We used 782 multipoint calibration curves obtained for 72 different analytical batches with high-pressure liquid chromatography equipped with an ultraviolet detector, and gas chromatography with electron capture, nitrogen phosphorus or mass spectrophotometer detectors. Quality criteria of the linear curves including regression coefficient, standard deviation of relative residuals and deviation of back calculated concentrations were calculated both for WLR and OLR methods. Moreover, the relative uncertainty of the predicted analyte concentration was estimated for both methods. It was concluded that calibration curve based on WLR complies with all the quality criteria set by international guidelines compared to those calculated with OLR. It means that all the data fit well with WLR for pesticide residue analysis. It was estimated that, regardless of the actual concentration range of the calibration, relative uncertainty at the lowest calibrated level ranged between 0.3% and 113.7% for OLR and between 0.2% and 22.1% for WLR. At or above 1/3 of the calibrated range, uncertainty of calibration curve ranged between 0.1% and 16.3% for OLR and 0% and 12.2% for WLR, and therefore, the two methods gave comparable results.

  19. High variation subarctic topsoil pollutant concentration prediction using neural network residual kriging

    Science.gov (United States)

    Sergeev, A. P.; Tarasov, D. A.; Buevich, A. G.; Subbotina, I. E.; Shichkin, A. V.; Sergeeva, M. V.; Lvova, O. A.

    2017-06-01

    The work deals with the application of neural networks residual kriging (NNRK) to the spatial prediction of the abnormally distributed soil pollutant (Cr). It is known that combination of geostatistical interpolation approaches (kriging) and neural networks leads to significantly better prediction accuracy and productivity. Generalized regression neural networks and multilayer perceptrons are classes of neural networks widely used for the continuous function mapping. Each network has its own pros and cons; however both demonstrated fast training and good mapping possibilities. In the work, we examined and compared two combined techniques: generalized regression neural network residual kriging (GRNNRK) and multilayer perceptron residual kriging (MLPRK). The case study is based on the real data sets on surface contamination by chromium at a particular location of the subarctic Novy Urengoy, Russia, obtained during the previously conducted screening. The proposed models have been built, implemented and validated using ArcGIS and MATLAB environments. The networks structures have been chosen during a computer simulation based on the minimization of the RMSE. MLRPK showed the best predictive accuracy comparing to the geostatistical approach (kriging) and even to GRNNRK.

  20. Allowable residual contamination levels for decommissioning the 115-F and 117-F facilities at the Hanford Site

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.

    1983-07-01

    This report contains the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for the 115-F and 117-F facilities at the Hanford Site. The purpose of this study is to provide data useful to UNC engineers in conducting safety and cost comparisons for decommissioning alternatives. The ARCL results are based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for three specific modes of future use of the land and facilities. These modes of use are restricted, controlled, and unrestricted. Information on restricted and controlled use is provided to permit a full consideration of decommissioning alternatives. Procedures are presented for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations and to determine instrument responses for various mixtures of radionuclides. Finally, a comparison is made between existing decommissioning guidance and the ARCL values calculated for unrestricted release of the 115-F and 117-F facilities. The comparison shows a good agreement

  1. Recent Advances and Uses of Monolithic Columns for the Analysis of Residues and Contaminants in Food

    Directory of Open Access Journals (Sweden)

    Mónica Díaz-Bao

    2015-02-01

    Full Text Available Monolithic columns are gaining interest as excellent substitutes to conventional particle-packed columns. These columns show higher permeability and lower flow resistance than conventional liquid chromatography columns, providing high-throughput performance, resolution and separation in short run times. Monoliths possess also great potential for the clean-up and preparation of complex mixtures. In situ polymerization inside appropriate supports allows the development of several microextraction formats, such as in-tube solid-phase and pipette tip-based extractions. These techniques using porous monoliths offer several advantages, including miniaturization and on-line coupling with analytical instruments. Additionally, monoliths are ideal support media for imprinting template-specific sites, resulting in the so-called molecularly-imprinted monoliths, with ultra-high selectivity. In this review, time-saving LC columns and preparative applications applied to the analysis of residues and contaminants in food in 2010–2014 are described, focusing on recent improvements in design and with emphasis in automated on-line systems and innovative materials and formats.

  2. Estimation of the residual bromine concentration after disinfection of cooling water by statistical evaluation.

    Science.gov (United States)

    Megalopoulos, Fivos A; Ochsenkuehn-Petropoulou, Maria T

    2015-01-01

    A statistical model based on multiple linear regression is developed, to estimate the bromine residual that can be expected after the bromination of cooling water. Make-up water sampled from a power plant in the Greek territory was used for the creation of the various cooling water matrices under investigation. The amount of bromine fed to the circuit, as well as other important operational parameters such as concentration at the cooling tower, temperature, organic load and contact time are taken as the independent variables. It is found that the highest contribution to the model's predictive ability comes from cooling water's organic load concentration, followed by the amount of bromine fed to the circuit, the water's mean temperature, the duration of the bromination period and finally its conductivity. Comparison of the model results with the experimental data confirms its ability to predict residual bromine given specific bromination conditions.

  3. Predicting the concentration of residual methanol in industrial formalin using machine learning

    OpenAIRE

    Heidkamp, William

    2016-01-01

    In this thesis, a machine learning approach was used to develop a predictive model for residual methanol concentration in industrial formalin produced at the Akzo Nobel factory in Kristinehamn, Sweden. The MATLABTM computational environment supplemented with the Statistics and Machine LearningTM toolbox from the MathWorks were used to test various machine learning algorithms on the formalin production data from Akzo Nobel. As a result, the Gaussian Process Regression algorithm was found to pr...

  4. On measurements of Effective Residual Ink Concentration (ERIC) of deinked papers using Kubelka-Munk theory

    Science.gov (United States)

    D.W. Vahey; J.Y. Zhu; C.J. Houtman

    2006-01-01

    The measurement of effective residual ink concentration (ERIC) in recycled papers depends on their opacity. For opacity less than 97.0%, the method is based on application of the Kubelka-Munk theory to diffuse reflection from papers measured once with a black backing and again with a thick backing of the same papers. At opacities above 97.0%, the two reflection values...

  5. Contaminant Release from Residual Waste in Closed Single-Shell Tanks and Other Waste Forms Associated with the Tanks

    International Nuclear Information System (INIS)

    Deutsch, William J.

    2008-01-01

    This chapter describes the release of contaminants from the various waste forms that are anticipated to be associated with closure of the single-shell tanks. These waste forms include residual sludge or saltcake that will remain in the tanks after waste retrieval. Other waste forms include engineered glass and cementitious materials as well as contaminated soil impacted by previous tank leaks. This chapter also describes laboratory testing to quantify contaminant release and how the release data are used in performance/risk assessments for the tank waste management units and the onsite waste disposal facilities. The chapter ends with a discussion of the surprises and lessons learned to date from the testing of waste materials and the development of contaminant release models

  6. A tiered analytical protocol for the characterization of heavy oil residues at petroleum-contaminated hazardous waste sites

    International Nuclear Information System (INIS)

    Pollard, S.J.T.; Kenefick, S.L.; Hrudey, S.E.; Fuhr, B.J.; Holloway, L.R.; Rawluk, M.

    1994-01-01

    The analysis of hydrocarbon-contaminated soils from abandoned refinery sites in Alberta, Canada is used to illustrate a tiered analytical approach to the characterization of complex hydrocarbon wastes. Soil extracts isolated from heavy oil- and creosote-contaminated sites were characterized by thin layer chromatography with flame ionization detection (TLC-FID), ultraviolet fluorescence, simulated distillation (GC-SIMDIS) and chemical ionization GC-MS analysis. The combined screening and detailed analytical methods provided information essential to remedial technology selection including the extent of contamination, the class composition of soil extracts, the distillation profile of component classes and the distribution of individual class components within various waste fractions. Residual contamination was characteristic of heavy, degraded oils, consistent with documented site operations and length of hydrocarbon exposure at the soil surface

  7. Effects of rapeseed residue on lead and cadmium availability and uptake by rice plants in heavy metal contaminated paddy soil.

    Science.gov (United States)

    Ok, Yong Sik; Usman, Adel R A; Lee, Sang Soo; Abd El-Azeem, Samy A M; Choi, Bongsu; Hashimoto, Yohey; Yang, Jae E

    2011-10-01

    Rapeseed (Brassica napus L.) has been cultivated for biodiesel production worldwide. Winter rapeseed is commonly grown in the southern part of Korea under a rice-rapeseed double cropping system. In this study, a greenhouse pot experiment was conducted to assess the effects of rapeseed residue applied as a green manure alone or in combinations with mineral N fertilizer on Cd and Pb speciation in the contaminated paddy soil and their availability to rice plant (Oryza sativa L.). The changes in soil chemical and biological properties in response to the addition of rapeseed residue were also evaluated. Specifically, the following four treatments were evaluated: 100% mineral N fertilizer (N100) as a control, 70% mineral N fertilizer+rapeseed residue (N70+R), 30% mineral N fertilizer+rapeseed residue (N30+R) and rapeseed residue alone (R). The electrical conductivity and exchangeable cations of the rice paddy soil subjected to the R treatment or in combinations with mineral N fertilizer treatment, N70+R and N30+R, were higher than those in soils subjected to the N100 treatment. However, the soil pH value with the R treatment (pH 6.3) was lower than that with N100 treatment (pH 6.9). Use of rapeseed residue as a green manure led to an increase in soil organic matter (SOM) and enhanced the microbial populations in the soil. Sequential extraction also revealed that the addition of rapeseed residue decreased the easily accessible fraction of Cd by 5-14% and Pb by 30-39% through the transformation into less accessible fractions, thereby reducing metal availability to the rice plant. Overall, the incorporation of rapeseed residue into the metal contaminated rice paddy soils may sustain SOM, improve the soil chemical and biological properties, and decrease the heavy metal phytoavailability. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Allowable residual contamination levels of radionuclides in soil from pathway analysis

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Baes, C.F. III.

    1987-01-01

    The uncertainty regarding radionuclide distributions among Remedial Action Program (RAP) sites and long-term decommissioning and closure options for these sites requires a flexible approach capable of handling different levels of contamination, dose limits, and closure scenarios. We identified a commercially available pathway analysis model, DECOM, which had been used previously in support of remedial activities involving contaminated soil at the Savannah River Plant. The DECOM computer code, which estimates concentrations of radionuclides uniformly distributed in soil that correspond to an annual effective dose equivalent, is written in BASIC and runs on an IBM PC or compatible microcomputer. We obtained the latest version of DECOM and modified it to make it more user friendly and applicable to the Oak Ridge National Laboratory (ORNL) RAP. Some modifications involved changes in default parameters or changes in models based on approaches used by the EPA in regulating remedial actions for hazardous substances. We created a version of DECOM as a LOTUS spreadsheet, using the same models as the BASIC version of DECOM. We discuss the specific modeling approaches taken, the regulatory framework that guided our efforts, the strengths and limitations of each approach, and areas for improvement. We also demonstrate how the LOTUS version of DECOM can be applied to specific problems that may be encountered during ORNL RAP activities. 18 refs., 2 figs., 3 tabs

  9. Methodology for setting risk-based concentrations of contaminants in soil and groundwater and application to a model contaminated site.

    Science.gov (United States)

    Fujinaga, Aiichiro; Uchiyama, Iwao; Morisawa, Shinsuke; Yoneda, Minoru; Sasamoto, Yuzuru

    2012-01-01

    In Japan, environmental standards for contaminants in groundwater and in leachate from soil are set with the assumption that they are used for drinking water over a human lifetime. Where there is neither a well nor groundwater used for drinking, the standard is thus too severe. Therefore, remediation based on these standards incurs excessive effort and cost. In contrast, the environmental-assessment procedure used in the United States and the Netherlands considers the site conditions (land use, existing wells, etc.); however, a risk assessment is required for each site. Therefore, this study proposes a new framework for judging contamination in Japan by considering the merits of the environmental standards used and a method for risk assessment. The framework involves setting risk-based concentrations that are attainable remediation goals for contaminants in soil and groundwater. The framework was then applied to a model contaminated site for risk management, and the results are discussed regarding the effectiveness and applicability of the new methodology. © 2011 Society for Risk Analysis.

  10. Effect of Residue Nitrogen Concentration and Time Duration on Carbon Mineralization Rate of Alfalfa Residues in Regions with Different Climatic Conditions

    Directory of Open Access Journals (Sweden)

    saeid shafiei

    2017-08-01

    Full Text Available Introduction Various factors like climatic conditions, vegetation, soil properties, topography, time, plant residue quality and crop management strategies affect the decomposition rate of organic carbon (OC and its residence time in soil. Plant residue management concerns nutrients recycling, carbon recycling in ecosystems and the increasing CO2 concentration in the atmosphere. Plant residue decomposition is a fundamental process in recycling of organic matter and elements in most ecosystems. Soil management, particularly plant residue management, changes soil organic matter both qualitatively and quantitatively. Soil respiration and carbon loss are affected by soil temperature, soil moisture, air temperature, solar radiation and precipitation. In natural agro-ecosystems, residue contains different concentrations of nitrogen. It is important to understand the rate and processes involved in plant residue decomposition, as these residues continue to be added to the soil under different weather conditions, especially in arid and semi-arid climates. Material and methods Organic carbon mineralization of alfalfa residue with different nitrogen concentrations was assessed in different climatic conditions using split-plot experiments over time and the effects of climate was determined using composite analysis. The climatic conditions were classified as warm-arid (Jiroft, temperate arid (Narab and cold semi-arid (Sardouiyeh using cluster analysis and the nitrogen (N concentrations of alfalfa residue were low, medium and high. The alfalfa residue incubated for four different time periods (2, 4, 6 and 8 months. The dynamics of organic carbon in different regions measured using litter bags (20×10 cm containing 20 g alfalfa residue of 2-10 mm length which were placed on the soil surface. Results and discussion The results of this study showed that in a warm-arid (Jiroft, carbon loss and the carbon decomposition rate constant were low in a cold semi

  11. [Contamination of Organophosphorus Pesticides Residue in Fresh Vegetables and Related Health Risk Assessment in Changchun, China].

    Science.gov (United States)

    Yu, Rui; Liu, Jing-shuang; Wang, Qi-cun; Liu, Qiang; Wang, Yang

    2015-09-01

    This study aims to investigate the concentrations of organophosphorus pesticides (OPs) in fresh vegetables. A total of Z14 samples from seven types of vegetables were collected from the suburb in Changchun City. The OPs were analyzed by gas chromatography coupled with flame photometric detector (GC-FPD). Target hazard quotients (THQ) were applied to estimate the potential health risk to inhabitants. Results showed that OPs concentrations exceeded the Maximum Residue Limit (MRL) in more than 23. 4% samples, and were not detected in only 7. 9% samples. Detection rates of OPs was as follow in the decreased order: diazinon (82. 2%) > phorate (45. 8%) > dimethoate (29. 4%) > parathion-methyl (27. 6%) > omethoate (23. 8%) > dichlorvos (22. 9%) > fenitrothion (21%) > fenthion (18. 7%) > parathion (18. 2%) > methamidophos (17. 3%) > malathion (12. 1%). The percentages above MRL for leaves were higher than for non-leafy vegetables. The order of percentages of OPs above MRL was as follows: green onion (82. 5%) > radish (37. 5%) > red pepper (17. 2%) > Chinese vegetable (14. 3%) > cucumber (3. 2%) > eggplant (2. 9%) > tomato (0%). 49. 5% vegetables samples showed more than one OP. The average target hazard quotients (ave THQ) were all less than one and the average Hazard Index (ave HI) was 0. 462, so that inhabitants who expose average OP levels may not experience adverse health effects.

  12. Comparison of two freshwater turtle species as monitors of radionuclide and chemical contamination: DNA damage and residue analysis

    International Nuclear Information System (INIS)

    Meyers-Schoene, L.; Shugart, L.R.; Beauchamp, J.J.; Walton, B.T.

    1993-01-01

    Two species of turtles that occupy different ecological niches were compared for their usefulness as monitors of freshwater ecosystems where both low-level radioactive and nonradioactive contaminants are present. The pond slider (Trachemys scripta) and common snapping turtle (Chelydra serpentina) were analyzed for the presence of 90 Sr, 137 Cs, 60 Co, and Hg, radionuclides and chemicals known to be present at the contaminated site, and single-strand breaks in liver DNA. The integrity of the DNA was examined by the alkaline unwinding assay, a technique that detects strand breaks as a biological marker of possible exposure to genotoxic agents. This measure of DNA damage was significantly increased in both species of turtles at the contaminated site compared with turtles of the same species at a reference site, and shows that contaminant-exposed populations were under more severe genotoxic stress than those at the reference site. The level of strand breaks observed at the contaminated site was high and in the range reported for other aquatic species exposed to deleterious concentrations of genotoxic agents such as chemicals and ionizing radiation. Statistically significantly higher concentrations of radionuclides and Hg were detected in the turtles from the contaminated area. Mercury concentrations were significantly higher in the more carnivorous snapping turtle compared with the slider; however, both species were effective monitors of the contaminants

  13. Pyrolysis and reutilization of plant residues after phytoremediation of heavy metals contaminated sediments: For heavy metals stabilization and dye adsorption.

    Science.gov (United States)

    Gong, Xiaomin; Huang, Danlian; Liu, Yunguo; Zeng, Guangming; Wang, Rongzhong; Wei, Jingjing; Huang, Chao; Xu, Piao; Wan, Jia; Zhang, Chen

    2018-04-01

    This study aimed to investigate the effect of pyrolysis on the stabilization of heavy metals in plant residues obtained after phytoremediation. Ramie residues, being collected after phytoremediation of metal contaminated sediments, were pyrolyzed at different temperatures (300-700 °C). Results indicated that pyrolysis was effective in the stabilization of Cd, Cr, Zn, Cu, and Pb in ramie residues by converting the acid-soluble fraction of metals into residual form and decreasing the TCLP-leachable metal contents. Meanwhile, the reutilization potential of using the pyrolysis products generated from ramie residues obtained after phytoremediation as sorbents was investigated. Adsorption experiments results revealed that the pyrolysis products presented excellent ability to adsorb methylene blue (MB) with a maximum adsorption capacity of 259.27 mg/g. This study demonstrated that pyrolysis could be used as an efficient alternative method for stabilizing heavy metals in plant residues obtained after phytoremediation, and their pyrolysis products could be reutilized for dye adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Variability of residue concentrations of ciprofloxacin in honey from treated hives.

    Science.gov (United States)

    Chan, Danny; Macarthur, Roy; Fussell, Richard J; Wilford, Jack; Budge, Giles

    2017-04-01

    Honey bees (Apis mellifera L.) were treated with a model veterinary drug compound (ciprofloxacin) in a 3-year study (2012-14) to investigate the variability of residue concentration in honey. Sucrose solution containing ciprofloxacin was administered to 45 hives (1 g of ciprofloxacin per hive) at the beginning of the honey flow in late May/mid-June 2012, 2013 and 2014. Buckfast honey bees (A. mellifera - hybrid) were used in years 2012 and 2013. Carniolan honey bees (A. mellifera carnica) were used instead of the Buckfast honey bees as a replacement due to unforeseen circumstances in the final year of the study (2014). Honey was collected over nine scheduled time points from May/June till late October each year. Up to five hives were removed and their honey analysed per time point. Honey samples were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine ciprofloxacin concentration. Statistical assessment of the data shows that the inter-hive variation of ciprofloxacin concentrations in 2012/13 is very different compared with that of 2014 with relative standard deviations (RSDs) of 138% and 61%, respectively. The average ciprofloxacin concentration for 2014 at the last time point was more than 10 times the concentration compared with samples from 2012/13 at the same time point. The difference between the 2012/13 data compared with the 2014 data is likely due to the different type of honey bees used in this study (2012/13 Buckfast versus 2014 Carniolan). Uncertainty estimates for honey with high ciprofloxacin concentration (upper 95th percentile) across all hives for 55-day withdrawal samples gave residual standard errors (RSEs) of 22%, 20% and 11% for 2012, 2013 and 2014, respectively. If the number of hives were to be reduced for future studies, RSEs were estimated to be 52% (2012), 54% (2013) and 26% (2014) for one hive per time point (nine total hives).

  15. The release of As, Cr and Cu from contaminated soil stabilized with APC residues under landfill conditions.

    Science.gov (United States)

    Travar, I; Kihl, A; Kumpiene, J

    2015-03-15

    The aim of this study was to investigate the stability of As, Cr and Cu in contaminated soil treated with air pollution control residues under landfill conditions. The influence of landfill gas and temperature on the release of trace elements from stabilized soil was simulated using a diffusion test. The air pollution control residues immobilized As through the precipitation of Ca-As minerals (calcium arsenate (Ca5H2(AsO4)3 × 5H2O), weilite (CaAsO4) and johnbaumite (Ca5(AsO4)3(OH)), incorporation of As into ettringite (Ca6Al2(SO4)3(OH)12 × 26H2O) and adsorption by calcite (CaCO3). The air pollution control residues generally showed a high resistance to pH reduction, indicating high buffer capacity and stability of immobilized As in a landfill over time. Generation of heat in a landfill might increase the release of trace elements. The release of As from stabilized soil was diffusion-controlled at 60 °C, while surface wash-off, dissolution, and depletion prevailed at 20 °C. The air pollution control residues from the incineration of municipal solid waste immobilized Cr, indicating its stability in a landfill. The treatment of soil with air pollution control residues was not effective in immobilization of Cu. Contaminated soils treated with air pollution control residues will probably have a low impact on overall leachate quality from a landfill. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Uranium uptake and accumulation in plants from soil contaminated with uranium in different concentrations

    International Nuclear Information System (INIS)

    Zhao Luxue; Tang Yongjin; Luo Xuegang

    2014-01-01

    The plants of Medicago sativa L., Hibiscus esulentus L, Waterspinach, Amaranthus retroflexus and Abutilon theophrasti Medic were employed as the indicator to investigate the uranium uptake and accumulation from soils contaminated with uranium (UO 2 (CH 3 COO) 2 · 2H 2 O) of 25 mg · kg -l , 75 mg · kg -1 , 125 mg · kg -l , 175 mg · kg -l respectively, in a pot experiment. The result shows that, U concentration in the aerial part and underground part of the whole plant increased with the rise of uranium concentration in the soils. In the contaminated soils with 25∼125 mg · kg -l concentrations of uranium, U content of Medicago sativa L is the highset (6.78 mg · kg -l , 61.53 mg · kg -l , 74.06 mg · kg -l separately). While in the 175 mg · kg -l concentration of uranium contaminated soils, U content of Hibiscus esulentus L is the highest (86.72 mg · kg -1 ), which is mainly because of U concentration in its roots have higher level of uranium (388.16 mg · kg -l ). Comprehensive analysis shows that Medicago sativa L. is a good plant for phytoextraction and Hibiscus esulentus L is a good immobilizing plant for phytoremediation. The results can provide some theoretical basis and technical support for remedying U-contaminated soils in different areas of our country. (authors)

  17. Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

    2016-01-01

    We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues.

  18. Effect of six different starter cultures on the concentration of residual nitrite in fermented sausages during in vitro human digestion.

    Science.gov (United States)

    Kim, Hyeong Sang; Hur, Sun Jin

    2018-01-15

    The objective of this study was to determine the effect of six different starter cultures of enterobacteria on the concentration of residual nitrite in fermented sausages during in vitro human digestion. Before digestion, the concentration of residual nitrite was dependent on starter culture in fermented sausage and ranged from 25.2 to 33.2mg/kg. Among the six starter cultures of enterobacteria, Pediococcus acidilactici, Pediococcus pentosaceus, and Staphylococcus carnosus showed higher nitrite depletion ability than the other three strains in fermented sausages. The concentration of residual nitrite in fermented sausages was significantly (psausages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Modeling the Concentration of Volatile and Semivolatile Contaminants in Direct Contact Membrane Distillation (DCMD) Product Water.

    Science.gov (United States)

    Winglee, Judith M; Bossa, Nathan; Rosen, David; Vardner, Jonathan T; Wiesner, Mark R

    2017-11-21

    Direct contact membrane distillation (DCMD) is an emerging water treatment technology that has high salt rejection; however, its commercialization potential for applications such as seawater desalination or industrial wastewater reuse may be limited by low rejection of volatile and semivolatile contaminants. In this manuscript, a contaminant concentration (CC) model describing the transport of volatile and semivolatile contaminants for DCMD systems was developed and validated using data from the bench-scale DCMD treatment of synthetic wastewaters. The DCMD tests showed that the more volatile contaminants (methyl-tert-butyl ether, acetone, pentanone, butanol, and hexanol) accumulated in the permeate collection stream at greater concentrations than in the feed stream. The validated CC model (average normalized root mean squared error ≤11.3%) was then used to evaluate the product water quality from the large-scale DCMD treatment of oil and gas produced waters. The modeled product water contaminant concentrations exceeded the Environmental Protection Agency limits for discharging to publicly owned treatment works. This indicated that DCMD treatment of produced waters may require additional processing to meet discharge requirements.

  20. Role of lauric acid-potassium hydroxide concentration on bacterial contamination of spray washed broiler carcasses

    Science.gov (United States)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed in a spray cabinet with various concentrations of lauric acid (LA)-potassium hydroxide (KOH) solutions. Fifty eviscerated carcasses and 5 ceca were obtained from the processing line of...

  1. Stabilization of in-tank residual wastes and external-tank soil contamination for the tank focus area, Hanford tank initiative: Applications to the AX Tank Farm

    International Nuclear Information System (INIS)

    Balsley, S.D.; Krumhansl, J.L.; Borns, D.J.; McKeen, R.G.

    1998-07-01

    A combined engineering and geochemistry approach is recommended for the stabilization of waste in decommissioned tanks and contaminated soils at the AX Tank Farm, Hanford, WA. A two-part strategy of desiccation and gettering is proposed for treatment of the in-tank residual wastes. Dry portland cement and/or fly ash are suggested as an effective and low-cost desiccant for wicking excess moisture from the upper waste layer. Getters work by either ion exchange or phase precipitation to reduce radionuclide concentrations in solution. The authors recommend the use of specific natural and man-made compounds, appropriately proportioned to the unique inventory of each tank. A filler design consisting of multilayered cementitous grout with interlayered sealant horizons should serve to maintain tank integrity and minimize fluid transport to the residual waste form. External tank soil contamination is best mitigated by placement of grouted skirts under and around each tank, together with installation of a cone-shaped permeable reactive barrier beneath the entire tank farm. Actinide release rates are calculated from four tank closure scenarios ranging from no action to a comprehensive stabilization treatment plan (desiccant/getters/grouting/RCRA cap). Although preliminary, these calculations indicate significant reductions in the potential for actinide transport as compared to the no-treatment option

  2. Stabilization of in-tank residual wastes and external-tank soil contamination for the tank focus area, Hanford tank initiative: Applications to the AX Tank Farm

    Energy Technology Data Exchange (ETDEWEB)

    Balsley, S.D.; Krumhansl, J.L.; Borns, D.J. [Sandia National Labs., Albuquerque, NM (United States); McKeen, R.G. [Alliance for Transportation Research, Albuquerque, NM (United States)

    1998-07-01

    A combined engineering and geochemistry approach is recommended for the stabilization of waste in decommissioned tanks and contaminated soils at the AX Tank Farm, Hanford, WA. A two-part strategy of desiccation and gettering is proposed for treatment of the in-tank residual wastes. Dry portland cement and/or fly ash are suggested as an effective and low-cost desiccant for wicking excess moisture from the upper waste layer. Getters work by either ion exchange or phase precipitation to reduce radionuclide concentrations in solution. The authors recommend the use of specific natural and man-made compounds, appropriately proportioned to the unique inventory of each tank. A filler design consisting of multilayered cementitous grout with interlayered sealant horizons should serve to maintain tank integrity and minimize fluid transport to the residual waste form. External tank soil contamination is best mitigated by placement of grouted skirts under and around each tank, together with installation of a cone-shaped permeable reactive barrier beneath the entire tank farm. Actinide release rates are calculated from four tank closure scenarios ranging from no action to a comprehensive stabilization treatment plan (desiccant/getters/grouting/RCRA cap). Although preliminary, these calculations indicate significant reductions in the potential for actinide transport as compared to the no-treatment option.

  3. Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

    International Nuclear Information System (INIS)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

    2016-01-01

    We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R 2  ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R 2  = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R 2  = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues. - Highlights: • We developed predictive equations linking contaminant concentrations in eggs to those in the mother. • Mercury concentrations in eggs were positively correlated with those in the mother. • The proportion of mercury transferred to eggs decreased as mercury in the mother increased. • The proportion of mercury transferred to eggs differed among species. • Selenium concentrations in eggs also were correlated with those in the mother's liver. - We examined the maternal transfer of mercury and

  4. Impact of water management practice scenarios on wastewater flow and contaminant concentration.

    Science.gov (United States)

    Marleni, N; Gray, S; Sharma, A; Burn, S; Muttil, N

    2015-03-15

    Due to frequent droughts and rapid population growth in urban areas, the adoption of practices to reduce the usage of fresh water is on the rise. Reduction in usage of fresh water can be achieved through various local water management practices (WMP) such as Water Demand Management (WDM) and use of alternative water sources such as Greywater Recycling (GR) and Rainwater Harvesting (RH). While the positive effects of WMPs have been widely acknowledged, the implementation of WMPs is also likely to lower the wastewater flow and increase the concentration of contaminants in sewage. These in turn can lead to increases in sewer problems such as odour and corrosion. This paper analyses impacts of various WMP scenarios on wastewater flow and contaminant load. The Urban Volume and Quality (UVQ) model was used to simulate wastewater flow and the associated wastewater contaminants from different WMP scenarios. The wastewater parameters investigated were those which influence odour and corrosion problems in sewerage networks due to the formation of hydrogen sulphide. These parameters are: chemical oxygen demand (COD), nitrate (NO3(-)), sulphate (SO4(2-)), sulphide (S(2-)) and iron (Fe) that were contributed by the households (not including the biochemical process in sewer pipe). The results will help to quantify the impact of WMP scenarios on odour and corrosion in sewerage pipe networks. Results show that the implementation of a combination of WDM and GR had highly increased the concentration of all selected contaminant that triggered the formation of hydrogen sulphide, namely COD, sulphate and sulphide. On the other hand, the RH scenario had the least increase in the concentration of the contaminants, except iron concentrations. The increase in iron concentrations is actually beneficial because it inhibits the formation of hydrogen sulphide. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Plant Mounds as Concentration and Stabilization Agents for Actinide Soil Contaminants in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    D.S. Shafer; J. Gommes

    2009-02-03

    Plant mounds or blow-sand mounds are accumulations of soil particles and plant debris around the base of shrubs and are common features in deserts in the southwestern United States. An important factor in their formation is that shrubs create surface roughness that causes wind-suspended particles to be deposited and resist further suspension. Shrub mounds occur in some plant communities on the Nevada Test Site, the Nevada Test and Training Range (NTTR), and Tonopah Test Range (TTR), including areas of surface soil contamination from past nuclear testing. In the 1970s as part of early studies to understand properties of actinides in the environment, the Nevada Applied Ecology Group (NAEG) examined the accumulation of isotopes of Pu, 241Am, and U in plant mounds at safety experiment and storage-transportation test sites of nuclear devices. Although aerial concentrations of these contaminants were highest in the intershrub or desert pavement areas, the concentration in mounds were higher than in equal volumes of intershrub or desert pavement soil. The NAEG studies found the ratio of contaminant concentration of actinides in soil to be greater (1.6 to 2.0) in shrub mounds than in the surrounding areas of desert pavement. At Project 57 on the NTTR, 17 percent of the area was covered in mounds while at Clean Slate III on the TTR, 32 percent of the area was covered in mounds. If equivalent volumes of contaminated soil were compared between mounds and desert pavement areas at these sites, then the former might contain as much as 34 and 62 percent of the contaminant inventory, respectively. Not accounting for radionuclides associated with shrub mounds would cause the inventory of contaminants and potential exposure to be underestimated. In addition, preservation of shrub mounds could be important part of long-term stewardship if these sites are closed by fencing and posting with administrative controls.

  6. Concentration-Discharge Behavior of Contaminants in a Stream Impacted by Acid Mine Drainage

    Science.gov (United States)

    Shaw, M. E.; Klein, M.; Herndon, E.

    2017-12-01

    Acid mine drainage (AMD) has severely degraded streams throughout the Appalachian coal region of the United States. AMD occurs when pyrite contained in coal is exposed to water and air during mining activities and oxidized to release high concentrations of sulfate, metals, and acidity into water bodies. Little is known about the concentration-discharge (CQ) relationships of solutes in AMD-impacted streams due to the complicated nature of acid mine drainage systems. For example, streams may receive inputs from multiple sources that include runoff, constructed treatment systems, and abandoned mines that bypass these systems to continue to contaminate the streams. It is important to understand the CQ relationships of contaminants in AMD-impacted streams in order to elucidate contaminant sources and to predict effects on aquatic ecosystems. Here, we study the CQ behaviors of acid and metals in a contaminated watershed in northeastern Ohio where limestone channels have been installed to remediate water draining from a mine pool into the stream. Stream chemistry was measured in samples collected once per day or once per hour during storm events, and stream flow was measured continuously at the watershed outlet. Increases in stream velocity during storm events resulted in an increase in pH (from 3 to 6) that subsequently decreased back to 3 as flow decreased. Additionally, Fe and Mn concentrations in the stream were high during baseflow (7 and 15 mg/L, respectively) and decreased with increasing discharge during storm events. These results indicate that the treatment system is only effective at neutralizing stream acidity and removing metals when water flow through the limestone channel is continuous. We infer that the acidic and metal-rich baseflow derives from upwelling of contaminated groundwater or subsurface flow from a mine pool. Ongoing studies aim to isolate the source of this baseflow contamination and evaluate the geochemical transformations that occur as it

  7. Sorptive removal of HgIIby red mud (bauxite residue) in contaminated landfill leachate.

    Science.gov (United States)

    Rubinos, David A; Barral, María T

    2017-01-02

    The ability of red mud (RM) (bauxite residue) to remove Hg II from landfill leachate (LL) was assessed. The studied aspects comprised the effects of time, pH, Hg II concentration and the sorption isotherm, besides the influence of chloride and representative organic ligands. Hg II removal by RM exhibited a complex kinetics where initial rapid sorption was followed by desorption at longer times. The sorption of Hg II on RM was strongly pH-dependent. Outstanding maximum sorption was observed at pH∼4-5 (≥99.6%), while it abruptly dropped at higher pH values down to a minimum ∼28% at pH∼10.5. Chloride decreased Hg II sorption at acid pH and shifted the pH max towards higher pH∼9.4, which opposes to sorption in LL and suggests Cl - did not primarily control the process in LL. Amongst the organic ligands, acetate and salicylate slightly affected Hg II sorption. Conversely, glycine affected sorption in a pH-dependent manner resembling that in LL, which suggests the relevant role of the organic nitrogenated compounds of LL. EDTA suppressed Hg II sorption at any pH. Hg II speciation modelling and dissolved organic matter (DOM) sorption support complexation of Hg II by DOM as the primary factor governing the removal of Hg II in LL. The sorption isotherm was better described by the Freundlich equation, which agrees with the heterogeneous composition of RM. The results indicate that Hg II sorption on RM is favorable, but reveal differences in sorption and reduced efficiency, in LL media. Notwithstanding, RM possesses a notable capacity to remove Hg II , even under the unhelpful complexing and competing conditions of LL.

  8. Environmental contaminant concentrations in Canada goose (Branta canadensis) muscle: probabilistic risk assessment for human consumers.

    Science.gov (United States)

    Horak, Katherine; Chipman, Richard; Murphy, Lisa; Johnston, John

    2014-09-01

    The issue of food insecurity affects millions of people in the United States every year. Often these people rely on soup kitchens, food banks, and shelters for proper meals, and these organizations often depend on donations to meet needs. One of the most limited food resources is meat. To help alleviate this problem, the U.S. Department of Agriculture Wildlife Services donates more than 60 tons of wild game (deer, moose, feral hogs, goats, geese, and ducks) to a variety of charitable organizations each year. Although commercially produced meat routinely undergoes screening for contaminants, potential exposure to environmental contaminants from eating wild game is not well characterized. In this study, the concentration of 17 contaminants of concern in the breast meat of wild geese was examined. These concentrations were then used in a probabilistic model to estimate potential risk associated with consumption of this meat. Based on model predictions, more than 99 % of all adults were below exposure limits for all of the compounds tested. For all consumer age classes modeled, consumption of wild goose meat may expose a small fraction of these populations to levels of lead higher than the recommended exposure limits. Similarly, mercury exposure was predicted to be higher than the recommended limits when the meat was served as steaks. This information about concentrations of contaminants of concern in goose meat and potential exposures associated with meat consumption based on probabilistic models will enable others to make informed decisions about the risks associated with the consumption of wild meat.

  9. Characterizing contaminant concentrations with depth by using the USGS well profiler in Oklahoma, 2003-9

    Science.gov (United States)

    Smith, S. Jerrod; Becker, Carol J.

    2011-01-01

    Since 2003, the U.S. Geological Survey (USGS) Oklahoma Water Science Center has been using the USGS well profiler to characterize changes in water contribution and contaminant concentrations with depth in pumping public-supply wells in selected aquifers. The tools and methods associated with the well profiler, which were first developed by the USGS California Water Science Center, have been used to investigate common problems such as saline water intrusion in high-yield irrigation wells and metals contamination in high-yield public-supply wells.

  10. A new one-platform flow cytometric method for residual cell counting in platelet concentrates.

    Science.gov (United States)

    Schmidt, Michael; Spengler, Hans-Peter; Lambrecht, Bernd; Hourfar, Michael K; Seifried, Erhard; Tonn, Torsten

    2009-12-01

    According to German regulations and guidelines, residual red blood cells (rRBCs) and residual white blood cells (rWBCs) must number fewer than 3 x 10(9) cells/unit and 1 x 10(6) cells/unit in platelet concentrates (PCs), respectively. Due to low levels of residual cells in final products, there is still a need for fast, reliable, and sensitive methods of automated detection of these cell types. In Part A, 21 PCs were spiked with predetermined numbers of red blood cells (RBCs) and white blood cells (WBCs). The linearity, precision, and accuracy of the BD Thrombo Count assay (BD Biosciences Europe) were tested and validated according to international guidelines. Finally in Part B, 100 PCs prepared from pooled buffy coats were tested by the BD Thrombo Count assay and compared with other methods, including Nageotte (rWBCs) and Neubauer (rRBCs) counting chambers and the flow cytometric BD LeucoCOUNT (Becton Dickinson) assay (rWBCs). The unspecific background of blank PC samples was fewer than 0.02 cells/microL for WBCs and fewer than 34 cells/microL for RBCs (mean, 21). Linear regression and precision analyses of spiked PC samples were determined for both WBCs (r(2) = 0.992; range, 0.6-6.0 WBCs/microL) and RBCs (r(2) = 0.999; 800-8000 RBCs/microL). No carryover of cells or drift in results was detected in the automated sample acquisition mode. Analysis according to statistical methods of Bland and Altman demonstrated a high correlation between BD Thrombo Count and the Neubauer manual counting chamber. This novel flow cytometric test is a quick and reliable single-tube assay that has been demonstrated as a potential alternative for the existing manual microscopic counting procedures that are both time-consuming and laborious.

  11. Trace Element Concentration and Speciation in Selected Mining-Contaminated Soils and Water in Willow Creek Floodplain, Colorado

    Directory of Open Access Journals (Sweden)

    R. Burt

    2011-01-01

    Full Text Available Long-term mining activities in the mountains around Creede, Colorado have resulted in significant contamination in soils and water in the Willow Creek floodplain. Total major and trace were determined for soils and water and sequential chemical extraction for soils. Objectives were to determine concentrations and potential reactivity of trace elements and investigate their relationship with other soil and water properties. Water trace elements showed significant variability among sites, ranging from 347 to 12108 μg/L. Relative trend showed (Zn > Sr > Ba > (Mn > W > Cd > (Sn > V ≈ Ni ≈ Cu > Co > (Ag. Soil trace elements showed significant short-range spatial variability, ranging from 2819 to 19274 mg/kg. Relative trend showed (Pb ≈ Zn > Mn > Ba > P > (As > Cu > Sr > V > Cd > Sb ≈ Ag > (Co ≈ Cr > Mo ≈ Sn ≈ Ni > (Be ≈ W > Se ≈ Hg. Predominant fractions were oxide, specifically-sorbed/carbonate bound, and residual. Water soluble and exchangeable fractions showed (Zn ≈ Cd > Pb and Cd > Zn > Pb, respectively. Mobility factors for highly contaminated soils showed Cd ≈ Zn > Pb > Cu > As.

  12. Progress on immobilisation of plutonium residues and shredded plutonium contaminated materials in cement

    International Nuclear Information System (INIS)

    Landles, A.J.; Awmack, A.F.; Baxter, W.

    1987-03-01

    Laboratory scale experiments have been carried out to study the feasibility of encapsulating plutonium contaminated materials in cement. A proposed grout of a 3:1 PFA/OPC mixture has been tested and some product evaluation carried out. (author)

  13. Pink shrimp (P. brasiliensis and P. paulensis) residue: influence of extraction method on carotenoid concentration.

    Science.gov (United States)

    Mezzomo, Natália; Maestri, Bianca; dos Santos, Renata Lazzaris; Maraschin, Marcelo; Ferreira, Sandra R S

    2011-09-15

    The main residue from the shrimp processing is formed by head and carapace and represents from 40 to 50% (w/w) of the integral shrimp. The recovery of the carotenoid fraction from this residue stands for an alternative to increase its aggregated value. Therefore, the objective of this study was to use the pink shrimp waste as raw material to obtain carotenoid enriched extracts, evaluating different pre-treatments and extraction methods. The shrimp waste was supplied by a local public market (Florianópolis, SC, Brazil). The investigation of the different pre-treatments applied to the raw material shows that cooking associated with milling and drying produced the extract richest in carotenoid fraction. The extraction methods considered in this work were Soxhlet, maceration and ultrasound by means of different organic solvents and also a vegetable oil as solvent. The extracts were evaluated in terms of yield, carotenoid profile, total carotenoid content (TCC), UV-Visible scanning spectrophotometry and mid-Fourier transform infrared spectroscopy (FTIR). The results indicate that shrimp waste can provide carotenoid enriched extracts, particularly astaxanthin, in concentrations up to 252 μg(astaxanthin)g(extract)(-1). The most adequate solvents were acetone and hexane: isopropanol (50:50, v/v) used in the maceration procedure. The UV-Vis results revealed the presence of carotenoids and flavonoids in the extracts while the FTIR spectroscopy indicated the existence of fatty acids, proteins, and phenolics. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Investigation of Health Effects According to the Exposure of Low Concentration Arsenic Contaminated Ground Water

    Directory of Open Access Journals (Sweden)

    Young-seoub Hong

    2017-11-01

    Full Text Available Recent epidemiological studies have reported adverse health effects, including skin cancer, due to low concentrations of arsenic via drinking water. We conducted a study to assess whether low arsenic contaminated ground water affected health of the residents who consumed it. For precise biomonitoring results, the inorganic (trivalent arsenite (As III and pentavalent arsenate (As V and organic forms (monomethylarsonate (MMA and dimethylarsinate (DMA of arsenic were separately quantified by combining high-performance liquid chromatography and inductively coupled plasma mass spectroscopy from urine samples. In conclusion, urinary As III, As V, MMA, and hair arsenic concentrations were significantly higher in residents who consumed arsenic contaminated ground water than control participants who consumed tap water. But, most health screening results did not show a statistically significant difference between exposed and control subjects. We presume that the elevated arsenic concentrations may not be sufficient to cause detectable health effects. Consumption of arsenic contaminated ground water could result in elevated urinary organic and inorganic arsenic concentrations. We recommend immediate discontinuation of ground water supply in this area for the safety of the residents.

  15. Arsenic Species in Chicken Breast: Temporal Variations of Metabolites, Elimination Kinetics, and Residual Concentrations.

    Science.gov (United States)

    Liu, Qingqing; Peng, Hanyong; Lu, Xiufen; Zuidhof, Martin J; Li, Xing-Fang; Le, X Chris

    2016-08-01

    Chicken meat has the highest per capita consumption among all meat types in North America. The practice of feeding 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, Rox) to chickens lasted for more than 60 years. However, the fate of Rox and arsenic metabolites remaining in chicken are poorly understood. We aimed to determine the elimination of Rox and metabolites from chickens and quantify the remaining arsenic species in chicken meat, providing necessary information for meaningful exposure assessment. We have conducted a 35-day feeding experiment involving 1,600 chickens, of which half were control and the other half were fed a Rox-supplemented diet for the first 28 days and then a Rox-free diet for the final 7 days. We quantified the concentrations of individual arsenic species in the breast meat of 229 chickens. Rox, arsenobetaine, arsenite, monomethylarsonic acid, dimethylarsinic acid, and a new arsenic metabolite, were detected in breast meat from chickens fed Rox. The concentrations of arsenic species, except arsenobetaine, were significantly higher in the Rox-fed than in the control chickens. The half-lives of elimination of these arsenic species were 0.4-1 day. Seven days after termination of Rox feeding, the concentrations of arsenite (3.1 μg/kg), Rox (0.4 μg/kg), and a new arsenic metabolite (0.8 μg/kg) were significantly higher in the Rox-fed chickens than in the control. Feeding of Rox to chickens increased the concentrations of five arsenic species in breast meat. Although most arsenic species were excreted rapidly when the feeding of Rox stopped, arsenic species remaining in the Rox-fed chickens were higher than the background levels. Liu Q, Peng H, Lu X, Zuidhof MJ, Li XF, Le XC. 2016. Arsenic species in chicken breast: temporal variations of metabolites, elimination kinetics, and residual concentrations. Environ Health Perspect 124:1174-1181; http://dx.doi.org/10.1289/ehp.1510530.

  16. Determination of solute organic concentration in contaminated soils using a chemical-equilibrium soil column system

    DEFF Research Database (Denmark)

    Gamst, Jesper; Kjeldsen, Peter; Christensen, Thomas Højlund

    2007-01-01

    Groundwater risk assessment of contaminated soils implies determination of the solute concentration leaching out of the soil. Determination based on estimation techniques or simple experimental batch approach has proven inadequate. Two chemical equilibrium soil column leaching tests...... for determination of solute concentration in a contaminated soil were developed; (1) a chemical Equilibrium and Recirculation column test for Volatile organic chemicals (ER-V) and (2) a chemical Equilibrium and Recirculation column test for Hydrophobic organic chemicals (ER-H). The two test systems were evaluated...... using two soils with different content of organic carbon (f(oc) of 1.5 and 6.5%, respectively). A quadruple blind test of the ER-V system using glass beads in stead of soil showed an acceptable recovery (65-85%) of all of the 11 VOCs tested. Only for the most volatile compound (heptane, K-H similar...

  17. Insect Residue Contamination on Wing Leading Edge Surfaces: A Materials Investigation for Mitigation

    Science.gov (United States)

    Lorenzi, Tyler M.; Wohl, Christopher J.; Penner, Ronald K.; Smith, Joseph G.; Siochi, Emilie J.

    2011-01-01

    Flight tests have shown that residue from insect strikes on aircraft wing leading edge surfaces may induce localized transition of laminar to turbulent flow. The highest density of insect populations have been observed between ground level and 153 m during light winds (2.6 -- 5.1 m/s), high humidity, and temperatures from 21 -- 29 C. At a critical residue height, dependent on the airfoil and Reynolds number, boundary layer transition from laminar to turbulent results in increased drag and fuel consumption. Although this represents a minimal increase in fuel burn for conventional transport aircraft, future aircraft designs will rely on maintaining laminar flow across a larger portion of wing surfaces to reduce fuel burn during cruise. Thus, insect residue adhesion mitigation is most critical during takeoff and initial climb to maintain laminar flow in fuel-efficient aircraft configurations. Several exterior treatments investigated to mitigate insect residue buildup (e.g., paper, scrapers, surfactants, flexible surfaces) have shown potential; however, implementation has proven to be impractical. Current research is focused on evaluation of wing leading edge surface coatings that may reduce insect residue adhesion. Initial work under NASA's Environmentally Responsible Aviation Program focused on evaluation of several commercially available products (commercial off-the-shelf, COTS), polymers, and substituted alkoxy silanes that were applied to aluminum (Al) substrates. Surface energies of these coatings were determined from contact angle data and were correlated to residual insect excrescence on coated aluminum substrates using a custom-built "bug gun." Quantification of insect excrescence surface coverage was evaluated by a series of digital photographic image processing techniques.

  18. Mirasol PRT system inactivation efficacy evaluated in platelet concentrates by bacteria-contamination model

    Directory of Open Access Journals (Sweden)

    Jocić Miodrag

    2011-01-01

    Full Text Available Background/Aim. Bacterial contamination of blood components, primarily platelet concentrates (PCs, has been identified as one of the most frequent infectious complications in transfusion practice. PC units have a high risk for bacterial growth/multiplication due to their storage at ambient temperature (20 ± 2°C. Consequences of blood contamination could be effectively prevented or reduced by pathogen inactivation systems. The aim of this study was to determine the Mirasol pathogen reduction technology (PRT system efficacy in PCs using an artificial bacteria-contamination model. Methods. According to the ABO blood groups, PC units (n = 216 were pooled into 54 pools (PC-Ps. PC-Ps were divided into three equal groups, with 18 units in each, designed for an artificial bacteria-contamination. Briefly, PC-Ps were contaminated by Staphylococcus epidermidis, Staphylococcus aureus or Escherichia coli in concentrations 102 to 107 colony forming units (CFU per unit. Afterward, PC-Ps were underwent to inactivation by Mirasol PRT system, using UV (l = 265-370 nm activated riboflavin (RB. All PC-Ps were assayed by BacT/Alert Microbial Detection System for CFU quantification before and after the Mirasol treatment. Samples from non-inactivated PC-P units were tested after preparation and immediately following bacterial contamination. Samples from Mirasol treated units were quantified for CFUs one hour, 3 days and 5 days after inactivation. Results. A complete inactivation of all bacteria species was obtained at CFU concentrations of 102 and 103 per PC-P unit through storage/ investigation period. The most effective inactivation (105 CFU per PC-P unit was obtained in Escherichia coli setting. Contrary, inactivation of all the three tested bacteria species was unworkable in concentrations of ≥ 106 CFU per PC-P unit. Conclusion. Efficient inactivation of investigated bacteria types with a significant CFU depletion in PC-P units was obtained - 3 Log for all

  19. [Well water pollution in the Khombole district: research on the contamination by organochlorine pesticide residues and organic substances (feces)].

