Effect of the addition of wheat bran stream on dough rheology and bread quality

Directory of Open Access Journals (Sweden)

Iuliana Banu

2012-08-01

Full Text Available The milling by-products have high nutritional value and can be incorporated into white flour. This study was aimed at comparatively examining the rheological behaviour of the doughs made from wheat white flour with different levels (3-30% of bran streams incorporated and from wholewheat. The results indicated significant correlations between the ash content of the wheat bran streams incorporated into flour and Alveograph, Rheofermentograph and Mixolab parameters. The white flour sample with 25% wheat bran streams had the ash content similar to wholewheat, but the dough rheology was improved. The quality of the white flour bread with 25% wheat bran streams was improved compared to the wholemeal bread.

Experience in the radiometric on-line determination of the ash content of raw lignite at the Hagenwerder power station

International Nuclear Information System (INIS)

Koerner, G.; Leonhardt, J.; Thuemmel, H.W.; Fritzsche, D.

1986-01-01

For power station feed control an ash monitoring system has been working for one year. It comprises a by-pass sampling system including the scatter-transmission ash gauge KRAS-1 (total error 3.8 weight percentage ash on dry basis) which is used for calibrating the non-contact on-stream computer-controlled ash gauge KRAS-2 based on the 2-energy transmission method (total error 4.5 weight percentage ash on dry basis). The economic benefit is estimated to 1.4 million Mark per year. (author)

Temporal and spatial variations in fly ash quality

Science.gov (United States)

Hower, J.C.; Trimble, A.S.; Eble, C.F.

2001-01-01

Fly ash quality, both as the amount of petrographically distinguishable carbons and in chemistry, varies in both time and space. Temporal variations are a function of a number of variables. Variables can include variations in the coal blend organic petrography, mineralogy, and chemistry; variations in the pulverization of the coal, both as a function of the coal's Hardgrove grindability index and as a function of the maintenance and settings of the pulverizers; and variations in the operating conditions of the boiler, including changes in the pollution control system. Spatial variation, as an instantaneous measure of fly ash characteristics, should not involve changes in the first two sets of variables listed above. Spatial variations are a function of the gas flow within the boiler and ducts, certain flow conditions leading to a tendency for segregation of the less-dense carbons in one portion of the gas stream. Caution must be applied in sampling fly ash. Samples from a single bin, or series of bins, m ay not be representative of the whole fly ash, providing a biased view of the nature of the material. Further, it is generally not possible to be certain about variation until the analysis of the ash is complete. ?? 2001 Elsevier Science B.V. All rights reserved.

Stream sediment sampling and analysis. Final report

International Nuclear Information System (INIS)

Means, J.L.; Voris, P.V.; Headington, G.L.

1986-04-01

The objectives were to sample and analyze sediments from upstream and downstream locations (relative to the Goodyear Atomic plant site) of three streams for selected pollutants. The three streams sampled were the Scioto River, Big Beaver Creek, and Big Run Creek. Sediment samples were analyzed for EPA's 129 priority pollutants (Clean Water Act) as well as isotopic uranium ( 234 U, 235 U, and 238 U) and technetium-99

Particulate hot gas stream cleanup technical issues

Energy Technology Data Exchange (ETDEWEB)

Pontius, D.H.; Snyder, T.R.

1999-09-30

The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: A study of archived basaltic to rhyolitic ash samples

Science.gov (United States)

Damby, David; Horwell, Claire J.; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

2017-01-01

BackgroundThe eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland’s volcanoes to Icelandic and Northern European populations. MethodsA physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. ResultsIcelandic ash can be of a respirable size (up to 11.3 vol.% < 4 μm), but the samples did not display physicochemical characteristics of pathogenic particulate in terms of composition or morphology. Ash particles were generally angular, being composed of fragmented glass and crystals. Few fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m2 g−1, which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO•), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after ‘refreshing’ sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m−2, with mafic samples releasing more iron

Ash-forming elements in four Scandinavian wood species part 3: Combustion of five spruce samples

Energy Technology Data Exchange (ETDEWEB)

Werkelin, Johan; Lindberg, Daniel; Skrifvars, Bengt-Johan; Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Piispankatu 8, FI-20500 Turku (Finland); Bostroem, Dan [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden)

2011-01-15

Forest residue is the remaining fraction after the outtake of timber, which comprises the tree tops and branches. It may as fuel cause damage to the combustion device through ash slagging and fouling. The objective of this work was to model the ash composition from well-specified samples of a spruce tree: wood, bark, twigs, needles, and shoots. Their ash at 1000 C was modelled using global chemical equilibrium calculations, and laboratory-made ash of the five samples was analyzed by XRD and SEM-EDXA. According to the results, the risk of slagging arises from the spruce foliage: molten alkali silicates from spruce needles and probably molten alkali phosphates from spruce shoots may cause problems in the furnace. Fouling caused by condensing alkali vapours can be produced by all five samples. The amount of alkali vapours in the flue gas was in the same order of magnitude for all five samples, in spite of large differences in their original alkali contents. (author)

Analysis of cement solidified product and ash samples and preparation of a reference material

International Nuclear Information System (INIS)

Ishimori, Ken-ichiro; Haraga, Tomoko; Shimada, Asako; Kameo, Yutaka; Takahashi, Kuniaki

2010-08-01

Simple and rapid analytical methods for radionuclides in low-level radioactive waste have been developed by the present authors. The methods were applied to simulated solidified products and actual metal wastes to confirm their usefulness. The results were summarized as analytical guide lines. In the present work, cement solidified product and ash waste were analyzed followed by the analytical guide lines and subjects were picked up and solved for the application of the analytical guide lines to these wastes. Pulverization and homogenization method for ash waste was improved to prevent a contamination since the radioactivity concentrations of the ash samples were relatively high. Pre-treatment method was altered for the cement solidified product and ash samples taking account for their high concentration of Ca. Newly, an analytical method was also developed to measure 129 I with a dynamic reaction cell inductively coupled plasma mass spectrometer. In the analytical test based on the improved guide lines, gamma-ray emitting nuclides, 60 Co and 137 Cs, were measured to estimate the radioactivity of the other alpha and beta-ray emitting nuclides. The radionuclides assumed detectable, 3 H, 14 C, 36 Cl, 63 Ni, 90 Sr, and alpha-ray emitting nuclides, were analyzed with the improved analytical guide lines and their applicability for cement solidified product and ash samples were confirmed. Additionally a cement solidified product sample was evaluated in terms of the homogeneity and the radioactivity concentrations in order to prepare a reference material for radiochemical analysis. (author)

Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: a study of archived basaltic to rhyolitic ash samples.

Science.gov (United States)

Damby, David E; Horwell, Claire J; Larsen, Gudrun; Thordarson, Thorvaldur; Tomatis, Maura; Fubini, Bice; Donaldson, Ken

2017-09-11

The eruptions of Eyjafjallajökull (2010) and Grímsvötn (2011), Iceland, triggered immediate, international consideration of the respiratory health hazard of inhaling volcanic ash, and prompted the need to estimate the potential hazard posed by future eruptions of Iceland's volcanoes to Icelandic and Northern European populations. A physicochemical characterization and toxicological assessment was conducted on a suite of archived ash samples spanning the spectrum of past eruptions (basaltic to rhyolitic magmatic composition) of Icelandic volcanoes following a protocol specifically designed by the International Volcanic Health Hazard Network. Icelandic ash can be of a respirable size (up to 11.3 vol.% fiber-like particles were observed, but those present comprised glass or sodium oxides, and are not related to pathogenic natural fibers, like asbestos or fibrous zeolites, thereby limiting concern of associated respiratory diseases. None of the samples contained cristobalite or tridymite, and only one sample contained quartz, minerals of interest due to the potential to cause silicosis. Sample surface areas are low, ranging from 0.4 to 1.6 m 2  g -1 , which aligns with analyses on ash from other eruptions worldwide. All samples generated a low level of hydroxyl radicals (HO • ), a measure of surface reactivity, through the iron-catalyzed Fenton reaction compared to concurrently analyzed comparative samples. However, radical generation increased after 'refreshing' sample surfaces, indicating that newly erupted samples may display higher reactivity. A composition-dependent range of available surface iron was measured after a 7-day incubation, from 22.5 to 315.7 μmol m -2 , with mafic samples releasing more iron than silicic samples. All samples were non-reactive in a test of red blood cell-membrane damage. The primary particle-specific concern is the potential for future eruptions of Iceland's volcanoes to generate fine, respirable material and, thus, to

Physical and chemical characterization of fly ashes from Swiss waste incineration plants and determination of the ash fraction in the nanometer range.

Science.gov (United States)

Buha, Jelena; Mueller, Nicole; Nowack, Bernd; Ulrich, Andrea; Losert, Sabrina; Wang, Jing

2014-05-06

Waste incineration had been identified as an important source of ultrafine air pollutants resulting in elaborated treatment systems for exhaust air. Nowadays, these systems are able to remove almost all ultrafine particles. However, the fate of ultrafine particles caught in the filters has received little attention so far. Based on the use of engineered nano-objects (ENO) and their transfer into the waste stream, it can be expected that not only combustion generated nanoparticles are found in fly ashes but that many ENO finally end up in this matrix. A more detailed characterization of the nanoparticulate fraction of fly ashes is therefore needed. Physical and chemical characterizations were performed for fly ashes from five selected waste incineration plants (WIPs) with different input materials such as municipal waste, wood and sewage sludge. The intrinsic densities of the fly ashes were in the range of 2.7-3.2 g/cm(3). When the fly ash particle became airborne, the effective density depended on the particle size, increasing from 0.7-0.8 g/cm(3) for 100-150 nm to 2 g/cm(3) for 350-500 nm. The fly ash samples were fractionated at 2 μm, yielding fine fractions (2 μm). The size distributions of the fine fractions in the airborne form were further characterized, which allowed calculation of the percentage of the fly ash particles below 100 nm. We found the highest mass-based percentage was about 0.07%; the number percentage in the fine fraction was in the range of 4.8% to 22%. Comparison with modeling results showed that ENO may constitute a considerable part of the fly ash particles below 100 nm. Chemical analyses showed that for the municipal waste samples Ca and Al were present in higher concentrations in the coarse fraction; for the mixed wood and sludge sample the P concentration was higher in the coarse fraction; for most other samples and elements they were enriched in the fine fraction. Electron microscopic images of fly ashes showed a wide range of

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

Science.gov (United States)

Frankforter, J.D.; Weyers, H.S.; Bales, J.D.; Moran, P.W.; Calhoun, D.L.

2010-01-01

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r 2 = 0.79-0.91) and CR-24 (r 2 = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP. ?? 2009 The Author(s).

Neotropical Amphibian Declines Affect Stream Ecosystem Properties

Science.gov (United States)

Connelly, S.; Pringle, C. M.; Bixby, R. J.; Whiles, M. R.; Lips, K. R.; Brenes, R.; Colon-Gaud, J. C.; Kilham, S.; Hunte-Brown, M.

2005-05-01

Global declines of amphibians are well documented, yet effects of these dramatic losses on ecosystem structure and function are poorly understood. As part of a larger collaborative project, we compared two upland Panamanian streams. Both streams are biologically and geologically similar; however, one stream (Fortuna) has recently experienced almost complete extirpation of stream-dwelling frogs, while the other (Cope) still has intact populations. We experimentally excluded tadpoles from localized areas in each stream. We then compared chlorophyll a, algal community composition, ash-free dry mass (AFDM), inorganic matter, and insect assemblages in control and exclusion areas. Additionally, we sampled the natural substrate of both streams monthly for chlorophyll a, algal community composition, AFDM, and inorganic matter. At Cope, chlorophyll a, AFDM, and inorganic matter were greater in areas where tadpoles were excluded than in their presence. Numbers of dominant algal species (e.g., Nupela praecipua and Eunotia siolii) were greater in the exclusion versus control treatments. Monthly sampling of natural substrate indicated higher chlorophyll a and AFDM at Cope compared to Fortuna. Our data suggest that stream-dwelling anuran larvae have significant impacts on algal communities. These results also have implications for predicting the relevance of short-term experimental manipulations to long-term, whole-stream processes.

Total lead (Pb) concentration in oil shale ash samples based on correlation to isotope Pb-210 gamma-spectrometric measurements

Energy Technology Data Exchange (ETDEWEB)

Vaasma, T.; Kiisk, M.; Tkaczyk, A.H. [University of Tartu (Estonia); Bitjukova, L. [Tallinn University of Technology (Estonia)

2014-07-01

Estonian oil shale consists of organic matter and mineral material and contains various amounts of heavy metals as well as natural radionuclides (from the U-238 and Th-232 series and K-40). Previous research has shown that burning oil shale in the large power plants causes these radionuclides to become enriched in different ash fractions and be partially emitted to the atmosphere via fly ash and flue gases. The activity concentrations (Bq/kg) of these nuclides in different oil shale ash fractions vary significantly. This is influenced by the boiler parameters and combustion conditions - prevailing temperatures, pressure, ash circulating mechanisms, fly ash particle size, chemical composition of ash and coexistence of macro and micro components. As with radionuclides, various heavy metals remain concentrated in the ash fractions and are released to the atmosphere (over 20 tons of Pb per year from Estonian oil shale power plants). Lead is a heavy metal with toxic influence on the nervous system, reproductive system and different organs in human body. Depending on the exposure pathways, lead could pose a long term health hazard. Ash samples are highly heterogeneous and exhibit great variability in composition and particle size. Determining the lead concentration in ash samples by modern methods like inductively coupled plasma mass spectroscopy (ICP-MS), flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectroscopy (GFAAS) and other techniques often requires time consuming, multistage and complex chemical sample preparation. The list of possible methods to use is lengthy, but it is a challenge to choose a suitable one to meet measurement needs and practical considerations. The detection limits, capital costs and maintenance expenses vary between the instruments. This work presents the development of an alternative measurement technique for our oil shale ash samples. Oil shale ash was collected from different boilers using pulverized fuel

Sampling methods for amphibians in streams in the Pacific Northwest.

Science.gov (United States)

R. Bruce Bury; Paul Stephen. Corn

1991-01-01

Methods describing how to sample aquatic and semiaquatic amphibians in small streams and headwater habitats in the Pacific Northwest are presented. We developed a technique that samples 10-meter stretches of selected streams, which was adequate to detect presence or absence of amphibian species and provided sample sizes statistically sufficient to compare abundance of...

Cementation and solidification of Rocky Flats Plant incinerator ash

International Nuclear Information System (INIS)

Phillips, J.A.; Semones, G.B.

1994-01-01

Cementation studies on various aqueous waste streams at Rocky Flats have shown this technology to be effective for immobilizing the RCRA constituents in the waste. Cementation is also being evaluated for encapsulation of incinerator ash. Experiments will initially evaluate a surrogate ash waste using a Taguchi experimental design to optimize the cement formulation and waste loading levels for this application. Variables of waste loading, fly ash additions, water/cement ratio, and cement type will be tested at three levels each during the course of this work. Tests will finally be conducted on actual waste using the optimized cement formulation developed from this testing. This progression of tests will evaluate the effectiveness of cement encapsulation for this waste stream without generating any additional wastes

Particulate hot gas stream cleanup technical issues

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep

Radioactivity of wood ash

International Nuclear Information System (INIS)

Rantavaara, A.; Moring, M.

2000-01-01

STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg -1 , in decreasing order: 137 Cs, 40 K, 90 Sr, 210 Pb, 226 Ra, 232 Th, 134 Cs, 235 U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and 210 Pb was hardly detectable. The NH 4 Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

Evaluation of radioactivity levels of coal, slag and fly ash samples used in Giresun province of Turkey

International Nuclear Information System (INIS)

Kara, A.; Chevik, U.; Damla, N.; Yeshilbag, Y.O.

2010-01-01

In present work natural radionuclides activities (236Ra, 232Th and 40K) of the different types of coal, slag and fly ash samples used in Giresun province (Eastern Black Sea region of Turkey) were measured by using gamma-ray spectrometry. These samples were collected as homogeneously and separately around Giresun province. The mean activity concentrations of 226Ra, 232Th and 40K radionuclides in coal, slag and fly ash samples were found as 107, 67 and 440 Bg.Kg - 1 for coal; 59, 25 and 268 Bg.kg - 1 for slag and 136, 60 and 417 Bg.kg - 1 for fly ash samples, respectively. To estimate health effect due to the aforementioned radionuclides, absorbed dose rates and annual effective doses have been calculated. These values were evaluated and compared with the internationally recommended values

Evaluation of environmental stress imposed by a coal-ash effluent: Wisconsin power plant impact study

Energy Technology Data Exchange (ETDEWEB)

Webster, K.E.; Forbes, A.M.; Magnuson, J.L.

1985-06-01

Effluent discharged from the coal-ash settling basin of the Columbia Generating Station (Wisconsin) modified water chemistry (increased trace metal concentrations, suspended solids and dissolved materials) and substrate quality (precipitation of chemical floc) in the receiving stream, the ash pit drain. To test the hypothesis that habitat avoidance could account for declines in macroinvertebrate density observed after discharge began, drift rates of two species were measured in laboratory streams containing combinations of reference and coal-ash-modified substrate and water. Contrary to the hypothesis, drift was uniformly lower in laboratory streams containing modified substrate and/or water compared to the reference condition for Gammarus pseudolimnaeus and Asellus racovitzai.

High temperature co-treatment of bottom ash and stabilized fly ashes from waste incineration

DEFF Research Database (Denmark)

Sørensen, Mette Abildgaard; Mogensen, E.P.B.; Lundtorp, Kasper

2001-01-01

Bottom ashes from two Danish municipal solid waste incineration plants were heated at 900 degreesC with iron oxide stabilized air pollution control residues at actual mass flow ratios (9:1), simulating a treating method for the residues. The two residues were cotreated, producing one combined...... ashes. The process, thus, fixates the metals in the solid residues without altering the leaching properties of the bottom ash too significantly. (C) 2001 Elsevier Science Ltd. All rights reserved....... stream that may be utilized as a secondary road construction material. Scanning electron microscope analysis and grain size distribution analysis indicated that sintering of the particles did not occur. Batch leaching tests at liquid/solid 10 I/kg at a range of pH-values (6-10) quantified with respect...

Exploring evaluation to influence the quality of pulverized coal fly ash. Co-firing of biomass in a pulverized coal plant or mixing of biomass ashes with pulverized coal fly ash; Verkennende evaluatie kwaliteitsbeinvloeding poederkoolvliegas. Bijstoken van biomassa in een poederkoolcentrale of bijmenging van biomassa-assen met poederkoolvliegas

Energy Technology Data Exchange (ETDEWEB)

Van der Sloot, H.A.; Cnubben, P.A.J.P [ECN Schoon Fossiel, Petten (Netherlands)

2000-08-01

In this literature survey the consequences of co-firing of biomass and mixing of biomass ash with coal fly ash on the coal fly ash quality is evaluated. Biomass ash considered in this context is produced by gasification, pyrolysis or combustion in a fluidized bed. The irregular shape of biomass ash obtained from gasification, pyrolysis or combustion has a negative influence on the water demand in concrete applications of the coal fly ash resulting from mixing biomass ash and coal fly ash. In case of co-firing, high concentrations of elements capable of lowering the ash melting point (e.g., Ca and Mg) may lead to more ash agglomeration. This leads to a less favourable particle size distribution of the coal fly ash, which has a negative impact on the water demand in cement bound applications. Gasification, pyrolysis and combustion may lead to significant unburnt carbon levels (>10%). The unburnt carbon generally absorbs water and thus has a negative influence on the water demand in cement-bound applications. The contribution of biomass ash to the composition of coal fly ash will not be significantly different, whether the biomass is co-fired or whether the biomass ash is mixed off-line with coal fly ash. The limit values for Cl, SO4 and soluble salts can form a limitation for the use of coal fly ash containing biomass for cement-bound applications. As side effects of biomass co-firing, the level of constituents such as Na, K, Ca and Mg may lead to slagging and fouling of the boiler. In addition, a higher emission of flue gas contaminants As, Hg, F, Cl and Br may be anticipated in case more contaminated biomass streams are applied. This may also lead to a higher contamination level of gypsum produced from flue gas cleaning residues. Relatively clean biomass streams (clean wood, cacao shells, etc.) will hardly lead to critical levels of elements from a leaching point of view. More contaminated streams, such as sewage sludge, used and preserved wood, petcoke and RDF

Determination of mercury in ash and soil samples by oxygen flask combustion method-Cold vapor atomic fluorescence spectrometry (CVAFS)

International Nuclear Information System (INIS)

Geng Wenhua; Nakajima, Tsunenori; Takanashi, Hirokazu; Ohki, Akira

2008-01-01

A simple method was developed for the determination of mercury (Hg) in coal fly ash (CFA), waste incineration ash (WIA), and soil by use of oxygen flask combustion (OFC) followed by cold vapor atomic fluorescence spectrometry (CVAFS). A KMnO 4 solution was used as an absorbent in the OFC method, and the sample containing a combustion agent and an ash or soil sample was combusted by the OFC method. By use of Hg-free graphite as the combustion agent, the determination of Hg in ash and soil was successfully carried out; the Hg-free graphite was prepared by use of a mild pyrolysis procedure at 500 deg. C. For six certified reference materials (three CFA samples and three soil samples), the values of Hg obtained by this method were in good agreement with the certified or reference values. In addition, real samples including nine CFAs collected from some coal-fired power plants, five WIAs collected from waste incineration plants, and two soils were analyzed by the present method, and the data were compared to those from microwave-acid digestion (MW-AD) method

Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents - 1. Hematological and population level assessment

Energy Technology Data Exchange (ETDEWEB)

Lohner, T.W.; Reash, R.J.; Willet, V.E.; Rose, L.A. [American Electrical Power Co., Columbus, OH (United States). Environmental Services Dept.

2001-07-01

Sunfish were collected from coal ash effluent-receiving streams and Ohio River watershed reference sites to assess the effects of exposure to low-level selenium concentrations. Selenium, copper, and arsenic concentrations were statistically higher in tissue samples from exposed fish than in reference fish. Leukopenia, lymphocytosis, and neutropenia were evident in exposed fish and were indicative of metal exposure and effect. White blood cell counts and percent lymphocyte values were significantly correlated with liver selenium concentrations. Plasma protein levels were significantly lower in exposed fish than in fish from the Ohio River, indicating that exposed fish may have been nutritionally stressed. Condition factors for fish from the ash pond-receiving streams were the same as, or lower than, those of fish from the reference sites. There was no evidence that the growth rate of fish in the receiving streams differed from that of fish in the reference streams. Despite liver selenium concentrations which exceeded reported toxicity thresholds and evidence of significant hematological changes, there were no significant differences in fish condition factors, liver-somatic indices, or length-weight regressions related to selenium.

Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

Science.gov (United States)

Eckels, David E.; Hass, William J.

1989-05-30

A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

Science.gov (United States)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

Disc valve for sampling erosive process streams

Science.gov (United States)

Mrochek, J.E.; Dinsmore, S.R.; Chandler, E.W.

1986-01-07

A four-port disc valve is described for sampling erosive, high temperature process streams. A rotatable disc defining opposed first and second sampling cavities rotates between fired faceplates defining flow passageways positioned to be alternatively in axial alignment with the first and second cavities. Silicon carbide inserts and liners composed of [alpha] silicon carbide are provided in the faceplates and in the sampling cavities to limit erosion while providing lubricity for a smooth and precise operation when used under harsh process conditions. 1 fig.

Particulate hot gas stream cleanup technical issues

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

This is the eleventh in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task 1 is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task 1 during the past quarter, analyses were completed on samples obtained during a site visit to the Power Systems Development Facility (PSDF). Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. An additional analysis was performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. A manuscript and poster were prepared for presentation at the Advanced Coal-Based Power and Environmental Systems `97 Conference scheduled for July 22 - 24, 1997. A summary of recent project work covering the mechanisms responsible for ash deposit consolidation and ash bridging in APF`s collecting PFB ash was prepared and presented at FETC-MGN in early July. The material presented at that meeting is included in the manuscript prepared for the Contractor`s Conference and also in this report. Task 2 work during the past quarter included mechanical testing and microstructural examination of Schumacher FT20 and Pall 326 as- manufactured, after 540 hr in service at Karhula, and after 1166 hr in service at

Ash Dieback on Sample Points of the National Forest Inventory in South-Western Germany

Directory of Open Access Journals (Sweden)

Rasmus Enderle

2018-01-01

Full Text Available The alien invasive pathogen Hymenoscyphus fraxineus causes large-scale decline of European ash (Fraxinus excelsior. We assessed ash dieback in Germany and identified factors that were associated with this disease. Our assessment was based on a 2015 sampling of national forest inventory plots that represent a supra-regional area. In the time from 2012 to 2015, the number of regrown ash trees corresponded to only 42% of the number of trees that had been harvested or died. Severe defoliation was recorded for almost 40% of the living trees in 2015, and more than half of the crowns mainly consisted of epicormic shoots. Necroses were present in 24% of root collars. A total of 14% of the trees were in sound condition, which sum up to only 7% of the timber volume. On average, trees of a higher social status or with a larger diameter at breast height were healthier. Collar necroses were less prevalent at sites with a higher inclination of terrain, but there was no evidence for an influence of climatic variables on collar necroses. The disease was less severe at sites with smaller proportions of the basal area of ash compared to the total basal area of all trees and in the north-eastern part of the area of investigation. The regeneration of ash decreased drastically.

Results of Macroinvertebrate Sampling Conducted at 33 SRS Stream Locations, July--August 1993

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L.