    Science.gov (United States)

    Diouf, A; Ciss, M; Diop, Y; Boye, C S; Diouf, S; Fall, M; Diop, A; Ba, D

    1998-01-01

    The study realized in the district of Khombole (SENEGAL) has permit to estimate the contamination levels of wells waters used by the populations. The research and the dosage of the organichlorine pesticide residues, nitrites and nitrates and microbiologic analysis have been done on 19 wells chosen after a drawning of lots. The organochlorine pesticide residues which have been found prove that the wells are permanently exposed to these chemical substances which don't constitute nevertheless a major risk for the populations health. The results of our research proved also that there is a real risk of intoxication with the nitrogen oxides. In effects more than 50% of the wells have revealed nitrates contents up to the indicative value (25 mg/l). As for the nitrates, with a few exceptions (5/18), the contents are superior to the authorized norm (0.1 mg/l). By another way the bacteriologic analysis has revealed in the one hand a DBT (Total Bacterian Count) up to 10,000 germs/l for all the wells, and in the other hand the presence of Escherichia coli, Enterococcus faecalis that confirm a faecal contamination.

  20. [A simple testing installation for the production of aerosols with constant bacteria-contaminated concentrations].

    Science.gov (United States)

    Herbst, M; Lehmhus, H; Oldenburg, B; Orlowski, C; Ohgke, H

    1983-04-01

    A simple experimental set for the production and investigation of bacterially contaminated solid-state aerosols with constant concentration is described. The experimental set consists mainly of a fluidized bed-particle generator within a modified chamber for formaldehyde desinfection. The special conditions for the production of a defined concentration of particles and microorganisms are to be found out empirically. In a first application aerosol-sizing of an Andersen sampler is investigated. The findings of Andersen (1) are confirmed with respect to our experimental conditions.

  1. Some radioactivity concentrations and ingestion dose projections arising from consumption of food containing Chernobyl contamination

    International Nuclear Information System (INIS)

    Paz, L.R. de la; Palattao, M.V.; Estacio, J.F.L.; Anden, A.

    1987-04-01

    Doses arising from the ingestion of radioactive contamination coming from Chernobyl accident are calculated using various radioactivity limits adopted by different organizations after the accident. These are compared with that allowed in the Philippines. Projected concentrations of Cs-137 and Cs-134 in various food items in the affected countries, one month and one year after the accident are calculated using a model proposed by Boone, Ng and Palms. Except for food produced in one or two hot spots, the projected concentrations after one year are expected to return to within the range of pre-Chernobyl values. (Auth.) 12 refs.; 13 tabs.; 6 figs

  2. Evaluation of droplet digital PCR for quantification of residual leucocytes in red blood cell concentrates.

    Science.gov (United States)

    Doescher, A; Loges, U; Petershofen, E K; Müller, T H

    2017-11-01

    Enumeration of residual white blood cells in leucoreduced blood components is essential part of quality control. Digital PCR has substantially facilitated quantitative PCR and was thus evaluated for measurements of leucocytes. Target for quantification of leucocytes by digital droplet PCR was the blood group gene RHCE. The SPEF1 gene was added as internal control for the entire assay starting with automated DNA extraction. The sensitivity of the method was determined by serial dilutions of standard samples. Quality control samples were analysed within 24 h, 7 days and 6 months after collection. Routine samples from leucodepleted red blood cell concentrates (n = 150) were evaluated in parallel by flow-cytometry (LeucoCount) and by digital PCR. Digital PCR reliably detected at least 0·4 leucocytes per assay. The mean difference between PCR and flow-cytometric results from 150 units was -0·01 (±1·0). DNA samples were stable for up to at least six months. PCR measurement of leucocytes in samples from plasma and platelet concentrates also provided valid results in a pilot study. Droplet digital PCR to enumerate leucocytes offers an alternative for quality control of leucoreduced blood products. Sensitivity, specificity and reproducibility are comparable to flow-cytometry. The option to collect samples over an extended period of time and the automatization introduce attractive features for routine quality control. © 2017 International Society of Blood Transfusion.

  3. Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

    Directory of Open Access Journals (Sweden)

    Diane Saint-Laurent

    2010-01-01

    Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

  4. Assessing atmospheric concentration of polychlorinated biphenyls by evergreen Rhododendron maximum next to a contaminated stream.

    Science.gov (United States)

    Dang, Viet D; Walters, David M; Lee, Cindy M

    2016-09-01

    Conifers are often used as an air passive sampler, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In the present study, the authors used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The present study area was located in a rural setting and approximately 2 km downstream of a former capacitor plant. Leaves from the same mature shrubs were collected in late fall 2010 and winter and spring 2011. Polychlorinated biphenyls were detected in the collected leaves, suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990 pg m(-3) , 2850 pg m(-3) , and 931 pg m(-3) in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former industrial source. Leaves had a consistent pattern of high concentrations of tetra-CBs and penta-CBs similar to the congener distribution in polyethylene passive samplers deployed in the water column, suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves. Environ Toxicol Chem 2016;35:2192-2198. © 2016 SETAC. © 2016 SETAC.

  5. Assessing atmospheric concentration of polychlorinated biphenyls (PCBs) by evergreen Rhododendron maximum next to a contaminated stream

    Science.gov (United States)

    Dang, Viet D.; Walter, W. David; Lee, Cindy M.

    2016-01-01

    Conifers are often used as an “air passive sampler”, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In this study, we used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The study area was located in a rural setting and approximately 2 km downstream of a former Sangamo-Weston (S-W) plant. Leaves from the same mature shrubs were collected in late fall 2010, and winter and spring 2011. PCBs were detected in the collected leaves suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990, 2850, and 931 pg m-3 in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former S-W plant. Leaves had a consistent pattern of high concentrations of tetra- and penta-CBs similar to the congener distribution in polyethylene (PE) passive samplers deployed in the water column suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves.

  6. Spatial uncoupling of biodegradation, soil respiration, and PAH concentration in a creosote contaminated soil

    International Nuclear Information System (INIS)

    Bengtsson, Goeran; Toerneman, Niklas; Yang Xiuhong

    2010-01-01

    Hotspots and coldspots of concentration and biodegradation of polycyclic aromatic hydrocarbons (PAHs) marginally overlapped at the 0.5-100 m scale in a creosote contaminated soil in southern Sweden, suggesting that concentration and biodegradation had little spatial co-variation. Biodegradation was substantial and its spatial variability considerable and highly irregular, but it had no spatial autocorrelation. The soil concentration of PAHs explained only 20-30% of the variance of their biodegradation. Soil respiration was spatially autocorrelated. The spatial uncoupling between biodegradation and soil respiration seemed to be governed by the aging of PAHs in the soil, since biodegradation of added 13 C phenanthrene covaried with both soil respiration and microbial biomass. The latter two were also correlated with high concentrations of phospholipid fatty acids (PLFAs) that are common in gram-negative bacteria. However, several of the hotspots of biodegradation coincided with hotspots for the distribution of a PLFA indicative of fungal biomass. - Hotspots of PAH biodegradation in a creosote contaminated soil do not coincide with hotspots of PAH concentration, microbial biomass and respiration.

  7. Organic co-solvent effect on the estimation of the equilibrium aqueous concentrations of oil residuals in Patagonian soil.

    Science.gov (United States)

    Nudelman, N S; Rios, S M; Katusich, O

    2002-09-01

    Determination of the equilibrium aqueous concentration and the distribution coefficients, K, in soil samples containing oil residuals of different age, was carried out using an organic co-solvent (methanol). It was found that the solvophobic theory could be applied for the interpretation of results. The behavior of the residuals turned out to be dependent on the co-solvent fraction and the age of the oil spill. The values of K vary between 900 (l kg(-1)) and 2,900 (l kg(-1)) showing a general and marked increase for residues of increasing age. The determined parameters are useful for the modeling of environmental impact on polluted soils.

  8. Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide.

    Science.gov (United States)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed for various times in a spray cabinet with a 2% lauric acid (LA)-1% potassium hydroxide (KOH) (w/v) solution. Forty eviscerated carcasses and 5 ceca were obtained from the processing l...

  9. De-contamination of pesticide residues in food by ionizing radiation

    International Nuclear Information System (INIS)

    Basfar, Ahmed A.; Mohamed, Khaled A.; Al-Saqer, Omar A.

    2012-01-01

    The role of gamma irradiation on removal of pesticides in aqueous solutions or in vegetables and fruits was investigated. Radiation - induced decontamination of pesticides is generally greater in aqueous solutions than in selected vegetables and fruits. Residues of malathion (0.5 ppm in potatoes, 8 ppm in onions and dates), pirimiphos-methyl (1 ppm in onions and grapes) and cypermethrin (0.05 ppm in potatoes and 0.1 ppm in onions) were not reduced to below maximum residue limits (MRLs) for irradiation doses up to 1 kGy. The same trend was observed when irradiation was performed for grapes fortified with malathion (8 ppm) and cypermethrin (2 ppm) for absorbed doses up to 2 kGy. Ionizing radiation reduced the residues of pirimiphos-methyl (0.05 ppm in potatoes at1 kGy, 1 ppm in grapes at 2 kGy and 0.1 ppm in dates at1 kGy), malathion (8 ppm in grapes at 7 kGy) and cypermethrin (2 ppm in grapes at 7 kGy) to below maximum residue limits (MRLs). - Highlights: ► The role of irradiation on removal of pesticides in aqueous solutions or in food products was investigated. ► Radiation-induced removal of pesticides is generally greater in aqueous solutions than in food products. ► Radiation can reduce the pirimiphos-methyl in potatoes, grapes and dates to below MRLs. ► Radiation can reduce the malathion and cypermethrin in grapes to below MRLs. ► Radiation is used for dual objectives of reducing pesticide residues and improving food safety.

  10. Hanford Tanks 241-C-203 and 241 C 204: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2007-05-23

    This report was revised in May 2007 to correct 90Sr values in Chapter 3. The changes were made on page 3.9, paragraph two and Table 3.10; page 3.16, last paragraph on the page; and Tables 3.21 and 3.31. The rest of the text remains unchanged from the original report issued in October 2004. This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.

  11. Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2004-10-28

    This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy.

  12. Hanford Tanks 241-C-203 and 241-C-204: Residual Waste Contaminant Release Model and Supporting Data

    International Nuclear Information System (INIS)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2004-01-01

    This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for the U.S. Department of Energy

  13. Optimization of the protein concentration process from residual peanut oil-cake

    Directory of Open Access Journals (Sweden)

    Gayol, M. F.

    2013-12-01

    Full Text Available The objective of this study was to find the best process conditions for preparing protein concentrate from residual peanut oil-cake (POC. The study was carried out on POC from industrial peanut oil extraction. Different protein extraction and precipitation conditions were used: water/ flour ratio (10:1, 20:1 and 30:1, pH (8, 9 and 10, NaCl concentration (0 and 0.5 M, extraction time (30, 60 and 120 min, temperature (25, 40 and 60 °C, extraction stages (1, 2 and 3, and precipitation pH (4, 4.5 and 5. The extraction and precipitation conditions which showed the highest protein yield were 10:1 water/flour ratio, extraction at pH 9, no NaCl, 2 extraction stages of 30 min at 40 °C and precipitation at pH 4.5. Under these conditions, the peanut protein concentrate (PC contained 86.22% protein, while the initial POC had 38.04% . POC is an alternative source of protein that can be used for human consumption or animal nutrition. Therefore, it adds value to an industry residue.El objetivo de este trabajo fue encontrar las mejores condiciones para obtener un concentrado de proteínas a partir de la torta residual de maní (POC. El estudio se llevó a cabo en POC provenientes de la extracción industrial de aceite de maní. Se utilizaron distintas condiciones para la extracción y precipitación de proteínas: relación agua / harina (10:1, 20:1 y 30:1, pH de extracción (8, 9 y 10, concentración de NaCl (0 y 0,5 M, tiempo de extracción (30, 60 y 120 min, temperatura (25, 40 y 60 °C, número de etapas de extracción (1, 2 y 3, y el pH de precipitación (4, 4,5 y 5. Las condiciones de extracción y de precipitación que mostraron mayor rendimiento de proteína fueron: relación de 10:1 en agua / harina, pH de extracción de 9, en ausencia de NaCl, 2 etapas de extracción de 30 min cada una a 40 °C y el pH de precipitación de 4,5. En estas condiciones, el concentrado de proteína de maní (PC fue de 86,22%, mientras que el porcentaje de proteínas de

  14. Effective radium concentration in topsoils contaminated by lead and zinc smelters

    Energy Technology Data Exchange (ETDEWEB)

    Girault, Frédéric, E-mail: girault@ipgp.fr [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Perrier, Frédéric; Poitou, Charles; Isambert, Aude [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, Paris, France. (France); Théveniaut, Hervé; Laperche, Valérie [Bureau de Recherches Géologiques et Minières, Orléans, France. (France); Clozel-Leloup, Blandine [Bureau de Recherches Géologiques et Minières, Villeurbanne, France. (France); Douay, Francis [Laboratoire Génie Civil et géo Environnement, ISA Lille, Lille, France. (France)

    2016-10-01

    Trace elements (TE) are indicative of industrial pollution in soils, but geochemical methods are difficult to implement in contaminated sites with large numbers of samples. Therefore, measurement of soil magnetic susceptibility (MS) has been used to map TE pollutions, albeit with contrasted results in some cases. Effective radium concentration (EC{sub Ra}), product of radium concentration by the emanation factor, can be measured in a cost-effective manner in the laboratory, and could then provide a useful addition. We evaluate this possibility using 186 topsoils sampled over about 783 km{sup 2} around two former lead and zinc smelters in Northern France. The EC{sub Ra} values, obtained from 319 measurements, range from 0.70 ± 0.06 to 12.53 ± 0.49 Bq·kg{sup −1}, and are remarkably organized spatially, away from the smelters, in domains corresponding to geographical units. Lead-contaminated soils, with lead concentrations above 100 mg·kg{sup −1} < 3 km from the smelters, are characterized on average by larger peak EC{sub Ra} values and larger dispersion. At large scales, away from the smelters, spatial variations of EC{sub Ra} correlate well with spatial variations of MS, thus suggesting that, at distance larger than 5 km, variability of MS contains a significant natural component. Larger EC{sub Ra} values are correlated with larger fine fraction and, possibly, mercury concentration. While MS is enhanced in the vicinity of the smelters and is associated with the presence of soft ferrimagnetic minerals such as magnetite, it does not correlate systematically with metal concentrations. When multiple industrial and urban sources are present, EC{sub Ra} mapping, thus, can help in identifying at least part of the natural spatial variability of MS. More generally, this study shows that EC{sub Ra} mapping provides an independent and reliable assessment of the background spatial structure which underlies the structure of a given contamination. Furthermore, EC{sub Ra

  15. An alternative screening model for the estimation of outdoor air concentration at large contaminated sites

    Science.gov (United States)

    Verginelli, Iason; Nocentini, Massimo; Baciocchi, Renato

    2017-09-01

    Simplified analytical solutions of fate and transport models are often used to carry out risk assessment on contaminated sites, to evaluate the long-term air quality in relation to volatile organic compounds in either soil or groundwater. Among the different assumptions employed to develop these solutions, in this work we focus on those used in the ASTM-RBCA ;box model; for the evaluation of contaminant dispersion in the atmosphere. In this simple model, it is assumed that the contaminant volatilized from the subsurface is dispersed in the atmosphere within a mixing height equal to two meters, i.e. the height of the breathing zone. In certain cases, this simplification could lead to an overestimation of the outdoor air concentration at the point of exposure. In this paper we first discuss the maximum source lengths (in the wind direction) for which the application of the ;box model; can be considered acceptable. Specifically, by comparing the results of ;box model; with the SCREEN3 model of U.S.EPA we found that under very stable atmospheric conditions (class F) the ASTM-RBCA approach provides acceptable results for source lengths up to 200 m while for very unstable atmospheric conditions (class A and B) the overestimation of the concentrations at the point of the exposure can be already observed for source lengths of only 10 m. In the latter case, the overestimation of the ;box model; can be of more than one order of magnitude for source lengths above 500 m. To overcome this limitation, in this paper we introduce a simple analytical solution that can be used for the calculation of the concentration at the point of exposure for large contaminated sites. The method consists in the introduction of an equivalent mixing zone height that allows to account for the dispersion of the contaminants along the source length while keeping the simplistic ;box model; approach that is implemented in most of risk assessment tools that are based on the ASTM-RBCA standard (e.g. RBCA

  16. Crucial role of mechanisms and modes of toxic action for understanding tissue residue toxicity and internal effect concentrations of organic chemicals

    NARCIS (Netherlands)

    Escher, B.I.; Ashauer, R.; Dyer, S.; Hermens, J.L.M.; van der Lee, J.H.; Leslie, H.A.; Mayer, P.; Meador, J.P.; Warne, M.S.J.

    2011-01-01

    This article reviews the mechanistic basis of the tissue residue approach for toxicity assessment (TRA). The tissue residue approach implies that whole-body or organ concentrations (residues) are a better dose metric for describing toxicity to aquatic organisms than is the aqueous concentration

  17. Stabilization of in-tank residuals and external-tank soil contamination: FY 1997 interim report

    International Nuclear Information System (INIS)

    Becker, D.L.

    1997-01-01

    This interim report evaluates various ways to stabilize decommissioned waste tanks and contaminated soils at the AX Tank Farm as part of a preliminary evaluation of end-state options for the Hanford tanks. Five technical areas were considered: (1) emplacement of smart grouts and/or other materials, (2) injection of chemical-getters into contaminated soils surrounding tanks (soil mixing), (3) emplacement of grout barriers under and around the tanks, (4) the use of engineered barriers over the tanks, and (5) the explicit recognition that natural attenuation processes do occur. Research topics are identified in support of key areas of technical uncertainty, in each of the five technical areas. Detailed cost/benefit analyses of the recommended technologies are not provided in this evaluation, performed by Sandia National Laboratories, Albuquerque, New Mexico

  18. Stabilization of in-tank residuals and external-tank soil contamination: FY 1997 interim report

    Energy Technology Data Exchange (ETDEWEB)

    Becker, D.L.

    1997-10-09

    This interim report evaluates various ways to stabilize decommissioned waste tanks and contaminated soils at the AX Tank Farm as part of a preliminary evaluation of end-state options for the Hanford tanks. Five technical areas were considered: (1) emplacement of smart grouts and/or other materials, (2) injection of chemical-getters into contaminated soils surrounding tanks (soil mixing), (3) emplacement of grout barriers under and around the tanks, (4) the use of engineered barriers over the tanks, and (5) the explicit recognition that natural attenuation processes do occur. Research topics are identified in support of key areas of technical uncertainty, in each of the five technical areas. Detailed cost/benefit analyses of the recommended technologies are not provided in this evaluation, performed by Sandia National Laboratories, Albuquerque, New Mexico.

  19. Risk assessment of dimethylfumarate residues in dwellings following contamination by treated furniture.

    Science.gov (United States)

    Rousselle, C; Pernelet-Joly, V; Mourton-Gilles, C; Lepoittevin, J P; Vincent, R; Lefranc, A; Garnier, R

    2014-05-01

    Recently, numerous cases of dermatitis induced by dimethylfumarate (DMFu) have been reported in Europe. DMFu has been used to prevent mold development in various items, although it is not registered as a biocide. In France, from October 2008 to December 2009, more than 100 cases were reported. Despite a ban on articles containing DMFu and the removal of potentially contaminated products, some people were still suffering from dermatitis or other health problems. The French Agency for Food, Environmental and Occupational Health & Safety was mandated to assess whether the existence in the past of DMFu-contaminated items in dwellings could continue to pose a threat to the health of inhabitants. A risk assessment was performed based on the classical risk analysis approach for environmental contaminants. Hazard assessment of DMFu with regard to its sensitizing properties was performed, based on human case reports collected in France between January 2009 and February 2010. For around half of the 132 individual cases reported, the causal link to DMFu was considered at least probable. An Organisation for Economic Co-Operation and Development (OECD) local lymph node assay performed in a study on mice showed strong sensitizing potential for DMFu. Exposure was assessed by measuring DMFu in items sampled in preselected dwellings. These investigations demonstrated that DMFu exposure can persist after removal of the primary contaminated items. We therefore concluded that there was clearly a risk of skin reactions in patients previously sensitized to DMFu. Furthermore, the available data do not support the existence of significant health effects through the respiratory route. © 2013 Society for Risk Analysis.

  20. Persistent environmental contaminants in human milk: concentrations and time trends in Italy.

    Science.gov (United States)

    Abballe, Annalisa; Ballard, Terri J; Dellatte, Elena; di Domenico, Alessandro; Ferri, Fabiola; Fulgenzi, Anna Rita; Grisanti, Giulio; Iacovella, Nicola; Ingelido, Anna Maria; Malisch, Rainer; Miniero, Roberto; Porpora, Maria Grazia; Risica, Serena; Ziemacki, Gianni; De Felip, Elena

    2008-08-01

    Breast milk monitoring studies of persistent and toxic environmental contaminants are of primary importance for carrying out an adequate risk assessment at the actual levels of human exposure and represent a major source of information on infant perinatal exposure. Milk specimens from mothers of the general population of the Venice and Rome areas were collected over the 1998-2001 period, pooled, and analyzed for selected persistent organic pollutants such as polychlorodibenzodioxins (PCDDs), polychlorodibenzofurans (PCDFs), polychlorobiphenyls (PCBs), organochlorinated pesticides (p,p'-DDE, p,p'-DDT, hexachlorobenzene), and polybromodiphenyl ethers (PBDEs), and the heavy metals Cd, Co, Cu, Hg, Mn, Pb, Sn, and Zn. The goal was to verify whether mother milk from the Venice area, whose lagoon is partly under direct industrial impact, had a contaminant load greater than that from the Rome area, primarily urban. For mothers from the Venice area, the correlation between fish and fishery product consumption and contaminant concentrations in milk was also explored, with however inconclusive results. The concentrations of PCDDs, PCDFs, dioxin-like PCBs, and organochlorinated pesticides determined in this study were compared with those available from a previous analytical work carried out on 1987 human milk pools of domestic origin: the declining trend of the aforesaid contaminants in milk is confirmed to be in agreement with what was observed in other European countries. The breast milk content of (137)Cs and (40)K radionuclides was also determined and compared with data obtained in other research programmes carried out in Italy: the health risk for breastfed infants was deemed to be not significant.

  1. Guidelines for developing spacecraft maximum allowable concentrations for Space Station contaminants

    Science.gov (United States)

    The National Aeronautics and Space Administration (NASA) is preparing to launch a manned space station by the year 1996. Because of concerns about the health, safety, and functioning abilities of the crews, NASA has requested that the National Research Council (NRC) through the Board on Environmental Studies and Toxicology (BEST) provide advice on toxicological matters for the space-station program. The Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants was established by the Committee on Toxicology (COT) to address NASA's concerns. Spacecraft maximum allowable concentrations (SMAC's) are defined as the maximum concentrations of airborne substances (such as gas, vapor, or aerosol) that will not cause adverse health effects, significant discomfort, or degradation in crew performance.

  2. Evaluation of ground calcite/water heavy media cyclone suspensions for production of residual plastic concentrates.

    Science.gov (United States)

    Gent, Malcolm; Sierra, Héctor Muñiz; Menéndez, Mario; de Cos Juez, Francisco Javier

    2018-01-01

    Viable recycled residual plastic (RP) product(s) must be of sufficient quality to be reusable as a plastic or source of hydrocarbons or fuel. The varied composition and large volumes of such wastes usually requires a low cost, high through-put recycling method(s) to eliminate contaminants. Cyclone separation of plastics by density is proposed as a potential method of achieving separations of specific types of plastics. Three ground calcite separation medias of different grain size distributions were tested in a cylindrical cyclone to evaluate density separations at 1.09, 1.18 and 1.27 g/cm 3 . The differences in separation recoveries obtained with these medias by density offsets produced due to displacement of separation media solid particles within the cyclone caused by centrifugal settling is evaluated. The separation density at which 50% of the material of that density is recovered was found to increase from 0.010 to 0.026 g/cm 3 as the separation media density increased from 1.09 to 1.27 g/cm 3 . All separation medias were found to have significantly low Ep 95 values of 0.012-0.033 g/cm 3 . It is also demonstrated that the presence of an excess content of 75%) resulted in reduced separation efficiencies. It is shown that the optimum separations were achieved when the media density offset was 0.03-0.04 g/cm 3 . It is shown that effective heavy media cyclone separations of RP denser than 1.0 g/cm 3 can produce three sets of mixed plastics containing: PS and ABS/SAN at densities of >1.0-1.09 g/cm 3 ; PC, PMMA at a density of 1.09-1.18 g/cm 3 ; and PVC and PET at a density of >1.27 g/cm 3 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evolution of residual-Zn available concentrations of Zn-EDTA chelate in two different soils.

    Science.gov (United States)

    Almendros, P.; Gonzalez, D.; Alvarez, J. M.

    2012-04-01

    Zinc chelates, such as Zn-EDTA have been widely used to correct deficiencies in this micronutrient in different crops. Several authors have suggested applying complexed forms of Zn to soils in order to offer an effective source of Zn to plants. When inorganic Zn sources are added to soils, the availability of Zn to plants tends to decrease with time. This is due to the aging of the metal or the transformation of the Zn that is normally available to plants into various less available forms. Soil properties are believed to influence the fixation and/or precipitation of added Zn. The objective of this study was to determine the changes over time in the concentrations of available residual-Zn in two different soils to which the Zn-EDTA chelate was applied. An experiment was conducted under controlled laboratory conditions in two different soils: an acidic soil [Typic Haploxeralf; field capacity, 6.65 g H2O/100 g soil; pHw (1/2.5, w/v), 6.2; texture USDA, sandy loam, with illite as the predominant clay; oxidizable organic carbon 0.29%; extractable P, 19.9 mg/kg] and a calcareous soil [Typic Calcixerept; field capacity, 20.5 g H2O/100 g soil; pHw (1/2.5, w/v), 8.2; texture USDA, loamy sand, with smectite as the predominant clay; oxidizable organic carbon 0.75%; extractable P, 12.6 mg/kg]. These soils were treated with a synthetic chelate, Zn-ethylenediaminetetraacetate (Zn-EDTA), at different rates of application [0 (nil-Zn), 5 and 10 mg Zn kg-1 soil]. The potential available Zn concentrations were estimated at four experimental times (0, 15, 45 and 75 d) by the Mehlich-3 and DTPA-AB extraction methods. The results obtained showed the evolution of available Zn over experimental time, for each treatment. The Zn concentrations in both soils showed significant differences over experimental time. Zn-EDTA applied at both Zn rates (5 and 10 mg Zn kg-1) was associated with high variations in available Zn concentrations. However, in both soils, the decreases in available Zn

  4. Residual effects of metal contamination on the soil quality: a field survey in central Portugal

    Science.gov (United States)

    Kikuchi, Ryunosuke; Gerardo, Romeu

    2017-04-01

    Agriculture is an important source of income and employment. But depletion and degradation of land challenge to producing safe food and other agricultural products to sustain livelihoods and meet the needs of urban populations. When developing or expanding an agricultural area, it becomes essential to access the soil quality. Even if the present source of contamination is not observed, it is a worth subject to evaluate whether or not any negative effects of the post contamination still last. For this purpose, a field survey (2 ha) was carried: a zinc and lead mining site that was abandoned about 50 years ago was researched at Sanguinheiro (40°18'N and 8°21'W) in Central Portugal. The area is characterized by very steep slopes that are confining with a small stream. The obtained results show that (i) the Pb content in the site (165 mg/kg) is higher than that in the background (67.7 mg/kg); (ii) the Zn content of local vegetation (Eucalyptus globulus) in the post-mining site is 2.1 times that in the control site, and (iii) dead bare ground is observed in some parts of the site. There is a possibility that great amounts of Zn and Pb accumulate in tissues of local vegetation. Although mining activity ended 50 years ago, the contents of Pb and Zn in the sampled soil were comparatively high in the site with about a 75% slope. It is concluded that not only the present contamination but also the post-environmental stress should be assessed to properly develop an agricultural area in terms of securing agricultural products.

  5. Contamination of magnetron sputtered metallic films by oxygen from residual atmosphere in deposition chamber

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Petr; Musil, Jindřich; Fitl, Přemysl; Novotný, Michal; Lančok, Ján; Bulíř, Jiří

    2015-01-01

    Roč. 12, č. 5 (2015), s. 416-421 ISSN 1612-8850 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR(CZ) GAP108/11/1312; GA ČR(CZ) GAP108/11/0958; GA ČR(CZ) GA14-10279S Institutional support: RVO:68378271 Keywords : contamination * low-pressure discharges * magnetron * metallic films * sputtering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.713, year: 2015

  6. Estimating the tensor-to-scalar ratio and the effect of residual foreground contamination

    Energy Technology Data Exchange (ETDEWEB)

    Fantaye, Y.; Leach, S.M.; Baccigalupi, C. [SISSA, Astrophysics Sector, via Bonomea 265, Trieste 34136 (Italy); Stivoli, F. [INRIA, Laboratoire de Recherche en Informatique, Université Paris-Sud 11, Bâtiment 490, 91405 Orsay Cedex (France); Grain, J. [CNRS, Institut d' Astrophysique Spatiale, Université Paris-Sud 11, Bâtiments 120-121, 91405 Orsay Cedex (France); Tristram, M. [CNRS, Laboratoire de l' Accélérateur Linéaire, Université Paris-Sud 11, Bâtiment 200, 91898 Orsay Cedex (France); Stompor, R., E-mail: fantaye@sissa.it, E-mail: stivoli@gmail.com, E-mail: julien.grain@ias.u-psud.fr, E-mail: leach@sissa.it, E-mail: tristram@lal.in2p3.fr, E-mail: bacci@sissa.it, E-mail: radek@apc.univ-paris7.fr [CNRS, Laboratoire Astroparticule and Cosmologie, 10 rue A. Domon et L. Duquet, F-75205 Paris Cedex 13 (France)

    2011-08-01

    We consider future balloon-borne and ground-based suborbital experiments designed to search for inflationary gravitational waves, and investigate the impact of residual foregrounds that remain in the estimated cosmic microwave background maps. This is achieved by propagating foreground modelling uncertainties from the component separation, under the assumption of a spatially uniform foreground frequency scaling, through to the power spectrum estimates, and up to measurement of the tensor to scalar ratio in the parameter estimation step. We characterize the error covariance due to subtracted foregrounds, and find it to be subdominant compared to instrumental noise and sample variance in our simulated data analysis. We model the unsubtracted residual foreground contribution using a two-parameter power law and show that marginalization over these foreground parameters is effective in accounting for a bias due to excess foreground power at low l. We conclude that, at least in the suborbital experimental setups we have simulated, foreground errors may be modeled and propagated up to parameter estimation with only a slight degradation of the target sensitivity of these experiments derived neglecting the presence of the foregrounds.

  7. Risk element immobilization/stabilization potential of fungal-transformed dry olive residue and arbuscular mycorrhizal fungi application in contaminated soils.

    Science.gov (United States)

    García-Sánchez, Mercedes; Stejskalová, Tereza; García-Romera, Inmaculada; Száková, Jiřina; Tlustoš, Pavel

    2017-10-01

    The use of biotransformed dry olive residue (DOR) as organic soil amendment has recently been proposed due to its high contents of stabilized organic matter and nutrients. The potential of biotransformed DOR to immobilize risk elements in contaminated soils might qualify DOR as a potential risk element stabilization agent for in situ soil reclamation practices. In this experiment, the mobility of risk elements in response to Penicillium chrysogenum-10-transformed DOR, Funalia floccosa-transformed DOR, Bjerkandera adusta-transformed DOR, and Chondrostereum purpureum-transformed DOR as well as arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae, inoculation was investigated. We evaluated the effect of these treatments on risk element uptake by wheat (Triticum aestivum L.) plants in a pot experiment with Cd, Pb, and Zn contaminated soil. The results showed a significant impact of the combined treatment (biotransformed DOR and AMF inoculation) on wheat plant growth and element mobility. The mobile proportions of elements in the treated soils were related to soil pH; with increasing pH levels, Cd, Cu, Fe, Mn, P, Pb, and Zn mobility decreased significantly (r values between -0.36 and -0.46), while Ca and Mg mobility increased (r = 0.63, and r = 0.51, respectively). The application of biotransformed DOR decreased risk element levels (Cd, Zn), and nutrient concentrations (Ca, Cu, Fe, Mg, Mn) in the aboveground biomass, where the elements were retained in the roots. Thus, biotransformed DOR in combination with AMF resulted in a higher capacity of wheat plants to grow under detrimental conditions, being able to accumulate high amounts of risk elements in the roots. However, risk element reduction was insufficient for safe crop production in the extremely contaminated soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Sensitive parameters in predicting exposure contaminants concentration in a risk assessment process.

    Science.gov (United States)

    Avagliano, Salvatore; Vecchio, Antonella; Belgiorno, Vincenzo

    2005-12-01

    A sensitivity analysis (SA) was conducted on the analytical models considered in the risk-based corrective-action (RBCA) methodology of risk analysis, as developed by the American Society for Testing of Materials (ASTM), to predict a contaminant's concentration in the affected medium at the point of human exposure. These models are of interest because evaluations regarding the best approach to contaminated site remediation are shifting toward increased use of risk-based decision, and the ASTM RBCA methodology represents the most effective and internationally widely used standardized guide for risk assessment process. This paper identifies key physical and chemical parameters that need additional precision and accuracy consideration in order to reduce uncertainty in models prediction, thereby saving time, money and engineering effort in the data collection process. SA was performed applying a variance-based method to organic contaminants migration models with reference to soil-to-groundwater leaching ingestion exposure scenario. Results indicate that model output strongly depends on the organic-carbon partition coefficient, organic-carbon content, net infiltration, Darcy velocity, source-receptor distance, and first-order decay constant.

  9. Further studies on the use of enzyme profiles to monitor residue accumulation in wildlife: Plasma enzymes in starlings fed graded concentrations of morsodren, DDE, Aroclor 1254, and malathion

    Science.gov (United States)

    Dieter, M.P.

    1975-01-01

    Wild-trapped starlings (Sturnus vulgaris) were fed concentrations of Morsodren (2, 4, and 8 ppm), DDE or Aroclor 1254 (5, 25, and 100 ppm), or malathion (8, 35, and 160 ppm) that were found to be sublethal in pen-reared Coturnix quail fed these amounts for 12 weeks. Plasma enzymes had to be measured earlier than planned in starlings fed Morsodren (at three weeks) or the organochlorine compounds (at seven weeks) because of unexpected, subsequent mortality. Variations in enzyme response were greater in wild than in pen-reared birds, but not enough to mask the toxicant-induced changes in enzyme activity. Cholinesterase activities decreased in birds fed Morsodren or malathion, and increased in those fed the organochlorine compounds. Lactate dehydrogenase activities increased two-fold in starlings fed Morsodren and two- to four-fold in those fed the organochlorine compounds, but only 50% in those fed malathion. Further examination of enzyme profiles showed that creatine kinase and aspartate aminotransferase activities increased two-to four-fold in birds fed Morsodren or the organochlorine compounds but not at all in those fed malathion. Thus the classes of environmental contaminants fed to starlings could be easily distinguished by these enzymatic parameters. Evaluation of enzymatic profiles appears to be a potentially valuable technique to monitor the presence of toxicants in wild populations, especially if used to complement standard chemical residue analyses. Here the residue analyses showed, after three weeks feeding, that mercury in the carcasses reflected the concentrations fed daily, whereas accumulation in the livers was two- to four-fold greater. After seven weeks feeding, liver residues of either organochlorine compound were about three-fold higher than the concentrations fed daily. However, four times as much DDE as Aroclor 1254 had accumulated in the carcasses.

  10. A SUMMARY OF TOTAL MERCURY CONCENTRATIONS IN FLORA AND FAUNA NEAR CONTAMINANT SOURCES IN THE GULF OF MEXICO

    Science.gov (United States)

    This report summarizes total mercury concentrations for environmental media collected from near-coastal areas including those impacted by contaminant sources common to the Gulf of Mexico. Water, sediment, fish, blue crabs, oysters, clams, mussels, periphyton and seagrasses were ...

  11. Miniaturized, High Flow, Low Dead Volume Pre-Concentrator for Trace Contaminants in Water under Microgravity Conditions, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized high flow, low dead-volume pre-concentrator for monitoring trace levels of contaminants in water under...

  12. Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Schaef, Herbert T.

    2007-05-23

    This report was revised in May 2007 to correct values in Section 3.4.1.7, second paragraph, last sentence; 90Sr values in Tables 3.22 and 3.32; and 99Tc values Table 4.3 and in Chapter 5. In addition, the tables in Appendix F were updated to reflect corrections to the 90Sr values. The rest of the text remains unchanged from the original report issued in May 2005. CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOE's Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contam¬inants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL.

  13. Polychlorinated biphenyl (PCB) contamination in Galveston Bay, Texas: Comparing concentrations and profiles in sediments, passive samplers, and fish.

    Science.gov (United States)

    Oziolor, Elias M; Apell, Jennifer N; Winfield, Zach C; Back, Jeffrey A; Usenko, Sascha; Matson, Cole W

    2018-05-01

    The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290-110,000 ng/g lipid in fish, and 4.5-2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Effect of pyrolysis temperature on characteristics and aromatic contaminants adsorption behavior of magnetic biochar derived from pyrolysis oil distillation residue.

    Science.gov (United States)

    Li, Hao; Mahyoub, Samah Awadh Ali; Liao, Wenjie; Xia, Shuqian; Zhao, Hechuan; Guo, Mengya; Ma, Peisheng

    2017-01-01

    The magnetic biochars were easily fabricated by thermal pyrolysis of Fe(NO 3 ) 3 and distillation residue derived from rice straw pyrolysis oil at 400, 600 and 800°C. The effects of pyrolysis temperature on characteristics of magnetic biochars as well as adsorption capacity for aromatic contaminants (i.e., anisole, phenol and guaiacol) were investigated carefully. The degree of carbonization of magnetic biochars become higher as pyrolysis temperature increasing. The magnetic biochar reached the largest surface area and pore volume at the pyrolysis temperature of 600°C due to pores blocking in biochar during pyrolysis at 800°C. Based on batch adsorption experiments, the used adsorbent could be magnetically separated and the adsorption capacity of anisole on magnetic biochars was stronger than that of phenol and guaiacol. The properties of magnetic biochar, including surface area, pore volume, aromaticity, grapheme-like-structure and iron oxide (γ-Fe 2 O 3 ) particles, showed pronounced effects on the adsorption performance of aromatic contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Contaminants of emerging concern in reverse osmosis brine concentrate from indirect/direct water reuse applications.

    Science.gov (United States)

    Romeyn, Travis R; Harijanto, Wesley; Sandoval, Sofia; Delagah, Saied; Sharbatmaleki, Mohamadali

    2016-01-01

    Water shortage is becoming more common due to droughts and global population increases resulting in the increasing popularity of water reuse to create new water sources. Reverse osmosis (RO) membrane systems are popular in these applications since they can produce drinking water quality effluent. Unfortunately, RO systems have the drawback of generating concentrate streams that contain contaminants rejected by the membrane including chemicals of emerging concern (CECs). CECs are chemicals such as hormones, steroids, pesticides, pharmaceuticals, and personal care products that are used for their intended purpose and then released into wastewater. CECs are believed to be detrimental to aquatic wildlife health and pose an unknown human health risk. This research gathered the existing knowledge on CEC presence in concentrate, available proven concentrate treatment methods, their CEC removal abilities, and current CEC regulations. It was found that 127 CECs have been measured in RO concentrate with 100 being detected at least once. The most potent treatment process available is UV/H2O2 as it offers the highest removal rates for the widest range of chemicals. The less expensive process of ozone/biologically activated carbon offers slightly lower removal abilities. This comprehensive report will provide the groundwork for better understanding, regulating and treating concentrate stream CECs.

  16. Proposal for Reference Soil Concentrations of Radiocesium Applicable to Accidentally Contaminated Rice and Soybean Fields

    International Nuclear Information System (INIS)

    Choi, Yong-Ho; Lim, Kwang-Muk; Jun, In; Kim, Byung-Ho; Keum, Dong-Kwon

    2014-01-01

    Radionuclides in arable soil can be transferred to food plants via root uptake. If radionuclide concentrations in food plants to be grown in contaminated soil are estimated to be higher than the authorized food standards, their culture needs to be cancelled or ameliorating practices need to be taken. Therefore, it is necessary to establish soil concentration limits or reference soil concentrations of radiocesium standing with the food standards in preparation for potential severe NPP accidents in this and adjacent countries. In the present study, reference soil concentrations of radiocesium for rice and soybean, two of the most important food plants in Korea, were provisionally established using all relevant domestic data of soil-to-plant transfer factor (TF). The reference soil concentrations of radiocesium for rice and soybean were calculated using available domestic TF data, and were proposed for provisional use at the time of a severe NPP accident. The present RSCs are based on limited numbers of 137 Cs TF values. More amounts of relevant TF data should be produced to have more reliable RSCs. For other staple-food plants such as Chinese cabbage and radish, RSCs of radiocesium should also be established. However, only a couple of relevant domestic TF values are available for these vegetables

  17. Proposal for Reference Soil Concentrations of Radiocesium Applicable to Accidentally Contaminated Rice and Soybean Fields

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong-Ho; Lim, Kwang-Muk; Jun, In; Kim, Byung-Ho; Keum, Dong-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Radionuclides in arable soil can be transferred to food plants via root uptake. If radionuclide concentrations in food plants to be grown in contaminated soil are estimated to be higher than the authorized food standards, their culture needs to be cancelled or ameliorating practices need to be taken. Therefore, it is necessary to establish soil concentration limits or reference soil concentrations of radiocesium standing with the food standards in preparation for potential severe NPP accidents in this and adjacent countries. In the present study, reference soil concentrations of radiocesium for rice and soybean, two of the most important food plants in Korea, were provisionally established using all relevant domestic data of soil-to-plant transfer factor (TF). The reference soil concentrations of radiocesium for rice and soybean were calculated using available domestic TF data, and were proposed for provisional use at the time of a severe NPP accident. The present RSCs are based on limited numbers of {sup 137}Cs TF values. More amounts of relevant TF data should be produced to have more reliable RSCs. For other staple-food plants such as Chinese cabbage and radish, RSCs of radiocesium should also be established. However, only a couple of relevant domestic TF values are available for these vegetables.

  18. Measurement methodology of vegetable samples from an area affected by residual contamination due to uranium mining sterile; Metodologia de medida de muestras vegetales procedentes de un terreno afectado por contaminacion residual debida a esteriles de mineria de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, N.; Suarez, J. A.; Yague, L.; Ortiz Gandia, M. I.; Marijuan, M. J.; Garcia, E.; Ortiz, T.; Alvarez, A.

    2013-07-01

    This paper presents the methodology established for radiological characterization of plant material generated during the first stage of the realization of a movement of land in an area of land affected by residual contamination due to the burial of sterile of uranium mining. (Author)

  19. The Effects of Arbuscular Mycorrhizal Fungi on Nitrogen Concentration of Berseem Clover in Contaminated Soil with Cadmium

    OpenAIRE

    H. Aram; A. Golchin

    2013-01-01

    The effects of Arbuscular Mycorrhizal fungi on nitrogen concentration of berseem clover were examined in contaminated soil with cadmium. Examined factors included: levels of arbuscular mycorrhizal fungi inoculation (Glomus mosseae) (With and without inoculation), and different levels of soil contamination by cadmium (0, 5, 10, 20, 40 and 80 mg.kg-1). The results showed that the effects of cadmium levels and mycorrhiza fungi were significant on nitrogen concentration (P≤ 0.01).  Arbuscular myc...

  20. Process for treating waste water having low concentrations of metallic contaminants

    Science.gov (United States)

    Looney, Brian B; Millings, Margaret R; Nichols, Ralph L; Payne, William L

    2014-12-16

    A process for treating waste water having a low level of metallic contaminants by reducing the toxicity level of metallic contaminants to an acceptable level and subsequently discharging the treated waste water into the environment without removing the treated contaminants.

  1. Predicting contaminant concentration at a pumping well with method combining statistical and mathematical models

    Science.gov (United States)

    Lim, J.; Bae, G.; Kaown, D.; Lee, K.

    2008-12-01

    In predicting contamination of groundwater, both the statistical and mathematical modeling methods are used in combination with one another with the aim of taking the advantage of each method. With a mathematical model based on the backward transport equation, probabilistic capture zones of pumping wells are delineated. And these capture zones are used as a buffer zone of each pumping well for a statistical regression model. Tobit regression model is used to investigate the influence of land use on contaminant concentration at a pumping well. Using probabilistic capture zones as buffer zones instead of circular zones, flow and transport regime near pumping wells can be considered in the regression model as well as different types of land use. The method is applied to a small agricultural basin in Chuncheon, Korea which is occupied by vegetation fields, orchards and small barns. Accordingly, chemical fertilizers and manures are frequently applied on the land surface for agricultural purposes. Area of land use type - vegetation fields, orchards, and small barns - within the probabilistic capture zones, land slope, and elevation are used as explanatory variables. As dependent variable, nitrate concentrations observed at pumping wells are used. The proposed method gives better prediction of nitrate concentration than the general regression model using circular buffer zones does. Also, it is expected that the proposed method can be effectively used to relate the loading mass of fertilizer and its concentration in ground water at pumping wells and further to suggest an allowable loading mass of fertilizer for preservation of ground water quality under regulatory limits.

  2. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    Science.gov (United States)

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.

  3. Foraging and fasting can influence contaminant concentrations in animals: an example with mercury contamination in a free-ranging marine mammal

    Science.gov (United States)

    Peterson, Sarah; Ackerman, Joshua T.; Crocker, Daniel E.; Costa, Daniel P.

    2018-01-01

    Large fluctuations in animal body mass in relation to life-history events can influence contaminant concentrations and toxicological risk. We quantified mercury concentrations in adult northern elephant seals (Mirounga angustirostris) before and after lengthy at sea foraging trips (n = 89) or fasting periods on land (n = 27), and showed that mercury concentrations in blood and muscle changed in response to these events. The highest blood mercury concentrations were observed after the breeding fast, whereas the highest muscle mercury concentrations were observed when seals returned to land to moult. Mean female blood mercury concentrations decreased by 30% across each of the two annual foraging trips, demonstrating a foraging-associated dilution of mercury concentrations as seals gained mass. Blood mercury concentrations increased by 103% and 24% across the breeding and moulting fasts, respectively, demonstrating a fasting-associated concentration of mercury as seals lost mass. In contrast to blood, mercury concentrations in female's muscle increased by 19% during the post-breeding foraging trip and did not change during the post-moulting foraging trip. While fasting, female muscle mercury concentrations increased 26% during breeding, but decreased 14% during moulting. Consequently, regardless of exposure, an animal's contaminant concentration can be markedly influenced by their annual life-history events.

  4. Geotechnical behavior of a tropical residual soil contaminated with soap solution

    Directory of Open Access Journals (Sweden)

    Yamile Valencia-González

    2015-01-01

    Full Text Available Los suelos tropicales son aquellos que debido a factores como el clima, la humedad y otras condiciones propias del trópico, p oseen características físicas, químicas, mineralógicas y mecánicas diferentes a los su elos de las zonas templadas. Dichas particularidades y la acción contaminante en el medio producida por el hombre, son la motivación del presente artículo, el cual pretende analizar u n suelo de origen residual tropical ubicado en el municipio de Guarne – A ntioquia (Colombia, mediante la realización de ensayos de laboratorio, algunos de los cuales son más adecuados para caracterizar este tipo de suelos (Clasificación Miniatura Compactado Tropical, S ucción, Pinhole Test, Desagregación, Índice de Colapso, Dif racción de rayos “X”, Microscopía Electrónica de Barrido, a muestras tanto en estado natural como contaminadas con una solución jabonosa, para establecer las diferencias entre las características geotécn icas de dicho suelo en ambas condiciones y posterior mente, discutir la influencia que tiene el contaminante en sus propiedades.

  5. Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  6. Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  7. Radiocesium concentrations in wholebody homogenates and several body compartments of naturally contaminated white-tailed deer

    International Nuclear Information System (INIS)

    Brisbin, I.L. Jr.; Smith, M.H.

    1975-01-01

    Radiocesium concentrations were determined for various tissues, organs, and other body compartments of 17 white-tailed deer collected from contaminated habitats on the AEC Savannah River Plant. Highest levels of radiocesium concentration were found in skeletal muscle, feces, kidney, and adrenal tissue, which averaged between 50 to 70 pCi radiocesium/g (dry weight). Liver and bone showed the lowest average values. With the exception of feces and rumen contents, nearly all tissues and organ compartments showed significant positive linear correlations between their respective radiocesium levels. Analyses of whole-body homogenates indicated that the deer examined averaged 9.91 pCi radiocesium/g (whole-body wet weight). These values were best predicted from the radiocesium contents of skeletal muscle, using the relationship: pCi radiocesium/g dry whole-body weight = 3.33 + 0.60 (pCi/g dry skeletal muscle). Calculation of a weighted ''predictive index'' indicated that concentrations in skeletal muscle best predicted the overall pattern and levels of radiocesium distribution within all compartments of the deer body. Radiocesium concentrations in the brain, heart, and liver, respectively, followed muscle in order of predictive ability

  8. Predicting redox-sensitive contaminant concentrations in groundwater using random forest classification

    Science.gov (United States)

    Tesoriero, Anthony J.; Gronberg, Jo Ann; Juckem, Paul F.; Miller, Matthew P.; Austin, Brian P.

    2017-08-01

    Machine learning techniques were applied to a large (n > 10,000) compliance monitoring database to predict the occurrence of several redox-active constituents in groundwater across a large watershed. Specifically, random forest classification was used to determine the probabilities of detecting elevated concentrations of nitrate, iron, and arsenic in the Fox, Wolf, Peshtigo, and surrounding watersheds in northeastern Wisconsin. Random forest classification is well suited to describe the nonlinear relationships observed among several explanatory variables and the predicted probabilities of elevated concentrations of nitrate, iron, and arsenic. Maps of the probability of elevated nitrate, iron, and arsenic can be used to assess groundwater vulnerability and the vulnerability of streams to contaminants derived from groundwater. Processes responsible for elevated concentrations are elucidated using partial dependence plots. For example, an increase in the probability of elevated iron and arsenic occurred when well depths coincided with the glacial/bedrock interface, suggesting a bedrock source for these constituents. Furthermore, groundwater in contact with Ordovician bedrock has a higher likelihood of elevated iron concentrations, which supports the hypothesis that groundwater liberates iron from a sulfide-bearing secondary cement horizon of Ordovician age. Application of machine learning techniques to existing compliance monitoring data offers an opportunity to broadly assess aquifer and stream vulnerability at regional and national scales and to better understand geochemical processes responsible for observed conditions.

  9. Spatial uncoupling of biodegradation, soil respiration, and PAH concentration in a creosote contaminated soil.

    Science.gov (United States)

    Bengtsson, Göran; Törneman, Niklas; Yang, Xiuhong

    2010-09-01

    Hotspots and coldspots of concentration and biodegradation of polycyclic aromatic hydrocarbons (PAHs) marginally overlapped at the 0.5-100 m scale in a creosote contaminated soil in southern Sweden, suggesting that concentration and biodegradation had little spatial co-variation. Biodegradation was substantial and its spatial variability considerable and highly irregular, but it had no spatial autocorrelation. The soil concentration of PAHs explained only 20-30% of the variance of their biodegradation. Soil respiration was spatially autocorrelated. The spatial uncoupling between biodegradation and soil respiration seemed to be governed by the aging of PAHs in the soil, since biodegradation of added 13C phenanthrene covaried with both soil respiration and microbial biomass. The latter two were also correlated with high concentrations of phospholipid fatty acids (PLFAs) that are common in gram-negative bacteria. However, several of the hotspots of biodegradation coincided with hotspots for the distribution of a PLFA indicative of fungal biomass. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Blood gas sample spiking with total parenteral nutrition, lipid emulsion, and concentrated dextrose solutions as a model for predicting sample contamination based on glucose result.

    Science.gov (United States)

    Jara-Aguirre, Jose C; Smeets, Steven W; Wockenfus, Amy M; Karon, Brad S

    2018-03-16

    Evaluate the effects of blood gas sample contamination with total parenteral nutrition (TPN)/lipid emulsion and dextrose 50% (D50) solutions on blood gas and electrolyte measurement; and determine whether glucose concentration can predict blood gas sample contamination with TPN/lipid emulsion or D50. Residual lithium heparin arterial blood gas samples were spiked with TPN/lipid emulsion (0 to 15%) and D50 solutions (0 to 2.5%). Blood gas (pH, pCO2, pO2), electrolytes (Na+, K+ ionized calcium) and hemoglobin were measured with a Radiometer ABL90. Glucose concentration was measured in separated plasma by Roche Cobas c501. Chart review of neonatal blood gas results with glucose >300 mg/dL (>16.65 mmol/L) over a seven month period was performed to determine whether repeat (within 4 h) blood gas results suggested pre-analytical errors in blood gas results. Results were used to determine whether a glucose threshold could predict contamination resulting in blood gas and electrolyte results with greater than laboratory-defined allowable error. Samples spiked with 5% or more TPN/lipid emulsion solution or 1% D50 showed glucose concentration >500 mg/dL (>27.75 mmol/L) and produced blood gas (pH, pO 2 , pCO 2 ) results with greater than laboratory-defined allowable error. TPN/lipid emulsion, but not D50, produced greater than allowable error in electrolyte (Na + ,K + ,Ca ++ ,Hb) results at these concentrations. Based on chart review of 144 neonatal blood gas results with glucose >250 mg/dL received over seven months, four of ten neonatal intensive care unit (NICU) patients with glucose results >500 mg/dL and repeat blood gas results within 4 h had results highly suggestive of pre-analytical error. Only 3 of 36 NICU patients with glucose results 300-500 mg/dL and repeat blood gas results within 4 h had clear pre-analytical errors in blood gas results. Glucose concentration can be used as an indicator of significant blood sample contamination with either TPN

  11. Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods

    Science.gov (United States)

    This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS). Sample preparation involves QuEChE...

  12. Time Evolution of Activity Concentration of Natural Emitters in a Scenario Affected By Previous Phosphogypsum Contamination

    Science.gov (United States)

    Villa, M.; Mantero, J.; Mosqueda, F.; Hurtado, S.; Manjón, G.; Vaca, F.; García-Tenorio, R.

    2008-08-01

    The estuary formed by the confluence of Tinto and Odiel river-mouths is located in the South of Spain, close to Huelva town. This estuary has been deeply studied through the years because it has a double particularity. On one hand, since the beginning of the 1960s, the estuary has been affected by direct and indirect phosphogypsum (pg.) releases from two phosphoric acid and fertilizers factories that are working in the area. On the other hand, the pyrite mining operations upstream the Odiel and Tinto rivers has caused historically the formation of H2SO4, through oxidation of the natural sulphur deposits, the acidification of the waters and the consequent mobilisation of heavy metals from the mining area to the Huelva estuary. As a consequence, enhancement contamination levels in natural emitters from the 238U series were found in the surroundings of the factories in the previous years to 1998. However, in 1998 the management policy of waste releases drastically changed in the area, and direct discharges to Tinto and Odiel River had to be ceased. A thorough study of the affected zone is being carried out. Riverbed sediments and water samples have been analyzed from four different sampling campaigns in the estuary during the years 1999, 2001, 2002 and 2005. Different radioanalytical techniques have been employed to obtain the activity concentrations of U-isotopes, Th-isotopes, 226Ra, 210Pb and 210Po. Furthermore, the results for the rates of de-contamination of the area are presented. This data will be discussed in order to establish the present status of the contamination in the area, and moreover, to predict the time-evolution of the self-cleaning

  13. Residual antibiofilm effects of various concentrations of double antibiotic paste used during regenerative endodontics after different application times.

    Science.gov (United States)

    Jenks, Daniel B; Ehrlich, Ygal; Spolnik, Kenneth; Gregory, Richard L; Yassen, Ghaeth H

    2016-10-01

    We investigated the residual antibiofilm effects of different concentrations of double antibiotic paste (DAP) applied on radicular dentin for 1 or 4 weeks. Dentin samples were prepared (n=120), sterilized and pretreated for 1 or 4 weeks with the clinically used concentration of DAP (500mg/mL), low concentrations of DAP (1, 5 or 50mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH) 2 ), or placebo paste. After the assigned treatment time, treatment pastes were rinsed off and the samples were kept independently in phosphate buffered saline for 3 weeks. Pretreated dentin samples were then inoculated with Enterococcus faecalis and bacterial biofilms were allowed to grow for an additional 3 weeks. Biofilms were then retrieved from dentin using biofilm disruption assays, diluted, spiral plated, and quantified. Fisher's Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05). Dentin pretreatment for 4 weeks with 5, 50 or 500mg/mL of DAP demonstrated significantly higher residual antibiofilm effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1mg/mL of DAP or Ca(OH) 2 did not provide a substantial residual antibiofilm effect regardless of the application time. Dentin pretreatment with 5mg/mL of DAP or higher for 4 weeks induced significantly higher residual antibiofilm effects in comparison to a 1 week pretreatment with the same concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Monitoring of the declining trend of Polychlorobifenyls concentration in milk of contaminated dairy cows

    Directory of Open Access Journals (Sweden)

    Gianfranco Piva

    2010-02-01

    Full Text Available Six pregnant heifers, coming from a herd with a history of high concentration of polychlorobifenyls (PCB into the milk, were fed with a very low-PCB diet starting from the 6th month of pregnancy. After parturition cows were milked for at least 190 d with a maximum of 270 d. Diet was made of: corn silage (31.7% of DMI, dehydrated alfalfa (13.3% of DMI, grass hay (3.7% of DMI and concentrate (51.3% of DMI. The average DMI was 23.12 kg/d. Milk production was recorded and samples of milk and blood were taken and analyzed for PCB (18, 28, 31, 52, 44, 101, 149, 118, 153, 138, 180 and 194 congeners content using a GC-MS technique. The average milk yield (kg/d of the 6 cows was 26.0, 22.5, 23.2, 24.5, 28.9, 29.3. The maximum PCB concentration of 100 ng/g of fat allowed by the Italian law was reached after 144-209 d of lactation. One animal after 204 days had a PCB concentration of 102 ng/g fat. If log10 of PCB concentration (ppb in milk fat is regressed against days in milking (DIM the following significant equation was obtained: log10 PCB (ng/g of milk fat= 2.796 -0.00474 DIM; r2 0.72; P<0.01 The initial level of contamination is not the main factor affecting the time required in order for PCB to return to below the legal threshold of 100 ng/g fat, while daily milk yield significantly affects PCB excretion. Body condition and energy balance could be important factors affecting PCB excretion. In the presence of high contamination, about 6 months of lactation are required in order to obtain milk with a sufficiently low PCB content. Among the seven congeners considered by Italian legislation, PCB 101, PCB 118, PCB 138, PCB 153 constitute almost all the PCBs found in tissues and milk, with a much smaller presence of PCB 180, and the numbers of the congeners PCB 28 and PCB 52 are almost insignificant, probably because they accumulate little in the body. The congeners PCB 138 and PCB 153 are those most frequently found. For PCB 138 the liver is the principal

  15. Dioxin concentration in milk, faeces and tissues of cows related to feed contamination

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, A.J.; Kamphues, J. [Inst. of Animal Nutrition, School of Veterinary Medicine, Hannover (Germany); Wiesmueller, T. [Federal State Office for Consumer Protection, Potsdam (Germany); Appuhn, H. [Agricultural Investigation and Research Inst., Hameln (Germany); Stehr, D. [District Government of Lueneburg (Germany); Severin, K. [Chamber for Agriculture, Hannover (Germany); Landmann, D. [Agricultural Teaching and Research Facility, Echem (Germany)

    2004-09-15

    Dioxin contamination of feed and food is a frequently discussed problem, even in the press. The EU legislation sets maximum levels for dioxins in food and feeding stuffs. The dioxin concentration of milk, faeces and tissues of lactating cows grazing in an area of higher dioxin level in the soil and grass, has been tested in part 1 of this small scale field study. Soil intake of grazing cows can reach 1.5 kg soil/d under extreme meteorological conditions. Considering that, the dioxin load of soil and the degree of contamination of feedstuffs could play an important role regarding the exposition of grazing animals. Due to repeated flooding the area the experiment took place was known for a higher dioxin level in soil and grass. The area was separated in a depression and an elevation (in flooding areas depressions are known for their higher dioxin level). Grassland is not only used for grazing animals, but also to obtain hay or grass silage. In part 2 of the field study grass silage obtained on the same area, was fed to dry cows to test whether or not there a risk for milk quality after parturition. The primary aim of this field study was to investigate different matrices at different moments of the experiment. The secondary aim was to develop recommendations on how to prevent or at least how to minimize the dioxin load of feed and with it of food, if food producing animals graze on such areas.

  16. A survey of chlortetracycline concentration in feed and its residue in chicken egg in commercial layer farms.

    Science.gov (United States)

    Kodimalar, K; Rajini, R A; Ezhilvalavan, S; Sarathchandra, G

    2014-06-01

    The worldwide increase in the use of antibiotics as an integral part of poultry and livestock production industry has recently received increasing attention as a contributory factor in the international emergence of antibiotic-resistant bacteria in human beings. To gauge the presence of the aforementioned scenario in the Indian context, a preliminary survey was conducted to assess the use of chlortetracycline (CTC) in 12 commercial layer farms and to quantify and confirm its residue in the egg. Samples of feed and eggs were collected at day 0 (prior to CTC addition), 3rd, 5th and 7th day during treatment and on the 9th and 14th day (2nd and 7th day after withdrawal of CTC) from each of the 12 commercial poultry farms studied. Concentration of CTC in feed was significantly (P less than 0.01) high on the 3rd, 5th and 7th day. On the 9th day and 14th day CTC concentration in feed was significantly (P less than 0.01) lower compared to the earlier 3 days studied. A highly significant difference (P less than 0.01) of the antibiotic residue in egg was observed in all the 5 days with high residual levels of CTC in egg. CTC in feed and its residue in egg were detected even on the 9th and 14th day respectively.

  17. Effects of Heterogeneities, Sampling Frequencies, Tools and Methods on Uncertainties in Subsurface Contaminant Concentration Measurements

    Science.gov (United States)

    Ezzedine, S. M.; McNab, W. W.

    2007-12-01

    Long-term monitoring (LTM) is particularly important for contaminants which are mitigated by natural processes of dilution, dispersion, and degradation. At many sites, LTM can require decades of expensive sampling at tens or even hundreds of existing monitoring wells, resulting in hundreds of thousands, or millions of dollars per year for sampling and data management. Therefore, contaminant sampling tools, methods and frequencies are chosen to minimize waste and data management costs while ensuring a reliable and informative time-history of contaminant measurement for regulatory compliance. The interplay play between cause (i.e. subsurface heterogeneities, sampling techniques, measurement frequencies) and effect (unreliable data and measurements gap) has been overlooked in many field applications which can lead to inconsistencies in time- histories of contaminant samples. In this study we address the relationship between cause and effect for different hydrogeological sampling settings: porous and fractured media. A numerical model has been developed using AMR-FEM to solve the physicochemical processes that take place in the aquifer and the monitoring well. In the latter, the flow is governed by the Navier-Stokes equations while in the former the flow is governed by the diffusivity equation; both are fully coupled to mimic stressed conditions and to assess the effect of dynamic sampling tool on the formation surrounding the monitoring well. First of all, different sampling tools (i.e., Easy Pump, Snapper Grab Sampler) were simulated in a monitoring well screened in different homogeneous layered aquifers to assess their effect on the sampling measurements. Secondly, in order to make the computer runs more CPU efficient the flow in the monitoring well was replaced by its counterpart flow in porous media with infinite permeability and the new model was used to simulate the effect of heterogeneities, sampling depth, sampling tool and sampling frequencies on the

  18. Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations.

    Science.gov (United States)

    Kachapulula, P W; Akello, J; Bandyopadhyay, R; Cotty, P J

    2017-06-01

    The aims of the study were to quantify aflatoxins, the potent carcinogens associated with stunting and immune suppression, in maize and groundnut across Zambia's three agroecologies and to determine the vulnerability to aflatoxin increases after purchase. Aflatoxin concentrations were determined for 334 maize and groundnut samples from 27 districts using lateral-flow immunochromatography. Seventeen per cent of crops from markets contained aflatoxin concentrations above allowable levels in Zambia (10 μg kg -1 ). Proportions of crops unsafe for human consumption differed significantly (P Aflatoxin in groundnut (39 μg kg -1 ) and maize (16 μg kg -1 ) differed (P = 0·032). Poor storage (31°C, 100% RH, 1 week) increased aflatoxin in safe crops by over 1000-fold in both maize and groundnut. The L morphotype of Aspergillus flavus was negatively correlated with postharvest increases in groundnut. Aflatoxins are common in Zambia's food staples with proportions of unsafe crops dependent on agroecology. Fungal community structure influences contamination suggesting Zambia would benefit from biocontrol with atoxigenic A. flavus. Aflatoxin contamination across the three agroecologies of Zambia is detailed and the case for aflatoxin management with atoxigenic biocontrol agents provided. The first method for evaluating the potential for aflatoxin increase after purchase is presented. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

  19. Effects of Bacillus subtilis ANSB060 on growth performance, meat quality and aflatoxin residues in broilers fed moldy peanut meal naturally contaminated with aflatoxins.

    Science.gov (United States)

    Fan, Yu; Zhao, Lihong; Ma, Qiugang; Li, Xiaoying; Shi, Huiqin; Zhou, Ting; Zhang, Jianyun; Ji, Cheng

    2013-09-01

    This study was conducted to investigate the toxic effects of aflatoxins and the efficacy of Bacillus subtilis ANSB060 for the amelioration of aflatoxicosis in broiler chickens. Six replicates of ten broilers each were assigned to one of seven dietary treatments, which were labeled C0 (basal diet); M0 (basal diet containing moldy peanut meal); C500 and C1000 (C0+500 or 1000 g/t aflatoxin biodegradation preparations, composed mainly of ANSB060); and M500, M1000 and M2000 (M0+500, 1000 or 2000 g/t aflatoxin biodegradation preparations). The concentrations of aflatoxin B₁, B₂, G₁ and G₂ in the moldy diets (M0, M500, M100 and M2000) fluctuated around 70.7±1.3, 11.0±1.5, 6.5±0.8 and 2.0±0.3 μg/kg, respectively. The results showed that the M0 diet caused a significant decrease in average daily weight gain and increased feed requirements, with a gain ratio increasing from d 8 to 42, deterioration in meat quality and aflatoxin residues in broilers' livers as compared with the C0 diet. The addition of ANSB060 to the aflatoxin-contaminated diets offset these negative effects, leading to the conclusion that ANSB060 has a protective effect on growth performance and meat quality while reducing the amount of aflatoxin residues in the livers of broilers fed naturally moldy peanut meal. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. A survey of chlortetracycline concentration in feed and its residue in ...

    Indian Academy of Sciences (India)

    2014-04-04

    Apr 4, 2014 ... Food Control 15 99–105. Kan C A and Petz M 2000 Residues of veterinary drugs in eggs and their distribution between yolk and white. J. Agri. Food Chem. 48 6397–6403. Kennedy DG, McCracken RJ, Hewitt SA and McEvoy JDG 1998. Metabolism of chlortetracycline: drug accumulation and excre-.

  1. EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

    2005-07-01

    Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

  2. EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

    Energy Technology Data Exchange (ETDEWEB)

    Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shen Zhenguo [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lou Laiqing [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: cexdli@polyu.edu.hk

    2006-12-15

    The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil.

  3. Persistent organochlorine residues in human breast milk from Hanoi and Hochiminh City, Vietnam contamination, accumulation kinetics and risk assessment for infants

    International Nuclear Information System (INIS)

    Minh, Nguyen Hung; Someya, Masayuki; Minh, Tu Binh; Kunisue, Tatsuya; Iwata, Hisato; Watanabe, Mafumi; Tanabe, Shinsuke; Viet, Pham Hung; Tuyen, Bui Cach

    2004-01-01

    Despite the ban on persistent organochlorines (OCs) in most of the developed nations, their usage continued until recently in many Asian developing countries including Vietnam, for agricultural purposes and vector-borne disease eradication programs. In this study, we collected human breast milk samples from the two big cities in Vietnam: Hanoi (n=42) and Hochiminh (n=44) and determined the concentrations of persistent OCs such as PCBs, DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and tris-4-chlorophenyl-methane (TCPMe). The contamination pattern of OCs was in the order of DDTs > PCBs > HCHs > CHLs∼HCB∼TCPMe. Compilation of available data indicated that DDT residue levels in human breast milk from Vietnam were among the highest values reported for Asian developing countries as well as developed nations. This result suggests recent usage of DDTs in both north and south Vietnam. Interestingly, in both cities, the p,p'-DDT portion was higher in multiparas than those in primiparas. Considering the fact that the interval between the first and the second child of a mother in Vietnam is usually short, this result probably indicates continuous intake of DDTs in the population. Analysis of infant exposure to DDTs via breast milk suggested that the daily intake rates for number of individuals are close to or above the threshold for adverse effects which may raise concern on children health. - It is suggested that daily intake rates of persistent organochlorines in mothers in Vietnam may result in health risk for nursing children

  4. Review of alternative residual contamination guides for the 324 Building B-Cell Cleanout Project. Phase 1

    International Nuclear Information System (INIS)

    Vargo, G.J.; Durham, J.S.; Brackenbush, L.W.

    1995-09-01

    This report provides a proposed residual contamination guide (RCG) for the 324 Building B-Cell Cleanout Project, Phase 1, at the Hanford Site. The RCG is expressed as a fraction of the amount of highly dispersible radioactive material that would result in offsite doses equal to the Pacific Northwest Laboratory radiological risk guidelines following the worst credible accident scenario for release of the holdup material. The proposed RCG is 10 -1 to 10 -2 of the PNL radiological risk guidelines. As part of the development of the RCG, a number of factors were considered. These include the need to provide an appropriate level of flexibility for other activities within the 324 Building that could contribute to the facility's overall radiological risk, uncertainties inherent in safety analyses, and the possible contribution of other 300 Area facilities to overall radiological risk. Because of these factors and the nature of the cleanout project, the RCG is expressed as a range rather than a point value. This report also provides guidance on determining conformance to the RCG, including inspection and measurement techniques, quality assurance requirements, and consideration of uncertainty

  5. Hanford Tanks 241-C-202 and 241-C-203 Residual Waste Contaminant Release Models and Supporting Data

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F.; Mattigod, Shas V.; Schaef, Herbert T.; Arey, Bruce W.

    2007-09-13

    As directed by Congress, the U. S. Department of Energy (DOE) established the Office of River Protection in 1998 to manage DOE's largest, most complex environmental cleanup project – retrieval of radioactive waste from Hanford tanks for treatment and eventual disposal. Sixty percent by volume of the nation's high-level radioactive waste is stored at Hanford in aging deteriorating tanks. If not cleaned up, this waste is a threat to the Columbia River and the Pacific Northwest. CH2M Hill Hanford Group, Inc., is the Office of River Protection's prime contractor responsible for the storage, retrieval, and disposal of Hanford's tank waste. As part of this effort, CH2M HILL Hanford Group, Inc. contracted with Pacific Northwest National Laboratory (PNNL) to develop release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, Inc., for DOE.

  6. Disposal of radioactive residuals requires careful planning

    International Nuclear Information System (INIS)

    Pontius, F.W.

    1994-01-01

    Radionuclides removed from source waters during water treatment become concentrated in residual liquids and sludges. Treatment technologies used to remove these contaminants from source waters may generate wastes that contain substantial radioactivity. Water systems that install one or more of these technologies in order to comply with the maximum contaminant levels (MCLs) eventually adopted must dispose of the residuals. Disposal of radionuclide-containing wastes can be especially difficult, depending on the nature and amount of radioactivity present

  7. Residues of legacy organochlorine contaminants in the milk of Alpine and Saanen goats from the central region of Mexico.

    Science.gov (United States)

    Schettino, Beatriz; Gutiérrez, Rey; Ortiz, Rutilio; Vega, Salvador; Urban, Georgina; Ramírez, Acacia

    2013-08-01

    This study investigated a suite of legacy organochlorine contaminants in the milk of two breeds of goats raised in the central region of Mexico, where this agricultural production is of national (Mexican) economic importance. Forty milk samples from Alpine and Saanen goats were assessed. It was found that the concentrations of the majority of organochlorine pesticides in milk samples were lower than those stipulated in Mexican and international regulation. The values in both breeds of goat exceeded the upper permissible limits of Codex Alimentarius for delta hexachloro cyclohexane (HCH) (17.3 of samples of Saanen) and heptachlor plus heptachlor epoxide (50 % and 13 % of samples). It may be concluded that milk from these goat breeds from central Mexico showed some risks of contamination in certain times of the year (dry season). However, under further assessment and use of pesticides the goat's milk will likely be safe for human consumption and for use in products such as cheeses, regional candies and desserts (cajeta). In recent years, goat milk production has increased in the central regions and it is an economic alternative to milk from livestock. It is necessary to continue the monitoring of goat's milk to assess the presence and control of HCHs through best management practices.

  8. Uncertainty assessment of gamma-aminobutyric acid concentration of different brain regions in individual and group using residual bootstrap analysis.

    Science.gov (United States)

    Chen, Meng; Liao, Congyu; Chen, Song; Ding, Qiuping; Zhu, Darong; Liu, Hui; Yan, Xu; Zhong, Jianhui

    2017-06-01

    The aim of this work is to quantify individual and regional differences in the relative concentration of gamma-aminobutyric acid (GABA) in human brain with in vivo magnetic resonance spectroscopy. Spectral editing Mescher-Garwood point resolved spectroscopy (MEGA-PRESS) sequence and GABA analysis toolkit (Gannet) were used to detect and quantify GABA in anterior cingulate cortex (ACC) and occipital cortex (OCC) of healthy volunteers. Residual bootstrap, a model-based statistical analysis technique, was applied to resample the fitting residuals of GABA from the Gaussian fitting model (referred to as GABA + thereafter) in both individual and group data of ACC and OCC. The inter-subject coefficient of variation (CV) of GABA + in OCC (20.66 %) and ACC (12.55 %) with residual bootstrap was lower than that of a standard Gaussian model analysis (21.58 % and 16.73 % for OCC and ACC, respectively). The intra-subject uncertainty and CV of OCC were lower than that of ACC in both analyses. The residual bootstrap analysis thus provides a more robust uncertainty estimation of individual and group GABA + detection in different brain regions, which may be useful in our understanding of GABA biochemistry in brain and its use for the diagnosis of related neuropsychiatric diseases.

  9. Distribuição e biodisponibilidade de crômio em solos contaminados por resíduos de couro Distribution and bioavailability of chromium in contaminated soils by tannery residues

    Directory of Open Access Journals (Sweden)

    Ademir dos Santos

    2009-01-01

    Full Text Available Samples of soil, water and sediment were collected and analyzed in order to evaluate chromium contamination due to deposition of tannery residues onto soils under different management regimes. The results showed that soils used for sugar cane cultivation were not adversely impacted. However, in the case of mango plantations, variable concentrations of chromium were measured in the soil profile, with 22.2% of values being higher than permitted legal limits, and 38.9% being at levels requiring remediation. Concentrations of bioavailable chromium were lower than the detection limit of the method (0.01 mg of chromium kg-1 of soil, indicating that all of the chromium present in the samples was either complexed or in an insoluble form. Chromium concentrations measured in samples of water and sediments were indicative of low mobility of the metal in soils. The main cause of differences found between soil samples obtained from different cultivations was the type of soil management.

  10. The Effects of Arbuscular Mycorrhizal Fungi on Nitrogen Concentration of Berseem Clover in Contaminated Soil with Cadmium

    Directory of Open Access Journals (Sweden)

    H. Aram

    2013-08-01

    Full Text Available The effects of Arbuscular Mycorrhizal fungi on nitrogen concentration of berseem clover were examined in contaminated soil with cadmium. Examined factors included: levels of arbuscular mycorrhizal fungi inoculation (Glomus mosseae (With and without inoculation, and different levels of soil contamination by cadmium (0, 5, 10, 20, 40 and 80 mg.kg-1. The results showed that the effects of cadmium levels and mycorrhiza fungi were significant on nitrogen concentration (P≤ 0.01.  Arbuscular mycorrhizal fungi increased nitrogen concentration in the root and aerial plant 30% and 40.3% respectively. Also cadmium in concentration of 80 mg.kg-1 reduced nitrogen concentration in root and aerial plant 28.3% and 35% respectively.

  11. Polychlorobenzenes and polychlorinated biphenyls in ash and soil from several industrial areas in North Vietnam: residue concentrations, profiles and risk assessment.

    Science.gov (United States)

    Nguyen, Thi Hue; Nguyen, Thi Thu Thuy; Nguyen, Hoang Tung

    2016-04-01

    Polychlorinated benzenes (PCBzs) including penta- and hexachlorobenzene can be unintentionally formed from thermal processes in different industrial activities, and very little information is available on the contamination and emission characteristics of these new persistent organic pollutants from industries in Vietnam. In this study, contamination of PCBzs (including penta- and hexachlorobenzene, named PeCBz and HCB, respectively) and PCBs (including CB-28, 52, 101, 153, 138, 180) in fly ash, bottom ash and soil from combustion processes of waste incineration, metallurgy (steel making and zinc production) and cement production from several provinces in the Northern Vietnam, including Hai Duong, Hanoi, Bac Ninh, Hai Phong and Thai Nguyen, was preliminary investigated. The PCBzs concentrations in fly ash, bottom ash and soil ranged from 2.7 to 100 ng g(-1), from 2.7 to 159 ng g(-1) and from 0.28 to 33.9 ng g(-1), respectively. Relatively high residues of PeCBz in fly ash and bottom ash from municipal waste incinerators in some provinces from the Northern Vietnam were encountered. Total PCBs concentrations ranged from 18.0 to 8260 ng g(-1), from 1.0 to 10600 ng g(-1) and from 14.5 to 130 ng g(-1) for the fly ash, bottom ash and soil, respectively. Daily intakes of PeCBz, HCB and PCBs through soil ingestion and dermal exposure estimated for children ranged 0.33-9.93 (mean 3.14), 0.39-21.1 (mean 4.9) and 6.09-1530 ng/kg bw/day (mean 346), respectively; and these intakes were about 4.7-5.4 times higher than those estimated for adult. The intakes of PeCBz and HCB were relatively low, while those for PCBs exceeded WHO TDI for some samples.

  12. Effect of Application of Increasing Concentrations of Contaminated Water on the Different Fractions of Cu and Co in Sandy Loam and Clay Loam Soils

    Directory of Open Access Journals (Sweden)

    John Volk

    2016-12-01

    Full Text Available This study aimed to establish the fate of copper (Cu and cobalt (Co in sandy loam and clay loam soils that had been irrigated with increasing concentrations of contaminated water. A sequential extraction procedure was used to determine the fractions of Cu and Co in these soils. The concentration of bioavailable Cu and Co on clay loam was 1.7 times that of sandy loam soil. Cu on sandy loam soil was largely in the organic > residual > exchangeable > water-soluble > carbonate fractions, whereas on clay loam soil the element was largely in organic > exchangeable > residual > carbonate > water-soluble fractions. Co was largely observed in the exchangeable, water-soluble, and carbonate fractions, but with no particular trend observed in both soil types. When crops are grown on sandy soils that have a low capacity to hold heavy metals, the resulting effect would be high uptake of the heavy metals in crop plants. Because the predominant forms of Cu and Co vary in soils, it is expected that the metals will behave differently in the soils.

  13. Concentrations of veterinary drug residues in milk from individual farms in Croatia

    Directory of Open Access Journals (Sweden)

    Nina Bilandžić

    2011-09-01

    Full Text Available A total of 119 raw milk samples collected at individual small milk-producing facilities and collection tanks of milk routes from five counties of east and north continental Croatia were examined for chloramphenicol, sulfonamides, tetracyclines, gentamicin, streptomycin, dihydrostreptomycin, flumequine and enrofloxacin from January to March of 2011. Immunoassay methods used for drug determination were validated according to the guidelines laid down by European Commission Decision 2002/657/EC. Data indicated that the methods are appropriate for the detection of antibiotics measured. Measured mean values (μg L-1 of antibiotics were: 0.005 for chloramphenicol, 3.67 for sulfonamides, 2.83 for tetracyclines, 1.10 for gentamicin, 2.64 for streptomycin, 7.67 for dihydrostreptomycin, 10.4 for flumequine and 4.11 for enrofloxacin. None of samples analyzed showed the presence of veterinary drug residues above the maximum residues levels (MRLs established by European Union and Croatian legislation. The calculated estimated daily intakes (EDIs for the average daily milk consumption of 300 mL for an adult in Croatia for examined antibiotics showed levels 20 to 1640 times lower than the values of acceptable daily intakes (ADIs fixed by European Medicines Agency and World Health Organization. This suggested that toxicological risk associated with the consumption of analysed milk could not be considered a public health issue with regards to these veterinary drugs.

  14. Process design of high-concentration benzimidazole wastewater treatment based on the molecular structure of contaminants.

    Science.gov (United States)

    Li, Chenru; Qian, Kun; Liu, Qinyao; Zhang, Qianyi; Yao, Chen; Song, Wei; Wang, Yihong

    2018-04-01

    Benzimidazole is an important intermediate in industry and it is usually difficult to be degraded by many treatment technologies. Looking for a highly effective, environment-friendly degradation process for benzimidazole wastewater is of great significance to reduce pollution. Based on the structure of contaminants, the micro-electrolysis (ME) coupled with the Fenton technique was chosen to degrade the industrial benzimidazole wastewater. Special feeding was applied to maintain the suitable hydrogen peroxide (H 2 O 2 ) concentration to produce the hydroxyl radicals (•OH) as much as possible and protect •OH from being quenched by excess H 2 O 2 according to the reaction mechanism. The results showed that this combined technique was highly efficient to decompose benzimidazole compounds. More chemical oxygen demand (COD) could be reduced when flow control was used, compared to the flow not being controlled. The COD removal rate could reach 85.2% at optimal parameters. Then the effluent of this process was combined with the existing biochemical system for further degradation. The studies of Ultraviolet Spectrophotometry, Fourier Transform Infrared Spectroscopy and Liquid Chromatography Mass Spectrometry showed that both 2-(a-Hydroxyethyl) benzimidazole and 2-Acetylbenzimidazole were decomposed to the isopropanolamine and aniline after the ME treatment; then the intermediates were oxidized into oxalic acid after the Fenton reaction.

  15. Effect of soil biochar concentration on the mitigation of emerging organic contaminant uptake in lettuce.

    Science.gov (United States)

    Hurtado, Carlos; Cañameras, Núria; Domínguez, Carmen; Price, Gordon W; Comas, Jordi; Bayona, Josep M

    2017-02-05

    Although crop uptake of emerging organic contaminants (EOC) from irrigation water and soils has been previously reported, successful mitigation strategies have not yet been established. In this study, soil was amended with a wood-based biochar (BC) at two rates (0, 2.5 and 5% w/w) to evaluate the effect on mitigation of EOC uptake (i.e. bisphenol A, caffeine, carbamazepine, clofibric acid, furosemide, ibuprofen, methyl dihydrojasmonate, tris(2-chloroethyl)phosphate, triclosan, and tonalide) in lettuce (Lactuca sativa L.). After 28 days of irrigation with water containing EOCs at 15μgL -1 , the average EOC concentration in roots and leaves decreased by 20-76% in biochar amended soil relative to non BC-amended soil. In addition, the enantiomeric fractions (EF) of ibuprofen (IBU) in biochar amended soils (EF=0.58) and unamended soils (EF=0.76) suggest that the IBU sorbed fraction in BC is more recalcitrant to its biodegradation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Distributional patterns of arsenic concentrations in contaminant plumes offer clues to the source of arsenic in groundwater at landfills

    Science.gov (United States)

    Harte, Philip T.

    2015-01-01

    The distributional pattern of dissolved arsenic concentrations from landfill plumes can provide clues to the source of arsenic contamination. Under simple idealized conditions, arsenic concentrations along flow paths in aquifers proximal to a landfill will decrease under anthropogenic sources but potentially increase under in situ sources. This paper presents several conceptual distributional patterns of arsenic in groundwater based on the arsenic source under idealized conditions. An example of advanced subsurface mapping of dissolved arsenic with geophysical surveys, chemical monitoring, and redox fingerprinting is presented for a landfill site in New Hampshire with a complex flow pattern. Tools to assist in the mapping of arsenic in groundwater ultimately provide information on the source of contamination. Once an understanding of the arsenic contamination is achieved, appropriate remedial strategies can then be formulated.

  17. Effect of Hydrogen Peroxide Concentration in Remediation of Oil-contaminated Soils with Use of Fenton Reaction

    Directory of Open Access Journals (Sweden)

    A. S. Yousefi

    2013-01-01

    Full Text Available Refining oil-contaminated soils has a great importance especially in oil producer countries such as Iran. Different methods have been provided to eliminate oil contaminations from soil. The aim of this study was to investigate the effect of Hydrogen peroxide concentration in refining oil-contaminated soils with Fenton chemical method. To do this, a calcareous soil complex sample was collected around the Tehran oil refinery and treated with 10 and 20 percent petroleum in three replications. After reaching to balance conditions, the sample was treated using0.01, 0.02,0.12,0.24,0.47 and 0.71 equivalent of Hydrogen peroxide. The results indicated that in all level of H2O2, the eliminating efficiency in 10 percent was more than 20 percent treatment. Also a significant difference between the levels of hydrogen peroxide used in the removal of oil pollution in both surface concentrations was obtained (P<0.01.

  18. Real-time amplification of HLA-DQA1 for counting residual white blood cells in filtered platelet concentrates.

    Science.gov (United States)

    Mohammadi, Tamimount; Reesink, Henk W; Vandenbroucke-Grauls, Christina M J E; Savelkoul, Paul H M

    2004-09-01

    BACKGROUND A real-time polymerase chain reaction (PCR) assay based on amplification of a conserved region of the HLA-DQA1 locus was developed and validated to assess its suitability in quantitating low levels of white blood cells (WBCs) in filtered platelet (PLT) concentrates (PCs). To determine the detection limit, serial dilutions of nonfiltered PCs with known quantities of WBCs were prepared. The analytical sensitivity and accuracy of the assay was tested with WBC concentrations ranging from 300 to 0.03 per microL with real-time PCR and flow cytometry. In addition, 126 random PCs were investigated to assess the capacity of the PCR method to quantify residual WBCs in clinical specimens. A sensitivity of 0.2 WBC equivalent per micro L (1.5 x 10(4) WBC equivalents/unit) was achieved. The assay was shown to be accurate and the HLA-DQA1 gene was reproducibly and consistently amplified in all tested samples (coefficient of variance of < 5%). Overall, the results of the PCR assay correlated well with those of the flow cytometry. The PCR assay detected a concentration of 3 WBCs per micro L (approximately 1 x 10(6) WBCs/unit) with 100 percent accuracy. Real-time PCR is rapid, sensitive, accurate, and reproducible. Hence this approach may prove suitable in routine monitoring of residual WBCs in PCs.

  19. High hole mobility p-type GaN with low residual hydrogen concentration prepared by pulsed sputtering

    Science.gov (United States)

    Arakawa, Yasuaki; Ueno, Kohei; Kobayashi, Atsushi; Ohta, Jitsuo; Fujioka, Hiroshi

    2016-08-01

    We have grown Mg-doped GaN films with low residual hydrogen concentration using a low-temperature pulsed sputtering deposition (PSD) process. The growth system is inherently hydrogen-free, allowing us to obtain high-purity Mg-doped GaN films with residual hydrogen concentrations below 5 × 1016 cm-3, which is the detection limit of secondary ion mass spectroscopy. In the Mg profile, no memory effect or serious dopant diffusion was detected. The as-deposited Mg-doped GaN films showed clear p-type conductivity at room temperature (RT) without thermal activation. The GaN film doped with a low concentration of Mg (7.9 × 1017 cm-3) deposited by PSD showed hole mobilities of 34 and 62 cm2 V-1 s-1 at RT and 175 K, respectively, which are as high as those of films grown by a state-of-the-art metal-organic chemical vapor deposition apparatus. These results indicate that PSD is a powerful tool for the fabrication of GaN-based vertical power devices.

  20. High hole mobility p-type GaN with low residual hydrogen concentration prepared by pulsed sputtering

    Directory of Open Access Journals (Sweden)

    Yasuaki Arakawa

    2016-08-01

    Full Text Available We have grown Mg-doped GaN films with low residual hydrogen concentration using a low-temperature pulsed sputtering deposition (PSD process. The growth system is inherently hydrogen-free, allowing us to obtain high-purity Mg-doped GaN films with residual hydrogen concentrations below 5 × 1016 cm−3, which is the detection limit of secondary ion mass spectroscopy. In the Mg profile, no memory effect or serious dopant diffusion was detected. The as-deposited Mg-doped GaN films showed clear p-type conductivity at room temperature (RT without thermal activation. The GaN film doped with a low concentration of Mg (7.9 × 1017 cm−3 deposited by PSD showed hole mobilities of 34 and 62 cm2 V−1 s−1 at RT and 175 K, respectively, which are as high as those of films grown by a state-of-the-art metal-organic chemical vapor deposition apparatus. These results indicate that PSD is a powerful tool for the fabrication of GaN-based vertical power devices.

  1. Treatment of emerging contaminants in wastewater treatment plants (WWTP) effluents by solar photocatalysis using low TiO2 concentrations

    International Nuclear Information System (INIS)

    Prieto-Rodriguez, L.; Miralles-Cuevas, S.; Oller, I.; Agüera, A.; Puma, G. Li; Malato, S.

    2012-01-01

    Highlights: ► Low TiO 2 concentration suitable for removal of contaminants in WWTP effluents. ► The low concentration of TiO 2 limits the reaction rate due to the loss of photons. ► Contaminant degradation >85% is possible after a certain reaction time. ► New developments in CPC photoreactors with as large an O.D. are necessary. - Abstract: The optimal photocatalyst concentration for industrial wastewater treatment in current photoreactor designs is several hundreds of milligrams per liter. However, the elimination of emerging contaminants (ECs), which are present at extremely low concentrations in waste water treatment plants (WWTP) effluents might be accomplished at much lower catalyst (TiO 2 ) concentrations. One of the main drawbacks of reducing catalyst loading below the optimum is the loss of useful photons which instead are transmitted through the TiO 2 suspension without being absorbed by the catalyst. Accordingly, in this work, laboratory and solar pilot-scale experiments were performed with real WWTP effluents to evaluate the kinetics of photocatalytic degradation of 52 emerging contaminants under realistic (ppb) concentrations. The analysis of the samples was accomplished by solid phase extraction (SPE) followed by liquid chromatography–mass spectrometry (LC–MS). In view of the results, low concentrations of TiO 2 of the order of tens of milligrams per liter were found to be insufficient for the degradation of the ECs in photoreactors with a short light-path length (29 cm). However, it was established that solar reactors of diameters of several hundreds of millimetres could be used for the efficient removal of ECs from WWTP effluents. The results presented show a general methodology for selecting the most efficient reactor diameter on the basis of the desired catalyst concentration.

  2. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA CONTAMINATED BUILDING MODLES VERSUS MEASURED AIR & SURFACE ACTIVITY CONCENTRATIONS

    Energy Technology Data Exchange (ETDEWEB)

    LLOYD, E.R.

    2006-11-02

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures.

  3. OPERATIONAL LIMITATIONS FOR DEMOLITION OF A HIGHLY ALPHA-CONTAMINATED BUILDING- MODELED VERSUS MEASURED AIR and SURFACE ACTIVITY CONCENTRATIONS

    International Nuclear Information System (INIS)

    LLOYD, E.R.

    2006-01-01

    The demolition of a facility historically used for processing and handling transuranic materials is considered. Residual alpha emitting radionuclide contamination poses an exposure hazard if released to the local environment during the demolition. The process of planning for the demolition of this highly alpha contaminated building, 232-Z, included a predemolition modeling analysis of potential exposures. Estimated emission rates were used as input to an air dispersion model to estimate frequencies of occurrence of peak air and surface exposures. Postdemolition modeling was also conducted, based on the actual demolition schedule and conditions. The modeling results indicated that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. During the demolition of 232-Z, airborne radiation and surface contamination were monitored. The resultant non-detect monitoring results indicate a significant level of conservatism in the modeled results. This comparison supports the use of more realistic assumption in the estimating emission rates. The resultant reduction in modeled levels of potential exposures has significant implications in terms of the projected costs of demolition of such structures

  4. Radiocesium concentrations of snakes from contaminated and non-contaminated habitats of the AEC Savannah River Plant

    International Nuclear Information System (INIS)

    Brisbin, I.L. Jr.; Staton, M.A.; Pinder, J.E. III.; Geiger, R.A.

    1974-01-01

    Concentration levels of 134 Cs and 137 Cs were determined for 117 snakes of 19 species collected on the AEC Savannah River Plant near Aiken, South Carolina. Snakes collected from the vicinity of a reactor effluent stream averaged 131.5 pCi radiocesium/g live weight, with a maximum of 1032.6 pCi/g, and represented the highest level of radiocesium concentration reported in the literature for any naturally-occurring wild population of vertebrate predators. These snakes had significantly higher concentrations of radiocesium than those collected in the vicinity of a reactor cooling reservoir which averaged 27.7 pCi/g live weight, with a maximum of 139.3 pCi/g. The radiocesium contents of snakes collected from uncontaminated habitats averaged 2.6 and 2.4 pCi/g live weight, respectively, and did not differ significantly from background radiation levels. Radiocesium concentrations approximated a log-normal frequency distribution, and no significant differences in frequency-distribution patterns could be demonstrated between collection areas. (U.S.)

  5. Alkali solution extraction of rice residue protein isolates: Influence of alkali concentration on protein functional, structural properties and lysinoalanine formation.

    Science.gov (United States)

    Hou, Furong; Ding, Wenhui; Qu, Wenjuan; Oladejo, Ayobami Olayemi; Xiong, Feng; Zhang, Weiwei; He, Ronghai; Ma, Haile

    2017-03-01

    This study evaluated the nutrient property and safety of the rice residue protein isolates (RRPI) product (extracted by different alkali concentrations) by exploring the protein functional, structural properties and lysinoalanine (LAL) formation. The results showed that with the rising of alkali concentration from 0.03M to 0.15M, the solubility, emulsifying and foaming properties of RRPI increased at first and then descended. When the alkali concentration was greater than 0.03M, the RRPI surface hydrophobicity decreased and the content of thiol and disulfide bond, Lys and Cys significantly reduced. By the analysis of HPLC, the content of LAL rose up from 276.08 to 15,198.07mg/kg and decreased to 1340.98mg/kg crude protein when the alkali concentration increased from 0.03 to 0.09M and until to 0.15M. These results indicated that RRPI alkaline extraction concentration above 0.03M may cause severe nutrient or safety problems of protein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A survey of chlortetracycline concentration in feed and its residue in ...

    Indian Academy of Sciences (India)

    Samples of feed and eggs were collected at day 0 (prior to CTC addition), 3rd, 5th and 7th day during treatment and on the 9th and 14th day (2nd and 7th day after withdrawal of CTC) from each of the 12 commercial poultry farms studied. Concentration of CTC in feed was significantly ( < 0.01) high on the 3rd, 5th and 7th ...

  7. Zero valent iron reduces toxicity and concentrations of organophosphate pesticides in contaminated groundwater

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Baun, Anders; Vastrup, Troels

    2013-01-01

    The potential of zero valent iron (ZVI) for remediation of contaminated groundwater from an abandoned chemical disposal site was examined through batch and column experiments. The key contaminants were organophosphate pesticides but the chemical analysis also comprised additional 22 compounds...... including synthesis intermediates and degradation products of organophosphates. The ZVI treatment showed that all the contaminants were degraded with the exception of two diesters (phosphorothioates). The most rapid reduction was found for methyl parathion, ethyl parathion and malathion, which had first....... The rapid degradation of the highly toxic organophosphates combined with the significant decrease in the ecotoxicological potential shows a promising potential for site remediation of organophosphates with ZVI technologies....

  8. Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism.

    Science.gov (United States)

    Li, Yunyi; Cundy, Andrew B; Feng, Jingxuan; Fu, Hang; Wang, Xiaojing; Liu, Yangsheng

    2017-05-01

    Large amounts of chromite ore processing residue (COPR) wastes have been deposited in many countries worldwide, generating significant contamination issues from the highly mobile and toxic hexavalent chromium species (Cr(VI)). In this study, sodium dithionite (Na 2 S 2 O 4 ) was used to reduce Cr(VI) to Cr(III) in COPR containing high available Fe, and then sodium phosphate (Na 3 PO 4 ) was utilized to further immobilize Cr(III), via a two-step procedure (TSP). Remediation and immobilization processes and mechanisms were systematically investigated using batch experiments, sequential extraction studies, X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Results showed that Na 2 S 2 O 4 effectively reduced Cr(VI) to Cr(III), catalyzed by Fe(III). The subsequent addition of Na 3 PO 4 further immobilized Cr(III) by the formation of crystalline CrPO 4 ·6H 2 O. However, addition of Na 3 PO 4 simultaneously with Na 2 S 2 O 4 (via a one-step procedure, OSP) impeded Cr(VI) reduction due to the competitive reaction of Na 3 PO 4 and Na 2 S 2 O 4 with Fe(III). Thus, the remediation efficiency of the TSP was much higher than the corresponding OSP. Using an optimal dosage in the two-step procedure (Na 2 S 2 O 4 at a dosage of 12× the stoichiometric requirement for 15 days, and then Na 3 PO 4 in a molar ratio (i.e. Na 3 PO 4 : initial Cr(VI)) of 4:1 for another 15 days), the total dissolved Cr in the leachate determined via Toxicity Characteristic Leaching Procedure (TCLP Cr) testing of our samples was reduced to 3.8 mg/L (from an initial TCLP Cr of 112.2 mg/L, i.e. at >96% efficiency). Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Ultraviolet Laser Damage Dependence on Contamination Concentration in Fused Silica Optics during Reactive Ion Etching Process

    Directory of Open Access Journals (Sweden)

    Laixi Sun

    2018-04-01

    Full Text Available The reactive ion etching (RIE process of fused silica is often accompanied by surface contamination, which seriously degrades the ultraviolet laser damage performance of the optics. In this study, we find that the contamination behavior on the fused silica surface is very sensitive to the RIE process which can be significantly optimized by changing the plasma generating conditions such as discharge mode, etchant gas and electrode material. Additionally, an optimized RIE process is proposed to thoroughly remove polishing-introduced contamination and efficiently prevent the introduction of other contamination during the etching process. The research demonstrates the feasibility of improving the damage performance of fused silica optics by using the RIE technique.