1994-12-01

In order to assess the health of the macroinvertebrate communities of SRS streams, the macroinvertebrate communities at 30 stream locations on SRS were sampled during the summer of 1993, using Hester-Dendy multiplate samplers. In addition, three off-site locations in the Upper Three Runs drainage were sampled in order to assess the potential for impact from off-site activities. In interpreting the data, it is important to recognize that these data were from a single set of collections. Macroinvertebrate communities often undergo considerable temporal variation, and are also greatly influenced by such factors as water depth, water velocity, and available habitat. These stations were selected with the intent of developing an on-going sampling program at a smaller number of stations, with the selection of the stations to be based largely upon the results of this preliminary sampling program. When stations within a given stream showed similar results, fewer stations would be sampled in the future. Similarly, if a stream appeared to be perturbed, additional stations or chemical analyses might be added so that the source of the perturbation could be identified. In general, unperturbed streams will contain more taxa than perturbed streams, and the distribution of taxa among orders or families will differ. Some groups of macroinvertebrates, such as Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies), which are collectively called EPT taxa, are considered to be relatively sensitive to most kinds of stream perturbation; therefore a reduced number of EPT taxa generally indicates that the stream has been subject to chemical or physical stressors. In coastal plain streams, EPT taxa are generally less dominant than in streams with rocky substrates, while Chironomidae (midges) are more abundant. (Abstract Truncated)

Microwave assisted aqua regia extraction of thallium from sediment and coal fly ash samples and interference free determination by continuum source ETAAS after cloud point extraction.

Science.gov (United States)

Meeravali, Noorbasha N; Madhavi, K; Kumar, Sunil Jai

2013-01-30

A simple cloud point extraction method is described for the separation and pre-concentration of thallium from the microwave assisted aqua regia extracts of sediment and coal fly ash samples. The method is based on the formation of extractable species of thallium and its interaction with hydrophobic solubilizing sites of Triton X-114 micelles in the presence of aqua regia and electrolyte NaCl. These interactions of micelles are used for extraction of thallium from a bulk aqueous phase into a small micelles-rich phase. The potential chloride interferences are eliminated effectively, which enabled interference free determination of thallium from aqua regia extracts using continuum source ETAAS. The parameters affecting the extraction process are optimized. Under the optimized conditions, pre-concentration factor and limit of detection are 40 and 0.2 ng g(-1), respectively. The recoveries are in the range of 95-102%. A characteristic mass, 13 pg was obtained. The accuracy of the method is verified by analyzing certified reference materials such as NIST 1633b coal fly ash, NIST 1944 marine sediment and GBW 07312 stream sediments. The results obtained are in good agreement with the certified values and method is also applied to real samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Effectiveness of stream-sediment sampling along the Rio Ojo Caliente, New Mexico

International Nuclear Information System (INIS)

Wenrich-Verbeek, K.J.

1977-01-01

During 1976 a detailed geochemical study was conducted of the water and stream sediments in the tributaries of the Rio Ojo Caliente above the USGS gaging station 4 km below La Madera to determine: (1) the source of the anomaly in the water and (2) why the stream sediment samples did not contain a corresponding anomaly. The low uranium content of the stream sediments from these high uranium waters can be explained by (1) the presence of a ground water source for the uranium and (2) insufficient time for the uranium in the water to be adsorbed onto the sediments. Although a stream sediment anomaly in the streams containing high uranium waters can not be established with a size fraction less than 150 μm, enough uranium has been adsorbed by the fine fraction that a small local anomaly can be outlined using only the fraction size less than 90 μm. Thus, because adsorption appears to be a major control on the uranium in the fine fraction and detrital minerals control the uranium in the coarse fraction, if it is assumed that buried deposits are of prime importance because most surface deposits have been recognized, then sampling should be restricted to the fine fraction (less than 90 μm). Nevertheless, in a case where ground water is the contributing source for uranium, as was shown above by the low anomalous uranium values, even in the fine fraction, stream sediment sampling alone is not an effective technique for detecting uranium anomalies. This emphasizes the necessity of water sampling in conjunction with stream-sediment sampling

Analysis Of DWPF Sludge Batch 7A (Macrobatch 8) Pour Stream Samples

International Nuclear Information System (INIS)

Johnson, F.

2012-01-01

The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7a (SB7a), also referred to as Macrobatch 8 (MB8), in June 2011. SB7a is a blend of the heel of Tank 40 from Sludge Batch 6 (SB6) and the SB7a material that was transferred to Tank 40 from Tank 51. SB7a was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Three pour stream glass samples and two Melter Feed Tank (MFT) slurry samples were collected while processing SB7a. These additional samples were taken during SB7a to understand the impact of antifoam and the melter bubblers on glass redox chemistry. The samples were transferred to the Savannah River National Laboratory (SRNL) where they were analyzed. The following conclusions were drawn from the analytical results provided in this report: (1) The sum of oxides for the official SB7a pour stream glass is within the Product Composition Control System (PCCS) limits (95-105 wt%). (2) The average calculated Waste Dilution Factor (WDF) for SB7a is 2.3. In general, the measured radionuclide content of the official SB7a pour stream glass is in good agreement with the calculated values from the Tank 40 dried sludge results from the SB7a Waste Acceptance Program Specification (WAPS) sample. (3) As in previous pour stream samples, ruthenium and rhodium inclusions were detected by Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS) in the official SB7a pour stream sample. (4) The Product Consistency Test (PCT) results indicate that the official SB7a pour stream glass meets the waste acceptance criteria for durability with a normalized boron release of 0.64 g/L, which is an order of magnitude less than the Environmental

Data quality objectives for the B-Cell waste stream classification sampling

International Nuclear Information System (INIS)

Barnett, J.M.

1998-01-01

This document defines the data quality objectives, (DQOS) for sampling the B-Cell racks waste stream. The sampling effort is concentrated on determining a ratio of Cs-137 to Sr-90 and Cs-137 to transuranics (TRU). Figure 1.0 shows the logic path of sampling effort. The flow chart begins with sample and data acquisition and progresses toward (a) statistical confidence and waste classification boundaries, (b) management decisions based on the input parameters and technical methods available, and (c) grout container volume/weight limits and radiation limits. The end result will be accurately classifying the B-Cell rack waste stream

Physico-chemical characteristics of water sample from Aiba Stream ...

African Journals Online (AJOL)

This study aimed at assessing the effectiveness of solar distillation in purification of water. The water sample collected from Aiba stream was subjected to double slope solar water distillation unit. The physico- chemical characteristics of the raw sample and the distillate were determined using standard methods. The.

Managing ash from the combustion of solid waste

International Nuclear Information System (INIS)

Hauser, R.

1992-01-01

This paper reports that with millions of tons of refuse being combusted each year, increasing concern over the environment impact of the residue produced has caused both regulators and the resource recovery industry to address the technical and regulatory issues relating to the safe handling and disposal of ash. The basic issue concerning solid waste combustion ash management in this country is how, based on past, recent, and ongoing scientific research, solid waste combustion ash should be handled. Typically, refuse contains approximately 20 to 25 percent residue, which is collected either on grates at the bottom of the combustion chamber or filtered from the exhaust gases by the air pollution control equipment. The fly ash component of the total residue stream is between 10 and 30 percent of the total residue while the bottom ash content ranges from 70 to 90 percent of the total weight, depending upon the air pollution control equipment utilized, especially acid gas scrubbing equipment

Radioactivity of wood ash; Puun tuhkan radioaktiivisuus

Energy Technology Data Exchange (ETDEWEB)

Rantavaara, A.; Moring, M

2000-01-01

STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg{sup -1}, in decreasing order: {sup 137}Cs, {sup 40}K, {sup 90}Sr, {sup 210}Pb,{sup 226}Ra, {sup 232}Th, {sup 134}Cs, {sup 235}U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and {sup 210}Pb was hardly detectable. The NH{sub 4}Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

Leachate Geochemical Results for Ash Samples from the June 2007 Angora Wildfire Near Lake Tahoe in Northern California

Science.gov (United States)

Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Adams, Monique; Lamothe, Paul J.; Todorov, Todor I.; Anthony, Michael W.

2008-01-01

This report releases leachate geochemical data for ash samples produced by the Angora wildfire that burned from June 24 to July 2, 2007, near Lake Tahoe in northern California. The leaching studies are part of a larger interdisciplinary study whose goal is to identify geochemical characteristics and properties of the ash that may adversely affect human health, water quality, air quality, animal habitat, endangered species, debris flows, and flooding hazards. The leaching study helps characterize and understand the interactions that occur when the ash comes in contact with rain or snowmelt, and helps identify the constituents that may be mobilized as run-off from these materials. Similar leaching studies were conducted on ash and burned soils from the October 2007 southern California wildfires (Hageman and others, 2008; Plumlee and others, 2007).

A multigear protocol for sampling crayfish assemblages in Gulf of Mexico coastal streams

Science.gov (United States)

William R. Budnick; William E. Kelso; Susan B. Adams; Michael D. Kaller

2018-01-01

Identifying an effective protocol for sampling crayfish in streams that vary in habitat and physical/chemical characteristics has proven problematic. We evaluated an active, combined-gear (backpack electrofishing and dipnetting) sampling protocol in 20 Coastal Plain streams in Louisiana. Using generalized linear models and rarefaction curves, we evaluated environmental...

Fusion characterization of biomass ash

DEFF Research Database (Denmark)

Ma, Teng; Fan, Chuigang; Hao, Lifang

2016-01-01

The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two...... stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, Tm, is proposed to represent the severe melting temperature of biomass ash. The fusion...... characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates....

False deformation temperatures for ash fusibility associated with the conditions for ash preparation

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Gupta, S.K.; Gupta, R.P.; Sanders, R.H.; Creelman, R.A.; Bryant, G.W. [University of Newcastle, Callaghan, NSW (Australia). Cooperative Research Centre for Black Coal Utilization, Dept. of Chemical Engineering

1999-07-01

A study was made to investigate the fusibility behaviour of coal ashes of high ash fusion temperatures. Coals and ashes formed in the boiler were sampled in several Australian power stations, with laboratory ashes being prepared from the coals. The laboratory ashes gave lower values for the deformation temperature (DT) than the combustion ashes when the ash had low levels of basic oxide components. Thermo-mechanical analysis, quantitative X-ray diffraction and scanning electron microscopy were used to establish the mechanisms responsible for the difference. Laboratory ash is finer than combustion ash and it includes unreacted minerals (such as quartz, kaolinite and illite) and anhydrite (CaSO{sub 4}). Fusion events which appear to be characteristic of reacting illite, at temperatures from 900 to 1200{degree}C, were observed for the laboratory ashes, these being associated with the formation of melt phase and substantial shrinkage. The combustion ashes did not contain this mineral and their fusion events were observed at temperatures exceeding 1300{degree}C. The low DTs of coal ashes with low levels of basic oxides are therefore a characteristic of laboratory ash rather than that found in practical combustion systems. These low temperatures are not expected to be associated with slagging in pulverised coal fired systems. 10 refs., 3 figs., 2 tabs.

Volcanic Ash fall Impact on Vegetation, Colima 2005

Science.gov (United States)

Garcia, M. G.; Martin, A.; Fonseca, R.; Nieto, A.; Radillo, R.; Armienta, M.

2007-05-01

An ash sampling network was established arround Colima Volcano in 2005. Ash fall was sampled on the North, Northeast, East, Southeast, South, Southwest and West of the volcano. Samples were analyzed for ash components, geochemistry and leachates. Ash fall ocurred on April (12), May (10, 23), June (2, 6, 9, 10, 12, 14), July (27), September (27), October (23) and November (24). Most of the ash is made of andesitic dome-lithics but shows diferences in crystal, juvenile material and lithic content. In May, some samples contained grey and dark pumice (scoria). Texture varies from phi >4 to phi 0. Leachate concentration were low: SO4 (7.33-54.19) Cl- (2.29-4.97) and F- (0.16-0.37). During 2005, Colima Volcano's ash fall rotted some of the guava and peach fruits and had a drying effect on spearment and epazote plants. Even these small ash amounts could have hindered sugar cane and agave growth.

Using high-frequency sampling to detect effects of atmospheric pollutants on stream chemistry

Science.gov (United States)

Stephen D. Sebestyen; James B. Shanley; Elizabeth W. Boyer

2009-01-01

We combined information from long-term (weekly over many years) and short-term (high-frequency during rainfall and snowmelt events) stream water sampling efforts to understand how atmospheric deposition affects stream chemistry. Water samples were collected at the Sleepers River Research Watershed, VT, a temperate upland forest site that receives elevated atmospheric...

Measurement of radon activity, exhalation rate and radiation dose in fly ash and coal samples from NTPC, Badarpur, Delhi, India

International Nuclear Information System (INIS)

Gupta, Mamta; Verma, K.D.; Mahur, A.K.; Prasad, R.; Sonkawade, R.G.

2013-01-01

In the present study radon activities and exhalation rates from fly ash and coal samples from NTPC (National Thermal Power Corporation) situated at Badarpur, Delhi, India, have been measured. 'Sealed Can Technique' using LR-115 type II track detectors was employed. In fly ash samples, radon activity has been found to vary from 400.0 ± 34.7 to 483.9 ± 38.1Bqm -3 with an average value of 447.1 ± 36.6 Bqm -3 and in coal samples, radon activity has been found to vary from 504.0 ± 39.0 to 932.1 ± 52.9 Bqm -3 with an average value of 687.2 ± 45.2 Bqm -3 . Radon exhalation rate from coal is found to be higher than radon exhalation rate from its ash products, whereas the opposite is expected. Indoor inhalation exposure (radon) effective dose has also been estimated. (author)

Ash fusion temperatures and the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.K.; Wall, T.F.; Creelman, R.A.; Gupta, R.P. [University of Newcastle, Newcastle, NSW (Australia). CRC for Black Coal Utilisation

1998-07-01

A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degree}C. The temperature corresponding to the rapid rate of shrinkage correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined using a scanning electron microscope (SEM) to identify the associated chemical and physical changes. The progressive changes in the range of chemical composition (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenisation, viscosity and ash fusion mechanisms. Alternate ash fusion temperatures based on different levels of shrinkage have also been suggested to characterise the ash deposition tendency of the coals. 13 refs., 9 figs.

Fusion characterization of biomass ash

Energy Technology Data Exchange (ETDEWEB)

Ma, Teng [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Sino-Danish Center for Education and Research, Beijing, 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Fan, Chuigang; Hao, Lifang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Li, Songgeng, E-mail: sgli@ipe.ac.cn [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Song, Wenli [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Lin, Weigang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

2016-08-20

Highlights: • A novel method is proposed to analyze fusion characteristics of biomass ash. • T{sub m} can represent the severe melting temperature of biomass ash. • Compared with AFT, TMA is the better choice to analyze the fusion characteristics of biomass ash. - Abstract: The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, T{sub m}, is proposed to represent the severe melting temperature of biomass ash. The fusion characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates.

Sampling the stream landscape: Improving the applicability of an ecoregion-level capture probability model for stream fishes

Science.gov (United States)

Mollenhauer, Robert; Mouser, Joshua B.; Brewer, Shannon K.

2018-01-01

Temporal and spatial variability in streams result in heterogeneous gear capture probability (i.e., the proportion of available individuals identified) that confounds interpretation of data used to monitor fish abundance. We modeled tow-barge electrofishing capture probability at multiple spatial scales for nine Ozark Highland stream fishes. In addition to fish size, we identified seven reach-scale environmental characteristics associated with variable capture probability: stream discharge, water depth, conductivity, water clarity, emergent vegetation, wetted width–depth ratio, and proportion of riffle habitat. The magnitude of the relationship between capture probability and both discharge and depth varied among stream fishes. We also identified lithological characteristics among stream segments as a coarse-scale source of variable capture probability. The resulting capture probability model can be used to adjust catch data and derive reach-scale absolute abundance estimates across a wide range of sampling conditions with similar effort as used in more traditional fisheries surveys (i.e., catch per unit effort). Adjusting catch data based on variable capture probability improves the comparability of data sets, thus promoting both well-informed conservation and management decisions and advances in stream-fish ecology.

Estimation of radon exhalation rate, natural radioactivity and radiation doses in fly ash samples from NTPC Dadri, (UP) India

International Nuclear Information System (INIS)

Gupta, Mamta; Verma, K.D.; Mahur, A.K.; Rajendra Prasad; Sonkawade, R.G.

2010-01-01

Fly ash produced by coal-burning in thermal power station has become a subject of world wide interest in recent years, because of its diverse uses in building materials such as bricks, sheets, cement and land filling etc. The knowledge of radio nuclides in fly ash plays an important role in health physics. Natural radioactivity and radon exhalation rate in fly ash samples collected from NTPC (National Thermal Power Corporation) Dadri, (UP.) India, have been studied. A high resolution gamma ray spectroscopic system has been used for the measurement of natural radioactivity. The activity concentration of natural radionuclides radium ( 226 Ra), thorium ( 232 Th) and potassium ( 40 K) were measured and radiological parameters were calculated. Radium concentration was found to vary from (81.01 ± 3.25) to (177.33 ±10.00) Bq kg -1 . Activity concentration of thorium was found to vary from (111.57 ± 3.21) to (178.50 ± 3.96) Bq kg -1 . Potassium activity was not significant in some samples, whereas, some other samples have shown potassium activity vary from (365.98 ± 4.85) to (495.95 ± 6.23) Bq kg -1 . Radon exhalation rates in these samples were also calculated by 'Sealed Can technique' using LR-115 type II detectors and found to vary from (80 ± 9) to (243 ± 16) mBqm -2 h -1 with an average value (155 ± 13) mBqm -2 h -1 . This study also presents the results of estimation of effective dose equivalent from exhalation rate, radium equivalent, absorbed gamma dose rates, external annual effective dose rate and values of external hazard index for the fly ash samples. (author)

Quadrature demodulation based circuit implementation of pulse stream for ultrasonic signal FRI sparse sampling

International Nuclear Information System (INIS)

Shoupeng, Song; Zhou, Jiang

2017-01-01

Converting ultrasonic signal to ultrasonic pulse stream is the key step of finite rate of innovation (FRI) sparse sampling. At present, ultrasonic pulse-stream-forming techniques are mainly based on digital algorithms. No hardware circuit that can achieve it has been reported. This paper proposes a new quadrature demodulation (QD) based circuit implementation method for forming an ultrasonic pulse stream. Elaborating on FRI sparse sampling theory, the process of ultrasonic signal is explained, followed by a discussion and analysis of ultrasonic pulse-stream-forming methods. In contrast to ultrasonic signal envelope extracting techniques, a quadrature demodulation method (QDM) is proposed. Simulation experiments were performed to determine its performance at various signal-to-noise ratios (SNRs). The circuit was then designed, with mixing module, oscillator, low pass filter (LPF), and root of square sum module. Finally, application experiments were carried out on pipeline sample ultrasonic flaw testing. The experimental results indicate that the QDM can accurately convert ultrasonic signal to ultrasonic pulse stream, and reverse the original signal information, such as pulse width, amplitude, and time of arrival. This technique lays the foundation for ultrasonic signal FRI sparse sampling directly with hardware circuitry. (paper)

Measurement of natural activity in peat ashes

International Nuclear Information System (INIS)

Suomela, J.

1985-01-01

High proportions of radioactive materials in peat ashes may involve radiation hazards during handling and deposition of these waste materials. Measurements have been performed to determine the content of radioactive materials in ashes from peat burning. The activities in fly ash and ''solid'' ash in seven peat-fired power plants in Sweden are presented. The methods of analysing and measuring peat ashes for activity from different radionuclides are described. The activity levels in ash samples are given

Efficiency of dioxin recovery from fly-ash samples during extraction and cleanup process, March 1989. Final report, 1 August 1987-30 September 1988

International Nuclear Information System (INIS)

Finkel, J.M.; James, R.H.; Baughman, K.W.

1989-03-01

The work supported Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency in its effort to monitor the hazardous composition, if any, of fly ash from various types of incinerators using different types of combustible materials. The analytical determination of dioxins in environmental samples in the parts per billion, trillion, and quadrillion levels requires meticulous, time-consuming, and very complex sample preparation and analysis procedures. A major part of the task was devoted to the evaluation of various extraction techniques of fly ash and cleanup of sample extracts by column chromatography. Several chromatographic media and eluting solvents were investigated. Each step in the sample preparation was evaluated by using 14 C-radiolabeled 2,3,7,8-tetrachlorodibenzo-p-dioxin and octochlorodibenzo-p-dioxin as a tracer. Radiolabeled dioxin allows the analyst to stop and evaluate each step of the procedure, each extract, and each column eluate fraction by liquid-scintillation computing. To validate the radiometric assay, dioxin was confirmed by gas chromatography/mass spectrometry. The report contains recovery data of spiked 2,3,7,8-tetrachlorodibenzo-p-dioxin and octochlorodibenzo-p-dioxin in carbon-free fly ash and fly ash containing from 0.1% to 10% carbon

Basic soil benefits from ash utilization

Energy Technology Data Exchange (ETDEWEB)

Martens, D.C.; Plank, C.O.

1970-01-01

The beneficial effects of fly ash application shown herein are expected to encourage future disposal of the material in agricultural soils. It is foreseen, however, that fly ash disposal in agricultural soils would be unsuccessful if adverse effects on crop production result from its misuse. It seems evident, therefore, that quality control measures will be required to insure proper disposal of the material in agricultural soils. It will be necessary to consider differences in chemical properties of various samples of fly ash and in chemical reactions of samples of fly ash and soils. Differences in tolerances of plants to soluble salt damage and to specific nutrient deficiencies and toxicities will also have to be taken into account. 9 tables.

High Purity Silica Production from Rice Husk Ash

International Nuclear Information System (INIS)

Yaminn Lwin; April Nwayy Nwayy Htett

2010-12-01

In this research, two types of raw material source, rice husk and rice husk ash, were used. Among the rice husk samples, taungpyan sample was chosen because it contains the maximum silica content and treated with (1,3,5) wt% sulphuric acid (96% concentration) and citric acid (99% concentration). These acid treated taungpyan samples and nonacid treated taungpyan sample were burned at 900C for 30 min. For rice husk ash samples, ash samples from fluidized combustor, fluidized gasifier and brick factory were collected. All of the rice husk ash samples were purified by alkaline extraction method with (2-3) N NaOH solution and followed by acid precipitation method with 5 N H2SO4 solution. According to the analysis and characterization, acid treated taungpyan sample (5 wt% citric acid) with the highest silica content (99.906 wt% and crystallization form) was obtained.

National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment pilot survey of Llano area, Texas

International Nuclear Information System (INIS)

Nichols, C.E.; Kane, V.E.; Minkin, S.C.; Cagle, G.W.

1976-01-01

A pilot geochemical survey of the Llano, Texas, area was conducted during February and March 1976. The purpose of this work was to prepare for a subsequent reconnaissance geochemical survey of uranium in Central Texas. Stream sediment, stream water, well water, and plant ash from five geologic areas were analyzed in the laboratory for approximately 25 parameters. Examples of anomalous values in stream sediment and stream water indicate the usefulness of both sample types in identifying anomalies at a regional reconnaissance-scale station spacing of approximately 5 km (3 mi). Groundwater samples, which generally best indicate the geochemistry of formations at depth in a survey of this type, represent another important tool in detecting uranium mineralization. Anomalies in San Saba County are associated with the Marble Falls-Smithwich Formations and the Strawn Series (Pennsylvanian), the Houy Formation (Devonian and lower Mississippian), and the Hickory Sandstone Member of the Riley Formation (Cambrian). In Burnet County anomalous values are due to the influence of the Valley Spring Formation (Precambrian); and in Blanco County anomalies are found associated with the Riley Formation

Quality characteristics of Greek fly ashes and potential uses

Energy Technology Data Exchange (ETDEWEB)

Skodras, G.; Grammelis, P.; Kakaras, E. [Institute for Solid Fuels Technology and Applications, Ptolemais (Greece); Karangelos, D.; Anagnostakis, M.; Hinis, E. [Nuclear Engineering Section, Mechanical Engineering Department, National Technical University of Athens, Athens (Greece)

2007-01-15

The main characteristics of fly ash from Greek coal-fired boilers are presented in this paper in relation to its exploitation potential. Both fuel and fly ash samples were collected and analyzed according to the ASTM Standards. Apart from the typical analyses (proximate, ultimate, ash analysis and calorific value), an ICP-AES spectrometer was used for the analysis of heavy metals in the ash. Experimental measurements in order to determine the radioactivity content of raw fuel and the fly ash were carried out as well. A representative fly ash sample from Ptolemais power plant was evaluated and tested as filler in Self-Compacting Concrete (SCC). Ashes from the Greek brown coal are classified in type C, most of the fly ash being produced in Ptolemais of Northern Greece, while the rest in Megalopolis. Ptolemais fly ash is rich in calcium compounds, while Megalopolis fly ash contains more pyrite. Increased heavy metal concentrations are observed in the fly ash samples of Greek coal. Greek fly ash appears to have not only pozzolanic but also hydraulic behaviour. Furthermore, Greek fly ash, depending on its origin, may have relatively high natural radioactivity content, reaching in the case of Megalopolis fly ash 1 kBq kg{sup -1} of {sup 226}Ra. The laboratory results showed that fly ashes can be a competitive substitute to conventional limestone filler material in SCC. Fly ash is mostly used in Greece in cement industry replacing cement clinker and aiming to the production of special types of Portland cements. However, a more aggressive utilisation strategy should be developed, since low quantities of the total produced fly ash are currently further utilised. (author)

Coal ash usage in environmental restoration at the Hanford site

Energy Technology Data Exchange (ETDEWEB)

Scanlon, P.L.; Sonnichsen, J.C.; Phillips, S.J.

1994-08-01

The ash stockpiled next to the 284E steam plant is mixed fly ash, bottom ash, and slag. The ash consists of (1) baghouse residue and (2) a mixture of bottom ash and slag which is washed out of the bottom of the boilers daily. In 1991, a Toxicity Characteristic Leaching Procedure (TCLP) was performed on several samples of this ash (Hazen Research 1991). This procedure is designed to determine the mobility of organic and inorganic anatytes present in liquid, solid, or multiphasic wastes (EPA 1994). The ash tested came from surge bins, conveyor samples, and bottom ash and fly ash from the boilers at 284E. Antimony, cadmium, germanium, molybdenum, silver, thallium, tungsten, and vanadium were tested for, but on all samples were below detection Limits for the testing method. Analytes present in relatively high concentrations (but less than one part per thousand) included barium, boron, chromium, fluorine, and zinc. The size of ash particles passing through a Taylor sieve series was very evenly distributed from 1 to 200m.