  10. Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings.

    Science.gov (United States)

    Beamer, P I; Sugeng, A J; Kelly, M D; Lothrop, N; Klimecki, W; Wilkinson, S T; Loh, M

    2014-05-01

    Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites.

  11. Quantification of pressure sensitive adhesive, residual ink, and other colored process contaminants using dye and color image analysis

    Science.gov (United States)

    Roy R. Rosenberger; Carl J. Houtman

    2000-01-01

    The USPS Image Analysis (IA) protocol recommends the use of hydrophobic dyes to develop contrast between pressure sensitive adhesive (PSA) particles and cellulosic fibers before using a dirt counter to detect all contaminants that have contrast with the handsheet background. Unless the sample contains no contaminants other than those of interest, two measurement steps...

  12. Chemical amendment and phytostabilization of an industrial residue contaminated with Zn and Cd Correção química e fitoestabilização de um resíduo industrial contaminado com Zn e Cd

    Directory of Open Access Journals (Sweden)

    Fabiana Soares dos Santos

    2007-10-01

    Full Text Available Phytostabilisation of a contaminated soil with heavy metals is considered a very appropriate technology to reduce erosion and dispersion of contaminants. A greenhouse study was conducted to evaluate the effects of both chemical amendments (calcium silicate and brewery sludge, and phytoremediation using the grass Brachiaria decumbens, on an industrial residue contaminated with Zn and Cd (industrial residue. Industrial residue samples placed into 30 L containers were amended with 20% brewery sludge, calcium silicate (2%, 3%, and 20% of brewery sludge + calcium silicate (2.5%, 4%, and were compared to the control treatment (non-amended residue. After pH stabilization, B. decumbens plants were grown on all treatments in order to evaluate the ability of the species to tolerate high Zn and Cd concentrations from the residue. Samples were collected twice, at planting and harvesting, for pH determination and simple extractions with water, sodium nitrate, acetic acid and DTPA. Differences in Zn and Cd concentrations in extracts allowed to estimate the concentrations of these elements in the most likely chemical forms they are found in the residue. Alkaline and organic industrial amendments reduced Zn and Cd percentages, both in the soluble and exchangeable fractions, as well as caused the predominance of Zn and Cd in the most stable chemical fractions, such as complexed and precipitated compounds. B. decumbens was tolerant to Zn and Cd from the industrial residue after addition of the amendments.A fitoestabilização de solos contaminados com metais pesados é considerada uma boa alternativa para reduzir a erosão e dispersão de contaminantes no ambiente. Foi conduzido um experimento em casa-de-vegetação com o objetivo de avaliar a contenção química (silicato de cálcio e lodo do biodigestor de uma cervejaria e a fitorremediação pela Brachiaria decumbens, de um resíduo industrial contaminado com Zn e Cd, utilizando vasos de 30 L. Os tratamentos

  13. Hybrid-renewable processes for biofuels production: concentrated solar pyrolysis of biomass residues

    Energy Technology Data Exchange (ETDEWEB)

    George, Anthe [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Geier, Manfred [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dedrick, Daniel E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    The viability of thermochemically-derived biofuels can be greatly enhanced by reducing the process parasitic energy loads. Integrating renewable power into biofuels production is one method by which these efficiency drains can be eliminated. There are a variety of such potentially viable "hybrid-renewable" approaches; one is to integrate concentrated solar power (CSP) to power biomass-to-liquid fuels (BTL) processes. Barriers to CSP integration into BTL processes are predominantly the lack of fundamental kinetic and mass transport data to enable appropriate systems analysis and reactor design. A novel design for the reactor has been created that can allow biomass particles to be suspended in a flow gas, and be irradiated with a simulated solar flux. Pyrolysis conditions were investigated and a comparison between solar and non-solar biomass pyrolysis was conducted in terms of product distributions and pyrolysis oil quality. A novel method was developed to analyse pyrolysis products, and investigate their stability.

  14. Investigations of residue of veterinary medicines and environmental contaminants during production cycle of Petrovska klobasa as part of compulsory parameters for food safety

    Directory of Open Access Journals (Sweden)

    Janković Vesna

    2012-01-01

    Full Text Available A significant factor in the protection of consumer health is the systematic and constant implementation of control for the presence of residue of biologically active substances and their metabolites in raw materials and in primary products of animal origin. As regards meat, an essential aspect of security is definitely the control of possible residue of veterinary medicines and environmental contaminants. In that respect, the objective of the national project entitled „Development of technology for drying and fermentation of the sausage petrovačka kobasica (Petrovská klobása - registered geographic origin under controlled conditions“, Number TR - 20037, was to protect the product petrovačka kobasica (Petrovská klobása with the appropriate appellation. A part of the compulsory investigations also included the establishing of the presence of residue of veterinary medicines and environmental contaminants in raw materials and in the finished product, which was also the aim of this work. [Projekat Ministarstva nauke Republike Srbije, br. TR-20037: Petrovská klobása - oznaka geografskog porekla u kontrolisanim uslovima

  15. [Chemical residues and contaminants in food of animal origin in Brazil: history, legislation and actions of sanitary surveillance and other regulatory systems].

    Science.gov (United States)

    Spisso, Bernardete Ferraz; Nóbrega, Armi Wanderley de; Marques, Marlice Aparecida Sípoli

    2009-01-01

    Food safety became a relevant subject due to the increasing search for a better way of life and consciousness of the consumers to stand on one's rights to acquire healthy products. The use of substances in animals destined for human consumption requires from pharmacokinetics to residue depletion studies, with the establishment of limitative values so that do not constitute a risk to health. Beyond the substances used deliberately, others coming from environment contamination or contamination of feeding stuffs consumed by these animals may reach human through the diet. The aims of this paper are to collect and discuss the main federal acts covering chemical residues and contaminants in food of animal origin in Brazil, besides those on measures to control veterinary medicinal products and additives for use in animal nutrition. The chronological presentation of the legal basis intends to facilitate the interpretation of the acts inside respective political and economics scenarios. The actions proposed from the different agents involved into the regulatory systems are discussed from the public health point of view.

  16. Assessment of the chlorinated hydrocarbons residues contamination in edible mushrooms from the North-Eastern part of Poland.

    Science.gov (United States)

    Gałgowska, Michalina; Pietrzak-Fiećko, Renata; Felkner-Poźniakowska, Barbara

    2012-11-01

    The aim of the study was to determine the content of chlorinated hydrocarbon residues in edible mushrooms from the north-eastern part of Poland. Material consisted of two species of fungi: Xerocomus mushrooms (Xerocomus badius), Boletus mushrooms (Boletus edulis). The dried samples (cups and cut-up material) were extracted with Soxhlet method in order to obtain lipid substances. In the fat chlorinated hydrocarbons were determined by Ludwicki et al. (1996) method. The separation and quantitative determination of DDT, DDE, DDD and γ-HCH were conducted with the method of gas chromatography using an electron capture detector - ECD. In all tested samples the presence of γ-HCH, DDT and its metabolites (DDE, DDD) was detected. The higher content of γ-HCH was found in Xerocomus mushrooms (average 0.125 μg/kg of mushrooms); in the Boletus mushrooms -0.11 μg/kg of mushrooms. The content of ΣDDT in cups of Xerocomus mushrooms was more than 2-fold higher than in those of Boletus mushrooms (3.78:1.71 mg/kg of mushrooms). The opposite relationship was observed for cut-up material. The higher concentration of ΣDDT was found in Boletus mushrooms (2.26 mg/kg of mushrooms) while in Xerocomus mushrooms this content was 0.91 mg/kg of mushrooms. Despite the fact that chlorinated hydrocarbons were determined in all samples under study, their contents do not exceed acceptable levels indicating that the consumption of mushrooms does not pose a health risk to consumers from the organochlorine compounds. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Schiff base: A high affinity chemical agent to decrease the concentration of aflatoxin M1 in raw milk contaminated artificially

    Directory of Open Access Journals (Sweden)

    Frane Delaš

    2012-03-01

    Full Text Available In the present study were conducted the effect of pH (5.5, 6.0 and 6.5 and concentration of new synthesized 3-/2-aminophenylimino-(p-toluoyl/-4-hydroxy-6-(p-tolyl-2H-pyrane-2-one (Schiff base on decrease the concentration of aflatoxin M1 (AFM1 in raw milk contaminated with known concentration of this toxin. Experiments were carried out at temperature of 4 °C during 35 days. At pH 5.5 Schiff base concentration of 0.1 µmol/L was lessening the concentration of AFM1 after 35 days by 55 %. However, at pH 6.5 the most effective concentration for lessening of AFM1 was 0.5 µmol/L. Schiff base was not effective at pH value of 7 or higher. The ability of Schiff base to act as antimycotoxigenic agent provides new perspective for possibly using this compound to control AFM1 contamination in milk and to extent shelf lives of this food. Detection of toxicity of investigated Schiff base was performed by using the brine shrimp (Artemia salina larvae as an biological indicator to determine their sensitivity to this chemical agent.

  18. Treatment of emerging contaminants in wastewater treatment plants (WWTP) effluents by solar photocatalysis using low TiO2 concentrations.

    Science.gov (United States)

    Prieto-Rodriguez, L; Miralles-Cuevas, S; Oller, I; Agüera, A; Li Puma, G; Malato, S

    2012-04-15

    The optimal photocatalyst concentration for industrial wastewater treatment in current photoreactor designs is several hundreds of milligrams per liter. However, the elimination of emerging contaminants (ECs), which are present at extremely low concentrations in waste water treatment plants (WWTP) effluents might be accomplished at much lower catalyst (TiO(2)) concentrations. One of the main drawbacks of reducing catalyst loading below the optimum is the loss of useful photons which instead are transmitted through the TiO(2) suspension without being absorbed by the catalyst. Accordingly, in this work, laboratory and solar pilot-scale experiments were performed with real WWTP effluents to evaluate the kinetics of photocatalytic degradation of 52 emerging contaminants under realistic (ppb) concentrations. The analysis of the samples was accomplished by solid phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS). In view of the results, low concentrations of TiO(2) of the order of tens of milligrams per liter were found to be insufficient for the degradation of the ECs in photoreactors with a short light-path length (29 cm). However, it was established that solar reactors of diameters of several hundreds of millimetres could be used for the efficient removal of ECs from WWTP effluents. The results presented show a general methodology for selecting the most efficient reactor diameter on the basis of the desired catalyst concentration. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

    International Nuclear Information System (INIS)

    Corrans, I.J.; Levin, J.

    1979-01-01

    Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20μm. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed [af

  20. Residual sarcoplasmic reticulum Ca2+ concentration after Ca2+ release in skeletal myofibers from young adult and old mice.

    Science.gov (United States)

    Wang, Zhong-Min; Tang, Shen; Messi, María Laura; Yang, Jenny J; Delbono, Osvaldo

    2012-04-01

    Contrasting information suggests either almost complete depletion of sarcoplasmic reticulum (SR) Ca(2+) or significant residual Ca(2+) concentration after prolonged depolarization of the skeletal muscle fiber. The primary obstacle to resolving this controversy is the lack of genetically encoded Ca(2+) indicators targeted to the SR that exhibit low-Ca(2+) affinity, a fast biosensor: Ca(2+) off-rate reaction, and can be expressed in myofibers from adult and older adult mammalian species. This work used the recently designed low-affinity Ca(2+) sensor (Kd = 1.66 mM in the myofiber) CatchER (calcium sensor for detecting high concentrations in the ER) targeted to the SR, to investigate whether prolonged skeletal muscle fiber depolarization significantly alters residual SR Ca(2+) with aging. We found CatchER a proper tool to investigate SR Ca(2+) depletion in young adult and older adult mice, consistently tracking SR luminal Ca(2+) release in response to brief and repetitive stimulation. We evoked SR Ca(2+) release in whole-cell voltage-clamped flexor digitorum brevis muscle fibers from young and old FVB mice and tested the maximal SR Ca(2+) release by directly activating the ryanodine receptor (RyR1) with 4-chloro-m-cresol in the same myofibers. Here, we report for the first time that the Ca(2+) remaining in the SR after prolonged depolarization (2 s) in myofibers from aging (~220 μM) was larger than young (~132 μM) mice. These experiments indicate that SR Ca(2+) is far from fully depleted under physiological conditions throughout life, and support the concept of excitation-contraction uncoupling in functional senescent myofibers.

  1. Observational assessment of the role of nocturnal residual-layer chemistry in determining daytime surface particulate nitrate concentrations

    Directory of Open Access Journals (Sweden)

    G. Prabhakar

    2017-12-01

    Full Text Available This study discusses an analysis of combined airborne and ground observations of particulate nitrate (NO3−(p concentrations made during the wintertime DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically resolved observations relevant to Air Quality study at one of the most polluted cities in the United States – Fresno, CA – in the San Joaquin Valley (SJV and focuses on developing an understanding of the various processes that impact surface nitrate concentrations during pollution events. The results provide an explicit case-study illustration of how nighttime chemistry can influence daytime surface-level NO3−(p concentrations, complementing previous studies in the SJV. The observations exemplify the critical role that nocturnal chemical production of NO3−(p aloft in the residual layer (RL can play in determining daytime surface-level NO3−(p concentrations. Further, they indicate that nocturnal production of NO3−(p in the RL, along with daytime photochemical production, can contribute substantially to the buildup and sustaining of severe pollution episodes. The exceptionally shallow nocturnal boundary layer (NBL heights characteristic of wintertime pollution events in the SJV intensify the importance of nocturnal production aloft in the residual layer to daytime surface concentrations. The observations also demonstrate that dynamics within the RL can influence the early-morning vertical distribution of NO3−(p, despite low wintertime wind speeds. This overnight reshaping of the vertical distribution above the city plays an important role in determining the net impact of nocturnal chemical production on local and regional surface-level NO3−(p concentrations. Entrainment of clean free-tropospheric (FT air into the boundary layer in the afternoon is identified as an important process that reduces surface-level NO3−(p and limits buildup during pollution episodes. The influence of dry deposition of HNO

  2. Observational assessment of the role of nocturnal residual-layer chemistry in determining daytime surface particulate nitrate concentrations

    Science.gov (United States)

    Prabhakar, Gouri; Parworth, Caroline L.; Zhang, Xiaolu; Kim, Hwajin; Young, Dominique E.; Beyersdorf, Andreas J.; Ziemba, Luke D.; Nowak, John B.; Bertram, Timothy H.; Faloona, Ian C.; Zhang, Qi; Cappa, Christopher D.

    2017-12-01

    This study discusses an analysis of combined airborne and ground observations of particulate nitrate (NO3-(p)) concentrations made during the wintertime DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically resolved observations relevant to Air Quality) study at one of the most polluted cities in the United States - Fresno, CA - in the San Joaquin Valley (SJV) and focuses on developing an understanding of the various processes that impact surface nitrate concentrations during pollution events. The results provide an explicit case-study illustration of how nighttime chemistry can influence daytime surface-level NO3-(p) concentrations, complementing previous studies in the SJV. The observations exemplify the critical role that nocturnal chemical production of NO3-(p) aloft in the residual layer (RL) can play in determining daytime surface-level NO3-(p) concentrations. Further, they indicate that nocturnal production of NO3-(p) in the RL, along with daytime photochemical production, can contribute substantially to the buildup and sustaining of severe pollution episodes. The exceptionally shallow nocturnal boundary layer (NBL) heights characteristic of wintertime pollution events in the SJV intensify the importance of nocturnal production aloft in the residual layer to daytime surface concentrations. The observations also demonstrate that dynamics within the RL can influence the early-morning vertical distribution of NO3-(p), despite low wintertime wind speeds. This overnight reshaping of the vertical distribution above the city plays an important role in determining the net impact of nocturnal chemical production on local and regional surface-level NO3-(p) concentrations. Entrainment of clean free-tropospheric (FT) air into the boundary layer in the afternoon is identified as an important process that reduces surface-level NO3-(p) and limits buildup during pollution episodes. The influence of dry deposition of HNO3 gas to the surface on

  3. Residues of dioxins (PCDD/Fs) and PCBs in eggs, fat and livers of laying hens following consumption of contaminated feed

    NARCIS (Netherlands)

    Traag, W.A.; Kan, C.A.; Weg, van der G.; Onstenk, C.G.M.; Hoogenboom, L.A.P.

    2006-01-01

    Laying hens were fed with feed from the Belgian dioxin incident diluted ten-fold with non-contaminated feed, resulting in concentrations of 61 ng TEQ kg(-1) PCDD/Fs, 23 ng TEQ kg(-1) non-ortho PCBs, 116 ng TEQ kg(-1) mono-ortho PCBs and 3.2 mg kg(-1) of the seven indicator PCBs. Following exposure

  4. Sex-steroid and thyroid hormone concentrations in juvenile alligators (Alligator mississippiensis) from contaminated and reference lakes in Florida, USA

    Science.gov (United States)

    Grain, D.A.; Guillette, L.J.; Pickford, D.B.; Percival, H.F.; Woodward, A.R.

    1998-01-01

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-171?? (E2), testosterone (T), triiodothyronine (T3), and thyroxine (T4) in juvenile alligators (60-140 cm total length) from two contaminated lakes and one reference lake in Florida. First, the data were analyzed by comparing hormone concentrations among males and females from the different lakes. Whereas there were no differences in plasma E2 concentrations among animals of the three lakes, male alligators from the contaminated lakes (Lake Apopka and Lake Okeechobee) had significantly lower plasma T concentrations compared 10 males from the reference take (Lake Woodruff). Concentrations of thyroid hormones also differed in animals of the three lakes, with T4 concentrations being elevated in Lake Okeechobee males compared to Lake Woodruff males. Second, the relationship between body size and hormone concentration was examined using regression analysis. Most notably for steroid hormones, no clear relationship was detected between E2 and total length in Apopka females (r2 0.09, p = 0.54) or between T and total length in Apopka males (r2 = 0.007, p = 0.75). Females from Apopka (r2 = 0.318, p = 0.09) and Okeechobee (r2 = 0.222, p = 0.09) exhibited weak correlations between T3 and total length. Males from Apopka (r2 = 0.015, p = 0.66) and Okeechobee (r2 = 0.128, p = 0.19) showed no correlation between T4 and total length. These results indicate: some of the previously reported abnormalities in steroid hormones of hatchling alligators persist, at least, through the juvenile years; steroid and thyroid hormones are related to body size in juvenile alligators from the reference lake, whereas alligators living in lakes Apopka and Okeechobee experience alterations in circulating thyroid and steroid

  5. Effect of Phosphate Addition on Cadmium Precipitation and Adsorption in Contaminated Arable Soil with a Low Concentration of Cadmium.

    Science.gov (United States)

    Kim, Sung Un; Owens, Vance N; Kim, Yong Gyun; Lee, Sang Mong; Park, Hyean Cheal; Kim, Keun Ki; Son, Hong Joo; Hong, Chang Oh

    2015-11-01

    The objectives of this study were to determine (1) the phosphorus (P) level required to induce cadmium (Cd) precipitation in a contaminated arable soil with low concentrations of Cd and (2) the primary mechanism of Cd immobilization at different P levels. Phosphorus was added at levels of 0 800, 1600, and 16,000 mg P kg(-1) to a soil containing 5.57 mg Cd kg(-1). The concentration of 1 M NH4OAc extractable Cd decreased significantly with P levels up to 1600 mg kg(-1) due to an increase in soil pH and negative charge of soil (psoil containing low levels of this heavy metal.

  6. Passive sampling methods for contaminated sediments: Scientific rationale supporting use of freely dissolved concentrations

    DEFF Research Database (Denmark)

    Mayer, Philipp; Parkerton, Thomas F.; Adams, Rachel G.

    2014-01-01

    point using passive samplers with different surface to volume ratios. Sampling in the kinetic regime is also possible and generally involves the application of performance reference compounds for the calibration. Based on previous research on hydrophobic organic contaminants, it is concluded that Cfree...

  7. EFFECTIVE CONCENTRATIONS OF 6 CONTAMINANTS TO LEMMA MINOR, PIMEPHALES PROMELA, DAPHNIA MAGNA, AND CERIODAPHNIA DUBIA

    Science.gov (United States)

    The research presented here resulted in EC50 and LOEC values for the contaminants copper, cadmium, diazinon, atrazine, and cyanide to the species Lemna Minor, Pimephales promelas, Daphnia magna, and Ceriodaphnia dubia. Observed values were used as benchmarks for assessing the se...

  8. Local contamination, and not feeding preferences, explains elevated PCB concentrations in Labrador ringed seals (Pusa hispida).

    Science.gov (United States)

    Brown, Tanya M; Iverson, Sara J; Fisk, Aaron T; Macdonald, Robie W; Helbing, Caren C; Reimer, Ken J

    2015-05-15

    Polychlorinated biphenyls (PCBs) in high trophic level species typically reflect the contributions of myriad sources, such that source apportionment is rarely possible. The release of PCBs by a military radar station into Saglek Bay, Labrador contaminated the local marine food web. For instance, while heavier (higher chlorinated) PCB profiles in some ringed seals (Pusa hispida) were previously attributed to this local source, differences in feeding preferences among seals could not be ruled out as a contributing factor. Herein, similar fatty acid profiles between those seals with 'local' PCB profiles and those with 'long-range' or background profiles indicate little support for the possibility that differential feeding ecologies underlay the divergent PCB profiles. Ringed seals appeared to feed predominantly on zooplankton (Mysis oculata and Themisto libellula), followed by the dusky snailfish (Liparis gibbus), arctic cod (Boreogadus saida), and shorthorn sculpin (Myoxocephalus scorpius). Principal components analysis (PCA) and PCB homolog profiles illustrated the extent of contamination of the Saglek food web, which had very different (and much heavier) PCB profiles than those food web members contaminated by 'long-range' sources. Locally contaminated prey had PCB levels that were higher (2- to 544-fold) than prey contaminated by 'long-range' sources and exceeded wildlife consumption guidelines for PCBs. The application of multivariate analyses to two distinct datasets, including PCB congeners (n=50) and fatty acids (n=65), afforded the opportunity to clearly distinguish the contribution of locally-released PCBs to a ringed seal food web from those delivered via long-ranged transport. Results from the present study strongly suggest that habitat use rather than differences in prey selection is the primary mechanism explaining the divergent PCB patterns in Labrador ringed seals. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Semiconducting iron silicide thin films on silicon (111) with large Hall mobility and low residual electron concentration

    Science.gov (United States)

    Muret, P.; Ali, I.; Brunel, M.

    1998-10-01

    Unprecedented Hall mobility, electron concentration and photoconductivity are demonstrated in semiconducting 0268-1242/13/10/020/img6-0268-1242/13/10/020/img7 thin films prepared on Si(111) surfaces by co-sputtering of iron and silicon followed by post-anneal. Characterization of the silicide as a function of the initial temperature and post-treatment shows that annealing temperatures above 0268-1242/13/10/020/img8C are needed to obtain single phase 0268-1242/13/10/020/img6-0268-1242/13/10/020/img7. Reactive deposition on substrates heated at 0268-1242/13/10/020/img11C leads to textured films. Majority carriers are electrons in all these unintentionally doped films. Hall concentrations between 0268-1242/13/10/020/img12 and 0268-1242/13/10/020/img13 electrons 0268-1242/13/10/020/img14 and respective Hall mobilities from 290 to 0268-1242/13/10/020/img15 are measured at room temperature, involving two different conduction band minima in these two extreme cases. Only deep centres exist in the samples having the lower carrier concentration. In such a situation, raw data must be corrected for the substrate contribution to extract values which are relevant for the 0268-1242/13/10/020/img6-0268-1242/13/10/020/img7 film alone. Photoconductivity also takes place in these samples: at 80 K, it shows a maximum value at the direct band gap of 0268-1242/13/10/020/img6-0268-1242/13/10/020/img7 while at 296 K a step still appears at the same energy. Such results are a consequence of the important decrease of the residual impurity concentration in comparison to values previously published.

  10. Contamination characteristics and degradation behavior of low-density polyethylene film residues in typical farmland soils of China.

    Science.gov (United States)

    Xu, Gang; Wang, Qunhui; Gu, Qingbao; Cao, Yunzhe; DU, Xiaoming; Li, Fasheng

    2006-01-01

    Low-density polyethylene (LDPE) film residues left in farmlands due to agricultural activities were extensively investigated to evaluate the present pollution situation by selecting the typical areas with LDPE film application, including Harbin, Baoding, and Handan of China. The survey results demonstrated that the film residues were ubiquitous within the investigated areas and the amount reached 2,400-8,200 g ha(-1). Breakage rates of the film residues were almost at the same level in the studied fields. There were relatively small amounts of film residues remaining in neighboring farmland fields without application of LDPE film. The studies showed that the sheets of LDPE residues had the same oxidative deterioration, which was probably due to photodegradation instead of biodegradation. The higher molecular weight components of the LDPE film gradually decreased, which were reflected by the appearance of some small flakes detached from the film bodies. LDPE films in the investigated fields gradually deteriorated and the decomposing levels developed with their left time increasing. The degradation behaviors of LDPE films were confirmed by using Fourier transform infrared (FTIR), scanning electron microscopic (SEM), and gel permeation chromatography analyses.

  11. Ecotracer: analyzing concentration of contaminants and radioisotopes in an aquatic spatial-dynamic food web model.

    Science.gov (United States)

    Walters, William J; Christensen, Villy

    2018-01-01

    Ecotracer is a tool in the Ecopath with Ecosim (EwE) software package used to simulate and analyze the transport of contaminants such as methylmercury or radiocesium through aquatic food webs. Ecotracer solves the contaminant dynamic equations simultaneously with the biomass dynamic equations in Ecosim/Ecospace. In this paper, we give a detailed description of the Ecotracer module and analyze the performance on two problems of differing complexity. Ecotracer was modified from previous versions to more accurately model contaminant excretion, and new numerical integration algorithms were implemented to increase accuracy and robustness. To test the mathematical robustness of the computational algorithm, Ecotracer was tested on a simple problem for which we know an analytical solution. These results demonstrated the effectiveness of the program numerics. A much more complex model, the release of the cesium radionuclide 137 Cs from the Fukushima Dai-ichi nuclear accident, was also modeled and analyzed. A comparison of the Ecotracer results to sampled 137 Cs measurements in the coastal ocean area around Fukushima show the promise of the tool but also highlight some important limitations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effect of fresh and mature organic amendments on the phytoremediation of technosols contaminated with high concentrations of trace elements.

    Science.gov (United States)

    Hattab, Nour; Motelica-Heino, Mikael; Faure, Olivier; Bouchardon, Jean-Luc

    2015-08-15

    Organic compounds resulting from the decomposition of organic amendments are used in the remediation of trace element (TE) contaminated soils. The mobility, phytoavailability and soil exposure intensity of molybdenum (Mo), chromium (Cr), zinc (Zn), copper (Cu), Cobalt (Co) and Arsenic (As) were evaluated in the phytoremediation of contaminated technosols after the addition of two organic matter types, fresh ramial chipped wood (RCW) and composted sewage sludge (CSS). The experiment consisted of nine main treatment blocks: (A) 3X unamended soil (NE), (B) 3X soil amended with RCW and (C) 3X soil amended with mature CSS. Total dissolved TE concentrations were determined in soil pore water (SPW) sampled by Rhizon samplers. The soil exposure intensity was assessed by standard Chelex 100 DGT (diffusive gradient in thin films) probes. TE phytoavailability was characterized by growing dwarf beans on potted soils and analyzing their foliar TE concentrations. The results of the present study indicate that the addition of fresh RCW and CSS has a positive effect on contaminated technosols. RCW decreased the mobility of all the studied TE in the SPW, whereas CSS reduced the mobility of Mo, Cr and Co, while it increased the mobility of Zn, Cu and As compared with the NE soil. The Zn soil exposure intensity assessed by DGT was not significantly changed by the addition of RCW and CSS, while the Cr soil exposure intensity was significantly decreased after RCW addition compared with the soil treated with CSS and the NE soil. In contrast Cu and Co were non labile in the three soils. Both RCW and CSS decreased the foliar concentration and the mineral mass of Mo, Zn, Cr, As and Co in the bean leaves but increased the foliar Cu concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Micropollutants in urban stormwater: occurrence, concentrations, and atmospheric contributions for a wide range of contaminants in three French catchments.

    Science.gov (United States)

    Gasperi, J; Sebastian, C; Ruban, V; Delamain, M; Percot, S; Wiest, L; Mirande, C; Caupos, E; Demare, D; Kessoo, M Diallo Kessoo; Saad, M; Schwartz, J J; Dubois, P; Fratta, C; Wolff, H; Moilleron, R; Chebbo, G; Cren, C; Millet, M; Barraud, S; Gromaire, M C

    2014-04-01

    This study aimed at: (a) providing information on the occurrence and concentration ranges in urban stormwater for a wide array of pollutants (n = 77); (b) assessing whether despite the differences between various catchments (land use, climatic conditions, etc.), the trends in terms of contamination level are similar; and (c) analyzing the contribution of total atmospheric fallout (TAF) with respect to sources endogenous to this contamination. The studied contaminants include conventional stormwater contaminants (polycyclic aromatic hydrocarbons (PAHs), Zn, Cu, Pb, etc.), in addition to poorly or undocumented pollutants such as nonylphenol and octylphenol ethoxylates (NPnEO and OPnEO), bisphenol A (BPA), polybrominated diphenyl ethers (PBDEs), a wide variety of pesticides, and various metals of relevance (As, Ti, Sr, V). Sampling and analysis were performed using homogeneous methods on three urban catchments with different land use patterns located in three distinct French towns. For many of these pollutants, the results do not allow highlighting a significant difference in stormwater quality at the scale of the three urban catchments considered. Significant differences were, however, observed for several metals (As, Cr, Cu, Ni, Sr and Zn), PAHs, and PBDEs, though this assessment would need to be confirmed by further experiments. The pollutant distributions between dissolved and particulate phases were found to be similar across the three experimental sites, thus suggesting no site dependence. Lastly, the contributions of TAF to stormwater contamination for micropollutants were quite low. This finding held true not only for PAHs, as previously demonstrated in the literature, but also for a broader range of molecules such as BPA, NPnEO, OPnEO, and PBDEs, whose high local production is correlated with the leaching of urban surfaces, buildings, and vehicles.

  14. Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

    DEFF Research Database (Denmark)

    Holm, P.E.; Christensen, T.H.

    1998-01-01

    Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... Cd L(-1) and 9 to 3600 mu g Zn L(-1), which were dominated by free metal ions as measured by an ion exchange-resin method. Annual leaching outflows were estimated from soil water concentrations to be 0.5-17 g Cd ha(-1) y(-1) and 9-3600 g Zn ha(-1) y(-1) per 100 mm of net percolation, corresponding...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...

  15. Multi-residue analysis of legacy POPs and emerging organic contaminants in Singapore's coastal waters using gas chromatography-triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Hui; Bayen, Stéphane; Kelly, Barry C

    2015-08-01

    A gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) based method was developed for determination of 86 hydrophobic organic compounds in seawater. Solid-phase extraction (SPE) was employed for sequestration of target analytes in the dissolved phase. Ultrasound assisted extraction (UAE) and florisil chromatography were utilized for determination of concentrations in suspended sediments (particulate phase). The target compounds included multi-class hydrophobic contaminants with a wide range of physical-chemical properties. This list includes several polycyclic and nitro-aromatic musks, brominated and chlorinated flame retardants, methyl triclosan, chlorobenzenes, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). Spiked MilliQ water and seawater samples were used to evaluate the method performance. Analyte recoveries were generally good, with the exception of some of the more volatile target analytes (chlorobenzenes and bromobenzenes). The method is very sensitive, with method detection limits typically in the low parts per quadrillion (ppq) range. Analysis of 51 field-collected seawater samples (dissolved and particulate-bound phases) from four distinct coastal sites around Singapore showed trace detection of several polychlorinated biphenyl congeners and other legacy POPs, as well as several current-use emerging organic contaminants (EOCs). Polycyclic and nitro-aromatic musks, bromobenzenes, dechlorane plus isomers (syn-DP, anti-DP) and methyl triclosan were frequently detected at appreciable levels (2-20,000pgL(-1)). The observed concentrations of the monitored contaminants in Singapore's marine environment were generally comparable to previously reported levels in other coastal marine systems. To our knowledge, these are the first measurements of these emerging contaminants of concern in Singapore or Southeast Asia. The developed method may prove beneficial for future environmental monitoring of hydrophobic organic contaminants

  16. Canada Geese at the Hanford Site - Trends in Reproductive Success, Migration Patterns, and Contaminant Concentrations

    International Nuclear Information System (INIS)

    Simmons, Mary Ann; Poston, Ted M.; Tiller, Brett L.; Stegen, Amanda; Hand, Kristine D.; Brandenberger, Jill M.

    2010-01-01

    Pacific Northwest National Laboratory (PNNL) has conducted several studies for the U.S. Department of Energy (DOE) to evaluate the status and condition of Canada geese on the Hanford Reach of the Columbia River. This report summarizes results of studies of Canada geese (Branta canadensis moffitti) at the Hanford Site dating back to the 1950s. Results include information on the nesting (reproductive) success of Canada geese using the Hanford Reach, review of the local and regional migration of this species using data from bird banding studies, and summary data describing monitoring and investigations of the accumulation of Hanford-derived and environmental contaminants by resident goose populations.

  17. Canada Geese at the Hanford Site – Trends in Reproductive Success, Migration Patterns, and Contaminant Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Mary Ann; Poston, Ted M.; Tiller, Brett L.; Stegen, Amanda; Hand, Kristine D.; Brandenberger, Jill M.

    2010-05-25

    Pacific Northwest National Laboratory (PNNL) has conducted several studies for the U.S. Department of Energy (DOE) to evaluate the status and condition of Canada geese on the Hanford Reach of the Columbia River. This report summarizes results of studies of Canada geese (Branta canadensis moffitti) at the Hanford Site dating back to the 1950s. Results include information on the nesting (reproductive) success of Canada geese using the Hanford Reach, review of the local and regional migration of this species using data from bird banding studies, and summary data describing monitoring and investigations of the accumulation of Hanford-derived and environmental contaminants by resident goose populations.

  18. Detection of low-concentration contaminants in solution by exploiting chemical derivatization in surface-enhanced Raman spectroscopy.

    Science.gov (United States)

    Hardy, Mike; Doherty, Matthew D; Krstev, Igor; Maier, Konrad; Möller, Torgny; Müller, Gerhard; Dawson, Paul

    2014-09-16

    A simple derivatization methodology is shown to extend the application of surface-enhanced Raman spectroscopy (SERS) to the detection of trace concentration of contaminants in liquid form. Normally in SERS the target analyte species is already present in the molecular form in which it is to be detected and is extracted from solution to occupy sites of enhanced electromagnetic field on the substrate by means of chemisorption or drop-casting and subsequent evaporation of the solvent. However, these methods are very ineffective for the detection of low concentrations of contaminant in liquid form because the target (ionic) species (a) exhibits extremely low occupancy of enhancing surface sites in the bulk liquid environment and (b) coevaporates with the solvent. In this study, the target analyte species (acid) is detected via its solid derivative (salt) offering very significant enhancement of the SERS signal because of preferential deposition of the salt at the enhancing surface but without loss of chemical discrimination. The detection of nitric acid and sulfuric acid is demonstrated down to 100 ppb via reaction with ammonium hydroxide to produce the corresponding ammonium salt. This yields an improvement of ~4 orders of magnitude in the low-concentration detection limit compared with liquid phase detection.

  19. Doxycycline and sulfadimethoxine transfer from cross-contaminated feed to chicken tissues.

    Science.gov (United States)

    Segato, G; Benetti, C; Angeletti, R; Montesissa, C; Biancotto, G

    2011-01-01

    During feed preparation at feed mills or during feed mixing in bins at farms, the accidental contamination of feed at trace levels by veterinary drug residues, commonly known as carry-over, can accidentally but frequently occur. To evaluate the concentrations of residual antimicrobials in poultry edible tissues, due to contaminated feed, sulfadimethoxine and doxycycline were administered for 10 days to chickens in poultry feed incurred at the contamination levels frequently found during national feed monitoring programmes (1-5 mg kg(-1)). Sulfadimethoxine and doxycycline residual concentrations detected in muscle (residue limits (MRLs) fixed by EC 470/2009 and EU 37/2010 Regulations for a preliminary risk evaluation.

  20. Degradation of trinitrotoluene in contaminated soils as affected by its initial concentrations and its binding to soil organic matter fractions.

    Science.gov (United States)

    Singh, Neera; Hennecke, Dieter; Hoerner, Jennifer; Koerdel, Werner; Schaeffer, Andreas

    2008-03-01

    Trinitrotoluene (TNT), a nitroaromatics, is a major pollutant in explosive contaminated soils. Present study reports the effect of initial concentration of TNT on its degradation kinetics in soils. Soils from two contaminated sites viz. Clausthal and Elsnig, Germany, were mixed with an uncontaminated reference soil to get different initial concentrations (mg/kg) viz Clausthal-1 (54.29), Clausthal-2 (30.86), Clausthal-3 (7.05) Elsnig-1 (879.67), Elsnig-2 (86.43); Elsnig-3 (8.16) and Elsnig-4 (0.99) and were spiked with ring UL-(14)C-TNT (100KBq/50g soil). Except Elsnig-1 and Elsnig-2 soils, TNT degraded at same rate in all the soils. Higher persistence of TNT in Elsnig-1 and Elsnig-2 soils appears to be due to higher initial concentrations of nitroaromatics which may be toxic to soil microorganisms. 2-Amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) were recovered as major metabolites of TNT. Distribution of bound (14)C-activity in different soil organic matter (SOM) fractions (humic acid, fulvic acid and humin) was assayed by alkali extraction of solvent extracted Clausthal-1 and Elsnig-1 soils. Results indicate that humic acid accounted for maximum bound activity followed by fulvic acid and humin fractions. Expressing (14)C-activity bound/unit weight of organic carbon content of SOM fractions showed that 3 times more (14)C-activity was bound to Elsnig humic acid than Clausthal humic acid. Similarly, activity associated with Elsnig fulvic acid was 7 times higher than that of Clausthal fulvic acid suggesting that chemical nature of SOM fractions plays a significant role in binding of contaminants.

  1. Reduction in penis size and plasma testosterone concentrations in juvenile alligators living in a contaminated environment.

    Science.gov (United States)

    Guillette, L J; Pickford, D B; Crain, D A; Rooney, A A; Percival, H F

    1996-01-01

    The development of the male reproductive ducts and external genitalia in vertebrates is dependent on elevated androgen concentrations during embryonic development and the period of postnatal growth. We have observed that a population of juvenile alligators living on Lake Apopka exhibit significantly smaller penis size (24% average decrease) and lower plasma concentrations of testosterone (70% lower concentrations) when compared to animals of similar size on Lake Woodruff. In addition to smaller phalli, no relationship exists between plasma testosterone concentrations and penile size in males from Lake Apopka, whereas a positive relationship exists for males from Lake Woodruff. The alligators on Lake Apopka are known to have elevated concentrations of the antiandrogenic DDT breakdown product p.p'-DDE stored in their fat. We suggest a number of hypotheses that could explain the modification in the phenotype of the juvenile male living in Lake Apopka. These modifications in phenotype include a smaller penis size, lower plasma androgen concentrations, and lack of responsiveness of the penis to the plasma androgens present.

  2. Concentrations, loads, and yields of particle-associated contaminants in urban creeks, Austin, Texas, 1999-2004

    Science.gov (United States)

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Guilfoyle, A.L.; Sunvison, M.W.

    2006-01-01

    Concentrations, loads, and yields of particle-associated (hydrophobic) contaminants (PACs) in urban runoff in creeks in Austin, Texas, were characterized using an innovative approach: large-volume suspended-sediment sampling. This approach isolates suspended sediment from the water column in quantities sufficient for direct chemical analysis of PACs. During 1999-2004, samples were collected after selected rain events from each of five stream sites and Barton Springs for a study by the U.S. Geological Survey, in cooperation with the City of Austin. Sediment isolated from composited samples was analyzed for major elements, metals, organochlorine compounds, and polycyclic aromatic hydrocarbons (PAHs). In addition, at the Shoal Creek and Boggy Creek sites, individual samples for some events were analyzed to investigate within-event variation in sediment chemistry. Organochlorine compounds detected in suspended sediment included chlordane, dieldrin, DDD, DDE, DDT, and polychlorinated biphenyls (PCBs). Concentrations of PACs varied widely both within and between sites, with higher concentrations at the more urban sites and multiple nondetections at the least-urban sites. Within-site variation for metals and PAHs was smaller than between-site variation, and concentrations and yields of these and the organochlorine compounds correlated positively to the percentage of urban land use in the watershed. Loads of most PACs tested correlated significantly with suspended-sediment loads. Concentrations of most PACs correlated strongly with three measures of urban land use. Variation in suspended-sediment chemistry during runoff events was investigated at the Shoal and Boggy Creek sites. Five of the eight metals analyzed, dieldrin, chlordane, PCBs, and PAHs were detected at the highest concentrations in the first sample collected at the Shoal Creek site, a first-flush effect, but not at the Boggy Creek site. Temporal patterns in concentrations of DDT and its breakdown products

  3. Does arsenic in soil contribute to arsenic urinary concentrations in a French population living in a naturally arsenic contaminated area?

    International Nuclear Information System (INIS)

    Fillol, Clemence; Dor, Frederic; Clozel, Blandine; Goria, Sarah; Seta, Nathalie

    2010-01-01

    A cross sectional study using environmental and biological samples was implemented to assess the association between arsenic (As) concentrations in the environment and urinary As levels of residents living in an area where the soil is naturally As rich. As was measured in drinking water, atmospheric particulate matter, and soil and a geographic information system was used to assign environmental concentrations closest to the participants' dwellings and the sum of inorganic As and metabolites in urine samples. The only potential source of As environmental contamination was from soil with a range of 13-131 mg As/kg of dry matter. As(V) was the only species present among As extracted from the analyzed soil samples. The chemical extraction showed a poor mobility of As soil. There was no difference between child and teenager, and adult urinary As concentrations, though men had higher urinary As concentrations than women (p < 0.001). Given the important differences in lifestyle between 7-18 year olds, men, and women, these groups were analyzed separately. Whilst we were unable to find a stable model for the 7-18 year old group, for the adult men group we found that seafood consumption in the 3 days prior to the investigation (p = 0.02), and beer (p = 0.03) and wine consumption in the 4 days before the study, were associated with As urinary levels (μg/L). In adult women, creatinine was the only variable significantly associated with As urinary concentration (μg/L). The concentrations we measured in soils were variable and although high, only moderately so and no link between As concentrations in the soil and urinary As concentrations could be found for either men or women. Some individual factors explained half of the variability of adult men urinary As levels. The unexplained part of the variability should be searched notably in As mobility in soil and uncharacterized human behavior.

  4. Does arsenic in soil contribute to arsenic urinary concentrations in a French population living in a naturally arsenic contaminated area?

    Energy Technology Data Exchange (ETDEWEB)

    Fillol, Clemence, E-mail: c.fillol@invs.sante.fr [Universite Paris Descartes, Laboratoire Sante Publique et Environnement, EA 4064, Paris (France); Institut de Veille Sanitaire, Departement Sante Environnement, Saint-Maurice (France); Dor, Frederic [Institut de Veille Sanitaire, Departement Sante Environnement, Saint-Maurice (France); Clozel, Blandine [BRGM French Geological Survey, Service Geologique Regional Lorraine, Vandoeuvre-les-Nancy (France); Goria, Sarah [Institut de Veille Sanitaire, Departement Sante Environnement, Saint-Maurice (France); Seta, Nathalie [Universite Paris Descartes, Laboratoire Sante Publique et Environnement, EA 4064, Paris (France); AP-HP, Hopital Bichat-Claude Bernard, Biochimie, Paris (France)

    2010-11-01

    A cross sectional study using environmental and biological samples was implemented to assess the association between arsenic (As) concentrations in the environment and urinary As levels of residents living in an area where the soil is naturally As rich. As was measured in drinking water, atmospheric particulate matter, and soil and a geographic information system was used to assign environmental concentrations closest to the participants' dwellings and the sum of inorganic As and metabolites in urine samples. The only potential source of As environmental contamination was from soil with a range of 13-131 mg As/kg of dry matter. As(V) was the only species present among As extracted from the analyzed soil samples. The chemical extraction showed a poor mobility of As soil. There was no difference between child and teenager, and adult urinary As concentrations, though men had higher urinary As concentrations than women (p < 0.001). Given the important differences in lifestyle between 7-18 year olds, men, and women, these groups were analyzed separately. Whilst we were unable to find a stable model for the 7-18 year old group, for the adult men group we found that seafood consumption in the 3 days prior to the investigation (p = 0.02), and beer (p = 0.03) and wine consumption in the 4 days before the study, were associated with As urinary levels ({mu}g/L). In adult women, creatinine was the only variable significantly associated with As urinary concentration ({mu}g/L). The concentrations we measured in soils were variable and although high, only moderately so and no link between As concentrations in the soil and urinary As concentrations could be found for either men or women. Some individual factors explained half of the variability of adult men urinary As levels. The unexplained part of the variability should be searched notably in As mobility in soil and uncharacterized human behavior.

  5. Measures for radiation prevention and remediation of islightly radioactive contaminated sites by phytoremediation and subsequent utilization of the loaded plant residues (PHYTOREST). Final report

    International Nuclear Information System (INIS)

    Willscher, Sabine; Werner, Peter; Jablonski, Lukasz; Wittig, Juliane

    2013-01-01

    contaminated geosubstrates now can be carried out within the radiation protection regulations. Hence, the project provides a substantial contribution to the radiation protection of HM/R contaminated soils. Within the research project, ways for the utilization of HM/R- contaminated plant residuals were highlighted; this gives a substantial contribution for minimization of wastes, the winning of sustainable bioenergy and the recycling of materials. Here, different ways of solutions were investigated. The research project was carried out within the scientific funding program ''Closedown and decommissioning of nuclear facilities''. The results of the project will contribute to the development of a biologically benign, sustainable technique for the remediation of large contaminated areas that originate mostly from the legacy of the former U mining. As a general result of this comprehensive research project, a phytostabilization/ phytoextraction of such SM/R contaminated sites is feasible with a protection of ground water, and the plant crop from phytoremediation of the HM/R contaminated field site can be utilized for the winning of bioenergy (gaseous/ liquid products or thermal utilization). The beneficial combination of phytoremediation and subsequent utilization of the biomass can be further developed to an innovative and sustainable remediation technology with national and international application potential.

  6. Egg laying sequence influences egg mercury concentrations and egg size in three bird species: Implications for contaminant monitoring programs

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Yee, Julie L.; Hartman, C. Alex

    2016-01-01

    Bird eggs are commonly used in contaminant monitoring programs and toxicological risk assessments, but intra-clutch variation and sampling methodology could influence interpretability. We examined the influence of egg laying sequence on egg mercury concentrations and burdens in American avocets, black-necked stilts, and Forster's terns. The average decline in mercury concentrations between the first and last egg laid was 33% for stilts, 22% for terns, and 11% for avocets, and most of this decline occurred between the first and second eggs laid (24% for stilts, 18% for terns, and 9% for avocets). Trends in egg size with egg laying order were inconsistent among species and overall differences in egg volume, mass, length, and width were mercury concentrations generally declined by 16% between the first and second eggs laid. Despite the strong effect of egg laying sequence, most of the variance in egg mercury concentrations still occurred among clutches (75%-91%) rather than within clutches (9%-25%). Using simulations, we determined that to accurately estimate a population's mean egg mercury concentration using only a single random egg from a subset of nests, it would require sampling >60 nests to represent a large population (10% accuracy) or ≥14 nests to represent a small colony that contained <100 nests (20% accuracy).

  7. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil.

    Science.gov (United States)

    Holmstrup, Martin; Sørensen, Jesper G; Overgaard, Johannes; Bayley, Mark; Bindesbøl, Anne-Mette; Slotsbo, Stine; Fisker, Karina V; Maraldo, Kristine; Waagner, Dorthe; Labouriau, Rodrigo; Asmund, Gert

    2011-01-01

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil.

    Science.gov (United States)

    Abeysinghe, Kasun S; Yang, Xiao-Dong; Goodale, Eben; Anderson, Christopher W N; Bishop, Kevin; Cao, Axiang; Feng, Xinbin; Liu, Shengjie; Mammides, Christos; Meng, Bo; Quan, Rui-Chang; Sun, Jing; Qiu, Guangle

    2017-05-01

    Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil-dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water-logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia. Environ Toxicol Chem 2017;36:1202-1210. © 2016 SETAC. © 2016 SETAC.

  9. Occurrence of natural Bacillus thuringiensis contaminants and residues of Bacillus thuringiensis-based insecticides on fresh fruits and vegetables

    DEFF Research Database (Denmark)

    Frederiksen, Kristine; Rosenquist, Hanne; Jørgensen, Kirsten

    2006-01-01

    A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins v...... isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic....

  10. The effect of selected fungicides on the chemical composition of strawberry fruits and contamination with dithiocarbamate residues

    Directory of Open Access Journals (Sweden)

    Wysocki Karol

    2014-12-01

    Full Text Available In a four-year field experiment, fenhexamid, iprodione, pyrimethanil and thiram were applied in four different series as fungicides recommended for the control of grey mold (Botrytis cinerea in strawberries. The plant protection products had no significant effect on the chemical composition of strawberry fruits of the Kent and Senga Sengana cultivars with the exception of an increase in the vitamin C level in ‘Kent’ strawberries. They also contributed to minor variations in the content of extract, total sugars, organic acids, polyphenols and anthocyanins. Dithiocarbamate residues were detected in all samples from the first harvest of strawberries that had been treated with the thiram fungicide

  11. DOE's process and implementation guidance for decommissioning, deactivation, decontamination, and remedial action of property with residual contamination

    International Nuclear Information System (INIS)

    Domotor, S.; Peterson, H. Jr.; Wallo, A. III

    1999-01-01

    This paper presents DOE's requirements, process, and implementation guidance for the control and release of property that may contain residual radioactive material. DOE requires that criteria and protocols for release of property be approved by DOE and that such limits be selected using DOE's As Low as is Reasonably Achievable (ALARA) process. A DOE Implementation Guide discusses how the levels and details (e.g., cleanup volumes, costs of surveys, disposal costs, dose to workers and doses to members of the public, social and economic factors) of candidate release options are to be evaluated using DOE's ALARA process. Supporting tools and models for use within the analysis are also highlighted. (author)

  12. Lindane residues in fish inhabiting Nigerian rivers

    International Nuclear Information System (INIS)

    Okereke, G.U.; Dje, Y.