Environmentally-Friendly Dense and Porous Geopolymers Using Fly Ash and Rice Husk Ash as Raw Materials

Directory of Open Access Journals (Sweden)

Daniele Ziegler

2016-06-01

Full Text Available This paper assesses the feasibility of two industrial wastes, fly ash (FA and rice husk ash (RHA, as raw materials for the production of geopolymeric pastes. Three typologies of samples were thus produced: (i halloysite activated with potassium hydroxide and nanosilica, used as the reference sample (HL-S; (ii halloysite activated with rice husk ash dissolved into KOH solution (HL-R; (iii FA activated with the alkaline solution realized with the rice husk ash (FA-R. Dense and porous samples were produced and characterized in terms of mechanical properties and environmental impact. The flexural and compressive strength of HL-R reached about 9 and 43 MPa, respectively. On the contrary, the compressive strength of FA-R is significantly lower than the HL-R one, in spite of a comparable flexural strength being reached. However, when porous samples are concerned, FA-R shows comparable or even higher strength than HL-R. Thus, the current results show that RHA is a valuable alternative to silica nanopowder to prepare the activator solution, to be used either with calcined clay and fly ash feedstock materials. Finally, a preliminary evaluation of the global warming potential (GWP was performed for the three investigated formulations. With the mix containing FA and RHA-based silica solution, a reduction of about 90% of GWP was achieved with respect to the values obtained for the reference formulation.

Leaching from biomass combustion ash

DEFF Research Database (Denmark)

Maresca, Alberto; Astrup, Thomas Fruergaard

2014-01-01

The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...

Ash fusion temperatures and the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.; Wall, T.F.; Creelman, R.A.; Gupta, R. [Univ. of Newcastle, Callaghan (Australia)

1996-12-31

A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to the rapid rate of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenization, viscosity and ash fusion mechanisms.

Ash fusion temperatures and the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Creelman, R.A.; Gupta, R.; Gupta, S. [Univ. of Newcastle (Australia)

1996-10-01

A mechanistic study is detailed in which coal ash is heated with the shrinkage and electrical resistance measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to rapid rates of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples where therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity are then quantified and related to the shrinkage events and standard ash fusion temperatures.

Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

Science.gov (United States)

Kostova, I.J.; Hower, J.C.; Mastalerz, Maria; Vassilev, S.V.

2011-01-01

Mercury capture by fly ash C was investigated at five lignite- and subbituminous-coal-burning Bulgarian power plants (Republika, Bobov Dol, Maritza East 2, Maritza East 3, and Sliven). Although the C content of the ashes is low, never exceeding 1.6%, the Hg capture on a unit C basis demonstrates that the low-rank-coal-derived fly ash carbons are more efficient in capturing Hg than fly ash carbons from bituminous-fired power plants. While some low-C and low-Hg fly ashes do not reveal any trends of Hg versus C, the 2nd and, in particular, the 3rd electrostatic precipitator (ESP) rows at the Republika power plant do have sufficient fly ash C range and experience flue gas sufficiently cool to capture measurable amounts of Hg. The Republika 3rd ESP row exhibits an increase in Hg with increasing C, as observed in other power plants, for example, in Kentucky power plants burning Appalachian-sourced bituminous coals. Mercury/C decreases with an increase in fly ash C, suggesting that some of the C is isolated from the flue gas stream and does not contribute to Hg capture. Mercury capture increases with an increase in Brunauer-Emmett-Teller (BET) surface area and micropore surface area. The differences in Hg capture between the Bulgarian plants burning low-rank coal and high volatile bituminous-fed Kentucky power plants suggests that the variations in C forms resulting from the combustion of the different ranks also influence the efficiency of Hg capture. ?? 2010 Elsevier Ltd.

Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

Energy Technology Data Exchange (ETDEWEB)

Kostova, I.J.; Hower, J.C.; Mastalerz, M.; Vassilev, S.V. [University of Kentucky, Lexington, KY (United States). Center of Applied Energy Research

2011-01-15

Mercury capture by fly ash C was investigated at five lignite- and subbituminous-coal-burning Bulgarian power plants (Republika, Bobov Dol, Maritza East 2, Maritza East 3, and Sliven). Although the C content of the ashes is low, never exceeding 1.6%, the Hg capture on a unit C basis demonstrates that the low-rank-coal-derived fly ash carbons are more efficient in capturing Hg than fly ash carbons from bituminous-fired power plants. While some low-C and low-Hg fly ashes do not reveal any trends of Hg versus C, the 2nd and, in particular, the 3rd electrostatic precipitator (ESP) rows at the Republika power plant do have sufficient fly ash C range and experience flue gas sufficiently cool to capture measurable amounts of Hg. The Republika 3rd ESP row exhibits an increase in Hg with increasing C, as observed in other power plants, for example, in Kentucky power plants burning Appalachian-sourced bituminous coals. Mercury/C decreases with an increase in fly ash C, suggesting that some of the C is isolated from the flue gas stream and does not contribute to Hg capture. Mercury capture increases with an increase in Brunauer-Emmett-Teller (BET) surface area and micropore surface area. The differences in Hg capture between the Bulgarian plants burning low-rank coal and high volatile bituminous-fed Kentucky power plants suggests that the variations in C forms resulting from the combustion of the different ranks also influence the efficiency of Hg capture.

Characterization of ashes from biofuels

Energy Technology Data Exchange (ETDEWEB)

Frandsen, F.J.; Hansen, L.A. [Technical Univ. of Denmark. Dept. of Chemical Engineering (Denmark); Soerensen, H.S. [Geological Survey of Denmark and Greenland (Denmark); Hjuler, K. [dk-TEKNIK. Energy and Environment (Denmark)

1998-02-01

One motivation for initiating the present project was that the international standard method of estimating the deposit propensity of solid fuels, of which a number of variants exist (e.g. ISO, ASTM, SD, DIN), has shown to be unsuitable for biomass ashes. This goal was addressed by the development of two new methods for the detection of ash fusibility behaviour based on Simultaneous Thermal Analysis (STA) and High Temperature Light Microscopy (HTLM), respectively. The methods were developed specifically for ashes from biofuels, but are suitable for coal ashes as well. They have been tested using simple salt mixtures, geological standards and samples from straw CHP and coal-straw PF combustion plants. All samples were run in a nitrogen atmosphere at a heating rate of 10 deg. C/min. In comparison with the standard method, the new methods are objective and have superior repeatability and sensitivity. Furthermore, the two methods enable the melting behavior to be characterized by a continuous measurement of melt fraction versus temperature. Due to this two-dimensional resolution of the results, the STA and HTLM methods provide more information than the standard method. The study of bottom ash and fly ash as well as deposit samples from straw test firings at the Haslev and Slagelse Combined Heat and Power plants resulted in a better understanding of mineral behaviour during straw grate firing. In these tests a number of straws were fired which had been carefully selected for having different qualities with respect to sort and potassium and chlorine contents. By studying bottom ashes from Slagelse it was found that the melting behaviour correlated with the deposition rate on a probe situated at the outlet part of the combustion zone. (EG)

Possibilities of utilizing power plant fly ashes

Directory of Open Access Journals (Sweden)

Mezencevová Andrea

2003-09-01

mechanical action. It is known, that performance of fly ash in concrete improves with its increased fineness. Intensive milling of fly ash leads to the increasing fly ash fineness and to the enhancement of its hydration activity. The cement-fly ash composites with 25 wt.% of activated fly ash as cement replacement have exhibited a higher 28-day compressive strength in comparison with a reference concrete sample without fly ash. An unfavorable effect in milling process is the agglomeration of fine particles of fly ash. By high-energy milling of fly ash with addition of surfactants, the ultrafine products can be prepared. Concrete samples containing such fly ash have achieved higher compressive strengths than the reference sample without fly ash or with addition of non-milled fly ash. The considerable physical effect of ultrafine fly ash consists in superior filling of spaces between coarser cement particles and in the favorable influence of hardness of the mixtures at setting.The current research activities in mechanochemistry are oriented to the mechanical activation of poly-component systems. The knowledge in this field indicate that by high-energy milling of fly ash as a poly-component system and following heating of prepared metastable precursors, the cement minerals could be prepared.

Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

OpenAIRE

A Minjigmaa; Ts Zolzaya; E Bayanjargal; B Davaabal; J Temuujin

2014-01-01

  Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on th...

Enrichment of {sup 210}Po and {sup 210}Pb in ash samples from oil shale-fired power plants in Estonia

Energy Technology Data Exchange (ETDEWEB)

Ozden, B. [University of Tartu, Institute of Physics/Ege University, Institute of Nuclear Sciences (Estonia); Vaasma, T.; Kiisk, M.; Suursoo, S.; Tkaczyk, A.H. [University of Tartu,Institute of Physics (Estonia)

2014-07-01

Energy production in Estonia is largely dependent on the oil shale industry. Oil shale is a fossil fuel typically characterized by relatively high mineral composition, modest organic fraction (varying between 10 and 65%), high ash content (usually 45% to 50%), and average lower heating value of 8.4 MJ/kg{sup -1}. Oil shale-fired power plants account for 85% of Estonian electricity production and produce up to 6 million tons of oil shale ash annually. This ash contains elevated amounts of natural radionuclides (from the {sup 238}U and {sup 232}Th series and {sup 40}K), which were bound to oil shale during its formation. These radionuclides become enriched in ash fractions during the combustion process and are partially emitted to the atmosphere via fly ash and flue gases. Oil shale-fired electricity production is foreseen to remain a dominant trend in Estonia, suggesting that the radionuclide emissions to the atmosphere will continue in the future. The natural radionuclides {sup 210}Po and {sup 210}Pb, with half-lives of 138 days and 22.3 years respectively, originate from the radioactive decay of radionuclides of {sup 238}U series present in the earth's crust. These radionuclides are also built up artificially in the environment due to waste discharge from phosphate, oil, and gas industries, combustion of fossil fuels and other energy production as technically enhanced natural radionuclides. There are few studies on oil shale power plants influence on the levels of natural radioactivity in the surrounding areas. Realo, et al. reported that the annual doses from fly ash depositions over a 30 year period are in the range 90 - 200 μSv a{sup -1}. A study previously initiated by the University of Tartu, Institute of Physics (IPh) evaluated enrichment in the activity concentrations of {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 232}Th, {sup 228}Ra and {sup 40}K in ash samples collected from Eesti Power Plant's circulating fluidized bed (CFB) boiler. According

Fusibility and sintering characteristics of ash

Energy Technology Data Exchange (ETDEWEB)

Ots, A. A., E-mail: aots@sti.ttu.ee [Tallinn University of Technology (Estonia)

2012-03-15

The temperature characteristics of ash fusibility are studied for a wide range of bituminous and brown coals, lignites, and shales with ratios R{sub B/A} of their alkaline and acid components between 0.03 and 4. Acritical value of R{sub B/A} is found at which the fusion temperatures are minimal. The sintering properties of the ashes are determined by measuring the force required to fracture a cylindrical sample. It is found that the strength of the samples increases sharply at certain temperatures. The alkali metal content of the ashes has a strong effect on their sintering characteristics.

Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

Science.gov (United States)

Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

2016-06-01

Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

Producing New Composite Materials by Using Tragacanth and Waste Ash

OpenAIRE

Yasar Bicer; Serif Yilmaz

2013-01-01

In present study, two kinds of thermal power plant ashes; one the fly ash and the other waste ash are mixed with adhesive tragacanth and cement to produce new composite materials. 48 new samples are produced by varying the percentages of the fly ash, waste ash, cement and tragacanth. The new samples are subjected to some tests to find out their properties such as thermal conductivity, compressive strength, tensile strength and sucking capability of water. It is found that; the thermal conduct...

Testing common stream sampling methods for broad-scale, long-term monitoring

Science.gov (United States)

Eric K. Archer; Brett B. Roper; Richard C. Henderson; Nick Bouwes; S. Chad Mellison; Jeffrey L. Kershner

2004-01-01

We evaluated sampling variability of stream habitat sampling methods used by the USDA Forest Service and the USDI Bureau of Land Management monitoring program for the upper Columbia River Basin. Three separate studies were conducted to describe the variability of individual measurement techniques, variability between crews, and temporal variation throughout the summer...

Idaho Nuclear Technology and Engineering Center (INTEC) (formerly ICPP) ash reutilization study

Energy Technology Data Exchange (ETDEWEB)

Langenwalter, T.; Pettet, M.; Ochoa, R.; Jensen, S.

1998-05-01

Since 1984, the coal-fired plant at the Idaho Nuclear Technology and Engineering Center (INTEC, formerly Idaho Chemical Processing Plant) has been generating fly ash at a rate of approximately 1,000 tons per year. This ash is hydrated and placed in an ash bury pit near the coal-fired plant. The existing ash bury pit will be full in less than 1 year at its present rate of use. A conceptual design to build a new ash bury pit was completed, and the new pit is estimated to cost $1.7 million. This report evaluates ash reutilization alternatives that propose to eliminate this waste stream and save the $1.7 million required to build a new pit. The alternatives include using ash for landfill day cover, concrete admixture, flowable fill, soil stabilization, waste remediation, and carbon recovery technology. Both physical and chemical testing, under the guidance of the American Society for Testing and Materials, have been performed on ash from the existing pit and from different steps within the facility`s processes. The test results have been evaluated, compared to commercial ash, and are discussed as they relate to reutilization alternatives. This study recommends that the ash be used in flowable fill concrete for Deactivation and Demolition work at the Idaho National Engineering and Environmental Laboratory.