    1997-01-01

    Analysis for residues of lindane in fish collected from various rivers close to rice agroecosystems showed that the concentrations of lindane ranged from none detectable to 3.4 mg kg -1 . Fish from rivers where strict regulations prohibits its use had no detectable lindane residues while appreciable amounts of lindane were found in fish were such restriction was not enforced with the variation attributed to the extent of use of lindane in the area of contamination. The investigation confirms that the use of lindane in rice production in Nigeria can cause the contamination of fish in nearby rivers. (author). 16 refs, 2 tab

  13. Multi-residue analysis of 90 emerging contaminants in liquid and solid environmental matrices by ultra-high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Petrie, Bruce; Youdan, Jane; Barden, Ruth; Kasprzyk-Hordern, Barbara

    2016-01-29

    Reported herein is new analytical methodology for the determination of 90 emerging contaminants (ECs) in liquid environmental matrices (crude wastewater, final effluent and river water). The application of a novel buffer, ammonium fluoride improved signal response for several ECs determined in negative ionisation mode. Most notably the sensitivity of steroid estrogens was improved by 4-5 times in environmental extracts. Method recoveries ranged from 40 to 152% in all matrices and method quantitation limits (MQLs) achieved were MQL in liquid environmental samples and digested sludge, respectively. To date, this is the most comprehensive multi-residue analytical method reported in the literature for the determination of ECs in both liquid and solid environmental matrices. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Holmstrup, Martin, E-mail: martin.holmstrup@dmu.d [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Sorensen, Jesper G. [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Overgaard, Johannes; Bayley, Mark [Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Bindesbol, Anne-Mette [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Slotsbo, Stine; Fisker, Karina V.; Maraldo, Kristine [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Waagner, Dorthe [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Labouriau, Rodrigo [Aarhus University, Faculty of Agricultural Sciences, Department of Genetics and Biotechnology, Research Centre Foulum, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Asmund, Gert [National Environmental Research Institute, Aarhus University, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2011-01-15

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. - Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation of aluminium and nickel has energetic costs.

  15. Assessment of radon concentration and heavy metal contamination in groundwater of Udhampur district, Jammu & Kashmir, India.

    Science.gov (United States)

    Kumar, Ajay; Sharma, Sumit; Mehra, Rohit; Kanwar, Priya; Mishra, Rosaline; Kaur, Inderpreet

    2018-04-01

    Radon concentration was measured in water samples of 41 different locations from Udhampur district of Jammu & Kashmir, India, by using RAD7 and Smart RnDuo monitor. The variation of radon concentration in water ranged from 1.44 ± 0.31 to 63.64 ± 2.88 Bq L -1 , with a mean value of 28.73 Bq L -1 using RAD7 and 0.64 ± 0.28 to 52.65 ± 2.50 Bq L -1 , with a mean value of 20.30 Bq L -1 using Smart RnDuo monitor, respectively. About 17.07% of the studied water samples recorded to display elevated radon concentration above the reference range suggested by United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR). The mean annual effective dose of these samples was determined, and 78.95% samples were found to be within the safe limits set by World Health Organisation (WHO) and European Council (EU). The study revealed good agreement between the values obtained with two methods. Heavy metals (Zn, Cd, Fe, Cu, Ni, As, Hg, Co, Pb and Cr) were determined in water samples by microwave plasma atomic emission spectrometer, and their correlation with radon content was also analysed.

  16. Influence of different sanitizers on food contaminant bacteria: effect of exposure temperature, contact time, and product concentration

    Directory of Open Access Journals (Sweden)

    Cezar Augusto Beltrame

    2012-06-01

    Full Text Available The efficiency of four Sanitizers - peracetic acid, chlorhexidine, quaternary ammonium, and organic acids - was tested in this work using different bacteria recognized as a problem to meat industry, Salmonella sp., S. aureus, E. coli and L. monocytogenes. The effects of sanitizer concentration (0.2, 0.5, 0.6, 1.0, 1.1 and 1.4%, at different temperatures (10 and 45 °C and contact time (2, 10, 15, 18 and 25 minutes were evaluated. Tests in an industrial plant were also carried out considering previously obtained results. In a general way, peracetic acid presented higher efficiencies using low concentration (0.2% and contact time (2 minutes at 10 °C. The tests performed in industrial scale showed that peracetic acid presented a good performance in concentration and contact time lower than that suggested by the suppliers. The use of chlorhexidine and quaternary ammonium led to reasonable results at the indicated conditions, and organic acids were ineffective under concentration and contact time higher than those indicated by the suppliers in relation to Staphylococcus aureus. The results, in general, show that the choice for the most adequate sanitizer depends on the microorganism contaminant, the time available for sanitizer application, and also on the process cost.

  17. Egg laying sequence influences egg mercury concentrations and egg size in three bird species: Implications for contaminant monitoring programs

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Yee, Julie L.; Hartman, C. Alex

    2016-01-01

    Bird eggs are commonly used in contaminant monitoring programs and toxicological risk assessments, but intra-clutch variation and sampling methodology could influence interpretability. We examined the influence of egg laying sequence on egg mercury concentrations and burdens in American avocets, black-necked stilts, and Forster's terns. The average decline in mercury concentrations between the first and last egg laid was 33% for stilts, 22% for terns, and 11% for avocets, and most of this decline occurred between the first and second eggs laid (24% for stilts, 18% for terns, and 9% for avocets). Trends in egg size with egg laying order were inconsistent among species and overall differences in egg volume, mass, length, and width were laying sequence, most of the variance in egg mercury concentrations still occurred among clutches (75%-91%) rather than within clutches (9%-25%). Using simulations, we determined that to accurately estimate a population's mean egg mercury concentration using only a single random egg from a subset of nests, it would require sampling >60 nests to represent a large population (10% accuracy) or ≥14 nests to represent a small colony that contained <100 nests (20% accuracy).

  18. Relationship between biomarker responses and contaminant concentration in selected tissues of flounder (Platichthys flesus from the Polish coastal area of the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Magdalena Podolska

    2008-09-01

    Full Text Available Previous studies in the Gulf of Gdańsk discussed the responses of selected enzymatic biomarkers to the contaminant gradient in fish and mussels. In the present study, flounder muscle and liver tissues were analyzed for polychlorinated biphenyls (PCB congeners: 28, 52, 101, 118, 138, 153 and 180, organochlorine pesticides (HCHs, HCB and DDTs, and trace metals (Pb, Cd, Zn, Cu, Hg, Cr. An attempt was made to identify the relationship between the measured enzymatic biomarker responses (cholinesterases, malic enzyme, isocitrate dehydrogenase, glutathione S-transferase and contaminant concentrations in selected flounder tissues. The observed differences in enzymatic biomarker levels suggest that chronic exposure to low-concentration mixtures of contaminants may be occurring in the studied area. However, no conclusive evidence was found of a clear link between the biomarker responses and contaminant concentrations in flounder tissues.

  19. Experimental investigation of concentration and stable isotopes signals during organic contaminants back diffusion

    DEFF Research Database (Denmark)

    Jin, Biao; Nika, Chrysanthi-Elisabeth; Rolle, Massimo

    2017-01-01

    -DCE back diffusion from an impervious layer. Intensive sampling (>1000 measurements) was carried out, including the withdrawal of aqueous samples at closely spaced (1 cm) outlet ports, as well as the high-resolution sampling of the source zone (agarose gel) at the end of each experiment. The transient...... behavior of the plumes originated by back diffusion was investigated by sampling the outlet ports at regular intervals in the experiments, each run for a total time corresponding to 15 pore volumes. The high-resolution sampling allowed us to resolve the spatial and temporal evolution of concentration...... [3], provided a good agreement with the experimental data...

  20. Separation and concentration of water-borne contaminants utilizing insulator-based dielectrophoresis.

    Energy Technology Data Exchange (ETDEWEB)

    Lapizco-Encinas, Blanca Hazalia; Fiechtner, Gregory J.; Cummings, Eric B.; Davalos, Rafael V.; Kanouff, Michael P.; Simmons, Blake Alexander; McGraw, Gregory J.; Salmi, Allen J.; Ceremuga, Joseph T.; Fintschenko, Yolanda

    2006-01-01

    This report focuses on and presents the capabilities of insulator-based dielectrophoresis (iDEP) microdevices for the concentration and removal of water-borne bacteria, spores and inert particles. The dielectrophoretic behavior exhibited by the different particles of interest (both biological and inert) in each of these systems was observed to be a function of both the applied electric field and the characteristics of the particle, such as size, shape, and conductivity. The results obtained illustrate the potential of glass and polymer-based iDEP devices to act as a concentrator for a front-end device with significant homeland security and industrial applications for the threat analysis of bacteria, spores, and viruses. We observed that the polymeric devices exhibit the same iDEP behavior and efficacy in the field of use as their glass counterparts, but with the added benefit of being easily mass fabricated and developed in a variety of multi-scale formats that will allow for the realization of a truly high-throughput device. These results also demonstrate that the operating characteristics of the device can be tailored through the device fabrication technique utilized and the magnitude of the electric field gradient created within the insulating structures. We have developed systems capable of handling numerous flow rates and sample volume requirements, and have produced a deployable system suitable for use in any laboratory, industrial, or clinical setting.

  1. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins

    Directory of Open Access Journals (Sweden)

    Liyuan Zhang

    2016-12-01

    Full Text Available Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize, M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize, M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060. The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB1 (M0 exhibited a decreasing tendency in average daily gain (ADG and total superoxide dismutase (T-SOD activity in serum, and T-SOD and glutathione peroxidase (GSH-Px activities in the liver significantly decreased along with the appearance of AFB1 and AFM1 compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks (p > 0.05, significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

  2. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins.

    Science.gov (United States)

    Zhang, Liyuan; Ma, Qiugang; Ma, Shanshan; Zhang, Jianyun; Jia, Ru; Ji, Cheng; Zhao, Lihong

    2016-12-22

    Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize), M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize), M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060). The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB₁ (M0) exhibited a decreasing tendency in average daily gain (ADG) and total superoxide dismutase (T-SOD) activity in serum, and T-SOD and glutathione peroxidase (GSH-Px) activities in the liver significantly decreased along with the appearance of AFB₁ and AFM₁ compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks ( p > 0.05), significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

  3. Studies by nuclear and physico-chemical methods of tissue's metallic contamination located around biomaterials. Toxicity measurements of several biomaterials residual radioactivity

    International Nuclear Information System (INIS)

    Guibert, Geoffroy

    2004-01-01

    Implants used as biomaterials fulfill conditions of functionality, compatibility and occasionally bio-activity. There are four main families of biomaterials: metals and metal alloys, polymers, bio-ceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. These debris develop different problems: toxicity, inflammatory reactions, prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters which have an influence on tissue response. We characterize metallic contamination coming from knee prosthesis into surrounding capsular tissue by depth migration, in vivo behaviours, content, size and nature of debris. The PIXE-RBS and STEM-EDXS methods, that we used, are complementary, especially about characterization scale. Debris contamination distributed in the whole articulation is very heterogeneous. Debris migrate on several thousands μm in tissue. Solid metallic particles, μm, are found in the most polluted samples, for both kinds of alloys TA6V and CrCoMo. In the mean volume analysed by PIXE, the in vivo mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TA6V debris and chemical evolution of CrCoMo debris. Complementary measures of TA6V grains, on a nano-metric scale by STEM-EDXS, show a dissolution of coarse grain (μm) in smaller grains (nm). Locally, TA6V grains of a phase are detected and could indicate a preferential dissolution of β phase (grain boundaries) with dropping of Al and V, both toxic and carcinogenic elements. A thin target protocol development correlates PIXE and histological analysis on the same zone. This protocol allows to locate other pathologies in relationship with weaker metal contamination, μg/g, thanks to the great sensitivity of PIXE method. Harmlessness with respect to the residual radioactivity of several natural or synthetic biomaterials is established, using ultra low background noise γ detection system. (author)

  4. Behavior of Trifolium repens and Lolium perenne growing in a heavy metal contaminated field: Plant metal concentration and phytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Bidar, G. [Laboratoire Sols et Environnement, Institut Superieur d' Agriculture, 48 Boulevard Vauban, 59046 Lille Cedex (France); LCE-EA2598, Toxicologie Industrielle et Environnementale, MREI2, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Universite du Littoral-Cote d' Opale, 189A Avenue Maurice Schumann, 59140 Dunkerque (France); Garcon, G. [LCE-EA2598, Toxicologie Industrielle et Environnementale, MREI2, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Universite du Littoral-Cote d' Opale, 189A Avenue Maurice Schumann, 59140 Dunkerque (France); Pruvot, C. [Laboratoire Sols et Environnement, Institut Superieur d' Agriculture, 48 Boulevard Vauban, 59046 Lille Cedex (France); Dewaele, D. [Centre Commun de Mesures, MREI 1, Universite du Littoral-Cote d' Opale, 145, Avenue Maurice Schumann, 59140 Dunkerque (France); Cazier, F. [Centre Commun de Mesures, MREI 1, Universite du Littoral-Cote d' Opale, 145, Avenue Maurice Schumann, 59140 Dunkerque (France); Douay, F. [Laboratoire Sols et Environnement, Institut Superieur d' Agriculture, 48 Boulevard Vauban, 59046 Lille Cedex (France); Shirali, P. [LCE-EA2598, Toxicologie Industrielle et Environnementale, MREI2, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Universite du Littoral-Cote d' Opale, 189A Avenue Maurice Schumann, 59140 Dunkerque (France)]. E-mail: pirouz.shirali@univ-littoral.fr

    2007-06-15

    The use of a vegetation cover for the management of heavy metal contaminated soils needs prior investigations on the plant species the best sustainable. In this work, behaviors of Trifolium repens and Lolium perenne, growing in a metal-polluted field located near a closed lead smelter, were investigated through Cd, Pb and Zn-plant metal concentrations and their phytotoxicity. In these plant species, metals were preferentially accumulated in roots than in shoots, as follow: Cd > Zn > Pb. Plant exposure to such metals induced oxidative stress in the considered organs as revealed by the variations in malondialdehyde levels and superoxide dismutase activities. These oxidative changes were closely related to metal levels, plant species and organs. Accordingly, L. perenne seemed to be more affected by metal-induced oxidative stress than T. repens. Taken together, these findings allow us to conclude that both the plant species could be suitable for the phytomanagement of metal-polluted soils. - Usefulness of Trifolium repens and Lolium perenne for the phytomanagement of heavy metal-contaminated soils.

  5. Degradation of fifteen emerging contaminants at microg L(-1) initial concentrations by mild solar photo-Fenton in MWTP effluents.

    Science.gov (United States)

    Klamerth, N; Rizzo, L; Malato, S; Maldonado, Manuel I; Agüera, A; Fernández-Alba, A R

    2010-01-01

    The degradation of 15 emerging contaminants (ECs) at low concentrations in simulated and real effluent of municipal wastewater treatment plant with photo-Fenton at unchanged pH and Fe=5 mg L(-1) in a pilot-scale solar CPC reactor was studied. The degradation of those 15 compounds (Acetaminophen, Antipyrine, Atrazine, Caffeine, Carbamazepine, Diclofenac, Flumequine, Hydroxybiphenyl, Ibuprofen, Isoproturon, Ketorolac, Ofloxacin, Progesterone, Sulfamethoxazole and Triclosan), each with an initial concentration of 100 microg L(-1), was found to depend on the presence of CO(3)(2-) and HCO(3)(-) (hydroxyl radicals scavengers) and on the type of water (simulated water, simulated effluent wastewater and real effluent wastewater), but is relatively independent of pH, the type of acid used for release of hydroxyl radicals scavengers and the initial H(2)O(2) concentration used. Toxicity tests with Vibrio fisheri showed that degradation of the compounds in real effluent wastewater led to toxicity increase. (c) 2009 Elsevier Ltd. All rights reserved.

  6. Utilizing Polymer-Coated Vials to Illustrate the Fugacity and Bioavailability of Chlorinated Pesticide Residues in Contaminated Soils

    Science.gov (United States)

    Andrade, Natasha A.; McConnell, Laura L.; Torrents, Alba; Hapeman, Cathleen J.

    2013-01-01

    Fugacity and bioavailability can be used to facilitate students' understanding of potential environmental risks associated with toxic chemicals and, therefore, should be incorporated in environmental chemistry and science laboratories. Although the concept of concentration is easy to grasp, fugacity and bioavailability can be challenging…

  7. Enhancement of Methane Concentration by Removing Contaminants from Biogas Mixtures Using Combined Method of Absorption and Adsorption

    Directory of Open Access Journals (Sweden)

    Muhammad Rashed Al Mamun

    2017-01-01

    Full Text Available We report a laboratory scale combined absorption and adsorption chemical process to remove contaminants from anaerobically produced biogas using cafeteria (food, vegetable, fruit, and cattle manure wastes. Iron oxide (Fe2O3, zero valent iron (Feo, and iron chloride (FeCl2 react with hydrogen sulfide (H2S to deposit colloidal sulfur. Silica gel, sodium sulfate (Na2SO4, and calcium oxide (CaO reduce the water vapour (H2O and carbon dioxide (CO2. It is possible to upgrade methane (CH4 above 95% in biogas using chemical or physical absorption or adsorption process. The removal efficiency of CO2, H2S, and H2O depends on the mass of removing agent and system pH. The results showed that Ca(OH2 solutions are capable of reducing CO2 below 6%. The H2S concentration was reduced to 89%, 90%, 86%, 85%, and 96% for treating with 10 g of FeCl2, Feo (with pH, Fe2O3, Feo, and activated carbon, respectively. The H2O concentration was reduced to 0.2%, 0.7%, 0.2%, 0.2%, and 0.3% for treating raw biogas with 10 g of silica gel and Na2SO4 for runs R1, R2, R3, R4, and R5, respectively. Thus, given the successful contaminant elimination, the combined absorption and adsorption process is a feasible system for biogas purification.

  8. Opening Address [International Conference on Remediation of Land Contaminated by Radioactive Material Residues, Astana (Kazakhstan), 18-22 May 2009

    International Nuclear Information System (INIS)

    Forsstroem, H.

    2014-01-01

    This conference creates a good opportunity to discuss the relevant issues relating to the environmental remediation of radioactively contaminated sites. It follows on from the environmental remediation conference that took place 10 years ago in Arlington, USA, and will allow discussion of the achievements, the successes, the failures and the lessons learned, as well as the new challenges that have emerged since that time. The conference will also provide a forum for discussions on: financing mechanisms and support for the international or multilateral organization of environmental remediation programmes; regulatory and safety issues; mature and innovative technologies; life cycle planning; and non-technical issues in environmental remediation. As a result, it is expected that the conference will encourage and assist the establishment of different partnerships, reveal synergies that can help in the full implementation of environmental remediation projects and provide a forum for improved coordination among the international organizations that support environmental remediation programmes, especially in this region. Finally, the conference will allow the IAEA to collect ideas for its programme and for the assistance it gives to its Member States

  9. Research to Support the Determination of Spacecraft Maximum Acceptable Concentrations of Potential Atmospheric Contaminants

    Science.gov (United States)

    Orr, John L.

    1997-01-01

    In many ways, the typical approach to the handling of bibliographic material for generating review articles and similar manuscripts has changed little since the use of xerographic reproduction has become widespread. The basic approach is to collect reprints of the relevant material and place it in folders or stacks based on its dominant content. As the amount of information available increases with the passage of time, the viability of this mechanical approach to bibliographic management decreases. The personal computer revolution has changed the way we deal with many familiar tasks. For example, word processing on personal computers has supplanted the typewriter for many applications. Similarly, spreadsheets have not only replaced many routine uses of calculators but have also made possible new applications because the cost of calculation is extremely low. Objective The objective of this research was to use personal computer bibliographic software technology to support the determination of spacecraft maximum acceptable concentration (SMAC) values. Specific Aims The specific aims were to produce draft SMAC documents for hydrogen sulfide and tetrachloroethylene taking maximum advantage of the bibliographic software.

  10. Rapid prediction of total petroleum hydrocarbons concentration in contaminated soil using vis-NIR spectroscopy and regression techniques.

    Science.gov (United States)

    Douglas, R K; Nawar, S; Alamar, M C; Mouazen, A M; Coulon, F

    2018-03-01

    Visible and near infrared spectrometry (vis-NIRS) coupled with data mining techniques can offer fast and cost-effective quantitative measurement of total petroleum hydrocarbons (TPH) in contaminated soils. Literature showed however significant differences in the performance on the vis-NIRS between linear and non-linear calibration methods. This study compared the performance of linear partial least squares regression (PLSR) with a nonlinear random forest (RF) regression for the calibration of vis-NIRS when analysing TPH in soils. 88 soil samples (3 uncontaminated and 85 contaminated) collected from three sites located in the Niger Delta were scanned using an analytical spectral device (ASD) spectrophotometer (350-2500nm) in diffuse reflectance mode. Sequential ultrasonic solvent extraction-gas chromatography (SUSE-GC) was used as reference quantification method for TPH which equal to the sum of aliphatic and aromatic fractions ranging between C 10 and C 35 . Prior to model development, spectra were subjected to pre-processing including noise cut, maximum normalization, first derivative and smoothing. Then 65 samples were selected as calibration set and the remaining 20 samples as validation set. Both vis-NIR spectrometry and gas chromatography profiles of the 85 soil samples were subjected to RF and PLSR with leave-one-out cross-validation (LOOCV) for the calibration models. Results showed that RF calibration model with a coefficient of determination (R 2 ) of 0.85, a root means square error of prediction (RMSEP) 68.43mgkg -1 , and a residual prediction deviation (RPD) of 2.61 outperformed PLSR (R 2 =0.63, RMSEP=107.54mgkg -1 and RDP=2.55) in cross-validation. These results indicate that RF modelling approach is accounting for the nonlinearity of the soil spectral responses hence, providing significantly higher prediction accuracy compared to the linear PLSR. It is recommended to adopt the vis-NIRS coupled with RF modelling approach as a portable and cost effective

  11. Use of a new type of mixer - settler for the treatment of residual water contaminated with crude petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Paulo, J.B.A. [UFRN, Natal, Program of Masters degree on Chem. Eng. (Brazil); Hadjiev, D. [Universite de Bretagne Sud, Procedes de Traitement des Effluents et des Dechets, 56 - Lorient (France)

    2001-07-01

    The aim of this work is to assess the separation efficiency in the case of dispersions and/or emulsions of the crude oil in water, using a new type of mixer-settler design called MDIF (Misturador Decantador a Inversao de Fascs/ Phase Inversion Mixer-Settler). The principle of phase inversion is used to decrease the distance between the drops of the disperse phase and the interface between the liquid phases involved in the process. The new equipment has shown advantages over the conventional extractors/separators for hydro-metallurgic applications. In this work, a real system has been studied which is commonly present in the petroleum industry. The first results show that the equipment presents a separation efficiency of practically 100% for concentrations in oil from 2000 to 4600 ppm. (authors)

  12. Risk element sorption/desorption characteristics of dry olive residue: a technique for the potential immobilization of risk elements in contaminated soils.

    Science.gov (United States)

    Hovorka, Miloš; Száková, Jiřina; García-Sánchez, Mercedes; Acebal, Mercedes Blanc; García-Romera, Inmaculada; Tlustoš, Pavel

    2016-11-01

    Olive oil production is one of the most relevant agroindustrial activities in the Mediterranean region and generates a huge amount of both solid and semi-solid wastes, the uncontrolled disposal of which might lead to serious environmental problems. Due to its organic matter and mineral nutrient content, the waste material can be applied to agricultural soil as a fertilizer. However, due to its high organic matter content, dry olive residue (DOR), commonly called "alperujo," has the potential to immobilize risk elements in contaminated soils. The main objective of this study was to assess the possible effect of DOR on sorption of risk elements such as cadmium (Cd), lead (Pb), and zinc (Zn) in the soil. A set of batch sorption experiments were carried out to assess the ability of DOR to adsorb Cd, Pb, and Zn where the effect of the preceding biotransformation of DOR by four species of fungi: Penicillium chrysogenum, Coriolopsis floccosa, Bjerkhandera adusta, and Chondrostereum purpureum was compared. The Freundlich and Langmuir sorption isotherms were calculated to assess the sorption characteristics of both transformed and non-transformed DOR. The results showed good potential sorption capacity of DOR, especially for Pb and to a lesser extent for Cd and Zn. Better sorption characteristics were reported for the biotransformed DOR samples, which are expected to show higher humification of the organic matter. However, the desorption experiments showed weakness and instability of the DOR-bound elements, especially in the case of Zn. Thus, future research should aim to verify the DOR sorption pattern in contaminated soil as well as the potential stabilization of the DOR element bounds where the increase of the pH levels of the DOR samples needs to be taken into account.

  13. False negative rate and other performance measures of a sponge-wipe surface sampling method for low contaminant concentrations.

    Energy Technology Data Exchange (ETDEWEB)

    Einfeld, Wayne; Krauter, Paula A.; Boucher, Raymond M.; Tezak, Mathew; Amidan, Brett G. (Pacific Northwest National Laboratory, Richland, WA); Piepel, Greg F. (Pacific Northwest National Laboratory, Richland, WA)

    2011-05-01

    Recovery of spores from environmental surfaces is known to vary due to sampling methodology, techniques, spore size and characteristics, surface materials, and environmental conditions. A series of tests were performed to evaluate a new, validated sponge-wipe method. Specific factors evaluated were the effects of contaminant concentrations and surface materials on recovery efficiency (RE), false negative rate (FNR), limit of detection (LOD) - and the uncertainties of these quantities. Ceramic tile and stainless steel had the highest mean RE values (48.9 and 48.1%, respectively). Faux leather, vinyl tile, and painted wood had mean RE values of 30.3, 25.6, and 25.5, respectively, while plastic had the lowest mean RE (9.8%). Results show a roughly linear dependence of surface roughness on RE, where the smoothest surfaces have the highest mean RE values. REs were not influenced by the low spore concentrations tested (3 x 10{sup -3} to 1.86 CFU/cm{sup 2}). The FNR data were consistent with RE data, showing a trend of smoother surfaces resulting in higher REs and lower FNRs. Stainless steel generally had the lowest mean FNR (0.123) and plastic had the highest mean FNR (0.479). The LOD{sub 90} varied with surface material, from 0.015 CFU/cm{sup 2} on stainless steel up to 0.039 on plastic. Selecting sampling locations on the basis of surface roughness and using roughness to interpret spore recovery data can improve sampling. Further, FNR values, calculated as a function of concentration and surface material, can be used pre-sampling to calculate the numbers of samples for statistical sampling plans with desired performance, and post-sampling to calculate the confidence in characterization and clearance decisions.

  14. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Yu Cheng Zhu

    Full Text Available Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate, Karate (λ-cyhalothrin, Vydate (oxamyl, Domark (tetraconazole, and Roundup (glyphosate at residue level had a mortality range of 1.3-13.3%, statistically similar to that of control (P>0.05. The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate. The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.. Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb and sulfoxaflor (3 ppm a.i. may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

  15. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera).

    Science.gov (United States)

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothrin), Vydate (oxamyl), Domark (tetraconazole), and Roundup (glyphosate) at residue level had a mortality range of 1.3-13.3%, statistically similar to that of control (P>0.05). The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate). The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.). Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb) and sulfoxaflor (3 ppm a.i.) may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

  16. Sustainable System for Residual Hazards Management

    International Nuclear Information System (INIS)

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour

    2004-01-01

    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today's waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous long-term management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by external intrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the long-term success of the prescribed system. In fact

  17. Bioaccessible Porosity: A new approach to assess residual contamination after bioremediation of hydrophobic organic compounds in sub-surface microporous environments

    Science.gov (United States)

    Akbari, A.; Ghoshal, S.

    2016-12-01

    We define a new parameter, "bioaccessible porosity", the fraction of aggregate volume accessible to soil bacteria, towards a priori assessment of hydrocarbon bioremediation end points. Microbial uptake of poorly soluble hydrocarbons occurs through direct uptake or micellar solubilzation/emulsification associated with biosurfactant production, and requires close proximity of bacteria and hydrocarbon phase. In subsurface microporous environments, bioremediation rates are attenuated when residual hydrophobic contamination is entrapped in sterically restrictive environments which is not accessible to soil bacteria. This study presents new approaches for characterization of the microstructure of porous media and as well, the ability of indigenous hydrocarbon degraders to access to a range of pore sizes. Bacterial access to poorly soluble hydrocarbons in soil micro pores were simulated with bioreactors with membranes with different pore sizes containing the hydrocarbon degrading bacteria, Dietzia maris. D. maris is Gram-positive, and nonmotile that we isolated as the major hydrocarbon degrader from a fine-grained, weathered, hydrocarbon-contaminated site soil. Under nutritional stress, planktonic D. maris cells were aggregated and accessed 5 µm but not 3 µm and smaller pores. However, when hexadecane was available at the pore mouth, D. maris colonized the pore mouth, and accessed pores as small as 0.4 µm. This suggests bacterial accessibility to different pore sizes is regulated by nutritional conditions. A combination of X-ray micro-CT scanning, gas adsorption and mercury intrusion porosimetry was used to characterize the range of pore sizes of soil aggregates. In case of the studied contaminated soil, the bioaccessible porosity were determined as 25% , 27% and 29% (assuming 4, 1, 0.4 µm respectively as accessibility criteria), and about 2.7% of aggregate volume was attributed to 0.006-0.4 µm pores. The 2% aggregate volume at an assumed saturation of 10% could

  18. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.

    1984-01-01

    A new process for recovery of plutonium and americium from pyrochemical waste has been demonstrated. It is based on chloride solution anion exchange at low acidity, which eliminates corrosive HCl fumes. Developmental experiments of the process flowsheet concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 = from high chloride-low acid solution. Americium and other metals are washed from the ion exchange column with 1N HNO 3 -4.8M NaCl. The plutonium is recovered, after elution, via hydroxide precipitation, while the americium is recovered via NaHCO 3 precipitation. All filtrates from the process are discardable as low-level contaminated waste. Production-scale experiments are now in progress for MSE residues. Flow sheets for actinide recovery from electrorefining and direct oxide reduction residues are presented and discussed

  19. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.

    1985-05-01

    We demonstrated a new process for recovering plutonium and americium from pyrochemical waste. The method is based on chloride solution anion exchange at low acidity, or acidity that eliminates corrosive HCl fumes. Developmental experiments of the process flow chart concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 2- from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO 3 -4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO 3 precipitation. All filtrates from the process can be discardable as low-level contaminated waste. Production-scale experiments are in progress for MSE residues. Flow charts for actinide recovery from electro-refining and direct oxide reduction residues are presented and discussed

  20. Comparison of long-term stability of containment systems for residues and wastes contaminated with naturally occurring radionuclides at an arid site and two humid sites

    International Nuclear Information System (INIS)

    Winters, M.; Merry-Libby, P.; Hinchman, R.

    1985-01-01

    The long-term stability of near-surface containment systems designed for the management of radioactive wastes and residues contaminated with naturally occurring radionuclides are compared at the three different sites. The containment designs are: (1) a diked 8.9-m high mound, including a 3.2-m layered cap at a site (humid) near Lewiston, New York, (2) a 6.8-m-high mound, including a similar 3.2-m cap at a site (humid) near Oak Ridge, Tennessee, and (3) 4.8-m deep trenches with 3.0-m backfilled caps at a site (arid) near Hanford, Washington. Geological, hydrological, and biological factors affecting the long-term (1000-year) integrity of the containment systems at each site are examined, including: erosion, flooding, drought, wildfire, slope and cover failure, plant root penetration, burrowing animals, other soil-forming processes, and land-use changes. For the containment designs evaluated, releases of radon-222 at the arid site are predicted to be several orders of magnitude higher than at the two humid sites - upon initial burial and at 1000 years (after severe erosion). Transfer of wastes containing naturally occurring radionuclides from a humid to an arid environment offers little or no advantage relative to long-term stability of the containment system and has a definite disadvantage in terms of gaseous radioactive releases. 26 references, 3 figures, 4 tables

  1. Measurement of underground contamination of non-aqueous phase liquids (NAPLs) on the basis of the radon concentration in ground level air

    International Nuclear Information System (INIS)

    Schubert, M.

    2001-01-01

    It was investigated whether measurements of radon concentrations in ground level air are a suitable method of detecting sub-surface soil contamination with non-aqueous phase liquids (NAPLs). The working postulation was that, due to the very high solubility of radon in NAPLs, and the resulting accumulation of radon in NAPLs, radon exhalation to the ground level air in the proximity of such NAPL contamination should be locally reduced, thus indicating contamination of sub-surface soils with NAPLs. The research work reported was to verify the working theory by way of experiments, and to finally develop a reliable detection method for NAPL contaminations. The investigations comprised theoretical studies, laboratory experiments, experiments in defined soil columns, and extensive field studies [de

  2. Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

    Directory of Open Access Journals (Sweden)

    Mohammed Hussain Essa

    2013-01-01

    Full Text Available In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg, was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD was used for the experimental design and response surface methodology (RSM was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whose R2 ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

  3. The determination of pesticide residues and contaminants in vegetables by means of neutron activation analysis. Part of a coordinated programme on nuclear detection and analysis

    International Nuclear Information System (INIS)

    Mongkolphanta, S.

    1977-11-01

    Neutron activation techniques have been applied to study the existence of pesticide residues (As, Br, Hg) and pollutants (Cd, Co, Zn) in local vegetable and fruit samples, polished and unpolished glutinous and non-glutinous milled rice, and fish caught in polluted and unpolluted areas of the Gulf of Thailand. Since the baseline levels of these toxic elements in vegetables, fruits, rice and fish are not known as yet, the results cannot be regarded as conclusive. Furthermore, no significant difference was observed in the concentration of these elements in fish caught in polluted and unpolluted areas. The Gulf of Thailand does not therefore appear to be polluted at present. The substoichiometric isotope dilution technique was successfully applied to mercury determinations, and only to a limited extent to Cd due to shutdown of the TRR-1 reactor

  4. Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

    Science.gov (United States)

    Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.

    2014-11-01

    The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard

  5. Seasonal concentrations of organic contaminants at the fall line of the Susquehanna River basin and estimated fluxes to northern Chesapeake Bay, USA

    Science.gov (United States)

    Foster, G.D.; Lippa, K.A.; Miller, C.V.

    2000-01-01

    Riverine fluxes of several pesticides and other organic contaminants from above the fall line of the Susquehanna River basin to northern Chesapeake Bay, USA, were quantified in 1994. Base flow and storm flow samples collected at the fall line of the river from February to December 1994 were analyzed for both dissolved and particulate phase contaminants. Measured concentrations of the organonitrogen and organophosphorus pesticides varied mainly in response to the timing of their application to agricultural fields. Conversely, the concentrations of the more particle-sorptive contaminants such as polychlorinated biphenyls (PCBs), organochlorine (OC) insecticides, and polycyclic aromatic hydrocarbons (PAHs) were more directly correlated with river flow throughout the year. Annual fluxes were almost entirely in the dissolved phase for the organonitrogen and organophosphorus pesticides, distributed between the dissolved and particulate phases for the PCBs and OC insecticides, and primarily in the particulate phase for the PAHs.

  6. Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals

    Science.gov (United States)

    Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Chromosome regions known as quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a populatio...

  7. Determination of the Residual Anthracene Concentration in Cultures of Haloalkalitolerant Actinomycetes by Excitation Fluorescence, Emission Fluorescence, and Synchronous Fluorescence: Comparative Study

    Directory of Open Access Journals (Sweden)

    Reyna del Carmen Lara-Severino

    2016-01-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are compounds that can be quantified by fluorescence due to their high quantum yield. Haloalkalitolerant bacteria tolerate wide concentration ranges of NaCl and pH. They are potentially useful in the PAHs bioremediation of saline environments. However, it is known that salinity of the sample affects fluorescence signal regardless of the method. The objective of this work was to carry out a comparative study based on the sensitivity, linearity, and detection limits of the excitation, emission, and synchronous fluorescence methods, during the quantification of the residual anthracene concentration from the following haloalkalitolerant actinomycetes cultures Kocuria rosea, Kocuria palustris, Microbacterium testaceum, and 4 strains of Nocardia farcinica, in order to establish the proper fluorescence method to study the PAHs biodegrading capacity of haloalkalitolerant actinobacteria. The study demonstrated statistical differences among the strains and among the fluorescence methods regarding the anthracene residual concentration. The results showed that excitation and emission fluorescence methods performed very similarly but sensitivity in excitation fluorescence is slightly higher. Synchronous fluorescence using Δλ=150 nm is not the most convenient method. Therefore we propose the excitation fluorescence as the fluorescence method to be used in the study of the PAHs biodegrading capacity of haloalkalitolerant actinomycetes.

  8. Residual radionuclide concentrations and estimated radiation doses at the former French nuclear weapons test sites in Algeria.

    Science.gov (United States)

    Danesi, P R; Moreno, J; Makarewicz, M; Louvat, D

    2008-11-01

    In order to assess the level of residual radioactivity and evaluate the radiological conditions at the former French nuclear testing sites of Reggane and Taourirt Tan Afella in the south of Algeria, the International Atomic Energy Agency, at the request of the government of Algeria, conducted a field mission to the sites in 1999. At these locations, France conducted a number of nuclear tests in the early 1960s. At the ground zero locality of the ''Gerboise Blanche'' atmospheric test (Reggane) and in the vicinity of a tunnel where radioactive lava was ejected during a poorly contained explosion (Taourirt Tan Afella), non-negligible levels of radioactive material could still be measured. Using the information collected and using realistic potential exposure scenarios, radiation doses to potential occupants and visitors to the sites were estimated.

  9. Translocation of Cd and Mn from Bark to Leaves in Willows on Contaminated Sediments: Delayed Budburst Is Related to High Mn Concentrations

    Directory of Open Access Journals (Sweden)

    Bart Vandecasteele

    2015-04-01

    Full Text Available Changes in the hydrology of sediments in tidal marshes or landfills may affect the uptake of metals in the vegetation. Leaf and stem samples of Salix cinerea (grey sallow were collected during four consecutive growing seasons at six contaminated plots on a polluted dredged sediment landfill and one plot on an uncontaminated reference site. The first three contaminated plots were already emerged in the first half of the first growing season, while the other three were submerged in the first year, but became increasingly dry over the study period. Foliar and stem cutting concentrations for Cd, Zn and Mn increased on the latter three plots over the four years. Willow bark contained high concentrations of Cd, Zn and Mn. In two consecutive greenhouse experiments with willow cuttings from different origins (uncontaminated and contaminated sites and grown under different soil conditions (uncontaminated and contaminated, we observed an important translocation of Mn from bark to shoots. In a third experiment with willow cuttings collected on soils with a range of heavy metal concentrations and, thus, with a broad range of Cd (4–67 mg/kg dry matter, Zn (247–660 mg/kg dry matter and Mn (38–524 mg/kg dry matter concentrations in the bark, high Mn concentrations in the bark were found to affect the budburst of willow cuttings, while no association of delayed budburst with Cd and Zn concentrations in the bark was found. We conclude that wood and, especially, bark are not a sink for metals in living willows. The high Mn concentrations in the bark directly or indirectly caused delayed or restricted budburst of the willow cuttings.

  10. It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass

    Science.gov (United States)

    Herzog, Mark; Ackerman, Joshua T.; Eagles-Smith, Collin A.; Hartman, Christopher

    2016-01-01

    In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to estimate egg volume from egg morphometrics) for American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster’s tern (Sterna forsteri). Egg densities (g/cm3) estimated for whole eggs (1.056 ± 0.003) were higher than egg densities estimated for egg contents (1.024 ± 0.001), and were 1.059 ± 0.001 and 1.025 ± 0.001 for avocets, 1.056 ± 0.001 and 1.023 ± 0.001 for stilts, and 1.053 ± 0.002 and 1.025 ± 0.002 for terns. The egg-shape coefficients for egg volume (K v ) and egg mass (K w ) also differed depending on whether the eggshell was included (K v = 0.491 ± 0.001; K w = 0.518 ± 0.001) or excluded (K v = 0.493 ± 0.001; K w = 0.505 ± 0.001), and varied among species. Although egg contaminant concentrations are rarely meant to include the eggshell, we show that the typical inclusion of the eggshell in egg density and egg volume estimates results in egg contaminant concentrations being underestimated by 6–13 %. Our results demonstrate that the inclusion of the eggshell significantly influences estimates of egg density, egg volume, and fresh egg mass, which leads to egg contaminant concentrations that are biased low. We suggest that egg contaminant concentrations be calculated on a fresh wet weight basis using only internal egg-content densities, volumes, and masses appropriate for the species. For the three waterbirds in our study, these corrected coefficients are 1.024 ± 0.001 for egg density, 0.493 ± 0.001 for K v , and 0.505 ± 0.001 for K w .

  11. Leaching of copper and nickel in soil-water systems contaminated by bauxite residue (red mud) from Ajka, Hungary: the importance of soil organic matter.

    Science.gov (United States)

    Lockwood, Cindy L; Stewart, Douglas I; Mortimer, Robert J G; Mayes, William M; Jarvis, Adam P; Gruiz, Katalin; Burke, Ian T

    2015-07-01

    Red mud is a highly alkaline (pH >12) waste product from bauxite ore processing. The red mud spill at Ajka, Hungary, in 2010 released 1 million m(3) of caustic red mud into the surrounding area with devastating results. Aerobic and anaerobic batch experiments and solid phase extraction techniques were used to assess the impact of red mud addition on the mobility of Cu and Ni in soils from near the Ajka spill site. Red mud addition increases aqueous dissolved organic carbon (DOC) concentrations due to soil alkalisation, and this led to increased mobility of Cu and Ni complexed to organic matter. With Ajka soils, more Cu was mobilised by contact with red mud than Ni, despite a higher overall Ni concentration in the solid phase. This is most probably because Cu has a higher affinity to form complexes with organic matter than Ni. In aerobic experiments, contact with the atmosphere reduced soil pH via carbonation reactions, and this reduced organic matter dissolution and thereby lowered Cu/Ni mobility. These data show that the mixing of red mud into organic rich soils is an area of concern, as there is a potential to mobilise Cu and Ni as organically bound complexes, via soil alkalisation. This could be especially problematic in locations where anaerobic conditions can prevail, such as wetland areas contaminated by the spill.

  12. Pesticide residue concentration in soil following conventional and Low-Input Crop Management in a Mediterranean agro-ecosystem, in Central Greece

    Energy Technology Data Exchange (ETDEWEB)

    Karasali, Helen, E-mail: e.karassali@bpi.gr [Laboratory of Chemical Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece); Marousopoulou, Anna [Laboratory of Chemical Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece); Machera, Kyriaki, E-mail: k.machera@bpi.gr [Laboratory of Pesticides Toxicology, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece)

    2016-01-15

    The present study was focused on the comparative evaluation of pesticide residues, determined in soil samples from Kopaida region, Greece before and after the implementation of Low-Input Crop Management (LCM) protocols. LCM has been suggested as an environmental friendly plant protection approach to be applied on crops growing in vulnerable to pollution ecosystems, with special focus on the site specific problems. In the case of the specific pilot area, the vulnerability was mainly related to the pollution of water bodies from agrochemicals attributed to diffuse pollution primarily from herbicides and secondarily from insecticides. A total of sixty-six soil samples, were collected and analyzed during a three-year monitoring study and the results of the determined pesticide residues were considered for the impact evaluation of applied plant protection methodology. The LCM was developed and applied in the main crops growing in the pilot area i.e. cotton, maize and industrial tomato. Herbicides active ingredients such as ethalfluralin, trifluralin, pendimethalin, S-metolachlor and fluometuron were detected in most samples at various concentrations. Ethalfluralin, which was the active ingredient present in the majority of the samples ranged from 0.01 μg g{sup −1} to 0.26 μg g{sup −1} soil dry weight. However, the amount of herbicides measured after the implementation of LCM for two cropping periods, was reduced by more than 75% in all cases. The method of analysis was based on the simultaneous extraction of the target compounds by mechanical shaking, followed by liquid chromatography mass spectrometric and gas chromatography electron capture (LC–MS/MS and GC–ECD) analysis. - Highlights: • Effect of Low Input Crop Management (LCM) in a vulnerable to pollution ecosystem. • LCM resulted in herbicide residues reduction in the range of 75 and 100% in all cases. • Conventional practices resulted in increased herbicide residues up to 18%. • Anthropogenic

  13. Real-time amplification of HLA-DQA1 for counting residual white blood cells in filtered platelet concentrates

    NARCIS (Netherlands)

    Mohammadi, Tamimount; Reesink, Henk W.; Vandenbroucke-Grauls, Christina M. J. E.; Savelkoul, Paul H. M.

    2004-01-01

    BACKGROUND A real-time polymerase chain reaction (PCR) assay based on amplification of a conserved region of the HLA-DQA1 locus was developed and validated to assess its suitability in quantitating low levels of white blood cells (WBCs) in filtered platelet (PLT) concentrates (PCs). STUDY DESIGN AND

  14. Enhanced primary treatment of concentrated black water and kitchen residues within DESAR concept using two types of anaerobic digesters

    NARCIS (Netherlands)

    Kujawa-Roeleveld, K.; Elmitwalli, T.A.; Zeeman, G.

    2006-01-01

    Anaerobic digestion of concentrated domestic wastewater streams - black or brown water, and solid fraction of kitchen waste is considered as a core technology in a source separation based sanitation concept (DESAR - decentralised sanitation and reuse). A simple anaerobic digester can be implemented

  15. Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles.

    Science.gov (United States)

    Bural, Canan; Aktaş, Esin; Deniz, Günnur; Ünlüçerçi, Yeşim; Bayraktar, Gülsen

    2011-08-01

    Residual methyl methacrylate (MMA) may leach from the acrylic resin denture bases and have adverse effects on the oral mucosa. This in vitro study evaluated and correlated the effect of the leaching residual MMA concentrations ([MMA]r) on in vitro cytotoxicity of L-929 fibroblasts. A total of 144 heat-polymerized acrylic resin specimens were fabricated using 4 different polymerization cycles: (1) at 74ºC for 9 h, (2) at 74ºC for 9 h and terminal boiling (at 100ºC) for 30 min, (3) at 74ºC for 9 h and terminal boiling for 3 h, (4) at 74ºC for 30 min and terminal boiling for 30 min. Specimens were eluted in a complete cell culture medium at 37ºC for 1, 2, 5 and 7 days. [MMA]r in eluates was measured using high-performance liquid chromatography. In vitro cytotoxicity of eluates on L-929 fibroblasts was evaluated by means of cell proliferation using a tetrazolium salt XTT (sodium 3´-[1-phenyl-aminocarbonyl)-3,4-tetrazolium]bis(4-methoxy-6-nitro)benzenesulphonic acid) assay. Differences in [MMA]r of eluates and cell proliferation values between polymerization cycles were statistically analyzed by Kruskal-Wallis, Friedman and Dunn's multiple comparison tests. The correlation between [MMA]r of eluates and cell proliferation was analyzed by Pearson's correlation test (p<0.05). [MMA]r was significantly (p<0.001) higher in eluates of specimens polymerized with cycle without terminal boiling after elution of 1 and 2 days. Cell proliferation values for all cycles were significantly (p<0.01) lower in eluates of 1 day than those of 2 days. The correlation between [MMA]r and cell proliferation values was negative after all elution periods, showing significance (p<0.05) for elution of 1 and 2 days. MMA continued to leach from acrylic resin throughout 7 days and leaching concentrations markedly reduced after elution of 1 and 2 days. Due to reduction of leaching residual MMA concentrations, use of terminal boiling in the polymerization process for at least 30 min and water

  16. Effect of leaching residual methyl methacrylate concentrations on in vitro cytotoxicity of heat polymerized denture base acrylic resin processed with different polymerization cycles

    Directory of Open Access Journals (Sweden)

    Canan Bural

    2011-08-01

    Full Text Available OBJECTIVES: Residual methyl methacrylate (MMA may leach from the acrylic resin denture bases and have adverse effects on the oral mucosa. This in vitro study evaluated and correlated the effect of the leaching residual MMA concentrations ([MMA]r on in vitro cytotoxicity of L-929 fibroblasts. MATERIAL AND METHODS: A total of 144 heat-polymerized acrylic resin specimens were fabricated using 4 different polymerization cycles: (1 at 74ºC for 9 h, (2 at 74ºC for 9 h and terminal boiling (at 100ºC for 30 min, (3 at 74ºC for 9 h and terminal boiling for 3 h, (4 at 74ºC for 30 min and terminal boiling for 30 min. Specimens were eluted in a complete cell culture medium at 37ºC for 1, 2, 5 and 7 days. [MMA]r in eluates was measured using high-performance liquid chromatography. In vitro cytotoxicity of eluates on L-929 fibroblasts was evaluated by means of cell proliferation using a tetrazolium salt XTT (sodium 3´-[1-phenyl-aminocarbonyl-3,4-tetrazolium]bis(4-methoxy-6-nitrobenzenesulphonic acid assay. Differences in [MMA]r of eluates and cell proliferation values between polymerization cycles were statistically analyzed by Kruskal-Wallis, Friedman and Dunn's multiple comparison tests. The correlation between [MMA]r of eluates and cell proliferation was analyzed by Pearson's correlation test (p<0.05. RESULTS: [MMA]r was significantly (p<0.001 higher in eluates of specimens polymerized with cycle without terminal boiling after elution of 1 and 2 days. Cell proliferation values for all cycles were significantly (p<0.01 lower in eluates of 1 day than those of 2 days. The correlation between [MMA]r and cell proliferation values was negative after all elution periods, showing significance (p<0.05 for elution of 1 and 2 days. MMA continued to leach from acrylic resin throughout 7 days and leaching concentrations markedly reduced after elution of 1 and 2 days. CONCLUSION: Due to reduction of leaching residual MMA concentrations, use of terminal boiling in

  17. Construction of a predictive model for concentration of nickel and vanadium in vacuum residues of crude oils using artificial neural networks and LIBS.