Idaho Nuclear Technology and Engineering Center (INTEC) (formerly ICPP) ash reutilization study

International Nuclear Information System (INIS)

Langenwalter, T.; Pettet, M.; Ochoa, R.; Jensen, S.

1998-05-01

Since 1984, the coal-fired plant at the Idaho Nuclear Technology and Engineering Center (INTEC, formerly Idaho Chemical Processing Plant) has been generating fly ash at a rate of approximately 1,000 tons per year. This ash is hydrated and placed in an ash bury pit near the coal-fired plant. The existing ash bury pit will be full in less than 1 year at its present rate of use. A conceptual design to build a new ash bury pit was completed, and the new pit is estimated to cost $1.7 million. This report evaluates ash reutilization alternatives that propose to eliminate this waste stream and save the $1.7 million required to build a new pit. The alternatives include using ash for landfill day cover, concrete admixture, flowable fill, soil stabilization, waste remediation, and carbon recovery technology. Both physical and chemical testing, under the guidance of the American Society for Testing and Materials, have been performed on ash from the existing pit and from different steps within the facility's processes. The test results have been evaluated, compared to commercial ash, and are discussed as they relate to reutilization alternatives. This study recommends that the ash be used in flowable fill concrete for Deactivation and Demolition work at the Idaho National Engineering and Environmental Laboratory

KINETICS OF FLY ASH BENEFICIATION BY CARBON BURNOUT

Energy Technology Data Exchange (ETDEWEB)

Dr. Joseph N.D. Dodoo; Dr. Joseph M. Okoh

2000-11-01

Surface area analyses performed on fly ash samples reveal that the surface area is controlled by carbon content. The higher surface areas found in large particles are due to the presence of highly porous carbonaceous particles. Adsorption-desorption isotherms and t-plots of fly ash samples indicate that fly ash is porous. BJH Adsorption/Desorption pore size analysis reveal that pore diameters are independent of sieve size. They appear to be dependent only on the nature of the material which confers porosity. Based on the results of Brown and Dykstra (41) it is reasonable to assume that calculations of reaction rates at temperatures above 550 C were confounded by weight losses from processes other than carbon oxidation and, therefore, are not useful in determination of the temperature dependence of carbon oxidation in fly ash. The results of the present study indicate that temperatures below 550 C should be used for future studies in order to satisfactorily assess the temperature dependence of carbon oxidation in fly ash. Furthermore, it is also advisable that percent carbon determinations be performed on fly ash samples after the oxidation reactions to determine whether all carbon present in fly ash is oxidized. This will ensure that reaction rates are representative of the complete oxidation of carbon. An inverse relationship was determined between reaction rates and oxygen concentration for this study. As discussed, this may be due to volatilization of volatiles from fly ash and ease of transport of products away from the reaction sites by the action of the vacuum applied to the samples. A more accurate determination of oxygen dependence of carbon oxidation can be accomplished by the use of specialty gases containing different concentrations of oxygen which could eliminate the need to apply vacuum to the samples.

Organic Seston Dynamics in Upland Neotropical Streams: Implications for Amphibian Declines

Science.gov (United States)

Peterson, S. D.; Colon-Gaud, C.; Whiles, M. R.; Hunte-Brown, M.; Connelly, S.; Kilham, S.; Pringle, C. M.; Lips, K. R.; Brenes, R.

2005-05-01

Organic seston represents food for filter feeders and a mechanism for downstream transport of energy and nutrients. As part of a study assessing the ecological impacts of stream-breeding anuran extirpations, we examined seston dynamics in 2 stream reaches with tadpoles (El Cope) and 2 without (Fortuna) in the Panamanian uplands. All reaches are high gradient with annual average discharge ranging from 46-102 L/s. Samples were collected multiple times per month at various discharges, sieved into fine (98μm) and very fine (1.6μm) fractions, and processed to estimate ash-free dry mass (AFDM), total C, and total N. Average annual concentrations ranged from 0.52- 2.51 mg/L (fine) and 2.04-3.14 mg/L (very fine), and total export ranged from 0.27-7,981 mg/s across all streams. On average, very fine particles comprised 78% of export from El Cope sites and 61% from Fortuna streams. Average total N export ranged from 5.32-30.53 mg/s in El Cope sites and 1.71-6.04 mg/s at Fortuna. Average particle quality (C/N) in El Cope streams was higher (7.6) than Fortuna streams (11.5). Lower export of very fine particles and lower seston quality in Fortuna streams suggests the loss of tadpoles may influence seston dynamics and quality in these systems.

Hydrogeochemical and stream sediment sampling for uranium in the sandstone environment

International Nuclear Information System (INIS)

Wenrich, K.J.

1985-01-01

Sandstone terranes commonly host uranium occurrences in the western United States. In addition, because sedimentary terranes, particularly shales and immature, not well cemented sandstone, contribute more sediment and soluble material than do plutonic, volcanic, or metamorphic terranes they are an excellent regime for hydrogeochemical and stream-sediment prospecting. Because of higher conductivity, and hence higher uranium content, of waters draining such environments the sampling need not be as precise nor the analytical detection limit as low as in other terranes to yield a successful survey. Nevertheless, reasonable preparation and care of the samples is recommended: (1) The water samples should be filtered through 0.45 μm membranes and acidified to a pH of less than 1. (2) Because the adsorption of uranium by organic material is so significant it is recommended that the reasonable finest stream-sediment fraction, 4 , conductivity, etc.) are useful in the data reduction towards the elimination of false anomalies. (author)

The use of shale ash in dry mix construction materials

Science.gov (United States)

Gulbe, L.; Setina, J.; Juhnevica, I.

2017-10-01

The research was made to determine the use of shale ash usage in dry mix construction materials by replacing part of cement amount. Cement mortar ZM produced by SIA Sakret and two types of shale ashes from Narva Power plant (cyclone ash and electrostatic precipitator ash) were used. Fresh mortar properties, hardened mortar bulk density, thermal conductivity (λ10, dry) (table value) were tested in mortar ZM samples and mortar samples in which 20% of the amount of cement was replaced by ash. Compressive strenght, frost resistance and resistance to sulphate salt solutions were checked. It was stated that the use of electrostatic precipitator ash had a little change of the material properties, but the cyclone ash significantly reduced the mechanical strength of the material.

Effect of class F fly ash on the durability properties of concrete

Directory of Open Access Journals (Sweden)

Ashish Kumer Saha

2018-01-01

Full Text Available The present study evaluates the application of class F fly ash as a partial replacement of binder in concrete. The compressive strength of the fly ash samples showed low early compressive strength comparing to the control samples. However, due to pozzolanic reaction strength was improved gradually over a longer period of time, whereas control samples stopped the strength growth after 56-d of curing. The drying shrinkage was reduced with the increment of fly ash content in the mix. The inclusion of fly ash as a binder reduced the porosity of the concrete. As a result, the fly ash concrete exhibited lower water sorptivity and chloride permeability. Furthermore, a significant drop of sorptivity and chloride permeability was observed for fly ash concrete between the curing period of 28–180 days. Microstructural morphology of fly ash samples was investigated to evaluate the reason behind the improved durability characteristics. Keywords: Fly ash, Compressive strength, Drying shrinkage, Permeable void, Water sorptivity, Chloride permeability

Rising from the ashes: Changes in salmonid fish assemblages after 30 months of the Puyehue-Cordon Caulle volcanic eruption.

Science.gov (United States)

Lallement, Mailén; Macchi, Patricio J; Vigliano, Pablo; Juarez, Santiago; Rechencq, Magalí; Baker, Matthew; Bouwes, Nicolaas; Crowl, Todd

2016-01-15

Events such as volcanic eruptions may act as disturbance agents modifying the landscape spatial diversity and increasing environmental instability. On June 4, 2011 the Puyehue-Cordon Caulle volcanic complex located on Chile (2236 m.a.s.l., 40° 02' 24" S- 70° 14' 26" W) experience a rift zone eruption ejecting during the first day 950 million metric tons into the atmosphere. Due to the westerly winds predominance, ash fell differentially upon 24 million ha of Patagonia Argentinean, been thicker deposits accumulated towards the West. In order to analyze changes on stream fish assemblages we studied seven streams 8, 19 and 30 months after the eruption along the ash deposition gradient, and compare those data to pre eruption ones. Habitat features and structure of the benthic macroinvertebrate food base of fish was studied. After the eruption, substantial environmental changes were observed in association with the large amount of ash fallout. In western sites, habitat loss due to ash accumulation, changes in the riparian zone and morphology of the main channels were observed. Turbidity was the water quality variable which reflected the most changes throughout time, with NTU values decreasing sharply from West to East sites. In west sites, increased Chironomid densities were recorded 8 months after the initial eruption as well as low EPT index values. These relationships were reversed in the less affected streams farther away from the volcano. Fish assemblages were greatly influenced both by habitat and macroinvertebrate changes. The eruption brought about an initial sharp decline in fish densities and the almost total loss of young of the year in the most western streams affecting recruitment. This effect diminished rapidly with distance from the emission center. Thirty months after the eruption, environmental changes are still occurring as a consequence of basin wide ash remobilization and transport.

Trace elements and As speciation analysis of fly ash samples from an Indonesian coal power plant by means of neutron activation analysis and synchrotron based techniques

International Nuclear Information System (INIS)

Muhayatun Santoso; Diah Dwiana Lestiani; Endah Damastuti; Syukria Kurniawat; Bennett, J.W.; Juan Jose Leani; Mateusz Czyzycki; Alessandro Migliori; Germanos Karydas, Andreas

2016-01-01

The elemental characterization of coal fly ash samples is required to estimate the coal burning emissions into the environment and to assess the potential impact into the biosphere. Fly ash samples collected from a coal fired power plant in center Java, Indonesia were characterized by instrumental neutron activation analysis at two different facilities (BATAN, ANSTO) and synchrotron based techniques at Elettra Italy. Assessment of thirty (30) elements and an investigation of the potential toxicity of As species in coal fly ash were presented. The results obtained are discussed and compared with those reported from other regions of the world. (author)

Possibilities of municipal solid waste incinerator fly ash utilisation.

Science.gov (United States)

Hartmann, Silvie; Koval, Lukáš; Škrobánková, Hana; Matýsek, Dalibor; Winter, Franz; Purgar, Amon

2015-08-01

Properties of the waste treatment residual fly ash generated from municipal solid waste incinerator fly ash were investigated in this study. Six different mortar blends with the addition of the municipal solid waste incinerator fly ash were evaluated. The Portland cement replacement levels of the municipal solid waste incinerator fly ash used were 25%, 30% and 50%. Both, raw and washed municipal solid waste incinerator fly ash samples were examined. According to the mineralogical composition measurements, a 22.6% increase in the pozzolanic/hydraulic properties was observed for the washed municipal solid waste incinerator fly ash sample. The maximum replacement level of 25% for the washed municipal solid waste incinerator fly ash in mortar blends was established in order to preserve the compressive strength properties. Moreover, the leaching characteristics of the crushed mortar blend was analysed in order to examine the immobilisation of its hazardous contents. © The Author(s) 2015.

Sampling, Splitting and Merging in Coinductive Stream Calculus

NARCIS (Netherlands)

M. Niqui (Milad); J.J.M.M. Rutten (Jan); C. Bolduc; J. Desharnais; B. Ktari

2010-01-01

textabstractWe study various operations for partitioning, projecting and merging streams of data. These operations are motivated by their use in dataflow programming and the stream processing languages. We use the framework of \\emph{stream calculus} and \\emph{stream circuits} for defining and

Sampling, splitting and merging in coinductive stream calculus

NARCIS (Netherlands)

M. Niqui (Milad); J.J.M.M. Rutten (Jan)

2009-01-01

htmlabstractWe study various operations for partitioning, projecting and merging streams of data. These operations are motivated by their use in dataflow programming and the stream processing languages. We use the framework of stream calculus and stream circuits for defining and proving properties

Wood ash used as partly sand and/or cement replacement in mortar

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Hansen, Esben Østergaard; Jensen, Pernille Erland

2016-01-01

, and the present work reports a characterization of three different WAs. Properties of mortar samples with the WAs used as partly cement and/or sand replacement are reported. Compressive strength development and porosity are the mortar properties in focus. The overall aim of the work is to evaluate the influence...... of the ashes were dry and sampled just after the incineration, whereas one ash had a water content of 15%, because the ash was sprayed with water to avoid dust during ash handling at the incineration plant. Regardless of replacing cement or sand with WAs, the compressive strength decreased compared...... to a reference without ash, however, the decrease was small for two of the ashes. Using the ash with the high LoI resulted in significantly lower compressive strength compared to the other two ashes. The mortar samples with two of the ashes (with low LoI) had qualities, which were very encouraging in order...

ELIMINATION OF THE CHARACTERIZATION OF DWPF POUR STREAM SAMPLE AND THE GLASS FABRICATION AND TESTING OF THE DWPF SLUDGE BATCH QUALIFICATION SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Amoroso, J.; Peeler, D.; Edwards, T.

2012-05-11

A recommendation to eliminate all characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification sample was made by a Six-Sigma team chartered to eliminate non-value-added activities for the Defense Waste Processing Facility (DWPF) sludge batch qualification program and is documented in the report SS-PIP-2006-00030. That recommendation was supported through a technical data review by the Savannah River National Laboratory (SRNL) and is documented in the memorandums SRNL-PSE-2007-00079 and SRNL-PSE-2007-00080. At the time of writing those memorandums, the DWPF was processing sludge-only waste but, has since transitioned to a coupled operation (sludge and salt). The SRNL was recently tasked to perform a similar data review relevant to coupled operations and re-evaluate the previous recommendations. This report evaluates the validity of eliminating the characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification samples based on sludge-only and coupled operations. The pour stream sample has confirmed the DWPF's ability to produce an acceptable waste form from Slurry Mix Evaporator (SME) blending and product composition/durability predictions for the previous sixteen years but, ultimately the pour stream analysis has added minimal value to the DWPF's waste qualification strategy. Similarly, the information gained from the glass fabrication and PCT of the sludge batch qualification sample was determined to add minimal value to the waste qualification strategy since that sample is routinely not representative of the waste composition ultimately processed at the DWPF due to blending and salt processing considerations. Moreover, the qualification process has repeatedly confirmed minimal differences in glass behavior from actual radioactive waste to glasses fabricated from simulants or batch chemicals. In

Elimination Of The Characterization Of DWPF Pour Stream Sample And The Glass Fabrication And Testing Of The DWPF Sludge Batch Qualification Sample

International Nuclear Information System (INIS)

Amoroso, J.; Peeler, D.; Edwards, T.

2012-01-01

A recommendation to eliminate all characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification sample was made by a Six-Sigma team chartered to eliminate non-value-added activities for the Defense Waste Processing Facility (DWPF) sludge batch qualification program and is documented in the report SS-PIP-2006-00030. That recommendation was supported through a technical data review by the Savannah River National Laboratory (SRNL) and is documented in the memorandums SRNL-PSE-2007-00079 and SRNL-PSE-2007-00080. At the time of writing those memorandums, the DWPF was processing sludge-only waste but, has since transitioned to a coupled operation (sludge and salt). The SRNL was recently tasked to perform a similar data review relevant to coupled operations and re-evaluate the previous recommendations. This report evaluates the validity of eliminating the characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification samples based on sludge-only and coupled operations. The pour stream sample has confirmed the DWPF's ability to produce an acceptable waste form from Slurry Mix Evaporator (SME) blending and product composition/durability predictions for the previous sixteen years but, ultimately the pour stream analysis has added minimal value to the DWPF's waste qualification strategy. Similarly, the information gained from the glass fabrication and PCT of the sludge batch qualification sample was determined to add minimal value to the waste qualification strategy since that sample is routinely not representative of the waste composition ultimately processed at the DWPF due to blending and salt processing considerations. Moreover, the qualification process has repeatedly confirmed minimal differences in glass behavior from actual radioactive waste to glasses fabricated from simulants or batch chemicals. In contrast, the

Treatment of low-level radioactive waste using Volcanic ash

International Nuclear Information System (INIS)

Valdezco, E.M.; Marcelo, E.A.; Junio, J.B.; Caseria, E.S.; Salom, D.S.; Alamares, A.L.

1997-01-01

The effective application of volcanic ash, an indigenous adsorptive material abundant in the Mt. Pinatubo area, in the removal of radioiodine from radioactive waste streams was demonstrated. Factors such as availability, low cost and comparative retention capacity with respect to activated charcoal make volcanic ash an attractive alternative in the conditioning of radioactive waste containing radioiodine. Chemical precipitation was employed in the treatment of low level aqueous waste containing 137 Cs. It was shown that there exists an optimum concentration of ferric ion that promotes maximum precipitation of caesium. It was further demonstrated that complete removal of caesium can be achieved with the addition of nickel hexacyanoferrate. (author). 5 refs, 3 figs

Treatment of low-level radioactive waste using Volcanic ash

Energy Technology Data Exchange (ETDEWEB)

Valdezco, E M; Marcelo, E A; Junio, J B; Caseria, E S; Salom, D S; Alamares, A L [Philippine Nuclear Research Inst., Manila (Philippines). Radiation Protection Services

1997-02-01

The effective application of volcanic ash, an indigenous adsorptive material abundant in the Mt. Pinatubo area, in the removal of radioiodine from radioactive waste streams was demonstrated. Factors such as availability, low cost and comparative retention capacity with respect to activated charcoal make volcanic ash an attractive alternative in the conditioning of radioactive waste containing radioiodine. Chemical precipitation was employed in the treatment of low level aqueous waste containing {sup 137}Cs. It was shown that there exists an optimum concentration of ferric ion that promotes maximum precipitation of caesium. It was further demonstrated that complete removal of caesium can be achieved with the addition of nickel hexacyanoferrate. (author). 5 refs, 3 figs.

Role of fly ash in the removal of organic pollutants from wastewater

Energy Technology Data Exchange (ETDEWEB)

M. Ahmaruzzaman [National Institute of Technology, Silchar (India). Department of Chemistry

2009-03-15

Fly ash, a relatively abundant and inexpensive material, is currently being investigated as an adsorbent for the removal of various organic pollutants from wastewater. The wastewater contains various types of phenolic compounds, such as chloro, nitro, amino, and other substituted compounds. Various types of pesticides, such as lindane, malathion, carbofuran, etc., and dyes, such as, methylene blue, crystal violet, malachite green, etc., are also present in the wastewater. These contaminants pollute the water stream. These organic pollutants, such as phenolic compounds, pesticides, and dyes, etc., can be removed very effectively using fly ash as adsorbent. This article presents a detailed review on the role of fly ash in the removal of organic pollutants from wastewater. Adsorption of various pollutants using fly ash has been reviewed. The adsorption mechanism and other influencing factors, favorable conditions, and competitive ions, etc., on the adsorption process have also been discussed in this paper. It is evident from the review that fly ash has demonstrated good removal capabilities for various organic compounds. 171 refs., 3 figs., 5 tabs.

Time-Efficiency of Sorting Chironomidae Surface-Floating Pupal Exuviae Samples from Urban Trout Streams in Northeast Minnesota, USA

Directory of Open Access Journals (Sweden)

Alyssa M Anderson

2012-10-01

Full Text Available Collections of Chironomidae surface-floating pupal exuviae (SFPE provide an effective means of assessing water quality in streams. Although not widely used in the United States, the technique is not new and has been shown to be more cost-efficient than traditional dip-net sampling techniques in organically enriched stream in an urban landscape. The intent of this research was to document the efficiency of sorting SFPE samples relative to dip-net samples in trout streams with catchments varying in amount of urbanization and differences in impervious surface. Samples of both SFPE and dip-nets were collected from 17 sample sites located on 12 trout streams in Duluth, MN, USA. We quantified time needed to sort subsamples of 100 macroinvertebrates from dip-net samples, and less than or greater than 100 chironomid exuviae from SFPE samples. For larger samples of SFPE, the time required to subsample up to 300 exuviae was also recorded. The average time to sort subsamples of 100 specimens was 22.5 minutes for SFPE samples, compared to 32.7 minutes for 100 macroinvertebrates in dip-net samples. Average time to sort up to 300 exuviae was 37.7 minutes. These results indicate that sorting SFPE samples is more time-efficient than traditional dip-net techniques in trout streams with varying catchment characteristics.doi: 10.5324/fn.v31i0.1380.Published online: 17 October 2012.

The analysis of mechanical properties of non autoclaved aerated concrete with the substitution of fly ash and bottom ash

Science.gov (United States)

Karolina, R.; Muhammad, F.

2018-02-01

Based on PP. No.85 of 1999 on the management of hazardous and toxic (B3), fly ash and bottom ash wastes are categorized into B3 waste because there are heavy metal oxide contents that can pollute the environment. One form of environmental rescue that can be applied is to utilize waste fly ash and bottom ash in the manufacture of concrete. In this research, fly ash and bottom ash waste are used as substitution of cement and fine aggregate to make lightweight concrete. The purpose of this research is to know the mechanical properties of non-autoclaved aerated lightweight concrete (NAAC) with FA and BA substitution to cement and fine aggregate which is expected to improve the quality of concrete. The NAAC lightweight concrete in this study is divided into 4 categories: normal NAAC lightweight concrete, NAAC lightweight NAAC substituted concrete with FA, NAAC lightweight concrete substituted with BA, and NAAC combined light weight from FA and BA with variations of 10%, 20% And 30%. The test specimen used in cylindrical shape, which was tested at the age of 28 days, amounted to 90 pieces and consisted of 10 variations. Each variation amounted to 9 samples. Based on the test results with FA and BA substitutions of 10%, 20%, and 30%, the highest compressive strength was achieved in samples with FA 30% of 12.687 MPa, maximum tensile strength achieved in samples with FA 30% of 1,540 MPa, The highest absorption was achieved in normal NAAC of 5.66%. Based on the weight of the contents of all samples, samples can be categorized in lightweight concrete, since the weight of the contents is less than 1900 kg / m3.

Land use/land cover and scale influences on in-stream nitrogen uptake kinetics

Science.gov (United States)

Covino, Tim; McGlynn, Brian; McNamara, Rebecca

2012-06-01

Land use/land cover change often leads to increased nutrient loading to streams; however, its influence on stream ecosystem nutrient transport remains poorly understood. Given the deleterious impacts elevated nutrient loading can have on aquatic ecosystems, it is imperative to improve understanding of nutrient retention capacities across stream scales and watershed development gradients. We performed 17 nutrient addition experiments on six streams across the West Fork Gallatin Watershed, Montana, USA, to quantify nitrogen uptake kinetics and retention dynamics across stream sizes (first to fourth order) and along a watershed development gradient. We observed that stream nitrogen (N) uptake kinetics and spiraling parameters varied across streams of different development intensity and scale. In more developed watersheds we observed a fertilization affect. This fertilization affect was evident as increased ash-free dry mass, chlorophylla, and ambient and maximum uptake rates in developed as compared to undeveloped streams. Ash-free dry mass, chlorophylla, and the number of structures in a subwatershed were significantly correlated to nutrient spiraling and kinetic parameters, while ambient and average annual N concentrations were not. Additionally, increased maximum uptake capacities in developed streams contributed to low in-stream nutrient concentrations during the growing season, and helped maintain watershed export at low levels during base flow. Our results indicate that land use/land cover change can enhance in-stream uptake of limiting nutrients and highlight the need for improved understanding of the watershed dynamics that control nutrient export across scales and development intensities for mitigation and protection of aquatic ecosystems.

Wildfire Ash: Chemical Composition, Ash-Soil Interactions and Environmental Impacts

Science.gov (United States)

Brook, Anna; Hamzi, Seham; Wittenberg, Lea

2015-04-01

produced ash has significant and not always constructive pedological, ecological, hydrological and geomorphological effects and impacts (Shakesby, 2011). Abundant scientific information is assembled either from control fires by collecting samples before and after wildfire event, or conducting laboratory experiments exanimating data under truly isolated conditions (Lugassi et al., 2013). However, an integration and synthesis of the knowledge about ash including deeper understanding of inter-correlation between chemical, physical and morphological compounds in open post-burn environment and its possible interactions in soil formation or impact on soil composition are highly needed. The main aim of the presented study was to advance the science of soil-fire relationship by recognizing the remains ash as a new soil-forming factor, on par with the traditionally recognized factors: parent material, topography, time, climate, organisms, and recently recognized human activity as the sixth factor. This research was conducted to develop new methods to assess impacts and quantify the contributions/influences of post-fire products, mainly ash, on soil composition and soil properties in post-burned environment. We conducted several controlled experiments using 40 soil samples (typical Mediterranean Rendzina soil, pH 6.84, a grayish-brown, humus- and free calcium carbonate- rich, intra-zonal). The samples include bare soils and different types and loads of forest litter, were exposed to different temperatures (200° C, 400° C and 600° C) in a muffle furnace for 2 hours (Pereira et al. 2011) as fire temperature plays a key role in determining ash properties. The ash produced at a low temperatures (50% carbon and retains many of the structural characteristics of the parent material. At higher temperatures, the residue ash is greyish, consisted of very fine particles that preserve almost none of the original structural characteristics of the fuel (Woods and Balfour, 2008) creating

Characterization of ash pond ashes from 3rd thermal power plant by SEM/EDX and XRD methods

Directory of Open Access Journals (Sweden)

A Minjigmaa

2014-10-01

Full Text Available   Coal combustion by products from ash pond of 3rdthermal power plant of Ulaanbaatar city have been collected in 2010 and 2013 years. The ash samples have been characterized by XRD, XRF and SEM-EDX methods in order to evaluate their chemical and mineralogical composition changes with disposed times. The mineralogical composition of ash varies with time though the chemical composition of the ashes were close each other. Possibly, inefficient operating condition of the TPS shows influence on the mineralogical composition.DOI: http://dx.doi.org/10.5564/mjc.v14i0.201Mongolian Journal of Chemistry 14 (40, 2013, p61-65

Derivation of site-specific selenium criteria for a Kentucky stream receiving fly ash effluent

International Nuclear Information System (INIS)

Reash, R.J.; Van Hassel, J.H.