    Science.gov (United States)

    Tarazona, José L; Guerrero, Jáder; Cabanzo, Rafael; Mejía-Ospino, E

    2012-03-01

    A predictive model to determine the concentration of nickel and vanadium in vacuum residues of Colombian crude oils using laser-induced breakdown spectroscopy (LIBS) and artificial neural networks (ANNs) with nodes distributed in multiple layers (multilayer perceptron) is presented. ANN inputs are intensity values in the vicinity of the emission lines 300.248, 301.200 and 305.081 nm of the Ni(I), and 309.310, 310.229, and 311.070 nm of the V(II). The effects of varying number of nodes and the initial weights and biases in the ANNs were systematically explored. Average relative error of calibration/prediction (REC/REP) and average relative standard deviation (RSD) metrics were used to evaluate the performance of the ANN in the prediction of concentrations of two elements studied here. © 2012 Optical Society of America

  18. Areal distribution and concentration of contaminants of concern in surficial streambed and lakebed sediments, Lake St. Clair and tributaries, Michigan, 1990-2003

    Science.gov (United States)

    Rachol, Cynthia M.; Button, Daniel T.

    2006-01-01

    As part of the Lake St. Clair Regional Monitoring Project, the U.S. Geological Survey evaluated data collected from surficial streambed and lakebed sediments in the Lake Erie-Lake St. Clair drainages. This study incorporates data collected from 1990 through 2003 and focuses primarily on the U.S. part of the Lake St. Clair Basin, including Lake St. Clair, the St. Clair River, and tributaries to Lake St. Clair. Comparable data from the Canadian part of the study area are included where available. The data are compiled into 4 chemical classes and consist of 21 compounds. The data are compared to effects-based sediment-quality guidelines, where the Threshold Effect Level and Lowest Effect Level represent concentrations below which adverse effects on biota are not expected and the Probable Effect Level and Severe Effect Level represent concentrations above which adverse effects on biota are expected to be frequent.Maps in the report show the spatial distribution of the sampling locations and illustrate the concentrations relative to the selected sediment-quality guidelines. These maps indicate that sediment samples from certain areas routinely had contaminant concentrations greater than the Threshold Effect Concentration or Lowest Effect Level. These locations are the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Big Beaver Creek, Red Run, and Paint Creek. Maps also indicated areas that routinely contained sediment contaminant concentrations that were greater than the Probable Effect Concentration or Severe Effect Level. These locations include the upper reach of the St. Clair River, the main stem and mouth of the Clinton River, Red Run, within direct tributaries along Lake St. Clair and in marinas within the lake, and within the Clinton River headwaters in Oakland County.Although most samples collected within Lake St. Clair were from sites adjacent to the mouths of its tributaries, samples analyzed for trace-element concentrations

  19. Heavy metals concentration in vegetables irrigated with contaminated and fresh water and estimation of their daily intakes in suburb areas of Hamadan, Iran.

    Science.gov (United States)

    Seid-Mohammadi, Abdolmotaleb; Roshanaei, Ghodratollah; Asgari, Ghorban

    2014-01-01

    This study was conducted to estimate the level of heavy metals accumulate in vegetables irrigated with contaminated water compared with those irrigated with fresh water in Hamadan, west of Iran in 2012. Sixty samples of different vegetables i.e., parsley, tarragon, sweat basil and leek irrigated with contaminated water and thirty six samples from three different adjacent areas irrigated with fresh water as control were analyzed to determine heavy metals. The concentration of heavy metals i.e., lead, cadmium and chromium were achieved using atomic adsorption spectrophotometer. The mean concentration of lead, chromium and cadmium regardless of the kind of vegetables irrigated with contaminated water was 6.24, 1.57 and 0.15 mg/kg, respectively. Moreover, metals uptake differences by the vegetables were recognized to vegetable differences in tolerance to heavy metals. Based on the above concentrations the dietary intakes of metals through vegetables consumption were 0.004, 0.0008 and 6E-05 mg/day in infants for lead, chromium and cadmium, respectively. The high concentration of these heavy metals in some vegetables might be attributed due to the use of untreated sanitary and industrial wastewater by farmers for the irrigation of vegetable lands. Therefore, treating of these wastewater and bioremediation of excess metals from polluted vegetation land could be considered.

  20. The influence of soil organic carbon on interactions between microbial parameters and metal concentrations at a long-term contaminated site

    Energy Technology Data Exchange (ETDEWEB)

    Muhlbachova, G. [Crop Research Institute, Drnovska 507, 161 06 Prague 6, Ruzyne (Czech Republic); Sagova-Mareckova, M., E-mail: sagova@vurv.cz [Crop Research Institute, Drnovska 507, 161 06 Prague 6, Ruzyne (Czech Republic); Omelka, M. [Charles University, Faculty of Mathematics and Physics, Dept. of Probability and Mathematical Statistics, Prague 8, Karlin (Czech Republic); Szakova, J.; Tlustos, P. [Czech University of Life Sciences, Department of Agroenvironmental Chemistry and Plant Nutrition, Prague 6, Suchdol (Czech Republic)

    2015-01-01

    The effects of lead, zinc, cadmium, arsenic and copper deposits on soil microbial parameters were investigated at a site exposed to contamination for over 200 years. Soil samples were collected in triplicates at 121 sites differing in contamination and soil organic carbon (SOC). Microbial biomass, respiration, dehydrogenase activity and metabolic quotient were determined and correlated with total and extractable metal concentrations in soil. The goal was to analyze complex interactions between toxic metals and microbial parameters by assessing the effect of soil organic carbon in the relationships. The effect of SOC was significant in all interactions and changed the correlations between microbial parameters and metal fractions from negative to positive. In some cases, the effect of SOC was combined with that of clay and soil pH. In the final analysis, dehydrogenase activity was negatively correlated to total metal concentrations and acetic acid extractable metals, respiration and metabolic quotient were to ammonium nitrate extractable metals. Dehydrogenase activity was the most sensitive microbial parameter correlating most frequently with contamination. Total and extractable zinc was most often correlated with microbial parameters. The large data set enabled robust explanation of discrepancies in organic matter functioning occurring frequently in analyzing of contaminated soil processes. - Highlights: • Soil organic carbon affected all interactions between metals and microorganisms. • Soil organic carbon adjustment changed correlations from positive to negative. • Ammonium nitrate extractable metals were the most influencing fraction. • Dehydrogenase activity was the most affected soil parameter. • Zinc was the most toxic metal among studied metals.

  1. The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991-2007

    International Nuclear Information System (INIS)

    McKinney, Melissa A.; Stirling, Ian; Lunn, Nick J.; Peacock, Elizabeth; Letcher, Robert J.

    2010-01-01

    Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(Σ-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, Σ DDT (and p,p'-DDE, p,p'-DDD, p,p'-DDT) decreased (-8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (-11%/year); β-HCH increased (+ 8.3%/year); and Σ PCB and Σ chlordane (CHL), both contaminants at highest concentrations in all years (> 1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (-1.6%/year to -6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). Σ chlorobenzene, octachlorostyrene, Σ mirex, Σ MeSO 2 -PCB and dieldrin did not significantly change. Increasing Σ PBDE levels (+ 13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or 'weathering' of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year

  2. Membrane distillation as an online concentration technique: application to the determination of pharmaceutical residues in natural waters.

    Science.gov (United States)

    Gethard, Ken; Mitra, Somenath

    2011-04-01

    Membrane distillation (MD) is presented for the first time as a real-time, online concentration technique, where the aqueous matrix is removed from the sample to enhance analyte enrichment. Therefore, MD is a universal method for a wide range of compounds and is unlike conventional membrane extractions that rely on the permeation of the solute into an extractant phase. The MD process showed excellent precision with relative standard deviation between 3% and 5%, linear calibration, and the detection limits for pharmaceutical compounds in the range of 0.01 to 20 mg L(-1) by HPLC-UV analysis. The temperature and flow rate of the feed solution were found to be important variables.

  3. Concentrations and compositions of organochlorine contaminants in sediments, soils, crustaceans, fishes and birds collected from Lake Tai, Hangzhou Bay and Shanghai city region, China

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Haruhiko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan)]. E-mail: nakata@sci.kumamoto-u.ac.jp; Hirakawa, Yuko [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kawazoe, Masahiro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, (Japan); Nakabo, Tetsuji [Kyoto University Museum, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Arizono, Koji [Faculty of Environmental and Symbiotic Sciences, Kumamoto Prefectural University, 3-1-100 Tsukide, Kumamoto 862-8502 (Japan); Abe, Shin-Ichi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Kitano, Takeshi [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Hideaki [Faculty of Education, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Watanabe, Izumi [Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchuu-city, Tokyo 183-8509 (Japan); Li Weihua [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China); Ding Xucheng [Shanghai Institute of Planned Parenthood Research, 2140 Xie Tu road, Shanghai 200032 (China)

    2005-02-01

    Contamination by persistent organochlorines (OCs), such as DDTs, hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) were examined in sediments, soils, fishes, crustaceans, birds, and aquaculture feed from Lake Tai, Hangzhou Bay, and in the vicinity of Shanghai city in China during 2000 and 2001. OCs were detected in all samples analyzed, and DDT and its metabolites were the predominant contaminants in most sediments, soils and biota. Concentrations of p,p'-DDT and ratio of p,p'-DDT to {sigma}DDTs were significantly higher in marine fishes than those in freshwater fishes. While the use of DDTs has been officially banned in China since 1983, these results indicate a recent input of technical DDTs into the marine environment around Hangzhou Bay. Comparison of organochlorine concentrations in fishes collected from Lake Tai and Hangzhou Bay suggests the presence of local sources of HCHs, chlordanes and PCBs at Lake Tai. Higher proportions of penta- and hexa-PCB congeners in fishes at Lake Tai may suggest the use of highly chlorinated PCB product, such as PCB{sub 5}, around this lake. To our knowledge, this is a first comprehensive study to examine the present status of organochlorine contamination in various environmental media, such as sediments, soils and wildlife, in China. - Elevated concentrations of DDTs were detected in sediments, soils, and wildlife collected from China.

  4. Uncovering the local inelastic interactions during manufacture of ductile cast iron: How the substructure of the graphite particles can induce residual stress concentrations in the matrix

    Science.gov (United States)

    Andriollo, Tito; Hellström, Kristina; Sonne, Mads Rostgaard; Thorborg, Jesper; Tiedje, Niels; Hattel, Jesper

    2018-02-01

    Recent X-ray diffraction (XRD) measurements have revealed that plastic deformation and a residual elastic strain field can be present around the graphite particles in ductile cast iron after manufacturing, probably due to some local mismatch in thermal contraction. However, as only one component of the elastic strain tensor could be obtained from the XRD data, the shape and magnitude of the associated residual stress field have remained unknown. To compensate for this and to provide theoretical insight into this unexplored topic, a combined experimental-numerical approach is presented in this paper. First, a material equivalent to the ductile cast iron matrix is manufactured and subjected to dilatometric and high-temperature tensile tests. Subsequently, a two-scale hierarchical top-down model is devised, calibrated on the basis of the collected data and used to simulate the interaction between the graphite particles and the matrix during manufacturing of the industrial part considered in the XRD study. The model indicates that, besides the viscoplastic deformation of the matrix, the effect of the inelastic deformation of the graphite has to be considered to explain the magnitude of the XRD strain. Moreover, the model shows that the large elastic strain perturbations recorded with XRD close to the graphite-matrix interface are not artifacts due to e.g. sharp gradients in chemical composition, but correspond to residual stress concentrations induced by the conical sectors forming the internal structure of the graphite particles. In contrast to common belief, these results thus suggest that ductile cast iron parts cannot be considered, in general, as stress-free at the microstructural scale.

  5. Enhanced primary treatment of concentrated black water and kitchen residues within DESAR concept using two types of anaerobic digesters.

    Science.gov (United States)

    Kujawa-Roeleveld, K; Elmitwalli, T; Zeeman, G

    2006-01-01

    Anaerobic digestion of concentrated domestic wastewater streams--black or brown water, and solid fraction of kitchen waste is considered as a core technology in a source separation based sanitation concept (DESAR--decentralised sanitation and reuse). A simple anaerobic digester can be implemented for an enhanced primary treatment or, in some situations, as a main treatment. Two reactor configurations were extensively studied; accumulation system (AC) and UASB septic tank at 15, 20 and 25 degrees C. Due to long retention times in an AC reactor, far stabilisation of treated medium can be accomplished with methanisation up to 60%. The AC systems are the most suitable to apply when the volume of waste to be treated is minimal and when a direct reuse of a treated medium in agriculture is possible. Digested effluent contains both liquid and solids. In a UASB septic tank, efficient separation of solids and liquid is accomplished. The total COD removal was above 80% at 25 degrees C. The effluent contains COD and nutrients, mainly in a soluble form. The frequency of excess sludge removal is low and sludge is well stabilised due to a long accumulation time.

  6. Predicting soil, water and air concentrations of environmental contaminants locally and regionally; multimedia transport and transformation models

    International Nuclear Information System (INIS)

    McKone, T.E.; Daniels, J.I.

    1991-01-01

    Environmental scientists recognize that the environment functions as a complex, interconnected system. A realistic risk-management strategy for many contaminants requires a comprehensive and integrated assessment of local and regional transport and transformation processes. In response to this need, we have developed multimedia models that simulate the movement and transformation of chemicals as they spread through air, water, biota, soils, sediments, surface water and ground water. Each component of the environment is treated as a homogeneous subsystem that can exchange water, nutrients, and chemical contaminants with other adjacent compartments. In this paper, we illustrate the use of multimedia models and measurements as tools for screening the potential risks of contaminants released to air and deposited onto soil and plants. The contaminant list includes the volatile organic compounds (VOCs) tetrachloroethylene (PCE) and trichloroethylene (TCE), the semi-volatile organic compound benzo(a)pyrene, and the radionuclides tritium and uranium-238. We examine how chemical properties effect both the ultimate route and quantity of human and ecosystem contact and identify sensitivities and uncertainties in the model results. We consider the advantages of multimedia models relative to environmental monitoring data. (au)

  7. Predicting soil, water, and air concentrations of environmental contaminants locally and regionally: Multimedia transport and transformation models

    International Nuclear Information System (INIS)

    McKone, T.E.; Daniels, J.I.

    1991-10-01

    Environmental scientists recognize that the environment functions as a complex, interconnected system. A realistic risk-management strategy for many contaminants requires a comprehensive and integrated assessment of local and regional transport and transformation processes. In response to this need, we have developed multimedia models that simulate the movement and transformation of chemicals as they spread through air, water, biota, soils, sediments, surface water, and ground water. Each component of the environment is treated as a homogeneous subsystem that can exchange water, nutrients, and chemical contaminants with other adjacent compartments. In this paper, we illustrate the use of multimedia models and measurements as tools for screening the potential risks of contaminants released to air and deposited onto soil and plants. The contaminant list includes the volatile organic compounds (VOCs) tetrachloroethylene (PCE) and trichloroethylene (TCE), the semi-volatile organic compound benzo(a)pyrene, and the radionuclides tritium and uranium-238. We examine how chemical properties effect both the ultimate route and quantity of human and ecosystem contact and identify sensitivities and uncertainties in the model results

  8. Optimization of elution salt concentration in stepwise elution of protein chromatography using linear gradient elution data. Reducing residual protein A by cation-exchange chromatography in monoclonal antibody purification.

    Science.gov (United States)

    Ishihara, Takashi; Kadoya, Toshihiko; Endo, Naomi; Yamamoto, Shuichi

    2006-05-05

    Our simple method for optimization of the elution salt concentration in stepwise elution was applied to the actual protein separation system, which involves several difficulties such as detection of the target. As a model separation system, reducing residual protein A by cation-exchange chromatography in human monoclonal antibody (hMab) purification was chosen. We carried out linear gradient elution experiments and obtained the data for the peak salt concentration of hMab and residual protein A, respectively. An enzyme-linked immunosorbent assay was applied to the measurement of the residual protein A. From these data, we calculated the distribution coefficient of the hMab and the residual protein A as a function of salt concentration. The optimal salt concentration of stepwise elution to reduce the residual protein A from the hMab was determined based on the relationship between the distribution coefficient and the salt concentration. Using the optimized condition, we successfully performed the separation, resulting in high recovery of hMab and the elimination of residual protein A.

  9. Fate of polychlorinated biphenyls in a contaminated lake ecosystem: Combining equilibrium passive sampling of sediment and water with total concentration measurements of biota

    DEFF Research Database (Denmark)

    Mäenpää, Kimmo; Leppänen, Matti T.; Figueiredo, Kaisa

    2015-01-01

    Equilibrium sampling devices can be applied to study and monitor the exposure and fate of hydrophobic organic chemicals on a thermodynamic basis. They can be used to determine freely dissolved concentrations and chemical activity ratios and to predict equilibrium partitioning concentrations...... of hydrophobic organic chemicals in biota lipids. The authors' aim was to assess the equilibrium status of polychlorinated biphenyls (PCBs) in a contaminated lake ecosystem and along its discharge course using equilibrium sampling devices for measurements in sediment and water and by also analyzing biota....... The authors used equilibrium sampling devices (silicone rubber and polyethylene [PE]) to determine freely dissolved concentrations and chemical activities of PCBs in the water column and sediment porewater and calculated for both phases the corresponding equilibrium concentrations and chemical activities...

  10. The role of bicarbonate in platelet additive solution for apheresis platelet concentrates stored with low residual plasma.

    Science.gov (United States)

    Radwanski, Katherine; Min, Kyungyoon

    2013-03-01

    Complex platelet additive solutions (PASs) are required to store platelet (PLT) concentrates with plasma levels below 30%. Previously, apheresis PLTs stored with 5% plasma in acetate- and bicarbonate-containing PAS maintained stable pH and bicarbonate levels during 7-day storage. Due to this observation, the necessity of added bicarbonate in PAS was investigated and whether the concurrent increase in PAS pH after bicarbonate addition had any effect on PLT storage. Apheresis PLTs were stored in 5% plasma-95% high- or low-pH PAS, with or without bicarbonate (n=10 per arm). Bicarbonate PAS PLTs were paired and nonbicarbonate PAS PLTs were paired (split from same double-dose collection). PLTs were evaluated for in vitro variables on Days 1 and 7 and up to Day 14 if the Day 7 pH was higher than 6.2. PLT pH was maintained above 7.3 to Day 14 in bicarbonate PAS PLTs while pH failures below 6.2 were observed in 4 of 10 and 2 of 10 units on Day 7 in low- and high-pH nonbicarbonate PAS arms, respectively. Day 7 in vitro variables in nonbicarbonate PAS PLTs with pH values of higher than 6.2 were comparable to Day 7 variables in bicarbonate PAS PLTs. The pH of bicarbonate PAS did have a small effect on pH and bicarbonate levels in PLT units, but did not have an effect on functional variables and metabolism. Bicarbonate was not required to maintain in vitro PLT function in 5% plasma-95% PAS, but was required as a pH buffer and increased PAS pH did not significantly contribute to this effect. © 2012 American Association of Blood Banks.

  11. Spatial and temporal trends in contaminant concentrations in Hexagenia nymphs following a coal ash spill at the Tennessee Valley Authority's Kingston Fossil Plant.

    Science.gov (United States)

    Smith, John G; Baker, Tyler F; Murphy, Cheryl A; Jett, R Trent

    2016-05-01

    A dike failure at the Tennessee Valley Authority Kingston Fossil Plant in East Tennessee, United States, in December 2008, released approximately 4.1 million m(3) of coal ash into the Emory River. From 2009 through 2012, samples of mayfly nymphs (Hexagenia bilineata) were collected each spring from sites in the Emory, Clinch, and Tennessee Rivers upstream and downstream of the spill. Samples were analyzed for 17 metals. Concentrations of metals were generally highest the first 2 miles downstream of the spill, and then decreased with increasing distance from the spill. Arsenic, B, Ba, Be, Mo, Sb, Se, Sr, and V appeared to have strong ash signatures, whereas Co, Cr, Cu, Ni, and Pb appeared to be associated with ash and other sources. However, the concentrations for most of these contaminants were modest and are unlikely to cause widespread negative ecological effects. Trends in Hg, Cd, and Zn suggested little (Hg) or no (Cd, Zn) association with ash. Temporal trends suggested that concentrations of ash-related contaminants began to subside after 2010, but because of the limited time period of that analysis (4 yr), further monitoring is needed to verify this trend. The present study provides important information on the magnitude of contaminant exposure to aquatic receptors from a major coal ash spill, as well as spatial and temporal trends for transport of the associated contaminants in a large open watershed. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  12. Slow-release nitrogen fertilizers can improve yield and reduce Cd concentration in pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil.

    Science.gov (United States)

    Zhang, Ran-Ran; Liu, Yue; Xue, Wan-Lei; Chen, Rong-Xin; Du, Shao-Ting; Jin, Chong-Wei

    2016-12-01

    Cadmium (Cd) pollution in vegetable crops has become a serious problem in recent years. Owing to the limited availability of arable land resources, large areas of Cd-contaminated lands are inevitably being used for the production of vegetables, posing great risks to human health via the food chain. However, strategies to improve yield and reduce Cd concentration in crops grown in contaminated soils are being developed. In the present study, using pot experiments, we investigated the effects of two slow-release nitrogen fertilizers (SRNFs), resin-coated ammonium nitrate (Osmocote 313s ), and resin-coated urea (urea 620 ), on the growth and Cd concentration of the Cd-contaminated pakchoi. The results showed that pakchoi grown in soil containing 5 mg kg -1 of Cd-induced oxidative stress (indicated by malondialdehyde (MDA), H 2 O 2 , and O 2 ·- ) and photosynthesis inhibition, which in turn was restored with the application of SRNFs. However, pakchoi grown in Cd-contaminated soil supplied with Osmocote 313s and urea 620 showed 103 and 203 % increase in fresh weight and 51-55 % and 44-56 % decrease in Cd concentration, respectively, as compared with their controls (pakchoi treated with instant soluble nitrogen fertilizers). On the basis of an increase in their tolerance index (47-238 %) and a decrease in their translocation factor (7.5-21.6 %), we inferred that the plants treated with SRNFs have a stronger tolerance to Cd and a lower efficiency of Cd translocation to edible parts than those treated with instant soluble nitrogen fertilizers. Therefore, in terms of both crop production and food safety, application of SRNFs could be an effective strategy for improving both biomass production and quality in pakchoi grown under Cd stress.

  13. Dynamics of 137Cs concentration in agricultural products in areas of Russia contaminated as a result of the accident at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Fesenko, S.V.; Alexakhin, R.M.; Spiridonov, S.I.; Sanzharova, N.I.

    1995-01-01

    The dynamics of 137 Cs concentration in the main types of agricultural products obtained in regions of Russia contaminated as a result of the Chernobyl Nuclear Power Plant (NPP) accident in 1986, have been analysed. The rate of decline of 137 Cs contamination in agricultural products during the period under study (1987-1992) was not uniform. Reductions of the 137 Cs content of produce was most rapid during the early years after the accident, as a consequence of the intensive application of countermeasures at that time. Half-life periods for 137 Cs content in milk (the basic dose-forming product) and the decrease in products for areas in Russia subjected to the most intensive contamination amounted to 1.6 to 4.8 years, depending on the scale of countermeasures carried out. Half-life periods of decrease of 137 Cs content in other types of agricultural products (grain, potato) were within the range of 2 to 7 years. Based on the comparison of the dynamics of 137 Cs levels in agricultural products of the regions where the countermeasures scales differed, the contribution of countermeasures and of natural biogeochemical processes to the decrease of 137 Cs contamination levels of the main types of agricultural products that determine the dose from internal irradiation of local population has been estimated. (author)

  14. CONCENTRATION AND DISTRIBUTION OF POLYCYCLIC AROMATIC HIDROCARBONS (PAHs DURING BIOREMEDIATION PROCESSES OF OIL-CONTAMINATED BEACH SEDIMENTS IN KARANG SONG BEACH, INDRAMAYU

    Directory of Open Access Journals (Sweden)

    Khozanah Khozanah

    2017-02-01

    Full Text Available Bioremediation research was conducted from June to September, 2010 in oil-contaminated beach sediment in Karang Song Beach, Indramayu. The objective of this paper is to determine concentration and distribution of polycyclic aromatic hydrocarbon (PAH during bioremediation processes. Upon 90 days biodegradation treatment, PAH concentration was reduced in several mesocosms. Concentration of PAH before treatment and after 90 day incubation were follows, Mesocosm A (110.499 mg/kg to 16.125 mg/kg,  Mesocosm B (217.067 mg/kg to  12.239 mg/kg,  Mesocosm C (102.016 mg/kg to  16.695 mg/kg, Mesocosm D (124.256 mg/kg to  60.869 mg/kg, Mesocosm E (117.723 mg/kg  to 50.663 mg/kg, Mesocosm F (143.495 mg/kg to 38.310 mg/kg, and Mesocosm G (9.838 mg/kg to 4.248 mg/kg. Generally, all mesocosms treatment  was reduced of PAH concentration, but there are no stable degraded after 60, and 90 days incubation. Fertilizer application has showed good influence for increasing degradation rate of bacteria to degraded oil contaminant.

  15. Identification of soil contamination hotspots with veterinary antibiotics using heavy metal concentrations and leaching data--a field study in China.

    Science.gov (United States)

    Ostermann, Anne; Gao, Jing; Welp, Gerhard; Siemens, Jan; Roelcke, Marco; Heimann, Lisa; Nieder, Rolf; Xue, Qiaoyun; Lin, Xianyong; Sandhage-Hofmann, Alexandra; Amelung, Wulf

    2014-11-01

    In regions with high livestock densities, the usage of antibiotics and metals for veterinary purposes or as growth promoters poses a risk in manured soils. We investigated to which degree the concentrations and depth distributions of Cu, Zn, Cr and As could be used as a tracer to discover contaminations with sulfonamides, tetracyclines and fluoroquinolones. Besides, we estimated the potential vertical translocation of antibiotics and compared the results to measured data. In the peri-urban region of Beijing, China, soil was sampled from agricultural fields and a dry riverbed contaminated by organic waste disposal. The antibiotic concentrations reached 110 μg kg(-1) sulfamethazine, 111 μg kg(-1) chlortetracycline and 62 μg kg(-1) enrofloxacin in the topsoil of agricultural fields. Intriguingly, total concentrations of Cu, Zn, Cr and As were smaller than 65, 130, 36 and 10 mg kg(-1) in surface soil, respectively, therewith fulfilling Chinese quality standards. Correlations between sulfamethazine concentrations and Cu or Zn suggest that in regions with high manure applications, one might use the frequently existing monitoring data for metals to identify potential pollution hotspots for antibiotics in topsoils. In the subsoils, we found sulfamethazine down to ≥2 m depth on agricultural sites and down to ≥4 m depth in the riverbed. As no translocation of metals was observed, subsoil antibiotic contamination could not be predicted from metal data. Nevertheless, sulfonamide stocks in the subsoil could be estimated with an accuracy of 35-200 % from fertilisation data and potential leaching rates. While this may not be sufficient for precise prediction of antibiotic exposure, it may very well be useful for the pre-identification of risk hotspots for subsequent in-depth assessment studies.

  16. Monitoring bacterial contamination in equine platelet concentrates obtained by the tube method in a clean laboratory environment under three different technical conditions.

    Science.gov (United States)

    Alvarez, M E; Giraldo, C E; Carmona, J U

    2010-01-01

    There is a growing interest in the use of autologous platelet concentrates (PCs) as treatment for chronic musculoskeletal diseases in horses. However, there is no information on the risk of bacterial contamination during their preparation. To: 1) assess the risk of bacterial contamination in equine PCs obtained by the tube method under 3 technical conditions: a) in a laminar flow cabinet, in a clean laboratory environment both with (b) and without (c) Bunsen burner; 2) identify the critical points of the process of PCs preparation with risk of bacterial contamination; and 3) identify the potential bacterial contaminants in the process and their antibiotic susceptibility. Bacteriological samples were taken from: the skin (shaved or unshaved) of the venipuncture site in 15 horses, both before and after being disinfected; hands and throat of the operator; caps of the tubes where the blood was processed; environment where the equine blood samples were collected; laboratory environment; laminar flow cabinet; bacteriological stove; and PCs obtained under 3 technical conditions. Bacteria were isolated from nonaseptically prepared equine skin, hands and throat of the operator, and the place where the blood samples were taken. Bacteria were not isolated from tube caps, laboratory environment, laminar flow cabinet or PCs. The isolated bacteria were normal biota from equine skin, human skin and throat, and environmental contaminants. Of the isolated bacteria, 23% were resistant to penicillin, 19% to ampicillin, 2.12% to ceftiofur, 3.2% to sulphamethoxazole/trimethoprim and 1.1% to enrofloxacin. Resistance to amikacin and gentamicin was not seen. Uncontaminated PCs can be obtained by the tube method in a clean laboratory environment without the need for either a laminar flow cabinet or a Bunsen burner. It is mandatory to perform the procedure following strict aseptic technique.

  17. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  18. Spatial and Temporal Variability in Nitrate Concentration below the Root Zone in an Almond Orchard and its Implications for Potential Groundwater Contamination

    Science.gov (United States)

    Baram, S.; Couvreur, V.

    2015-12-01

    Spatial and Temporal Variability in Nitrate Concentration below the Root Zone in an Almond Orchard and its Implications for Potential Groundwater Contamination S. Baram1, M. Read1, D. Smart2, T. Harter1, J Hopmans11Department of Land, Air & Water Resources University of California Davis 2Department of Viticulture and Enology University of California Davis Estimates of water and fertilizer losses below the root zone of nitrogen (N) intensive agricultural orchard crops are major concern in groundwater protection. However, microscopic and macroscopic heterogeneity in unsaturated soils make accurate loss estimates very challenging. In this study we aimed to examine field scale variability in nitrate (NO3-) losses below the root zone (>250cm) of a 15 years old almond orchard in Madera county California. Based on a soil variability survey, tensiometers and solution samplers were installed at 17 locations around the 40 acre orchard. The hydraulic potential and the NO3- concentrations were monitored over two growing seasons. Nitrate concentrations varied spatially and temporarily, and ranged from below to more than 30 times higher than the drinking water contamination standard of >10 mg NO3--N L-1. Principal component analysis of the relations between the NO3- concentration, presence of a hard pan in the subsurface, its depth and thickness, and the fertigation and irrigation events indicated that none of these factors explained the observed variability in pore-water NO3- concentrations, with hard pan being the most dominant factor. Throughout the irrigation season minimal leaching was observed, yet post-harvest and preseason flooding events led to deep drainage. Due to the high spatial and temporal variability in the NO3- concentration and the potential for deep drainage following a wet winter or flooding event we conclude that the most efficient way to protect ground water is by transitioning to high frequency low nitrogen fertigation which would retain NO3-in the active

  19. Fate of polychlorinated biphenyls in a contaminated lake ecosystem: combining equilibrium passive sampling of sediment and water with total concentration measurements of biota.

    Science.gov (United States)

    Mäenpää, Kimmo; Leppänen, Matti T; Figueiredo, Kaisa; Mayer, Philipp; Gilbert, Dorothea; Jahnke, Annika; Gil-Allué, Carmen; Akkanen, Jarkko; Nybom, Inna; Herve, Sirpa

    2015-11-01

    Equilibrium sampling devices can be applied to study and monitor the exposure and fate of hydrophobic organic chemicals on a thermodynamic basis. They can be used to determine freely dissolved concentrations and chemical activity ratios and to predict equilibrium partitioning concentrations of hydrophobic organic chemicals in biota lipids. The authors' aim was to assess the equilibrium status of polychlorinated biphenyls (PCBs) in a contaminated lake ecosystem and along its discharge course using equilibrium sampling devices for measurements in sediment and water and by also analyzing biota. The authors used equilibrium sampling devices (silicone rubber and polyethylene [PE]) to determine freely dissolved concentrations and chemical activities of PCBs in the water column and sediment porewater and calculated for both phases the corresponding equilibrium concentrations and chemical activities in model lipids. Overall, the studied ecosystem appeared to be in disequilibrium for the studied phases: sediment, water, and biota. Chemical activities of PCBs were higher in sediment than in water, which implies that the sediment functioned as a partitioning source of PCBs and that net diffusion occurred from the sediment to the water column. Measured lipid-normalized PCB concentrations in biota were generally below equilibrium lipid concentrations relative to the sediment (CLip ⇌Sed ) or water (CLip ⇌W ), indicating that PCB levels in the organisms were below the maximum partitioning levels. The present study shows the application versatility of equilibrium sampling devices in the field and facilitates a thermodynamic understanding of exposure and fate of PCBs in a contaminated lake and its discharge course. © 2015 SETAC.

  20. Determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.

    Science.gov (United States)

    Saha, Jayanta Kumar; Panwar, N R; Singh, M V

    2010-09-01

    Cadmium and lead are important environmental pollutants with high toxicity to animals and human. Soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. Present experiment was carried out with the objective of quantifying the limits of Pb and Cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. Two separate sets of pot experiment were carried out for these two heavy metals with graded levels of application doses of Pb at 0.4-150 mg/kg and Cd at 0.02-20 mg/kg to an acidic light textured alluvial soil. Spinach crop was grown for 50 days on these treated soils after a stabilization period of 2 months. Upper limit of background concentration levels (C(ul)) of these metals were calculated through statistical approach from the heavy metals concentration values in leaves of spinach crop grown in farmers' fields. Lead and Cd concentration limits in soil were calculated by dividing C(ul) with uptake response slope obtained from the pot experiment. Cumulative loading limits (concentration limits in soil minus contents in uncontaminated soil) for the experimental soil were estimated to be 170 kg Pb/ha and 0.8 kg Cd/ha. Based on certain assumptions on application rate and computed cumulative loading limit values, maximum permissible Pb and Cd concentration values in municipal solid waste (MSW) compost were proposed as 170 mg Pb/kg and 0.8 mg Cd/kg, respectively. In view of these limiting values, about 56% and 47% of the MSW compost samples from different cities are found to contain Pb and Cd in the safe range.

  1. Accounting for Genotype-by-Environment Interactions and Residual Genetic Variation in Genomic Selection for Water-Soluble Carbohydrate Concentration in Wheat.

    Science.gov (United States)

    Ovenden, Ben; Milgate, Andrew; Wade, Len J; Rebetzke, Greg J; Holland, James B

    2018-04-16

    Abiotic stress tolerance traits are often complex and recalcitrant targets for conventional breeding improvement in many crop species. This study evaluated the potential of genomic selection to predict water-soluble carbohydrate concentration (WSCC), an important drought tolerance trait, in wheat under field conditions. A panel of 358 varieties and breeding lines constrained for maturity was evaluated under rainfed and irrigated treatments across two locations and two years. Whole-genome marker profiles and factor analytic mixed models were used to generate genomic estimated breeding values (GEBVs) for specific environments and environment groups. Additive genetic variance was smaller than residual genetic variance for WSCC, such that genotypic values were dominated by residual genetic effects rather than additive breeding values. As a result, GEBVs were not accurate predictors of genotypic values of the extant lines, but GEBVs should be reliable selection criteria to choose parents for intermating to produce new populations. The accuracy of GEBVs for untested lines was sufficient to increase predicted genetic gain from genomic selection per unit time compared to phenotypic selection if the breeding cycle is reduced by half by the use of GEBVs in off-season generations. Further, genomic prediction accuracy depended on having phenotypic data from environments with strong correlations with target production environments to build prediction models. By combining high-density marker genotypes, stress-managed field evaluations, and mixed models that model simultaneously covariances among genotypes and covariances of complex trait performance between pairs of environments, we were able to train models with good accuracy to facilitate genetic gain from genomic selection. Copyright © 2018, G3: Genes, Genomes, Genetics.

  2. Pesticide residue concentration in soil following conventional and Low-Input Crop Management in a Mediterranean agro-ecosystem, in Central Greece.

    Science.gov (United States)

    Karasali, Helen; Marousopoulou, Anna; Machera, Kyriaki

    2016-01-15

    The present study was focused on the comparative evaluation of pesticide residues, determined in soil samples from Kopaida region, Greece before and after the implementation of Low-Input Crop Management (LCM) protocols. LCM has been suggested as an environmental friendly plant protection approach to be applied on crops growing in vulnerable to pollution ecosystems, with special focus on the site specific problems. In the case of the specific pilot area, the vulnerability was mainly related to the pollution of water bodies from agrochemicals attributed to diffuse pollution primarily from herbicides and secondarily from insecticides. A total of sixty-six soil samples, were collected and analyzed during a three-year monitoring study and the results of the determined pesticide residues were considered for the impact evaluation of applied plant protection methodology. The LCM was developed and applied in the main crops growing in the pilot area i.e. cotton, maize and industrial tomato. Herbicides active ingredients such as ethalfluralin, trifluralin, pendimethalin, S-metolachlor and fluometuron were detected in most samples at various concentrations. Ethalfluralin, which was the active ingredient present in the majority of the samples ranged from 0.01 μg g(-1) to 0.26 μg g(-1) soil dry weight. However, the amount of herbicides measured after the implementation of LCM for two cropping periods, was reduced by more than 75% in all cases. The method of analysis was based on the simultaneous extraction of the target compounds by mechanical shaking, followed by liquid chromatography mass spectrometric and gas chromatography electron capture (LC-MS/MS and GC-ECD) analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. COULD MUSHROOMS ACT AS CONCENTRATION PATHWAYS TO INTERNAL CONTAMINA-TION OF SOME MARGINALIZED COMMUNITIES BY 137CS IN SLOVAKIA?

    Directory of Open Access Journals (Sweden)

    Juraj Miššík

    2015-02-01

    Full Text Available The aim of this study was to obtain some preliminary data necessary for the assessment of the possible existence of small-area local sources of contaminated mushrooms in forested areas with comparatively low inventory of man-made 137Cs. On the study plot near Čierne-Svrčinovec (North-western Slovakia 31 samples were collected during periodic sampling in the years 2012-2013 and analysed by gamma-spectrometry. Activities 137Cs in mushrooms from entire sampling plot followed the lognormal distribution with extremely high variation and high positive skew, with projected three-sigma (99.75% range from 0.49 Bq.kg-1 to 1537 Bq.kg-1 (dry weight, d.w. and with geometrical average of 27.4 Bq.kg-1 (d.w.. Another 11 samples were collected or bought from roadside vendors living in Roma slums near villages Richnava and Kluknava (Spiš region, eastern Slovakia. Obtained edible wild mushrooms were in a good shape despite prolonged drought indicating existence of well hidden forested sites in slum surroundings. Highest activity of 137Cs in this set was recorded in Boletus edulis (263.3 ± 20.3 Bq.kg-1 (d.w.. Both geometric mean (49.0 Bq.kg-1 and expectation value (91.2 Bq.kg-1 d.w. of lognormal distribution were higher than that of the study plot on NW Slovakia. No sample exceeded the legal radiohygienic limit for radiocesium contamination. The limited extent of presented study only slightly indicates the possibility of slow changes in spatial redistribution of bioavailable 137Cs in forest ecosystem. However, available data on this subject from different sources suggest that there is no reason for massive occurrence of highly contaminated fruiting bodies in small areas surrounding settlements, where some critical groups of individuals, who are used to consume large amounts of mushrooms from limited geographical area could in such case develop significant internal contamination.

  4. The impact of sewage-contaminated river water on groundwater ammonium and arsenic concentrations at a riverbank filtration site in central Delhi, India

    Science.gov (United States)

    Groeschke, Maike; Frommen, Theresa; Taute, Thomas; Schneider, Michael

    2017-11-01

    The groundwater abstracted at a well field near the Yamuna River in Central Delhi, India, has elevated ammonium (NH4 +) concentrations up to 35 mg/L and arsenic (As) concentrations up to 0.146 mg/L, constituting a problem with the provision of safe drinking and irrigation water. Infiltrating sewage-contaminated river water is the primary source of the NH4 + contamination in the aquifer, leading to reducing conditions which probably trigger the release of geogenic As. These conclusions are based on the evaluation of six 8-27-m deep drillings, and 13 surface-water and 69 groundwater samples collected during seven field campaigns (2012-2013). Results indicate that losing stream conditions prevail and the river water infiltrates into the shallow floodplain aquifer (up to 16 m thickness), which consists of a 1-2-m thick layer of calcareous nodules (locally known as kankar) overlain by medium sand. Because of its higher hydraulic conductivity (3.7 × 10-3 m/s, as opposed to 3.5 × 10-4 m/s in the sand), the kankar layer serves as the main pathway for the infiltrating water. However, the NH4 + plume front advances more rapidly in the sand layer because of its significantly lower cation exchange capacity. Elevated As concentrations were only observed within the NH4 + plume indicating a causal connection with the infiltrating reducing river water.

  5. The importance of quality control in validating concentrations of contaminants of emerging concern in source and treated drinking water samples.

    Science.gov (United States)

    Batt, Angela L; Furlong, Edward T; Mash, Heath E; Glassmeyer, Susan T; Kolpin, Dana W

    2017-02-01

    A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods were used to determine these CECs, including six analytical methods to measure 174 pharmaceuticals, personal care products, and pesticides. A three-component quality assurance/quality control (QA/QC) program was designed for the subset of 174 CECs which allowed us to assess and compare performances of the methods used. The three components included: 1) a common field QA/QC protocol and sample design, 2) individual investigator-developed method-specific QA/QC protocols, and 3) a suite of 46 method comparison analytes that were determined in two or more analytical methods. Overall method performance for the 174 organic chemical CECs was assessed by comparing spiked recoveries in reagent, source, and treated water over a two-year period. In addition to the 247 CECs reported in the larger drinking water study, another 48 pharmaceutical compounds measured did not consistently meet predetermined quality standards. Methodologies that did not seem suitable for these analytes are overviewed. The need to exclude analytes based on method performance demonstrates the importance of additional QA/QC protocols. Published by Elsevier B.V.

  6. Dicofol residues in eggs and carcasses of captive American kestrels

    Science.gov (United States)

    Wiemeyer, Stanley N.; Clark, D.R.; Spann, J.W.; Belisle, A.A.; Bunck, C.M.

    2001-01-01

    American kestrels (Falco sparverius) were fed diets containing 0 (control), 1, 3, 10, and 30 ?g/g (wet wt) of Kelthane?. Residues of dicofol and its metabolites were then analyzed in the eggs and carcasses of females. Significant differences occurred among treatments for residues of both p,p'-dicofol and p,p'-dechlorodicofol (DCD) in both eggs and carcasses and for p,p'-dicholorbenzophenone (DCBP) in eggs. Residue concentrations increased with increasing treatment exposure. Residues of p,p'-dicofol, p,p'-DCD, and p,p'-DCBP in eggs were significantly correlated with eggshell quality parameters. Significant correlations also occurred among contaminants in eggs and for individual contaminants between eggs and carcasses. The lowest-observed-dietary-effect concentration for eggshell thinning was 3 ?g/g, whereas 1 ?g/g may be considered to be near a no-observable-adverse-effect concentration. Concentrations of dicofol in potential prey items and eggs of wild birds generally have been lower than dietary-effect concentrations or concentrations in tissues or eggs associated with eggshell thinning and reduced reproductive success.

  7. Organic and Inorganic Pollutant Concentrations Suggest Anthropogenic Contamination of Soils Along the Manali-Leh Highway, Northwestern Himalaya, India.

    Science.gov (United States)

    Dasgupta, Rajarshi; Crowley, Brooke E; Barry Maynard, J

    2017-05-01

    Most studies on roadside soil pollution have been performed in areas where petrol is the main fuel. Very little work has been conducted in regions where diesel predominates. We collected soil samples from four sites that span a precipitation gradient along the Manali-Leh Highway in northwestern Himalaya, India. This road traverses rough terrain and most of the vehicles that travel along it are diesel-driven. At each site, we collected samples at incremental distances from the highway (0, 2, 5, 10, 20, and 150 m), and at each distance we collected samples from three depths (3, 9, and 15 cm). We assessed the concentrations of 10 heavy metals (Al, Fe, Cr, Cu, Pb, Ni, Co, Zn, V, and Ba), total sulphur, and total organic carbon (TOC) at each distance, and we measured the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) at 2 m from the highway. Overall, we found that metal concentrations are low and there is no relationship between concentrations and distance from the highway, or depth within the soil profile. Sulphur concentrations, on the other hand, are high in roadside soils and there is a negative relationship between concentration and distance from the highway. PAH concentrations are low, but the proportion of different ringed species suggests that their source is anthropogenic. Correlations between TOC and the various pollutants further suggest that diesel vehicles and potentially biomass combustion are starting to affect the roadside environment in remote northwestern India. We suggest that pollutant concentrations be regularly monitored.

  8. Contamination of boreholes water by 76 pesticides molecules in the ...

    African Journals Online (AJOL)

    user2

    76 residues of pesticides, especially insecticides, herbicides and fungicides, with accumulated contents which could average 0.350 or 350 μg/L per borehole. Indeed, all the prospected boreholes were contaminated. Every molecules of pesticides analyzed were present with at least 1 μg/L, some molecules concentration ...

  9. Rediscovery of an old article reporting that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation, indicating that exposure doses of A-bomb survivors were largely underestimated.

    Science.gov (United States)

    Sutou, Shizuyo

    2017-09-01

    The A-bomb blast released a huge amount of energy: thermal radiation (35%), blast energy (50%), and nuclear radiation (15%). Of the 15%, 5% was initial radiation released within 30 s and 10% was residual radiation, the majority of which was fallout. Exposure doses of hibakusha (A-bomb survivors) were estimated solely on the basis of the initial radiation. The effects of the residual radiation on hibakusha have been considered controversial; some groups assert that the residual radiation was negligible, but others refute that assertion. I recently discovered a six-decade-old article written in Japanese by a medical doctor, Gensaku Obo, from Hiroshima City. This article clearly indicates that the area around the epicenter in Hiroshima was heavily contaminated with residual radiation. It reports that non-hibakusha who entered Hiroshima soon after the blast suffered from severe acute radiation sickness, including burns, external injuries, fever, diarrhea, skin bleeding, sore throat and loss of hair-as if they were real hibakusha. This means that (i) some of those who entered Hiroshima in the early days after the blast could be regarded as indirect hibakusha; (ii) 'in-the-city-control' people in the Life Span Study (LSS) must have been irradiated more or less from residual radiation and could not function properly as the negative control; (iii) exposure doses of hibakusha were largely underestimated; and (iv) cancer risk in the LSS was largely overestimated. Obo's article is very important to understand the health effects of A-bombs so that the essence of it is translated from Japanese to English with the permission of the publisher. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  10. Using trace element concentrations in Corbicula fluminea to identify potential sources of contamination in an urban river

    International Nuclear Information System (INIS)

    Loeffler Peltier, Gretchen; Meyer, Judith L.; Jagoe, Charles H.; Hopkins, William A.

    2008-01-01

    We used the biomonitor, Corbicula fluminea, to investigate the contributions of trace elements associated with different point sources and land uses in a large river. Trace elements were analyzed in tissues of clams collected from 15 tributary streams draining five land use or point source types: agriculture, forest, urban, coal-fired power plant (CFPP), and wastewater (WWTP). Clams from forested catchments had elevated Hg concentrations, and concentrations of arsenic and selenium were highest (5.0 ± 0.2 and 13.6 ± 0.9 μg g -1 dry mass (DM), respectively) in clams from CFPP sites. Cadmium concentrations were significantly higher in clams from urban and CFPP sites (4.1 ± 0.2 and 3.6 ± 0.9 μg g -1 DM, respectively). Non-metric multidimensional scaling (NMS) of tissue concentrations in clams clustered at CFPP and forest/agriculture sites at opposite ends of the ordination space, and the distribution of sites was driven by Cu, Zn, Cd, and Hg. - C. fluminea collected downstream of CFPPs had elevated tissue concentrations of trace elements

  11. Using trace element concentrations in Corbicula fluminea to identify potential sources of contamination in an urban river

    Energy Technology Data Exchange (ETDEWEB)

    Loeffler Peltier, Gretchen [University of Georgia, Institute of Ecology, Athens, GA 30602 (United States)], E-mail: gl232@columbia.edu; Meyer, Judith L. [University of Georgia, Institute of Ecology, Athens, GA 30602 (United States); Jagoe, Charles H.; Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29802 (United States)

    2008-07-15

    We used the biomonitor, Corbicula fluminea, to investigate the contributions of trace elements associated with different point sources and land uses in a large river. Trace elements were analyzed in tissues of clams collected from 15 tributary streams draining five land use or point source types: agriculture, forest, urban, coal-fired power plant (CFPP), and wastewater (WWTP). Clams from forested catchments had elevated Hg concentrations, and concentrations of arsenic and selenium were highest (5.0 {+-} 0.2 and 13.6 {+-} 0.9 {mu}g g{sup -1} dry mass (DM), respectively) in clams from CFPP sites. Cadmium concentrations were significantly higher in clams from urban and CFPP sites (4.1 {+-} 0.2 and 3.6 {+-} 0.9 {mu}g g{sup -1} DM, respectively). Non-metric multidimensional scaling (NMS) of tissue concentrations in clams clustered at CFPP and forest/agriculture sites at opposite ends of the ordination space, and the distribution of sites was driven by Cu, Zn, Cd, and Hg. - C. fluminea collected downstream of CFPPs had elevated tissue concentrations of trace elements.

  12. Complete reduction of highly concentrated contaminants in piggery waste by a novel process scheme with an algal-bacterial symbiotic photobioreactor.

    Science.gov (United States)

    Lee, Young-Shin; Han, Gee-Bong

    2016-07-15

    The complete reduction of highly concentrated contaminants in piggery waste was achieved with an innovative process scheme consecutively combining autothermal thermophilic aerobic digestion (ATAD), an expanded granular sludge bed (EGSB) and a microalgal-bacterial symbiotic vertical photobioreactor (VPBR), followed by biomass recycling for effluent polishing. Contaminants in piggery waste, such as high organic and inorganic matter, total nitrogen (TN), and total phosphorus (TP) contents, were successfully reduced in the newly implemented system. The concentrations of volatile solids (VS) and the chemical oxygen demand (COD) for organic matter in the feed were reduced by approximately 99.3% and 99.7%, respectively, in the innovative system. The overall reduction efficiencies in TN, ammoniacal nitrogen, and TP were 98.8, 98.4, and 93.5%, respectively, through ammonia gas emission, coagulated sludge disposal, and the algal-bacterial symbiotic polishing process. Fecal coliform density was decreased to <1.7 × 10(4) CFU g(-1) total solids. Biogas and CH4 in the EGSB were generated in the range of 0.36-0.79 and 0.18-0.44 L g(-1) [VS removed], respectively, and contained 245 ± 19 ppm (v/v) [H2S]. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The effects of Pantoea sp. strain Y4-4 on alfalfa in the remediation of heavy-metal-contaminated soil, and auxiliary impacts of plant residues on the remediation of saline-alkali soils.

    Science.gov (United States)

    Li, Shuhuan; Wang, Jie; Gao, Nanxiong; Liu, Lizhu; Chen, Yahua

    2017-04-01

    The plant-growth-promoting rhizobacterium (PGPR) Y4-4 was isolated from plant rhizosphere soil and identified as Pantoea sp. by 16S rRNA sequence analysis. The effects of strain Y4-4 on alfalfa grown in heavy-metals-contaminated soil was investigated using a pot experiment. In a Cu-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 22.6% and 21%, and Cu accumulation increased by 15%. In a Pb-Zn-rich environment, the shoot dry mass and total dry mass of plants inoculated with strain Y4-4 increased by 23.4% and 22%, and Zn accumulation increased by 30.3%. In addition, the salt tolerance and biomass of wheat seedlings could be improved by applying strain Y4-4 mixed with plant residue as a result of the Cu-rich plant residues providing copper nutrition to wheat. This study offers an efficient PGPR with strong salt tolerance and a safe strategy for the post-treatment of plant residue.

  14. Using trace element concentrations in Corbicula fluminea to identify potential sources of contamination in an urban river

    Energy Technology Data Exchange (ETDEWEB)

    Peltier, G.L.; Meyer, J.L.; Jagoe, C.H.; Hopkins, W.A. [University of Georgia, Athens, GA (United States)

    2008-07-15

    We used the biomonitor, Corbicula fluminea, to investigate the contributions of trace elements associated with different point sources and land uses in a large river. Trace elements were analyzed in tissues of clams collected from 15 tributary streams draining five land use or point source types: agriculture, forest, urban, coal-fired power plant (CFPP), and wastewater (WWTP). Clams from forested catchments had elevated Hg concentrations, and concentrations of arsenic and selenium were highest (5.0 {+-} 0.2 and 13.6 {+-} 0.9 {mu}g{sup -1} dry mass (DM), respectively) in clams from CFPP sites. Cadmium concentrations were significantly higher in clams from urban and CFPP sites (4.1 {+-} 0.2 and 3.6 {+-} 0.9 {mu}g{sup -1} DM, respectively). Non-metric multidimensional scaling (NMS) of tissue concentrations in clams clustered at CFPP and forest/agriculture sites at opposite ends of the ordination space, and the distribution of sites was driven by Cu, Zn, Cd, and Hg.

  15. The decision-making process in dealing with populations living in areas contaminated by the uranium mining residues in Eastern Germany

    International Nuclear Information System (INIS)

    Kraus, W.; Ettenhuber, E.

    1998-01-01

    The radiological intervention situation created by uranium mining and milling residues is part of a more general problem: mining and other industrial residues with exposure to enhanced natural radiation. That part of the decision-making that should follow the principles of the radiological protection system is far from being a pre-established process. Problems are discussed that are connected with the justification and optimization of remediation measures, the establishing and meaning of action levels, as well as legal and institutional problems. They are the basis of considering the societal aspects of decision-making. The impact of public concerns on the decisions and their relation to the historic and social heritage and economic situation on the one hand, and experiences with different attempts to influence public attitudes towards radiological risks and decisions to be made on the other hand are dealt with. (author)

  16. Heavy metal concentrations of the endoparasitoid Glyptapanteles liparidis bouche (hymenoptera) in contaminated Lymantria dispar L. Larvaie (lepidoptera)

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, C. [Univ. of Vienna (Austria)

    1995-10-01

    The braconid wasp Glyptapanteles liparidis is one of the main parasitoids of the forest pest insect Lymantria dispar (gypsy moth) and therefore a regulator of the pest population. The eggs of the endoparasitoid are deposited in early larval stages of the host. The parasitoid larvae develop in the haemolymph of the host and feed exclusively on the nutrients of the haemolymph. Applied metals at the No-observed-effect-concentration level for L. dispar did not affect G. liparidis directly. Instead the parasitoid development is probably influenced by the alteration of the trophic situations within the host due to its metal stress. This study provides information on the metal concentration of the parasitoid larvae shortly before their eclosion from the host. 19 refs., 1 fig., 1 tab.

  17. Natural radioactivity in petroleum residues

    International Nuclear Information System (INIS)

    Gazineu, M.H.P.; Gazineu, M.H.P.; Hazin, C.A.; Hazin, C.A.

    2006-01-01

    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the 238 U and 232 Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of 226 Ra, 228 Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for 226 Ra, 228 Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for 226 Ra, 40.5 to 1,550.0 kBq/kg for 228 Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  18. Natural radioactivity in petroleum residues

    Energy Technology Data Exchange (ETDEWEB)

    Gazineu, M.H.P. [UNICAP, Dept. de Quimica, Recife (Brazil); Gazineu, M.H.P.; Hazin, C.A. [UFPE, Dept. de Energia Nuclear, Recife (Brazil); Hazin, C.A. [Centro Regional de Ciencias Nucleares/ CNEN, Recife (Brazil)

    2006-07-01

    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the {sup 238}U and {sup 232}Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of {sup 226}Ra, {sup 228}Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for {sup 226}Ra, {sup 228}Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for {sup 226}Ra, 40.5 to 1,550.0 kBq/kg for {sup 228}Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  19. Effects of polycyclic aromatic hydrocarbons on germination and subsequent growth of grasses and legumes in freshly contaminated soil and soil with aged PAHs residues

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.; Flowers, T.H.; Duncan, H.J.; Alder, J. [University of Glasgow, Glasgow (United Kingdom). Glasgow Marine Technological Centre

    2006-06-15

    The relevance of germination trials for screening plants that may have potential for use in the phytoremediation of PAH contaminated land was evaluated. The germination and subsequent growth of 7 grass and legume species were evaluated in soil spiked with a pure PAH mixture or coal tar and soil from a former coking plant heavily contaminated with aged PAHs. None of these treatments adversely affected germination of the plants. However, apart from Lolium perenne all species exhibited reduced growth in the coking plant soil after 12 weeks growth when compared to the untreated soil. In the coal tar spiked soil 4 out of the 7 species showed reduced growth, as did 3 out of the 7 in the soil spiked with a mixture of 7 PAHs. Therefore, germination studies alone would not predict the success of subsequent growth of the species tested in the ranges of soil PAH levels studied.

  20. Stabilization of in-tank residual wastes and external-tank soil contamination for the tank focus area, Hanford Tank Initiative: Applications to the AX tank farm

    Energy Technology Data Exchange (ETDEWEB)

    Becker, D.L.

    1997-11-03

    This report investigates five technical areas for stabilization of decommissioned waste tanks and contaminated soils at the Hanford Site AX Farm. The investigations are part of a preliminary evacuation of end-state options for closure of the AX Tanks. The five technical areas investigated are: (1) emplacement of cementations grouts and/or other materials; (2) injection of chemicals into contaminated soils surrounding tanks (soil mixing); (3) emplacement of grout barriers under and around the tanks; (4) the explicit recognition that natural attenuation processes do occur; and (5) combined geochemical and hydrological modeling. Research topics are identified in support of key areas of technical uncertainty, in each of the five areas. Detailed cost-benefit analyses of the technologies are not provided. This investigation was conducted by Sandia National Laboratories, Albuquerque, New Mexico, during FY 1997 by tank Focus Area (EM-50) funding.

  1. Graphic Three-Axes Presentation of Residual Gas Analyser Data

    Science.gov (United States)

    Johnson, Kenneth R.; Levi, Alejandro G.

    1996-01-01

    Residual gas analyzers (RGA) are commonly used to measure the composition of residual gases in thermal-vacuum test chambers. Measurements from RGAs are often used to identify and quantify outgassing contaminants from a test article during thermal-vacuum testing. RGA data is typically displayed as snapshots in time, showing instantaneous concentrations of ions from ionized residual gas molecules at different atomic masses. A method was devised by the authors to present RGA data in a three-axis format, plotting atomic mass unit (AMU), ion concentration as a function of AMU, and time, to provide a clear graphic visualization ot trends in gas concentration changes and to initiate a valuable analytical tool to interpret test article outgassing rates during thermal-vacuum testing.

  2. Using Tracer Technology to Characterize Contaminated Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Maresca, Joseph, W., Jr., Ph.D.; Bratton, Wesley, L., Ph.D., P.E.; Dickerson, Wilhelmina; Hales, Rochelle

    2005-12-30

    The Pipeline Characterization Using Tracers (PCUT) technique uses conservative and partitioning, reactive or other interactive tracers to remotely determine the amount of contaminant within a run of piping or ductwork. The PCUT system was motivated by a method that has been successfully used to characterize subsurface soil contaminants and is similar in operation to that of a gas chromatography column. By injecting a ?slug? of both conservative and partitioning tracers at one end (or section) of the piping and measuring the time history of the concentration of the tracers at the other end (or another section) of the pipe, the presence, location, and amount of contaminant within the pipe or duct can be determined. The tracers are transported along the pipe or duct by a gas flow field, typically air or nitrogen, which has a velocity that is slow enough so that the partitioning tracer has time to interact with the contaminant before the tracer slug completely passes over the contaminate region. PCUT not only identifies the presence of contamination, it also can locate the contamination along the pipeline and quantify the amount of residual. PCUT can be used in support of deactivation and decommissioning (D&D) of piping and ducts that may have been contaminated with hazardous chemicals such as chlorinated solvents, petroleum products, radioactive materials, or heavy metals, such as mercury.

  3. Influence of compost application on arsenic uptake by beans (Phaseolus vulgaris L.), irrigated with arsenic-contaminated waters at four different concentrations

    Science.gov (United States)

    Caporale, A. G.; Pigna, M.; Sommella, A.; Cozzolino, V.; Violante, A.

    2012-04-01

    The presence of arsenic (As) in soils and/or groundwaters, used for agricultural purposes, causes a strong abiotic stress to the cultivated plants, which results in the reduction of biomasses and yields, and the abundance of non-tradable products. It is therefore desirable to identify and develop production techniques capable of limiting the mobility and phyto-availability of As in soil, through the stabilization of the metalloid on the more recalcitrant soil fractions. Incorporation of compost into soil for As immobilization offers various potential advantages over other methods such as low-cost, simple methodology and low environmental impact. We studied the influence of compost application on the mobility and phyto-availability of As in soil, the growth of the bean plants irrigated with As-contaminated waters and their own As uptake. Bean was selected as test plant, because this crop is grown in several As-contaminated areas and suffers As toxicity. Bean plants growth was significantly affected by As and compost treatments. Increasing As concentration in the irrigation water decreased markedly the dry biomass, as a consequence of As phytotoxicity. The influence of compost application on plants growth was also significant, indicating the ability of the compost to alleviate the As phytotoxicity. Arsenic caused a reduction of the photosynthesis rate. By increasing As concentration in irrigation water, in fact, bean leaves showed a decrease in both chlorophyll A and B concentrations in their own mesophylls. However, by increasing level of compost application there was an increase of both chlorophylls concentrations in bean leaves. Arsenic concentration in roots was higher than that in shoots and bean yield. Bean plants showed a typical behavior of the plants sensitive to As toxicity, which usually tend to limit the As translocation from roots to shoots and yield. A low As allocation in bean yield is desirable, because a high As content in edible part of the plants

  4. Pesticide residues in brain tissues of dairy cattle in Lembang

    Directory of Open Access Journals (Sweden)

    Indraningsih

    2006-03-01

    Full Text Available The use of pesticides to control plant diseases may cause residual formation in crops, its byproduct and environmental. Furthermore, the use of agriculture byproduct as animal feed may cause poisoning or residual formation in animal products. The purpose of this study is to investigate of pesticide residues in brain tissues of dairy cattle in relation to animal feed as a contamination source. Samples consisted of animal feeds (19 samples of fodder and 6 samples of feed, 31 samples of sera and 25 samples of brain tissues of dairy cattle collected from Lembang, West Java. Feeds and fodders were collected from dairy farms located in Lembang. Sera were directly collected from 31 heads of Frisien Holstein (FH cattle from the same location, while brain tissues of FH cattle were collected from a local animal slaughtering house. Pesticide residues were analysed using gas chromatography (GC. Both residues of organochlorines and organophosphates were detected from brain tissues with average residue concentration OP was 22.7 ppb and OC was 5.1 ppb and a total residue was 27.8 ppb. The pesticide residues in brain tissues are new information that should be taken into consideration since the Indonesian consumed this tissues as an oval. Although pesticides residue concentration was low, pathological changes were noted microscopically from the brain tissues including extracellular vacuolisation, focal necrosis, haemorrhages, dilatation of basement membrane without cellular infiltration. Both pesticide residues were also detected in sera, where OP (9.0 ppb was higher than OC (4.9 ppb. These pesticides were also detected in animal feeds consisting fodders and feeds. Residues of OP (12.0 ppb were higher than OC (1.8 ppb in feeds, but residues of OP (16.8 ppb were lower than OC (18.7 ppb in fodders. Although, pesticide residues in sera and brain tissues were below the maximum residue limits (MRL of fat, the presence of pesticides in brain tissues should be taken

  5. Development of a multi-residue analytical method, based on liquid chromatography-tandem mass spectrometry, for the simultaneous determination of 46 micro-contaminants in aqueous samples.

    Science.gov (United States)

    Nödler, Karsten; Licha, Tobias; Bester, Kai; Sauter, Martin

    2010-10-15

    A multi-residue analytical method based on high-performance liquid chromatographic separation, electrospray ionization with tandem mass spectrometric detection (HPLC/MS-MS) was developed for the simultaneous analysis of 46 basic, neutral and acidic compounds covering a wide range of polarity (logK(OW)MQL) in surface and seawater ranged from 1.2 to 28 ng/L, in wastewater from 5.0 to 160 ng/L, respectively. In order to demonstrate the applicability of the method, river water, treated wastewater and seawater were analyzed. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Modelling (137)Cs concentrations in moose (1986-2012) from areas highly contaminated by the Chernobyl fallout.

    Science.gov (United States)

    Weimer, Robert N; Sundell-Bergman, Synnöve; Sonesten, Lars; Wikenros, Camilla; Rosén, Klas

    2016-08-01

    Data from long term annual monitoring of (137)Cs concentrations in harvested moose (Alces alces) were empirically modelled by applying multivariate data analysis that is able to from relatively raw datasets show how the many various impact variables are related (Principal component analysis, PCA). In the later stage regression modelling (Partial least squares, PLS) was applied to analyse which environmental and physiological factors were significant (i.e. of predictive value) based on the measured (X) activity concentrations in moose meat. The data sets originate from two different forest dominated areas in Sweden. One area is located inland (Heby municipality) and the other borders to the Baltic Sea (Gävle municipality). In inland with 20% farmland, GIS-software was used to calculate the proportion of different habitat types and (137)Cs deposition around individual killing spots. This model reveals that the proportions of farmland and forest around the killing spot were significant parameters, second to deposition and years since fallout. Significance was also obtained for the proportions of mire and water bodies, the amount of rain in summer and the age of the moose. In the other model based on data from the coastal area with only about 4% farmland, the coordinates of the moose killing spots were not recorded in the data sets. In the resulting model the temperature in July was the most important parameter, second to years since fallout. Significance was also found for the following parameters: temperature and rainfall in several summer months, the approximate north- and eastward location of the killing spot and to which age category (adult/calf) the harvested moose belonged. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Sensitive mutant detection by concentrating mutant DNA with allele-specific capture and its application to analysis of contaminated grains in rice.

    Science.gov (United States)

    Kohata, Ryuya; Koitabashi, Kosuke; Kitashiba, Hiroyasu; Nishio, Takeshi

    2018-03-12

    We developed a method for detection of mutants in a large number of plants, and found this method to be applicable to detection of a mutant allele at a concentration of 1/1000. Many techniques for SNP analysis have been developed, but most of these techniques are not so sensitive to be used for detection of mutants in a large number of plants. Although some highly sensitive methods of SNP analysis have been reported, they are costly. In the present study, a method for concentrating mutant DNA was examined for sensitive detection of an SNP allele in a bulked DNA sample. PCR products of mutant alleles were captured by biotin-labeled oligonucleotide conjugated with streptavidin-coated magnetic beads. By repeated captures of each strand and combining both strands, mutant alleles with a concentration of 1/1000 in wild-type alleles were detectable by CAPS or dCAPS analysis. Indirect capture of a mutant allele was possible, but efficiency was slightly lower than that of the direct capture. The developed method was applied to detection of contamination of rice grains by grains of a different cultivar. Possible applications of this method are discussed.

  8. Small mammals as monitors of environmental contaminants

    International Nuclear Information System (INIS)

    Talmage, S.S.; Walton, B.T.

    1991-01-01

    The merit of using small mammals as monitors of environmental contaminants was assessed using data from the published literature. Information was located on 35 species of small mammals from 7 families used to monitor heavy metals, radionuclides, and organic chemicals at mine sites, industrial areas, hazardous and radioactive waste disposal sites, and agricultural and forested land. To document foodchain transfer of chemicals, concentrations in soil, vegetation, and invertebrates, where available, were included. The most commonly trapped North American species were Peromyscus leucopus, Blarina brevicauda, and Microtus pennsylvanicus. In these species, exposure to chemicals was determined from tissue residue analyses, biochemical assays, and cytogenetic assays. Where enough information was available, suitable target tissues, or biological assays for specific chemicals were noted. In general, there was a relationship between concentrations of contaminants in the soil or food, and concentrations in target tissues of several species. This relationship was most obvious for the nonessential heavy metals, cadmium, lead, and mercury and for fluoride. Kidney was the single best tissue for residue analyses of inorganic contaminants. However, bone should be the tissue of choice for both lead and fluorine. Exposure to lead was also successfully documented using biochemical and histopathological endpoints. Bone was the tissue of choice for exposure to 90Sr, whereas muscle was an appropriate tissue for 137Cs. For organic contaminants, exposure endpoints depended on the chemical(s) of concern. Liver and whole-body residue analyses, as well as enzyme changes, organ histology, genotoxicity, and, in one case, population dynamics, were successfully used to document exposure to these contaminants

  9. Surface Tension Estimates for Droplet Formation in Slurries with Low Concentrations of Hydrophobic Particles, Polymer Flocculants or Surface-Active Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Mahoney, Lenna A.; Blanchard, Jeremy; Bamberger, Judith A.

    2011-06-10

    In support of the K-Basin project, Pacific Northwest National Laboratory (PNNL) was requested to evaluate the appropriate surface tension value to use in models predicting the formation of droplets from spray leaks of K-Basin slurries. The specific issue was whether it was more appropriate to use the surface tension of pure water in model predictions for all plausible spray leaks or to use a lower value. The surface tension of K-Basin slurries is potentially affected not only by particles but by low concentrations of nonionic polyacrylamide flocculant and perhaps by contaminants with surfactant properties, which could decrease the surface tension below that of water. A lower surface tension value typically results in smaller droplets being formed with a larger fraction of droplets in the respirable size range, so using the higher surface tension value of pure water is not conservative and thus needs a strong technical basis.

  10. Use of filler limestone and construction and demolition residues for remediating soils contaminated with heavy metals: an assessment by means of plant uptake.

    Science.gov (United States)

    Banegas, Ascension; Martinez-Sanchez, Maria Jose; Agudo, Ines; Perez-Sirvent, Carmen

    2010-05-01

    A greenhouse trial was carried out to evaluate the assimilation of heavy metals by three types of horticultural plants (lettuce, broccoli and alfalfa), different parts of which are destined for human and animal consumption (leaves, roots, fruits). The plants were cultivated in four types of soil, one uncontaminated (T1), one soil collected in the surrounding area of Sierra Minera (T2), the third being remediated with residues coming from demolition and construction activities (T3) and the four remediated with filler limestone (T4). To determine the metal content, soil samples were first ground to a fine powder using an agate ball mill. Fresh vegetable samples were separated into root and aboveground biomass and then lyophilized. The DTPA-extractable content was also determined to calculate the bioavailable amount of metal. Finally, the translocation factor (TF) and bioconcentration factor (BCF) were calculated. Arsenic levels were obtained by using atomic fluorescence spectrometry with an automated continuous flow hydride generation (HG-AFS) spectrometer and Cd, Pb and Zn was determined by electrothermal atomization atomic absorption spectrometry (ETAAS) or flame atomic absorption spectrometry (FAAS). Samples of the leached water were also obtained and analyzed. According to our results, the retention of the studied elements varies with the type of plant and is strongly decreased by the incorporation of filler limestone and/or construction and demolition residues to the soils. This practice represents a suitable way to reduce the risk posed to the biota by the presence of high levels of heavy metal in soil.

  11. The determination of pesticide residues and contaminants in fish and rice. Part of a coordinated programme on nuclear detection and analysis

    International Nuclear Information System (INIS)

    Lee, C.; Kim, Y.S.

    1975-03-01

    Neutron activation involving chemical procedures was used in order to present a reliable picture of the backgrounds of toxic elements such as Hg, As, Cd, Br, Cu and others in the biosphere. This report covers the analyses of reference kale samples, rice, fresh-water fish, marine fish, river water, fruits and farm products. Two results of Hg contents which were obtained by two independent methods indicated the difference in matrix effects depending on the type of samples, e.g., the standard reference kale of Bowen and fish showed the same effect while rice was different. Among fresh-water fish, snakeheads contained high Hg contents compared to other species. This could be attributed to their characteristics of feeding on fish. The analytical results of fish and waters of Han River show that the river is heavily contaminated with Hg and Cd of which sources are manifold and increase in number as the stream flows downward. Some species of marine fish which are expected to dwell on the sea beds or sea shores contained relatively high Hg and/or Cd contents compared to other species. Some interpretations of the analytical results were attempted with the object of pointing out the sources of the contamination, but this met some difficulties

  12. Organochlorine pesticides in soil, air, and vegetation at and around a contaminated site in southwestern China: Concentration, transmission, and risk evaluation.

    Science.gov (United States)

    Fang, Yanyan; Nie, Zhiqiang; Die, Qingqi; Tian, Yajun; Liu, Feng; He, Jie; Huang, Qifei

    2017-07-01

    Remediation and management of contaminated sites have become a prevalent problem under the current situation in China. The present study was conducted to investigate the concentration, transmission, and health risk of organochlorine pesticides (OCPs) in soil, air, and vegetation at and around a typical pesticide-contaminated site located in southwestern China. Exchange flux between soil and air was calculated to investigate the transmission of OCPs. Hexachlorocyclohexane (ΣHCHs, top soil: 19.1 mg/kg d.w., air: 52.3 ng/m 3 , vegetation: 0.17 mg/kg d.w.) and dichlorodiphenyltrichloroethane (ΣDDTs, top soil: 200 mg/kg d.w., air: 130 ng/m 3 , vegetation: 0.78 mg/kg d.w.) were the dominant pollutants at the contaminated site. Around the site, the soil, air, and vegetation samples had higher OCP concentrations than those in the normal areas, which were found to be dominated by ΣHCHs (top soil: 129 ng/g d.w., air: 5.09 ng/m 3 , vegetation: 81.8 ng/g d.w.) and ΣDDTs (top soil: 360 ng/g, air: 7.47 ng/m 3 , vegetation: 189 ng/g d.w.). The fugacity fractions of OCPs (>0.7) showed a net volatilization from soil into air, indicating that soil is an obvious pollution source for the atmosphere, especially at the site. Through human health risk evaluation, serious carcinogenic risk (CR n ) and hazardous index (HI n ) were found at the site (CR n : 7.4 × 10 -6 -1.04 × 10 -4 , HI n : 0.02 to 8.97) and the nearby areas (CR n : 3.37 × 10 -6 for adults and 1.68 × 10 -6 for children on average). Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Temporal variations in gaseous elemental mercury concentrations at a contaminated site: Main factors affecting nocturnal maxima in daily cycles

    Science.gov (United States)

    Esbrí, José M.; Martínez-Coronado, Alba; Higueras, Pablo L.

    2016-01-01

    Mercury is considered to be a global pollutant and it has been globally transported as gaseous elemental mercury (GEM). International networks for the continuous monitoring of mercury, all of which are based on background sites, study the dispersion pattern of this metal and trends in its evolution in time and space. However, information about seasonal and daily cycling of polluted sites is scarce. The aim of the work described here was to cover this gap in knowledge. For this purpose, continuous (GEM) measurements were carried out in Almadén town from November 2011 to September 2013. Meteorological data were also collected during this time. GEM data show an average concentration during the sampling period (2011-2013) of 27.4 ng m-3, with a range of 0.8-686.9 ng m-3. The results highlighted seasonal and daily cycles of GEM in Almadén town, with seasonally higher levels in summer (686.9 ng m-3) and significantly daily higher levels during the night. A multiple linear regression model has established wind speed as the best GEM predictor in all seasons during the night, while the best predictor in winter is relative humidity, temperature in spring, solar radiation in summer and wind speed in autumn during the day. These results provide evidence that, in mining polluted sites like Almadén, photochemical reactions have a negligible impact on GEM levels during the daytime and that meteorological parameters are more relevant. Further studies on diurnal GEM cycling in polluted sites must be carried out to obtain a realistic local risk assessment, taking into account night GEM levels and their importance in each case study.

  14. Critical body residues (CBRs) for ecotoxicological soil quality assessment: copper in earthworms

    NARCIS (Netherlands)

    Ma, W.C.

    2005-01-01

    The term `critical body residue` (CBR) was defined as the lowest observed total body concentration of a contaminant in an organism, which is associated with the occurrence of adverse toxic effects in either individuals or populations of a defined age or stage of development. In this study, internal

  15. Transfer of flubendazole and tylosin at cross contamination levels in the feed to egg matrices and distribution between egg yolk and egg white.

    Science.gov (United States)

    Vandenberge, V; Delezie, E; Delahaut, P; Pierret, G; De Backer, P; Daeseleire, E; Croubels, S

    2012-05-01

    Chemical residues may be present in eggs from laying hens' exposure to drugs or contaminants. These residues may pose risks to human health. In this study, laying hens received experimental feed containing flubendazole or tylosin at cross contamination levels of 2.5, 5, and 10% of the therapeutic dose. Eggs were collected daily and analysis of the whole egg, egg white, and egg yolk was performed using liquid chromatography tandem mass spectrometry. Highest concentrations of the parent molecule flubendazole, as well as the hydrolyzed and the reduced metabolite, were detected in egg yolk. Residue concentrations of the parent molecule were higher compared with those of the metabolites in all egg matrices. No tylosin residue concentrations were detected above the limit of quantification for all concentration groups and in all egg matrices. Neither molecule exceeded the set maximum residue limits.

  16. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan, E-mail: jan.svensson@ki.se [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Bergman, Ann-Charlotte [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Adamson, Ulf [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Blombaeck, Margareta [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Wallen, Hakan; Joerneskog, Gun [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of

  17. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    International Nuclear Information System (INIS)

    Svensson, Jan; Bergman, Ann-Charlotte; Adamson, Ulf; Blombäck, Margareta; Wallén, Håkan; Jörneskog, Gun

    2012-01-01

    Highlights: ► Fibrinogen was incubated in vitro with glucose or aspirin. ► Acetylations and glycations were found at twelve lysine sites by mass spectrometry. ► The labeling by aspirin and glucose occurred dose-dependently. ► No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent – a phenomenon called “aspirin resistance”. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to “aspirin resistance” in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5–10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the α-chain: αK191, αK208, αK224, αK429, αK457, αK539, αK562, in the β-chain: βK233, and in the γ-chain: γK170 and γK273. Glycations were found at βK133 and γK75, alternatively γK85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [ 14 C-acetyl]salicylic acid and [ 14 C]glucose, a labeling of 0.013–0.084 and 0.12–0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9–100 μM aspirin) and physiologically (2–8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of

  18. Woody biomass phytoremediation of contaminated brownfield land

    International Nuclear Information System (INIS)

    French, Christopher J.; Dickinson, Nicholas M.; Putwain, Philip D.

    2006-01-01

    Economic and environmental regeneration of post-industrial landscapes frequently involves some element of re-afforestation or tree planting. We report field trials that evaluate whether woody biomass production is compatible with managing residual trace element contamination in brownfield soils. Large-scale mapping of contamination showed a heterogenous dispersion of metals and arsenic, and highly localised within-site hotspots. Yields of Salix, Populus and Alnus were economically viable, showing that short-rotation coppice has a potentially valuable role in community forestry. Mass balance modelling demonstrated that phytoextraction potentially could reduce contamination hotspots of more mobile elements (Cd and Zn) within a 25-30-year life cycle of the crops. Cd and Zn in stems and foliage of Salix were 4-13 times higher than EDTA-extractable soil concentrations. Lability of other trace elements (As, Pb, Cu, Ni) was not increased 3 years after planting the coppice; woody biomass may provide an effective reduction of exposure (phytostabilisation) to these less mobile contaminants. - Field trials show short-rotation coppice provides effective risk management and remediation solutions to hotspots of residual metal and As contamination of brownfield land

  19. The emerging farmed fish species meagre (Argyrosomus regius): how culinary treatment affects nutrients and contaminants concentration and associated benefit-risk balance.

    Science.gov (United States)

    Costa, Sara; Afonso, Cláudia; Bandarra, Narcisa Maria; Gueifão, Sandra; Castanheira, Isabel; Carvalho, Maria Luísa; Cardoso, Carlos; Nunes, Maria Leonor

    2013-10-01

    The effect of cooking methods (boiling, grilling, and roasting) on the proximate and mineral composition, contaminants concentration and fatty acids profile was evaluated aiming to understand the benefits and risks associated to the consumption of the emerging farmed fish meagre (Argyrosomus regius). All the treatments led to lower moisture content. After grilling and roasting, the SFA, MUFA and PUFA contents increased. There was no degradation of EPA and DHA during the culinary processes. Significant retention of minerals in grilled and roasted meagre samples was registered. For Pb and Cd there were no concentration differences between culinary treatments and regarding raw fish. Whereas As level was higher in grilled meagre, total Hg and Me-Hg values were augmented in grilled and roasted meagre. The consumption of meagre is advisable due to the low and healthy fat, high selenium and protein content. Grilling would be the best culinary treatment due to the retention of protein, EPA, DHA and minerals. But as the risk of ingestion of Me-Hg content also increases, based on the risk assessment, intake should not exceed two weekly meals, provided that no other important Me-Hg food source is present in the diet. Otherwise, even this maximum threshold should be lower. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Influence of solution acidity and CaCl2 concentration on the removal of heavy metals from metal-contaminated rice soils

    International Nuclear Information System (INIS)

    Kuo, S.; Lai, M.S.; Lin, C.W.

    2006-01-01

    Soil washing is considered a useful technique for remediating metal-contaminated soils. This study examined the release edges of Cd, Zn, Ni, Cr, Cu or Pb in two contaminated rice soils from central Taiwan. The concentrations exceeding the trigger levels established by the regulatory agency of Taiwan were Cu, Zn, Ni and Cr for the Ho-Mei soil and Pb for the Nan-Tou soil. Successive extractions with HCl ranging from 0 to 0.2 M showed increased release of the heavy metals with declining pH, and the threshold pH value below which a sharp increase in the releases of the heavy metals was highest for Cd, Zn, and Ni (pH 4.6 to 4.9), intermediate for Pb and Cu (3.1 to 3.8) and lowest for Fe (2.1), Al (2.2) and Cr (1.7) for the soils. The low response slope of Ni and Cr particularly for the rice soils make soil washing with the acid up to the highest concentration used ineffective to reduce their concentrations to below trigger levels. Although soil washing with 0.1 M HCl was moderately effective in reducing Cu, Pb, Zn and Cd, which brought pH of the soils to 1.1 ± 0.1 (S.D.), the concurrent release of large quantities of Fe and Al make this remediation technique undesirable for the rice soils containing high clay. Successive washings with 0.01 M HCl could be considered an alternative as the dissolution of Fe and Al was minimal, and between 46 to 64% of Cd, Zn, and Cu for the Ho-Mei soil and 45% of Pb in the Na-Tou soil were extracted after four successive extractions with this dilute acid solution. The efficacy of Cd extraction improved if CaCl 2 was added to the acid solution. The correlation analysis revealed that Cr extracted was highly correlated (P < 0.001) with Fe extracted, whereas the Cu, Ni, Zn, Cd or Pb extracted was better correlated (P < 0.001) with Al than with Fe extracted. It is possible that the past seasonal soil flooding and drainage in the soils for rice production was conducive to incorporating Cr within the structure of Fe oxide, thereby making them

  1. Remaining Sites Verification Package for the 600-243 Petroleum-Contaminated Soil Bioremediation Pad. Attachment to Waste Site Reclassification Form 2007-033

    International Nuclear Information System (INIS)

    Capron, J.M.

    2008-01-01

    The 600-243 waste site consisted of a bioremediation pad for petroleum-contaminated soils resulting from the 1100 Area Underground Storage Tank (UST) upgrades in 1994. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  2. Prevalence of antibiotic residues in commercial milk and its variation by season and thermal processing methods

    Directory of Open Access Journals (Sweden)

    Fathollah Aalipour

    2013-01-01

    Full Text Available Aims: In this study, the prevalence of antibiotic residues in pasteurized and sterilized commercial milk available in Shahre-kourd, Iran, was investigated. In addition, the influence of seasonal temperature changes on the prevalence of contamination was studied. Materials and Methods: Commercial milk samples of 187, including 154 pasteurized and 33 sterilized, milk samples were collected from the market between early January 2012 and late July of the same year. The presence of antibiotic residues was detected using the microbiological detection test kit, Eclipse 100, as a semi-quantitative method. Results: The results showed that 37 of the samples (19.8% have contained antibiotic residues above the European Union Maximum Residues Limits (EU-MRLs, of which 28 samples (14.97% were found to be contaminated but at the concentrations below the EU-MRLs. There was no significant difference between the contamination rate of pasteurized and Ultra High Temperature (UHT-sterilized samples. Similarly, variation of weather temperature with seasons had no effect on the contamination prevalence of milk samples ( P > 0.05. Conclusion: Based on the result of this study, antibiotics residues were present in the majority of milk samples. Neither the season nor the type of thermal processing of the commercial milks had noticeable impact on the prevalence level of the milk samples. However, an increasing trend of prevalence level for antibiotic residues was observed with increasing the temperature through the warm season.

  3. Influence of Bacillus subtilis ANSB060 on growth, digestive enzyme and aflatoxin residue in Yellow River carp fed diets contaminated with aflatoxin B1.

    Science.gov (United States)

    Fan, Yu; Liu, Laiting; Zhao, Lihong; Wang, Xinping; Wang, Dacai; Huang, Churan; Zhang, Jianyun; Ji, Cheng; Ma, Qiugang

    2018-03-01

    Aflatoxin B 1 (AFB 1 ) elicits serious threats to public health due to its widespread occurrence, as well as its teratogenic, carcinogenic and mutagenic effects. This study aimed to evaluate the toxicity of AFB 1 and assess the ameliorative efficacy of Bacillus subtilis ANSB060 on aflatoxicosis in Yellow River carp. A total of 750 juvenile Yellow River carp were allocated into five dietary treatments for 60 days. Diet C0 represented for the negative control, diet M0 containing about 50 μg AFB 1 /kg diet represented for the positive control, and diet M0.25, M0.5 and M1.0 was diet M0 supplemented with B. subtilis ANSB060 at a dose of 0.25 × 10 9 , 0.5 × 10 9 and 1.0 × 10 9  CFU/kg diet, respectively. The results showed that supplementation of strain ANSB060 restored the reduced body weight and enhanced feed conversion ratio of carp induced by AFB 1 towards normal. ANSB060 could also relieve the alterations in hepatic morphology, improve digestive enzyme activities of hepatopancreas and intestine, as well as decrease AFB 1 residues in carp's hepatopancreas and gonad. It is concluded that ANSB060 has a protective effect in carp with aflatoxicosis, with a promising potential in feed industrial applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. GKSS-workshop: contaminated sludges. Treatment and utilization fine graned residues; GKSS-Workshop: Kontaminierte Schlaemme. Behandlung und Nutzungsmoeglichkeiten feinkoerniger Reststoffe

    Energy Technology Data Exchange (ETDEWEB)

    Alvermann, G.; Luther, G.; Niemeyer, B. [eds.] [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Zentralabteilung Technikum

    2000-07-01

    New regulations, such as the materials recycling act, soil protection act and unsolved problems related to the treatment of contaminated sludges, the utilisation of the gained products demand the development of innovative techniques for industrial, dredged or drilling sludges. The workshop offered a platform for intensive discussions between representatives of industry, research institutions, associations, and authorities. The main aim of the workshop was the presentation of fundamental background of sludge processing and advanced technical solutions. The available proceedings contain 21 lectures held on the workshop with the following ranges of topics of the sludge treatment: legislation, R and D-funding, technological bases, decontamination processes, dewatering and drying processes, recycling and immobilization. (orig.) [German] Neue Gesetze wie das Kreislaufwirtschafts- oder das Bundes-Bodenschutzgesetz und anstehende Probleme bei der Beseitigung belasteter Schlaemme - zum Beispiel Industrie-, Bohr- und Baggergutschlaemme - erfordern die Entwicklung innovativer Techniken zu ihrer Aufbereitung, Reinigung bzw. Verwertung. Der Workshop bot ein Formung zur intensiven Diskussion zwischen Industrie, Forschung, Verbaenden und Behoerden. Ziel war es, unterschiedliche Methoden der Schlammbehandlung zu eroertern, Loesungswege aufzuzeigen und Moeglichkeiten fuer Kooperationen zu erarbeiten. Der vorliegende Band enthaelt Beitraege der Referenten, die sich auf folgende Themenbereiche der Schlammbehandlung konzentrieren: juristische Aspekte, Foerdermoeglichkeiten, Grundlagen, Aufbereitung von Schlaemmen, Entwaesserung und Trocknung von Schlaemmen, Verwertung und Immobilisierung. (orig.)

  5. JV Task 99-Integrated Risk Analysis and Contaminant Reduction, Watford City, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Jaroslav Solc; Barry W. Botnen

    2007-05-31

    The Energy & Environmental Research Center (EERC) conducted a limited site investigation and risk analyses for hydrocarbon-contaminated soils and groundwater at a Construction Services, Inc., site in Watford City, North Dakota. Site investigation confirmed the presence of free product and high concentrations of residual gasoline-based contaminants in several wells, the presence of 1,2-dichloroethane, and extremely high levels of electrical conductivity indicative of brine residuals in the tank area south of the facility. The risk analysis was based on compilation of information from the site-specific geotechnical investigation, including multiphase extraction pilot test, laser induced fluorescence probing, evaluation of contaminant properties, receptor survey, capture zone analysis and evaluation of well head protection area for municipal well field. The project results indicate that the risks associated with contaminant occurrence at the Construction Services, Inc. site are low and, under current conditions, there is no direct or indirect exposure pathway between the contaminated groundwater and soils and potential receptors.

  6. Improving yield and composition of protein concentrates from green tea residue in an agri-food supply chain: Effect of pre-treatment

    NARCIS (Netherlands)

    Zhang, Chen; Krimpen, Van Marinus M.; Sanders, Johan P.M.; Bruins, Marieke E.

    2016-01-01

    Rather than improving crop-production yield, developing biorefinery technology for unused biomass from the agri-food supply chain may be the crucial factor to reach sustainable global food security. A successful example of food-driven biorefinery is the extraction of protein from green tea residues,

  7. Ecological risk assessment of pesticide residues in coastal lagoons of Nicaragua.

    Science.gov (United States)

    Carvalho, Fernando P; Villeneuve, Jean-Pierre; Cattini, Chantal; Tolosa, Immaculada; Montenegro-Guillén, S; Lacayo, Martha; Cruz, Adela

    2002-10-01

    A detailed investigation on the contamination with chlorinated hydrocarbons and organophosphorous pesticides of the coastal lagoon system of Chinandega district, Nicaragua, allowed the identification of contaminant sources and lagoon areas currently more contaminated. The discharge of rivers into the lagoons is the main transport pathway of pesticide residues; whereas atmospheric depositions are likely to be the main pathway for the introduction of PCBs into the lagoons. Analysis of water samples indicates widespread contamination with soluble organophosphorous compounds, such as dichlorvos, up to 410 ng L(-1), diazinon, up to 150 ng L(-1), and chlorpyrifos, up to 83 ng L(-1). Analyses of suspended matter for low solubility organochlorine (OC) compounds revealed very high concentrations of toxaphene, up to 17,450 ng g(-1) dry weight (dw), total DDTs up to 478 ng g(-1), Aroclor 1254, up to 119 ng g(-1) (dw), and lower concentrations for other compounds. Lagoon sediments contain high concentrations also of toxaphene, from 7.9 to 6,900 ng g(-1) (dw), and DDTs, from 1.5 to 321 ng g(-1) (dw), and lower concentrations of chlorpyrifos, hexachlorocyclohexanes, chlordane and other residues. Concentrations of OCs in soft tissues of clams are statistically correlated with the concentrations of the same compounds in bottom sediments, indicating that sediments are a source of contaminants to biota. In some areas of the lagoon system, concentration of residues in sediments are far above recommended threshold guideline values for protection of aquatic life, and may cause acute and chronic toxic effects on more sensitive aquatic species. Despite the ban on the use of toxaphene and DDT, residues of these compounds are still entering the lagoons due to erosion of, and leaching from, agriculture soils in the region. Measures for protection of the lagoon ecosystem are discussed.

  8. Alternativas de utilização de resíduos sólidos alcalinos na disposição de resíduos contaminados: estudo de caso no estado do Rio de Janeiro, Brasil Alkaline residues alternatives for use in the landfill of a contaminated solid residues: case study from Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Wilma de Carvalho Pereira

    2008-06-01

    Full Text Available Este trabalho tem como objetivo o estudo dos elementos potencialmente contaminantes presentes nos rejeitos industriais que são dispostos no meio ambiente e, por processo de lixiviação, carreados para os corpos hídricos. Dois tipos de resíduos foram estudados. Um deles, proveniente da indústria de produção de aço (escória da aciaria, de características alcalina. Este rejeito é considerado relativamente estável pelos padrões vigentes devido às suas características (CdThe goal of this work is to study the potentially contaminating trace elements present in industrial waste that is discharged into the environment though lixiviation process to water resources. Two types of waste were studied. The first one, a refuse slag from steel industry, an alkaline residue. Even though this waste is considered relatively stable within the established standards set by current legislation due to its characteristics (Cd<0.5 mg/Kg, Pb<10 mg/Kg, Co<5 mg/Kg, Cu=61 mg/Kg, Ni<1.5 mg/Kg, Zn=75 mg/Kg, there is so far no feasible alternative for its total reutilization. The other one a residue from the electroplating industry (Class I: ABNT, 1987, closed down in 1998.

  9. Uncovering the local inelastic interactions during manufacture of ductile cast iron: How the substructure of the graphite particles can induce residual stress concentrations in the matrix

    DEFF Research Database (Denmark)

    Andriollo, Tito; Hellström, Kristina; Sonne, Mads Rostgaard

    2018-01-01

    Recent X-ray diffraction (XRD) measurements have revealed that plastic deformation and a residual elastic strain field can be present around the graphite particles in ductile cast iron after manufacturing, probably due to some local mismatch in thermal contraction. However, as only one component...... of the elastic strain tensor could be obtained from the XRD data, the shape and magnitude of the associated residual stress field have remained unknown. To compensate for this and to provide theoretical insight into this unexplored topic, a combined experimental-numerical approach is presented in this paper....... First, a ma terial equivalent to the ductile cast iron matrix is manufactured and subjected to dilato- metric and high-temperature tensile tests. Subsequently, a two-scale hierarchical top-down model is devised, calibrated on the basis of the collected data and used to simulate the interaction between...

  10. Concentration levels of zearalenone and its metabolites in urine, muscle tissue, and liver samples of pigs fed with mycotoxin-contaminated oats.

    Science.gov (United States)

    Zöllner, Peter; Jodlbauer, Justus; Kleinova, Martina; Kahlbacher, Hermann; Kuhn, Thomas; Hochsteiner, Werner; Lindner, Wolfgang

    2002-04-24

    The content of zearalenone and its metabolites in urine and tissue samples from pigs fed zearalenone-contaminated oats was established by analytical methods combining solid-phase extraction cleanup of the samples with highly selective liquid chromatography-mass spectrometry (LC-MS)/MS detection. Investigation of the urine samples revealed that approximately 60% of zearalenone was transformed in vivo to alpha-zearalenol and its epimer beta-zearalenol in a mean ratio of 3:1. Zeranol and taleranol as further metabolites could only be detected in trace amounts. Zearalanone was identified at considerable concentrations, though only in a couple of samples. In contrast, liver samples contained predominantly alpha-zearalenol, and to a minor extent beta-zearalenol and zearalenone, with a mean ratio of alpha-/beta-zearalenol of 2.5:1, while zeranol, taleranol, or zearalanone could not be identified in any of the investigated samples. The degree of glucoronidation was established for zearalenone as 27% in urine and 62% in liver; for alpha-zearalenol as 88% in urine and 77% in liver; and for beta-zearalenol as 94% in urine and 29% in liver. Analyses of muscle tissue revealed relatively high amounts of nonglucuronidated zeranol and alpha-zearalenol together with traces of taleranol and zearalenone, indicating that the metabolism of zearalenone and its metabolites is not restricted to hepatic and gastrointestinal metabolic pathways.

  11. Contamination analysis unit

    International Nuclear Information System (INIS)

    Gregg, H.R.; Meltzer, M.P.

    1996-01-01

    The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig

  12. Surface tritium contamination studies

    International Nuclear Information System (INIS)

    Sienkiewicz, C.J.

    1986-01-01

    Glovebox wipe surveys were conducted to correlate surface tritium contamination with atmospheric tritium levels. Surface contamination was examined as a function of tritium concentration and limited to the HT/T 2 form. The previously predicted relationship between atmospheric HTO concentration and cleanup times was examined in order to predict a model for atmospheric detritiation of stainless steel enclosures. 2 figures, 2 tables

  13. Control of residual carbon concentration in GaN high electron mobility transistor and realization of high-resistance GaN grown by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    He, X.G. [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Zhao, D.G., E-mail: dgzhao@red.semi.ac.cn [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Jiang, D.S.; Liu, Z.S.; Chen, P.; Le, L.C.; Yang, J.; Li, X.J. [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Zhang, S.M.; Zhu, J.J.; Wang, H.; Yang, H. [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215125 (China)

    2014-08-01

    GaN films were grown by metal-organic chemical vapor deposition (MOCVD) under various growth conditions. The influences of MOCVD growth parameters, i.e., growth pressure, ammonia (NH{sub 3}) flux, growth temperature, trimethyl-gallium flux and H{sub 2} flux, on residual carbon concentration ([C]) were systematically investigated. Secondary ion mass spectroscopy measurements show that [C] can be effectively modulated by growth conditions. Especially, it can increase by reducing growth pressure up to two orders of magnitude. High-resistance (HR) GaN epilayer with a resistivity over 1.0 × 10{sup 9} Ω·cm is achieved by reducing growth pressure. The mechanism of the formation of HR GaN epilayer is discussed. An Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistor structure with a HR GaN buffer layer and an additional low-carbon GaN channel layer is presented, exhibiting a high two dimensional electron gas mobility of 1815 cm{sup 2}/Vs. - Highlights: • Influence of MOCVD parameters on residual carbon concentration in GaN is studied. • GaN layer with a resistivity over 1 × 10{sup 9} Ω·cm is achieved by reducing growth pressure. • High electron mobility transistor (HEMT) structures were prepared. • Control of residual carbon content results in HEMT with high 2-D electron gas mobility.

  14. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  15. Effects of contaminants on naiad mollusks (Unionidae): a review

    Science.gov (United States)

    Havlik, M.E.; Marking, L.L.

    1987-01-01

    Although the uptake, storage, and elimination of contaminants by naiad mollusks has been studied, relatively little information is available on toxicity. Contaminants appear to have destroyed some populations directly by exerting toxic effects, or indirectly by causing or contributing to the elimination of essential food organisms or host fish. The most frequently studied contaminants are Cd, Cu, Mn-Mn64, Pb-Pb210. and Zn-Zn65. Manganese seems to be most readily taken up and stored in tissues; no apparent damage has been reported from tissue concentrations of thousands of parts per million (ppm) and the element appears to be essential to metabolism. Zinc and cadmium also accumulate at high levels in tissues. Lead was never found to be lethal in the studies reviewed. Various common contaminants have been reported to be toxic at the following concentrations (ppm): cadmium. 2; copper sulfate, 2 to 18.7; ammonia, 5; potassium. 11; chromium, 12.4; arsenic trioxide, 16; copper, 19; and zinc, 66. In long-term exposures, concentrations of copper as low as 25 parts per billion (ppb) were lethal. Fry of fish infected with 20-35 glochidia were more sensitive than uninfected fish to toluene, naphthalene, and crude oil. Although few specific adverse impacts of contaminants have become clearly evident, circumstantial evidence leaves little doubt that contaminants have been responsible for decreases in population density, range, and diversity. Stresses that have been responsible for the disappearance of naiad mollusks in contaminated areas have not generally been identified, and the components of the stresses have seldom been quantitatively and qualitatively correlated with the composition and size of the naiad fauna. Often two or more factors appear to work in combination to produce the total stress that adversely affects populations. Naiad mollusks are important indio caters of contaminants in the environment; residues in soft tissue indicate recent or current exposure, and

  16. Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera)

    OpenAIRE

    Zhu, Yu Cheng; Yao, Jianxiu; Adamczyk, John; Luttrell, Randall

    2017-01-01

    Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothr...

  17. Weld Residual Stress in Corner Boxing Joints

    OpenAIRE

    Kazuyoshi, Matsuoka; Tokuharu, Yoshii; Ship Research Institute, Ministry of Transport; Ship Research Institute, Ministry of Transport

    1998-01-01

    Fatigue damage often occurs in corner boxing welded joints because of stress concentration and residual stress. The hot spot stress approach is applicable to stress concentration. However, the number of suitable methods for estimating residual stress in welded joints is limited. The purpose of this paper is to clarify the residual stress in corner boxing joints. The method of estimating residual stresses based on the inherent stress technique is presented. Residual stress measurements are per...

  18. Milk quality parameters associated with the occurrence of veterinary drug residues in bulk tank milk

    Directory of Open Access Journals (Sweden)

    Lidia Cristina Almeida Picinin

    Full Text Available ABSTRACT Veterinary drug residues in bulk tank milk are important to all sectors of the dairy chain because they are one of the major factors which determine the safety of the final product. This study attempted to identify milk quality parameters that are associated with the occurrence of veterinary drug residues using multivariate principal component analysis (PCA. A total of 132 raw milk samples were collected from 45 dairy farms in the state of Minas Gerais - Brazil and analyzed for 42 analytes, including pyrethroids, macrocyclic lactones and antibacterials, using liquid chromatography coupled with mass spectrometry in tandem mode and gas chromatography with electron capture detection. Out of the 132 milk samples, 40 samples tested positive for at least one analyte (above the detection limit. The milk parameters associated with the antimicrobial residues by confirmatory tests were lactose and nonfat concentrations, as revealed by PCA. This analysis showed that fat and total solid concentrations, as well as the somatic cell and total bacteria counts were associated with macrocyclic lactone residues in bulk tank milk. A PCA assessing pyrethroid residues in bulk tank milk revealed that the lactose and nonfat solid concentrations and titratable acidity were inversely associated with these residues. Thus, the data analysis indicated that the veterinary drug residues were associated with certain milk quality parameters that can be used to target farms at higher risk of veterinary drug residue contamination for testing programs in combination with incentives, education and training programs to improve mammary health, milk hygiene and safety.

  19. Determination of the Minimum Inhibitory Concentration of the Barberry Extract and the Dried Residue of Red Grape and Their Effects on the Growth Inhibition of Sausage Bacteria by Using Response Surface Methodology (RSM

    Directory of Open Access Journals (Sweden)

    Fatemeh Riazi

    2015-09-01

    Full Text Available Background and Objectives: With regard to the hazards of nitrite, application of natural preservatives in order to reduce the microbial load of meat and meat products is increasing. Owing to their anti-bacterial properties, red barberry and the dried residue of red grape could be suitable replacers for nitrite. Materials and Methods: Agar dilution method was employed in order to determine the minimum inhibitory concentration (MIC of the barberry extract and the dried residue of red grape. The anti-microbial effects of the barberry extract (0-600 mg/kg, the dried residue of red grape (0-2% and nitrite (30-90 mg/kg were investigated on the total viable counts of Clostridium perfringens, as well as on the psychrophilic bacteria after 30 days of storage at 4°C. Finally, the effects of the three independent variables in the optimal sample were examined on the growth of the inoculated C. perfringens. Results: The MIC of the barberry extract and the dried residue of red grape on Staphylococcus aureus was 3 and 6 (mg/ml, respectively. In the case of Escherichia coli, it was 4 and 7 (mg/ml, respectively. The barberry extract and nitrite reduced the growth of the living aerobic bacteria significantly. The spores of the inoculated C. perfringens had no growth in the optimum sample during storage. Conclusions: The barberry extract and the dried residue of red grape as natural preservatives, could partially substitute for nitrite in order to reduce the microbial load of sausage.

  20. RESRAD analysis of the validity of generic limits on residual 238U radioactivity in soil

    International Nuclear Information System (INIS)

    Wood, R.; Eckart, R.

    1991-01-01

    Unrestricted use of sites contaminated by radioactive material requires that an acceptable level of residual radioactive contamination (in picocuries per gram of soil) be determined. Acceptable levels often are stated by regulatory bodies as residual isotope concentrations generic across all sites. For example, the past US Nuclear Regulatory Commission position on residual depleted uranium in soil was 35 pCi/g for unrestricted site release. The goal of this study is to show, using calculational methods typically employed in cleanup studies, that generic residual contamination limits may not provide consistent levels of protection to future site residents. Site-specific analysis containing conservative site use assumptions should be performed to ensure minimal future health risks. This study investigated three different sites contaminated with equal 238 U concentrations (35 pCi/g of soil). Results were calculated using the US Department of Energy code RESRAD, which employs pathway analysis methods to determine radionuclide uptake, performs dose calculations using ICRP-30 methods, and provides output at user-selected time intervals. The dose calculations used dose conversion factors that would, for each pathway, maximize the dose received from that pathway. The output selected for this study was the annual effective dose equivalent (AEDE) to the maximum individual

  1. Influence of sodium chloride and weak organic acids (flux residues) on electrochemical migration of tin on surface mount chip components

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    The electrolytic properties of sodium chloride and no-clean solder flux residue, and their effects on electrochemical migration and dendrite growth on surface mount chip capacitors were investigated. The leakage current dependency on concentration of contaminants was measured by a solution...

  2. Effect of Plant Growth Promoting Rhizobacteria on the Concentration and Uptake of Macro Nutrients by Corn in a Cd-contaminated Calcareous Soil under Drought Stress

    Directory of Open Access Journals (Sweden)

    shahrzad karami

    2017-02-01

    Full Text Available Introduction: Heavy metals such as cadmium (Cd are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress. Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria, four levels of Cd (5, 10, 20, and 40 mg kg-1, and three levels of drought stress (without stress, 80, and 65% of field capacity. The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO42, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO were planted at

  3. Increase in the carbohydrate content of the microalgae Spirulina in culture by nutrient starvation and the addition of residues of whey protein concentrate.

    Science.gov (United States)

    Vieira Salla, Ana Cláudia; Margarites, Ana Cláudia; Seibel, Fábio Ivan; Holz, Luiz Carlos; Brião, Vandré Barbosa; Bertolin, Telma Elita; Colla, Luciane Maria; Costa, Jorge Alberto Vieira

    2016-06-01

    Non-renewable sources that will end with time are the largest part of world energy consumption, which emphasizes the necessity to develop renewable sources of energy. This necessity has created opportunities for the use of microalgae as a biofuel. The use of microalgae as a feedstock source for bioethanol production requires high yields of both biomass and carbohydrates. With mixotrophic cultures, wastewater can be used to culture algae. The aim of the study was to increase the carbohydrate content in the microalgae Spirulina with the additions of residues from the ultra and nanofiltration of whey protein. The nutrient deficit in the Zarrouk medium diluted to 20% and the addition of 2.5% of both residue types led to high carbohydrate productivity (60 mg L(-1) d(-1)). With these culture conditions, the increase in carbohydrate production in Spirulina indicated that the conditions were appropriate for use with microalgae as a feedstock in the production of bioethanol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effect of Manuka honey gel on the transforming growth factor β1 and β3 concentrations, bacterial counts and histomorphology of contaminated full-thickness skin wounds in equine distal limbs.

    Science.gov (United States)

    Bischofberger, A S; Dart, C M; Horadagoda, N; Perkins, N R; Jeffcott, L B; Little, C B; Dart, A J

    2016-01-01

    To investigate the effect of 66% Manuka honey gel on the concentrations of transforming growth factor (TGF)-β1 and TGF-β3, bacterial counts and histomorphology during healing of contaminated equine distal limb wounds. In this experimental study of 10 Standardbred horses, five full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus and six similar wounds were created on the contralateral metacarpus. Wounds were assigned to three groups: non-contaminated control wounds; contaminated control wounds; contaminated wounds treated daily with 1 mL Manuka honey gel topically for 10 days. For the contaminated wounds, faeces were applied for 24 h after wound creation. In five horses wounds were bandaged and in the other five horses wounds were left without a bandage. Biopsies were taken on days 1, 2, 7 and 10 after wounding to evaluate the effects of Manuka honey gel, wound contamination and bandaging on TGF-β1 and TGF-β3 concentrations, aerobic and anaerobic bacterial counts, and histomorphology. Manuka honey gel had no significant effect on TGF-β1 and TGF-β3 concentrations or wound bacterial counts. Manuka honey gel decreased wound inflammation (days 7, 10), increased angiogenesis (days 2, 7, 10), increased fibrosis and collagen organisation (day 7) and increased epithelial hyperplasia (days 7, 10). Treatment with Manuka honey gel resulted in a more organised granulation tissue bed early in wound repair, which may contribute to enhanced healing of equine distal limb wounds. © 2016 Australian Veterinary Association.

  5. Laboratory study on the bioremediation of petrochemical sludge-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Morelli, I.S.; Del Panno, M.T.; De Antoni, G.L.; Painceira, M.T. [Universidad Nacional de La Plata, Buenos Aires (Argentina). Facultad de Ciencia Exactas, Laboratorio de Biodegradacion Microbiologica de Hidrocarburos

    2005-06-01

    This study evaluated by biological and chemical analyses the effectiveness of bioremediation of sludge from the petrochemical industry in systems containing artificially contaminated soil. The sludge-soil systems were prepared with three different initial concentrations of sludge, and during bioremediation 86-95% of the hydrocarbons was eliminated. Simultaneously, soil bacterial populations and inhibition of seed germination by aqueous extracts increased in all sludge-soil systems during the first 180 days of treatment. After 1 year of bioremediation, a loss in the catabolic capacity of the Gram-negative bacterial population was observed, but was not dependent on the initial sludge concentration. Furthermore, residual levels of hydrocarbons and seed germination inhibitory effect decreased sharply, but some level of toxicity remained in the systems containing the highest initial sludge concentration. Independent of the initial sludge concentration, the contaminated soils did not re-establish their original features even when residual hydrocarbon concentrations suggested the end of the process. (author)

  6. Evaluation of the immunological and hematological effects of chronic exposure of adult Peromyscus leucopus to Aroclor 1254 at concentrations equivalent to those at contaminated sites

    Science.gov (United States)

    Arena, S.R.; Segre, M.; French, J.B.

    2000-01-01

    Polychlorinated biphenyls are known to cause adverse health effects to biological systems; however, limited data is available on their effects on the immune system of wild species. Previous work by our lab found that 4 and 6-week old white-footed mice (Perornyscus leucopus) born from dams injected with a single dose (300 mg/kg) of Aroclor 1254, had altered immunological, hematological, and biochemical responses. The present study examines various immunological parameters of 22-week old white footed mice born from dams chronically exposed to Aroclor 1254 at concentrations equivalent to those at contaminated sites. Females were fed diets containing either Aroclor 1254 in corn oil or corn off only, for 3 months, then bred; pups were maintained on the same diets as their mothers. At 22 weeks of age, 31 of the young Peromyscus were analyzed. Body and organ weights were taken and immune function was evaluated by assessing blood profiles, cellularity of thymus and spleen, antibody response to the antigen DNP-KLH, and the in vitro proliferative response to the T-cell mitogen Conconavalin A (Con A). Liver weights and liver to body weight ratios in the treated mice were significantly higher compared to controls, while the combined weights of the adrenal glands were significantly lower. In addition, the number of thymocytes in the treated mice was significantly lower than that of the controls; however, thymocytes of treated mice had a higher degree of proliferation to Con A. Taken together, these results and those obtained from our previous study, indicate that monitoring of vulnerable immunological parameters in white-footed mice may be a useful indicator of exposure.

  7. Tungsten contamination in ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Polignano, M.L., E-mail: maria.polignano@st.com; Barbarossa, F.; Galbiati, A.; Magni, D.; Mica, I.

    2016-06-15

    In this paper the tungsten contamination in ion implantation processes is studied by DLTS analysis both in typical operating conditions and after contamination of the implanter by implantation of wafers with an exposed tungsten layer. Of course the contaminant concentration is orders of magnitude higher after contamination of the implanter, but in addition our data show that different mechanisms are active in a not contaminated and in a contaminated implanter. A moderate tungsten contamination is observed also in a not contaminated implanter, however in that case contamination is completely not energetic and can be effectively screened by a very thin oxide. On the contrary, the contamination due to an implantation in a previously contaminated implanter is reduced but not suppressed even by a relatively thick screen oxide. The comparison with SRIM calculations confirms that the observed deep penetration of the contaminant cannot be explained by a plain sputtering mechanism.

  8. 40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

  9. Dietary exposure to tetracycline residues through milk consumption in Iran.

    Science.gov (United States)

    Aalipour, Fathollah; Mirlohi, Maryam; Jalali, Mohammad; Azadbakht, Leila

    2015-01-01

    The abundant use of tetracycline antibiotics in veterinary medicine may result in the presence of their residues in milk at unsafe concentrations that can adversely affect public health. The aim of the current study was to evaluate the risk of tetracycline residue (TET) intake via milk consumption amongst different age groups of human consumers in Iran. To quantify the drug residues, HPLC analysis was performed under isocratic conditions using UV detection at 355 nm. Milk consumption patterns were determined using a recent nutrition survey in Iran. The average concentration of total TETs in milk was determined to be 252.41 μg/kg, which is approximately 2.5 times greater than the maximum residue limit (MRL) set by codex. Of the four different tetracycline antibiotics analyzed, oxytetracyclin had the highest share (86 %) of the determined contamination. Daily exposure to TETs through milk using an average data on milk consumption was estimated to range from 58-62 μg. but, distribution based exposure to TETs in milk appeared as 0-99.3 μg per day. Risk characterization of dietary exposure to TETs residue via milk intake in different age groups showed that considering the standard dietary recommendation that advices on two servings of milk per day (480 ml), consumers may receive 7-30 % of the determined ADI via bovine milk consumption.

  10. A simple methodology to evaluate influence of H2O2 and Fe(2+) concentrations on the mineralization and biodegradability of organic compounds in water and soil contaminated with crude petroleum.

    Science.gov (United States)

    Mater, L; Rosa, E V C; Berto, J; Corrêa, A X R; Schwingel, P R; Radetski, C M

    2007-10-22

    Simple measurements of H2O2 concentration or CO2 evolution were used to evaluate the effectiveness of the use of Fenton's reagent to mineralize organic compounds in water and soil contaminated by crude petroleum. This methodology is suitable for application in small treatment and remediation facilities. Reagent concentrations of H2O2 and Fe(2+) were found to influence the reaction time and temperature, as well as the degree of mineralization and biodegradability of the sample contaminants. Some H2O2/Fe(2+) combinations (H2O2 greater than 10% and Fe(2+) greater than 50mM) resulted in a strong exothermic reaction, which causes peroxide degradation and violent gas liberation. Up to 75% TOC removal efficiency was attained in water and 70% in soil when high H2O2 (20%) and low Fe(2+) (1mM) concentrations were used. Besides increasing the degree of mineralization, the Fenton's reaction enhances the biodegradability of petroleum compounds (BOD5/COD ratios) by a factor of up to 3.8 for contaminated samples of both water and soil. Our experiments showed that low reagent concentrations (1% H2O2 and 1mM Fe(2+)) were sufficient to start the degradation process, which could be continued using microorganisms. This leads to a decrease in reagent costs in the treatment of petroleum-contaminated water and soil samples. The simple measurements of H2O2 concentration or CO2 evolution were effective to evaluate the Fenton's reaction efficiency.

  11. Alternative Nonvolatile Residue Analysis with Contaminant Identification

    Data.gov (United States)

    National Aeronautics and Space Administration — Cleanliness verification is required in numerous industries including spaceflight ground support, electronics, medical and aerospace. Currently at KSC, requirements...

  12. Hole traps associated with high-concentration residual carriers in p-type GaAsN grown by chemical beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Elleuch, Omar, E-mail: mr.omar.elleuch@gmail.com; Wang, Li; Lee, Kan-Hua; Demizu, Koshiro; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2015-01-28

    The hole traps associated with high background doping in p-type GaAsN grown by chemical beam epitaxy are studied based on the changes of carrier concentration, junction capacitance, and hole traps properties due to the annealing. The carrier concentration was increased dramatically with annealing time, based on capacitance–voltage (C–V) measurement. In addition, the temperature dependence of the junction capacitance (C–T) was increased rapidly two times. Such behavior is explained by the thermal ionization of two acceptor states. These acceptors are the main cause of high background doping in the film, since the estimated carrier concentration from C–T results explains the measured carrier concentration at room temperature using C–V method. The acceptor states became shallower after annealing, and hence their structures are thermally unstable. Deep level transient spectroscopy (DLTS) showed that the HC2 hole trap was composed of two signals, labeled HC21 and HC22. These defects correspond to the acceptor levels, as their energy levels obtained from DLTS are similar to those deduced from C–T. The capture cross sections of HC21 and HC22 are larger than those of single acceptors. In addition, their energy levels and capture cross sections change in the same way due to the annealing. This tendency suggests that HC21 and HC22 signals originate from the same defect which acts as a double acceptor.

  13. Hole traps associated with high-concentration residual carriers in p-type GaAsN grown by chemical beam epitaxy

    International Nuclear Information System (INIS)

    Elleuch, Omar; Wang, Li; Lee, Kan-Hua; Demizu, Koshiro; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi

    2015-01-01

    The hole traps associated with high background doping in p-type GaAsN grown by chemical beam epitaxy are studied based on the changes of carrier concentration, junction capacitance, and hole traps properties due to the annealing. The carrier concentration was increased dramatically with annealing time, based on capacitance–voltage (C–V) measurement. In addition, the temperature dependence of the junction capacitance (C–T) was increased rapidly two times. Such behavior is explained by the thermal ionization of two acceptor states. These acceptors are the main cause of high background doping in the film, since the estimated carrier concentration from C–T results explains the measured carrier concentration at room temperature using C–V method. The acceptor states became shallower after annealing, and hence their structures are thermally unstable. Deep level transient spectroscopy (DLTS) showed that the HC2 hole trap was composed of two signals, labeled HC21 and HC22. These defects correspond to the acceptor levels, as their energy levels obtained from DLTS are similar to those deduced from C–T. The capture cross sections of HC21 and HC22 are larger than those of single acceptors. In addition, their energy levels and capture cross sections change in the same way due to the annealing. This tendency suggests that HC21 and HC22 signals originate from the same defect which acts as a double acceptor

  14. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.

    1942-10-15

    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  15. Electrochemical oxidation of trace organic contaminants in reverse osmosis concentrate using RuO2/IrO2-coated titanium anodes.

    Science.gov (United States)

    Radjenovic, Jelena; Bagastyo, Arseto; Rozendal, René A; Mu, Yang; Keller, Jürg; Rabaey, Korneel

    2011-02-01

    During membrane treatment of secondary effluent from wastewater treatment plants, a reverse osmosis concentrate (ROC) containing trace organic contaminants is generated. As the latter are of concern, effective and economic treatment methods are required. Here, we investigated electrochemical oxidation of ROC using Ti/Ru(0.7)Ir(0.3)O(2) electrodes, focussing on the removal of dissolved organic carbon (DOC), specific ultra-violet absorbance at 254 nm (SUVA(254)), and 28 pharmaceuticals and pesticides frequently encountered in secondary treated effluents. The experiments were conducted in a continuously fed reactor at current densities (J) ranging from 1 to 250 A m(-2) anode, and a batch reactor at J = 250 A m(-2). Higher mineralization efficiency was observed during batch oxidation (e.g. 25.1 ± 2.7% DOC removal vs 0% removal in the continuous reactor after applying specific electrical charge, Q = 437.0 A h m(-3) ROC), indicating that DOC removal is depending on indirect oxidation by electrogenerated oxidants that accumulate in the bulk liquid. An initial increase and subsequent slow decrease in SUVA(254) during batch mode suggests the introduction of auxochrome substituents (e.g. -Cl, NH(2)Cl, -Br, and -OH) into the aromatic compounds. Contrarily, in the continuous reactor ring-cleaving oxidation products were generated, and SUVA(254) removal correlated with applied charge. Furthermore, 20 of the target pharmaceuticals and pesticides completely disappeared in both the continuous and batch experiments when applying J ≥ 150 A m(-2) (i.e. Q ≥ 461.5 A h m(-3)) and 437.0 A h m(-3) (J = 250 A m(-2)), respectively. Compounds that were more persistent during continuous oxidation were characterized by the presence of electrophilic groups on the aromatic ring (e.g. triclopyr) or by the absence of stronger nucleophilic substituents (e.g. ibuprofen). These pollutants were oxidized when applying higher specific electrical charge in batch mode (i.e. 1.45 kA h m(-3) ROC

  16. Study of correlation between viral and bacterial contamination of waste water

    International Nuclear Information System (INIS)

    Khoffi, Nessrine

    2013-01-01

    Our study was developped following two main axes: the detection of fecal indicators (Escherichia coli) and the investigation of enteroviruses indicators of viral contamination in 3 Tunisian WWTP residues. The detection of enetroviruses was performed by real time PCR. Enteroviruses were detected in all samples whiles, 26 pour cent strongly positive, 53 pour cent moderately positive and 21 pour cent weakly positive. In addition, all samples were contaminated by E.coli with a decrease of concentration in effluent compared to influent. The results showed that E. coli is sensitive to biological treatment in charguia. A correlation between viral and bacterial contamination may be considered.

  17. Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

    Science.gov (United States)

    Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

    2009-01-01

    Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet-to-blood relation explained an additional 12% of the total variation in fillet Cd. Collectively, the results indicate that blood sampling

  18. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  19. Concentration of elements in whole-body fish, fish fillets, fish muscle plugs, and fish eggs from the 2008 Missouri Department of Conservation General Contaminant Monitoring Program

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

    2009-01-01

    This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in whole-body fish, fish fillets, fish muscle plugs, and fish eggs. Whole-body, fillet, or egg samples of catfish (Ictalurus punctatus, Ictalurus furcatus, Pylodictis olivaris), largemouth bass (Micropterus salmoides), walleye (Sander vitreus), crappie (Pomoxis annularis, Pomoxis nigromaculatus), shovelnose sturgeon (Scaphirhynchus platorynchus), northern hog sucker (Hypentelium nigricans), and Missouri saddled darter (Etheostoma tetrazonum) were collected from 23 sites as part of the Missouri Department of Conservation's Fish Contaminant Monitoring Program. Fish dorsal muscle plugs also were collected from walleye (Sander vitreus) at one of the sites.

  20. Radionuclide concentration variations in the fuel and residues of oil shale-fired power plants: Estimations of the radiological characteristics over a 2-year period.

    Science.gov (United States)

    Vaasma, Taavi; Loosaar, Jüri; Kiisk, Madis; Tkaczyk, Alan Henry

    2017-07-01

    Several multi-day samplings were conducted over a 2-year period from an oil shale-fired power plant operating with pulverized fuel type of boilers that were equipped with either novel integrated desulphurization system and bag filters or with electrostatic precipitators. Oil shale, bottom ash and fly ash samples were collected and radionuclides from the 238 U and 232 Th series as well as 40 K were determined. The work aimed at determining possible variations in the concentrations of naturally occurring radionuclides within the collected samples and detect the sources of these fluctuations. During the continuous multi-day samplings, various boiler parameters were recorded as well. With couple of exceptions, no statistically significant differences were detected (significance level 0.05) between the measured radionuclide mean values in various ash samples within the same sampling. When comparing the results between multiple years and samplings, no statistically significant variations were observed between 238 U and 226 Ra values. However, there were significant differences between the values in the fly ashes when comparing 210 Pb, 40 K, 228 Ra and 232 Th values between the various samplings. In all cases the radionuclide activity concentrations in the specific fly ash remained under 100 Bq kg -1 , posing no radiological concerns when using this material as an additive in construction or building materials. Correlation analysis between the registered boiler parameters and measured radionuclide activity concentrations showed weak or no correlation. The obtained results suggest that the main sources of variations are due to the characteristics of the used fuel. The changes in the radionuclide activity concentrations between multiple years were in general rather modest. The radionuclide activity concentrations varied dominantly between 4% and 15% from the measured mean within the same sampling. The relative standard deviation was however within the same range as the

  1. The residue levels of narasin in eggs of laying hens fed with unmedicated and medicated feed.

    Science.gov (United States)

    Rokka, Mervi; Eerola, Susanna; Perttilä, Ulla; Rossow, Laila; Venäläinen, Eija; Valkonen, Eija; Valaja, Jarmo; Peltonen, Kimmo

    2005-01-01

    Laying hens were fed contaminated feed containing narasin 2.5 mg/kg for 21 days followed by a 7 day withdrawal period, hens in the control group were fed unmedicated feed. Eggs were collected during trial days 0, 3, 7, 14, 21 and after the withdrawal period of 7 days. The concentration of narasin in yolks and egg whites was analyzed by a liquid chromatography-mass spectrometry method. Narasin was found to accumulate in yolks, where the narasin concentration increased during the treatment. The concentration of narasin varied from 5.9 to 13.8 microg/kg (mean 10.6 microg/kg) in yolks after 21 day feeding periods. The concentrations of narasin ranged from residues were not found in egg whites of the laying hens fed contaminated feed nor in either yolks or egg whites of the laying hens fed unmedicated feed. The effect of cooking was also tested on the amount of narasin residues in eggs. Cooking for 10 min did not significantly influence the narasin residues in eggs. Traces of lasalocid were also found in the yolks. The traces of lasalocid are attributable to an accidental contamination of the feed during its manufacture.

  2. Effects of Milk Yield, Feed Composition, and Feed Contamination with Aflatoxin B1 on the Aflatoxin M1 Concentration in Dairy Cows’ Milk Investigated Using Monte Carlo Simulation Modelling

    Directory of Open Access Journals (Sweden)

    H. J. van der Fels-Klerx

    2016-10-01

    Full Text Available This study investigated the presence of aflatoxin M1 (AfM1 in dairy cows’ milk, given predefined scenarios for milk production, compound feed (CF contamination with aflatoxin B1 (AfB1, and inclusion rates of ingredients, using Monte Carlo simulation modelling. The model simulated a typical dairy farm in the Netherlands. Six different scenarios were considered, based on two lactation and three CF composition scenarios. AfB1 contamination of the CF was based on results from the Dutch national monitoring programme for AfB1 in feed materials from 2000 until 2010. Monitoring data from feed materials used in CF production for dairy cattle in the Netherlands were used. Additionally, AfB1 contamination data from an incident in maize in 2013 were used. In each scenario, five different transfer equations of AfB1 from feed to AfM1 in the milk were used, and 1000 iterations were run for each scenario. The results showed that under these six scenarios, the weekly farm concentration of AfM1 in milk was above the EC threshold in less than 1% of the iterations, with all five transfer equations considered. However, this increased substantially in weeks when concentrations from the contaminated maize batch were included, and up to 28.5% of the iterations exceeded the EC threshold. It was also observed that an increase in the milk production had a minimal effect on the exceedance of the AfM1 threshold due to an apparent dilution effect. Feeding regimes, including the composition of CF and feeding roughages of dairy cows, should be carefully considered based on the potential AfM1 contamination of the farm’s milk.

  3. Pesticide contamination of fruits and vegetables - A market basket survey from selected regions in Ghana

    International Nuclear Information System (INIS)

    Asiedu, Eric

    2013-07-01

    A market - basket survey was carried out with the aim of determining the concentration levels of pesticides, in lettuce, garden eggs, pineapple and mango from some selected regions in Ghana and to assess the potential health risk associated with exposure to the pesticide residues from fruits and vegetables consumption. A total of 192 fresh samples of fruits and vegetables were randomly collected under normal purchase conditions from 12 major towns and cities in the three regions of Ghana. The samples were extracted and analyzed for organophosphates, synthetic pyrethroids and organo chlorine pesticides. The percentage of samples of fruits and vegetables with pesticide residues in Lettuce, Garden eggs, Pineapple and Mango were 52%, 40%, 45%, 48% respectively and concentrations of pesticides did not vary significantly in samples as well as the sampling areas (p>0.05) even though there were differences in residual concentrations of pesticides . The differences in residual concentrations of pesticides could be due to different agricultural practices adopted by farmers and also accessibility of the pesticides. The average residue concentrations range from 0.01-0.45 mg/kg, 0.01-0.30 mg/kg and 0.01-1.27 mg/kg for organophosphates, synthetic pyrethroids and organo chlorine pesticides respectively. Lindane, chloropyrifos and cypermethrin were the most frequent organo chlorine, organophosphate and synthetic pyrethroid pesticides respectively while lettuce was the most frequently contaminated sample. Comparing the concentration levels of organo chlorine pesticides residue with the maximum residue limits (MRLs) adopted by the FAO/WHO Codex Alimentarious Commission shows that some of the fruits and vegetables sold on Ghanaian markets are contaminated even though the levels are generally low. Health risk analysis indicates that heptachlor in particular may be of public concern since its concentration levels exceeded the reference dose in all the four different types of samples

  4. Assessment of contaminant concentrations in sediments, fish and mussels sampled from the North Atlantic and European regional seas within the ICON project

    NARCIS (Netherlands)

    Robinson, Craig D.; Webster, Lynda; Martínez-Gómez, Concepción; Burgeot, Thierry; Gubbins, Matthew J.; Thain, John E.; Vethaak, A. Dick; McIntosh, Alistair D.; Hylland, Ketil

    Understanding the status of contaminants in the marine environment is a requirement of European Union Directives and the Regional Seas Conventions, so that measures to reduce pollution can be identified and their efficacy assessed. The international ICON workshop (Hylland et al., in this issue) was

  5. Heavy metal contamination in bats in Britain

    International Nuclear Information System (INIS)

    Walker, L.A.; Simpson, V.R.; Rockett, L.; Wienburg, C.L.; Shore, R.F.

    2007-01-01

    Toxic metals are bioaccumulated by insectivorous mammals but few studies (none from Britain) have quantified residues in bats. We measured renal mercury (Hg), lead (Pb) and cadmium (Cd) concentrations in bats from south-west England to determine how they varied with species, sex, age, and over time, and if they were likely to cause adverse effects. Residues were generally highest in whiskered bats (Myotis mystacinus). Compared with other species, pipistrelle (Pipistrellus spp) and Natterer's bats (Myotis nattereri) had significantly lower kidney Hg and Pb concentrations, respectively. Renal Hg increased over time in pipistrelles but the contributory sources are unknown. Kidney Pb did not decrease over time despite concurrent declines in atmospheric Pb. Overall, median renal metal concentrations were similar to those in bats from mainland Europe and 6- to 10-fold below those associated with clinical effect, although 5% of pipistrelles had kidney Pb residues diagnostic of acute lead poisoning. - Heavy metal contamination has been quantified in bats from Britain for the first time and indicates increased accumulation of Hg and no reduction in Pb

  6. Short communication: Macrocyclic lactone residues in butter from Brazilian markets.

    Science.gov (United States)

    Macedo, Fabio; Marsico, Eliane Teixeira; Conte-Júnior, Carlos Adam; de Almeida Furtado, Leonardo; Brasil, Taila Figueredo; Pereira Netto, Annibal Duarte

    2015-06-01

    Macrocyclic lactones (ML) are commonly used in drug formulations for the treatment of parasites in cattle. In Brazil, except for drugs (or formulations) with long-term (half-life) effects, ML are registered for use in bovines. Indiscriminate use of ML may result in the presence of residues in milk and dairy products due to their lipophilic properties and thermal stability. This study applied a method of liquid chromatography with fluorimetric detection, recently developed and validated for the determination of residues of abamectin, doramectin, ivermectin, and moxidectin in butter. The method was applied to 38 samples of commercial butter purchased in the metropolitan area of Rio de Janeiro, Brazil, between June and September 2013, analyzed in triplicate. Ivermectin was detected in 89.5% of the samples, with concentrations between 0.3 and 119.4 µg/kg; 76.3% of the samples contained doramectin (0.6 to 64.7 µg/kg) and 55.2% contained abamectin (0.7 to 4.5 µg/kg). Most butter samples (76.3%) contained residues of more than 1 ML; however, no residues of moxidectin were detected. The results showed a high incidence of the presence of avermectins in butter samples. Butter is not included in the Brazilian National Plan for Control of Residues and Contaminants in Animal Products. As ML residues concentrate in lipophilic compounds, butter and other fatty dairy products should be screened for the presence of ML residues. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Measurement of Total and Free Urinary Phenol and Paraben Concentrations over the Course of Pregnancy: Assessing Reliability and Contamination of Specimens in the Norwegian Mother and Child Cohort Study.

    Science.gov (United States)

    Guidry, Virginia T; Longnecker, Matthew P; Aase, Heidi; Eggesbø, Merete; Zeiner, Pål; Reichborn-Kjennerud, Ted; Knudsen, Gun P; Bertelsen, Randi J; Ye, Xiaoyun; Calafat, Antonia M; Engel, Stephanie M

    2015-07-01

    Exposures to environmental phenols and parabens may be harmful, especially in utero. Prior studies have demonstrated high within-person variability of urinary concentrations across pregnancy. We sought to measure phenol and paraben biomarker concentrations for the Norwegian Mother and Child Cohort (MoBa) study, assess within-person variability, and investigate any possible external phenol or paraben contamination of specimens. We collected three spot urine samples at approximately 17, 23, and 29 weeks gestation in a hospital setting and added a preservative containing ethyl paraben. We measured urinary concentrations and within-person variability for phenols and parabens in a MoBa sample (n = 45), including a subgroup of 15 participants previously randomly selected for a bisphenol A (BPA) exposure study who had unusually high total BPA concentrations. Additionally, we compared reliability results for total, conjugated, and free concentrations of phenolic compounds. We detected total and free BPA, butyl paraben, propyl paraben, and methyl paraben in 100% of samples, total benzophenone-3 in 95% of samples, and infrequently detected free benzophenone-3 and total and free 2,4-dichlorophenol and 2,5-dichlorophenol. Intraclass correlation coefficients (ICCs) for total, conjugated, and free concentrations ranged from relatively low for BPA to moderate for propyl paraben. ICCs were generally similar overall and by subgroup. Using conjugated concentrations improved reliability estimates only for BPA. Measuring total and free concentrations, an approach that may be useful for future studies, allowed us to identify likely BPA and butyl paraben contamination of archived MoBa urine specimens.

  8. Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards

    Science.gov (United States)

    Al-Waili, Noori; Salom, Khelod; Al-Ghamdi, Ahmed; Ansari, Mohammad Javed

    2012-01-01

    Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey. PMID:23097637

  9. Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards

    Directory of Open Access Journals (Sweden)

    Noori Al-Waili

    2012-01-01

    Full Text Available Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey.

  10. Antibiotic, pesticide, and microbial contaminants of honey: human health hazards.

    Science.gov (United States)

    Al-Waili, Noori; Salom, Khelod; Al-Ghamdi, Ahmed; Ansari, Mohammad Javed

    2012-01-01

    Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey.

  11. Residual risk

    African Journals Online (AJOL)

    ing the residual risk of transmission of HIV by blood transfusion. An epidemiological approach assumed that all HIV infections detected serologically in first-time donors were pre-existing or prevalent infections, and that all infections detected in repeat blood donors were new or incident infections. During 1986 - 1987,0,012%.

  12. Measurement of Total and Free Urinary Phenol and Paraben Concentrations over the Course of Pregnancy: Assessing Reliability and Contamination of Specimens in the Norwegian Mother and Child Cohort Study

    Science.gov (United States)

    Longnecker, Matthew P.; Aase, Heidi; Eggesbø, Merete; Zeiner, Pål; Reichborn-Kjennerud, Ted; Knudsen, Gun P.; Bertelsen, Randi J.; Ye, Xiaoyun; Calafat, Antonia M.; Engel, Stephanie M.

    2015-01-01

    Background Exposures to environmental phenols and parabens may be harmful, especially in utero. Prior studies have demonstrated high within-person variability of urinary concentrations across pregnancy. Objectives We sought to measure phenol and paraben biomarker concentrations for the Norwegian Mother and Child Cohort (MoBa) study, assess within-person variability, and investigate any possible external phenol or paraben contamination of specimens. Methods We collected three spot urine samples at approximately 17, 23, and 29 weeks gestation in a hospital setting and added a preservative containing ethyl paraben. We measured urinary concentrations and within-person variability for phenols and parabens in a MoBa sample (n = 45), including a subgroup of 15 participants previously randomly selected for a bisphenol A (BPA) exposure study who had unusually high total BPA concentrations. Additionally, we compared reliability results for total, conjugated, and free concentrations of phenolic compounds. Results We detected total and free BPA, butyl paraben, propyl paraben, and methyl paraben in 100% of samples, total benzophenone-3 in 95% of samples, and infrequently detected free benzophenone-3 and total and free 2,4-dichlorophenol and 2,5-dichlorophenol. Intraclass correlation coefficients (ICCs) for total, conjugated, and free concentrations ranged from relatively low for BPA to moderate for propyl paraben. ICCs were generally similar overall and by subgroup. Conclusions Using conjugated concentrations improved reliability estimates only for BPA. Measuring total and free concentrations, an approach that may be useful for future studies, allowed us to identify likely BPA and butyl paraben contamination of archived MoBa urine specimens. Citation Guidry VT, Longnecker MP, Aase H, Eggesbø M, Zeiner P, Reichborn-Kjennerud T, Knudsen GP, Bertelsen RJ, Ye X, Calafat AM, Engel SM. 2015. Measurement of total and free urinary phenol and paraben concentrations over the course of

  13. Full Scan MS in Comprehensive Qualitative and Quantitative Residue Analysis in Food and Feed Matrices: How Much Resolving Power is Required?

    NARCIS (Netherlands)

    Kellmann, M.; Muenster, H.; Zomer, P.; Mol, J.G.J.

    2009-01-01

    In LC full scan based MS screening methods correct mass assignment is essential. Parameters affecting the accuracy of mass assignment, i.e., analyte concentration, complexity of the matrix, and resolving power, were studied using typical examples from the field of residue and contaminant analysis in

  14. Erythromycin residue in honey from the Southern Marmara region of Turkey.

    Science.gov (United States)

    Gunes, Nazmiye; Cibik, Recep; Gunes, Mesut Ertan; Aydin, Levent

    2008-11-01

    Honey samples, collected from the Southern Marmara region of Turkey, were analysed for erythromycin residues by liquid chromatography-mass spectrometry using electrospray ionization in the positive ion mode (LC-ESI-MS). Fifty samples, comprising chestnut, pine, linden and multi-flower honeys, were collected directly from hives and analyzed. The limit of detection and quantification were 6 and 20 ng g(-1), respectively, and recovery ranged from 85 to 89%. Four of the honey samples (8%) were found to be contaminated with erythromycin residues at concentrations ranging from 50 to 1776 ng g(-1). An erythromycin-fortified cake feeding assay was also performed in a defined hive to test the transfer of erythromycin residue to the honey matrix. In this test hive, the residue level in the honey, 3 months after dosing, was approximately 28 ng g(-1).

  15. Petroleum hydrocarbon contaminations in the intertidal seawater after the Hebei Spirit oil spill--effect of tidal cycle on the TPH concentrations and the chromatographic characterization of seawater extracts.

    Science.gov (United States)

    Kim, Moonkoo; Hong, Sang Hee; Won, Jongho; Yim, Un Hyuk; Jung, Jee-Hyun; Ha, Sung Yong; An, Joon Geon; Joo, Changkyu; Kim, Eunsic; Han, Gi Myung; Baek, Seongho; Choi, Hyun-Woo; Shim, Won Joon

    2013-02-01

    In December 2007, the oil tanker Hebei Spirit released approximately 12,547,000 L of crude oil off the west coast of Korea, impacting more than 375 km of coastline. The seawater TPH concentrations immediately after the spill ranged from 1.5 to 7310 μg L⁻¹, with an average of 732 μg L⁻¹. The concentrations appeared to decrease drastically to 2.0-224 μg L⁻¹ in one month after the spill. The TPH concentrations in seawater fluctuated with time thereafter because of the remobilization of oil by continuing shoreline cleanup activities and subsequent wave/tidal actions. Seawater TPH concentrations were much higher during high tide than during low tide due to the resuspension of stranded oil. The variation of TPH levels in seawater also matched the spring-neap tidal cycle in the study areas for the first three weeks of the study. Comparisons of the gas chromatograms of the seawater with the water accommodated fraction and the cargo oil indicated that seawater samples were contaminated mainly by the dispersed droplets of spilled oil. One year of monitoring revealed that the oil content in seawater had clearly decreased at most sites, although some regional fluctuations of oil contamination were noted until June 2008. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Evaluation of chlorine dioxide gas residues on selected food produce.

    Science.gov (United States)

    Trinetta, Valentina; Vaidya, Nirupama; Linton, Richard; Morgan, Mark

    2011-01-01

    In recent years, the consumption of fresh fruits and vegetables has greatly increased, and so has its association with contamination of several foodborne pathogens (Listeria, Salmonella, and Escherichia coli). Hence, there is a need to investigate effective sanitizer systems for produce decontamination. Chlorine dioxide (ClO(2)), a strong oxidizing gas with broad spectrum and sanitizing properties, has previously been studied for use on selected fruits and vegetables. ClO(2) gas treatments show great potential for surface pathogen reduction; however its use from a residue safety standpoint has yet to be assessed. Thus, the objective of this study was to evaluate residues of ClO(2), chlorite, chlorate, and chloride on selected fresh produce surfaces after treatment with ClO(2) gas. A rinse procedure was used and water samples were analyzed by N, N-diethyl-p-phenylenediamine and ion chromatography method (300.0). Seven different foods--tomatoes, oranges, apples, strawberries, lettuce, alfalfa sprouts, and cantaloupe--were analyzed after ClO(2) treatment for surface residues. Very low residues were detectable for all the food products except lettuce and alfalfa sprouts, where the measured concentrations were significantly higher. Chlorine dioxide technology leaves minimal to no detectable chemical residues in several food products, thus result in no significant risks to consumers. Practical Application: Potential for chlorine dioxide gas treatments as an effective pathogen inactivation technology to produce with minimal risk for consumers.

  17. Pesticide residues in four rivers running through an intensive ...

    African Journals Online (AJOL)

    Pesticide residues in four rivers running through an intensive agricultural area, Kilimanjaro, Tanzania. ... pesticide contamination as the rivers are important sources of domestic water in the area. Water samples were extracted ... JASEM. Keywords: Pesticide residues, Surface water, Sediment, Environmental contamination ...

  18. Trace metals in antifouling paint particles and their heterogeneous contamination of coastal sediments

    International Nuclear Information System (INIS)

    Singh, Nimisha; Turner, Andrew

    2009-01-01

    Antifouling paint residues collected from the hard-standings of a marine leisure boat facility have been chemically characterised. Scanning electron microscopy revealed distinct layers, many containing oxidic particles of Cu and Zn. Quantitative analysis indicated concentrations of Cu and Zn averaging about 300 and 100 mg g -1 , respectively, and small proportions of these metals ( -1 , respectively. Estuarine sediment collected near a boatyard contained concentrations of Cu and Zn an order of magnitude greater than respective concentrations in 'background' sediment, and mass balance calculations suggested that the former sample was contaminated by about 1% by weight of paint particles. Clearly, antifouling residues represent a highly significant, heterogeneous source of metallic contamination in the marine environment where boating activities occur.

  19. Selenium concentrations in the razorback sucker (Xyrauchen texanus): Substitution of non-lethal muscle plugs for muscle tissue in contaminant assessment

    Science.gov (United States)

    Waddell, B.; May, T.

    1995-01-01

    A single muscle plug was collected from each of 25 live razorback suckers inhabiting the Colorado River basin and analyzed for selenium by instrumental neutron activation. Eight fish from Ashley Creek and three from Razorback Bar exhibited selenium concentrations exceeding 8 μg/g, a level associated with reproductive failure in fish. Concentrations of selenium in eggs and milt were significantly correlated with selenium concentrations in muscle plugs and together indicate a possible explanation for the decline of this species in the Colorado River basin. Muscle plugs (<50mg) and muscle tissue (20 g) were collected from dorsal, anterior, and posterior areas of common carp, flannelmouth sucker, and an archived razorback sucker and analyzed for selenium. Concentrations of selenium in muscle plugs were significantly correlated with selenium concentrations in muscle tissue from the same location and fish (r=0.97). Coefficients of variation for selenium concentrations in each fish were <6.5% for muscle tissue, but ranged from 1.5 to 32.4% for muscle plugs. Increased variation in muscle plugs was attributed to lower selenium concentrations found in the anterior muscle plugs of flannelmouth suckers. Mean selenium concentrations in muscle plugs and tissue from dorsal and posterior areas and muscle tissue from the anterior area were not significantly different. The non-lethal collection of a muscle plug from dorsal and posterior areas of the razorback sucker and other fish species may provide an accurate assessment of selenium concentrations that exist in adjacent muscle tissue.

  20. Integrating Individual-Based Indices of Contaminant Effects

    Directory of Open Access Journals (Sweden)

    Christopher L. Rowe

    2001-01-01

    Full Text Available Habitat contamination can alter numerous biological processes in individual organisms. Examining multiple individual-level responses in an integrative fashion is necessary to understand how individual health or fitness reflects environmental contamination. Here we provide an example of such an integrated perspective based upon recent studies of an amphibian (the bullfrog, Rana catesbeiana that experiences several, disparate changes when larval development occurs in a trace element�contaminated habitat. First, we present an overview of studies focused on specific responses of individuals collected from, or transplanted into, a habitat contaminated by coal combustion residues (CCR. These studies have reported morphological, behavioral, and physiological modifications to individuals chronically interacting with sediments in the CCR-contaminated site. Morphological abnormalities in the oral and tail regions in contaminant-exposed individuals influenced other properties such as grazing, growth, and swimming performance. Behavioral changes in swimming activities and responses to stimuli appear to influence predation risk in the contaminant-exposed population. Significant changes in bioenergetics in the contaminated habitat, evident as abnormally high energetic expenditures for survival (maintenance costs, may ultimately influence production pathways (growth, energy storage in individuals. We then present a conceptual model to examine how interactions among the affected systems (morphological, behavioral, physiological may ultimately bring about more severe effects than would be predicted if the responses were considered in isolation. A complex interplay among simultaneously occurring biological changes emerges in which multiple, sublethal effects ultimately can translate into reductions in larval or juvenile survival, and thus reduced recruitment of juveniles into the population. In systems where individuals are exposed to low concentrations of

  1. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  2. Snapping Turtles (Chelydra serpentina) from Canadian Areas of Concern across the southern Laurentian Great Lakes: Chlorinated and brominated hydrocarbon contaminants and metabolites in relation to circulating concentrations of thyroxine and vitamin A.

    Science.gov (United States)

    Letcher, Robert J; Lu, Zhe; de Solla, Shane R; Sandau, Courtney D; Fernie, Kimberly J

    2015-11-01

    The metabolites of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), as well as other halogenated phenolic contaminants (HPCs) have been shown to have endocrine-disrupting properties, and have been reported with increasing frequency in the blood of wildlife, and mainly in mammals and birds. However, little is known about the persistence, accumulation and distribution of these contaminants in long-lived freshwater reptiles. In the present study, in addition to a large suite of chlorinated and brominated contaminants, metabolites and HPCs, we assessed and compared hydroxylated (OH) PCBs and OH-PBDEs relative to PCBs and PBDEs, respectively, in the plasma of adult male common snapping turtles (Chelydra serpentina). Blood samples were collected from 62 snapping turtles (2001-2004) at 12 wetland sites between the Detroit River and the St. Lawrence River on the Canadian side of the Laurentian Great Lakes of North America. Turtles were sampled from sites designated as Areas of Concern (AOCs) and from a relatively clean reference site in southern Georgian Bay (Tiny Marsh), Lake Huron. Plasma concentrations of Σ46PCB (10-340 ng/g wet weight (ww)) and Σ28OH-PCB (3-83 ng/g ww) were significantly greater (pturtles from the Turkey Creek and Muddy Creek-Wheatley Harbour sites in Lake Erie compared with the reference site turtles. The HPC, pentachlorophenol (PCP), had a mean concentration of 9.6±1.1 ng/g ww. Of the 28 OH-CB congeners screened for, 4-OH-CB187 (42±7 ng/g ww) was the most concentrated of all HPCs measured. Of the 14 OH-BDE congeners examined, four (4'-OH-BDE17, 3-OH-BDE47, 5-OH-BDE47 and 4'-OH-BDE49) were consistently found in all plasma samples. p,p'-DDE was the most concentrated of the 18 organochlorine pesticides (OCPs) examined. The mean concentrations of circulating total thyroxine (TT4), dehydroretinol and retinol in the plasma of the male snapping turtles regardless of sampling site were 5.4±0.3, 81±4.7 and 291±13 ng

  3. Environmental contaminants in great blue herons (Ardea herodias) from the lower Columbia and Willamette Rivers, Oregon and Washington, USA