1993-01-01

Blaine Creek, a fifth-order tributary to the Big Sandy River in eastern Kentucky, receives fly ash effluent from Kentucky Power Company's Big Sandy Plant fly ash pond near the creek's mouth. Long-term biosurvey/physicochemical data and speciation studies were used to derive proposed site-specific selenium water quality criteria. Biosurvey results from 1982--1990 were consistent in showing no adverse effects of fly ash discharge, even during low flow conditions when the effluent comprised 75% of creek flow. Five macroinvertebrate parameters (taxa richness, total abundance, EPT taxa, number caddisflies and chironomids) were significantly correlated with % effluent, indicating enhanced communities at high instream waste concentrations. Several fish metrics similarly showed greater enhancement at high % effluent conditions. Selenium speciation studies indicated that selenite (Se 4+ ) represented 100% of total selenium in the effluent. Total selenium concentrations were low at fully mixed downstream reaches. US EPA's Recalculation Procedure was used to calculate site-specific selenium criteria based on Se 4+ toxicity data for resident species. These criteria are higher than statewide criteria which are based on selenium, effects at waterbodies having low turnover rates

Temporal evolution of wildfire ash and its implications for water pollution

Science.gov (United States)

Santin, Cristina; Doerr, Stefan H.; Otero, Xose L.; Chafer, Chris J.

2015-04-01

Ash, the burnt residue generated from combustion of vegetation, litter and surface soil, covers the ground after every wildfire. The effects of wildfire ash on the post-fire landscape are many and very diverse. It is a source of nutrients and can, therefore, help the recovery of vegetation after fire. Furthermore, in its initial state, the ash layer on the ground can protect the bare soil from rain splash erosion and can act as an adsorbent layer, preventing or delaying post-fire water erosion by runoff. However, when the adsorbent capability of the ash layer is exceeded, this highly erodible material can be transported into the hydrological network and be a major contributor to water contamination. Most previous studies on post-fire erosion and water contamination have focused on soil erosion and associated sediment transfer and overlooked the ash component or, when considered, ash has been included as an unidentified part of the eroded sediment. One of the reasons for overlooking this key post-fire component is the difficulty of ash sampling before it is lost by wind or water erosion or altered by aging on-site. Here we compare the water contamination potential of ash obtained from two fires in the dry eucalyptus forest environment of the Sydney tablelands, Australia: i) 'aged ash' produced during the severe Balmoral wildfire and sampled two months after the event (Jan. 2014) and ii) 'fresh ash' sampled immediately after a high-intensity experimental fire in the same region (Sept. 2014). At the time of sampling, neither of the ash types had been affected by water erosion, however, the aged ash had been subjected to rainfall events and, potentially, to wind erosion during the two months of exposure. Vegetation type, fuel loads and fire severity, determined using remote sensing and on-site observations, were comparable between both areas sampled. Ash physicochemical properties differed, with 'fresh ash' having higher pH and EC values and higher concentration of

Incineration of a typical LWR combustible waste and analysis of the resulting ash

International Nuclear Information System (INIS)

Treat, R.L.; Lokken, R.O.; Schliebe, M.J.

1983-05-01

In this study 4540 kg (10,000 lb) of simulated nuclear power plant combustion wastes were burned in a controlled-air incinerators. The purpose of this work was to generate ashes suitable for solidification, the products of which will be analyzed to determine if they are suitable for disposal. Two different types of waste were burned: resin and simulated crud, and general trash (paper, plastics, wood, rubber, and cloth). Volume-reduction ratios (unburned waste: ash) were 13:1 and 22:1, respectively. Approximately 20% of the ash was lost due to adherence to incinerator walls and entrainment in the off-gas stream. Losses of the volatile species cesium and iodine were 79% and 100%, respectively. The ashes were not hygroscopic, but they exhibited a pH of 4.6 to 5.0 when water was added. Corrosion of mild steel drums would occur within this pH range. The ashes contained a significant quantity of clinkers haveing lengths as great as 20 cm (8 in.). Most of the clinkers were fully incinerated and easy to crush, suggesting that standard comminuting equipment should be effective in reducing the size of clinkers to allow their solidification with the fine ashes

The stability of clay using volcanic ash of Mount Sinabung North Sumatera and sugarcane bagasse ash with cbr and uct value

Directory of Open Access Journals (Sweden)

Hastuty Ika Puji

2017-01-01

Full Text Available Soil is the fundamental material that is extremely as the place of establishment of a structure or construction, both building and road constructions. However, not all soil is well used in the constructions field, as there are several types of soil that are problematic in terms of both the soil bearing capacity and deformation. The clay with carrying capacity and low shear strength needs to stabilized in order to meet the technical requirements to be used as sub grade. The add materials that are typically used for soil stabilization are cement, lime or a mixture of two or three of the added materials. In this study, the added material use volcanic ash of Mount Sinabung at North Sumatera and sugarcane bagasse ash. The purpose of this study was to determine an index value of properties as the result of the addition of 4% volcanic ash and variations in content of bagasse ash on clay and then to determine the compressive strength for maximum testing UCT (Unconfined Compression Test and understand the value of CBR (California Bearing Capacity as the consequence of the addition of a stabilizing agent, as well as optimum level of addition of bagasse ash. The result showed that the original soil sample has the water content 12.35%, specific gravity of 2.65, liquid limit of 46.73% and plasticity index of 26.44%. The compressive strength value of 1.38 kg/cm2. Base on the USCS classification, the soil sample including the type CL while base on AASHTO classification, soil samples are include this A-7-6 type. After the soil is stabilized with a wide variety of sugarcane bagasse ash content value obtained the largest unconfined compression test in 4% addition level volcanic ash + 10% sugarcane bagasse ash is equal to 5.1kg/cm2 and the result California Bearing capacity value on the optimal mix of 4% volcanic ash + 4% sugarcane bagasse ash is equal to 13.91%.

Recirculation of biomass ashes onto forest soils: Ash composition, mineralogy and leaching properties

DEFF Research Database (Denmark)

Maresca, Alberto; Hyks, J.; Astrup, Thomas Fruergaard

2017-01-01

In Denmark, increasing amounts of wood ashes are generated from biomass combustion for energy production. The utilisation of ashes on top of forest soil for liming purposes has been proposed asan alternative to landfilling. Danish wood ash samples were collected and characterised with respect......, minor and trace elements were affected significantly by pH: high releases of PO4 3-, Mg, Zn, Cu and Cd were found for acidic conditions relevant to forest soils, while the highest releases of Mo and Cr were observed in alkaline conditions. Mineral phases were selected based on XRD analyses...... critical element compared with soil quality criteria, whereas the maximum theoretical loads of Ba, Cd, Cr, Sr, Mo, Ni, Pb, Sb, Se, Sn and V were relatively low....

Natural radioactivity level in coal and ash collected from Baoji coal-fired power plant

International Nuclear Information System (INIS)

Jia Xiaodan; Lu Xinwei

2006-01-01

Specific activities of natural radionuclides 226 Ra, 232 Th and 40 K were assessed in coal (3 samples), fly ash (17 samples) and bottom ash (6 samples) collected from Baoji coal-fired power plant. This paper analyzed the characteristics of 226 Ra, 232 Th and 40 K contents in bottom ash and fly ash, and studied the concentration factors of these radionuclides in ash in relation to those in coal. The level of natural radionuclides 226 Ra, 232 Th and 40 K of coal collected from Baoji coal-fired power plant are in the range of radionuclides contents of Chinese coal. The natural radioactivity level of fly ash collected from Baoji coal-fired power plant is close to Beijing and Shanghai coal-fired power plants. The paper farther assessed the possibility of fly ash of Baoji coal-fired power plant used as building materials according to the state standard. The results show that there are 29% samples exceeding the state limit when fly ash used as building materials. So the usage of fly ash in building material should be controlled. (authors)

Characterisation of wood combustion ashes

DEFF Research Database (Denmark)

Maresca, Alberto

The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

Column leaching from biomass combustion ashes

DEFF Research Database (Denmark)

Maresca, Alberto; Astrup, Thomas Fruergaard

2015-01-01

The utilization of biomass combustion ashes for forest soil liming and fertilizing has been addressed in literature. Though, a deep understanding of the ash chemical composition and leaching behavior is necessary to predict potential benefits and environmental risks related to this practice....... In this study, a fly ash sample from an operating Danish power plant based on wood biomass was collected, chemically characterized and investigated for its leaching release of nutrients and heavy metals. A column leaching test was employed. The strongly alkaline pH of all the collected eluates suggested...

Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

Directory of Open Access Journals (Sweden)

Nabih K.

2014-04-01

Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28μm and of big particles(300 μm. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

Losses of radionuclides related to high temperature ashing

International Nuclear Information System (INIS)

Carlsson, G.

1985-01-01

When measuring radionuclides in samples from the environment of nuclear power plants, a sample preparation step, such as high temperature ashing is often necessary. Althoug much used, this method is subject to controversy because of the risk of losses of several elements. A study, including the ashing of synthetically prepared samples has been undertaken. Controlled and moderate temperature rise rate and a final temperature not exceeding 550 deg. C has been shown vital for recovery

Water Adsorption Isotherms on Fly Ash from Several Sources.

Science.gov (United States)

Navea, Juan G; Richmond, Emily; Stortini, Talia; Greenspan, Jillian

2017-10-03

In this study, horizontal attenuated total reflection (HATR) Fourier-transform infrared (FT-IR) spectroscopy was combined with quartz crystal microbalance (QCM) gravimetry to investigate the adsorption isotherms of water on fly ash, a byproduct of coal combustion in power plants. Because of composition variability with the source region, water uptake was studied at room temperature as a function of relative humidity (RH) on fly ash from several regions: United States, India, The Netherlands, and Germany. The FT-IR spectra show water features growth as a function of RH, with water absorbing on the particle surface in both an ordered (ice-like) and a disordered (liquid-like) structure. The QCM data was modeled using the Brunauer, Emmett, and Teller (BET) adsorption isotherm model. The BET model was found to describe the data well over the entire range of RH, showing that water uptake on fly ash takes place mostly on the surface of the particle, even for poorly combusted samples. In addition, the source region and power-plant efficiency play important roles in the water uptake and ice nucleation (IN) ability of fly ash. The difference in the observed water uptake and IN behavior between the four samples and mullite (3Al 2 O 3 ·2SiO 2 ), the aluminosilicate main component of fly ash, is attributed to differences in composition and the density of OH binding sites on the surface of each sample. A discussion is presented on the RH required to reach monolayer coverage on each sample as well as a comparison between surface sites of fly ash samples and enthalpies of adsorption of water between the samples and mullite.

Fixed-bed studies of the interactions between mercury and coal combustion fly ash

Energy Technology Data Exchange (ETDEWEB)

Dunham, Grant E.; DeWall, Raymond A. [Energy and Environmental Research Center, 15 North 23rd Street, Grand Forks, ND 58203 (United States); Senior, Constance L. [Reaction Engineering International, 77 West 200 South, Suite 210, Salt Lake City, UT 84101 (United States)

2003-08-15

Sixteen different fly ash samples, generated from both pilot-scale and full-scale combustion systems, were exposed to a simulated flue gas containing either elemental mercury or HgCl{sub 2} in a bench-scale reactor system at the Energy and Environmental Research Center to evaluate the interactions and determine the effects of temperature, mercury species, and ash type on adsorption of mercury and oxidation of elemental mercury. The fly ash samples were characterized for surface area, loss on ignition, and forms of iron in the ash. While many of the ash samples oxidized elemental mercury, not all of the samples that oxidized mercury also captured elemental mercury. However, no capture of elemental mercury was observed without accompanying oxidation. Generally, oxidation of elemental mercury increased with increasing amount of magnetite in the ash. However, one high-carbon subbituminous ash with no magnetite showed considerable mercury oxidation that may have been due to unburned carbon. Surface area as well as the nature of the surface appeared to be important for oxidation and adsorption of elemental mercury. The capacity of the ash samples for HgCl{sub 2} was similar to that for elemental mercury. There was a good correlation between the capacity for HgCl{sub 2} and the surface area; capacity decreased with increasing temperature.

Transcriptomic signatures of ash (Fraxinus spp. phloem.

Directory of Open Access Journals (Sweden)

Xiaodong Bai

2011-01-01

Full Text Available Ash (Fraxinus spp. is a dominant tree species throughout urban and forested landscapes of North America (NA. The rapid invasion of NA by emerald ash borer (Agrilus planipennis, a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra, green (F. pennsylvannica and white (F. americana are highly susceptible, the Asian species Manchurian ash (F. mandshurica is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem.Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3 revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species.The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis, and in future ash breeding programs for marker development.

On the removal of hexavalent chromium from a Class F fly ash.

Science.gov (United States)

Huggins, F E; Rezaee, M; Honaker, R Q; Hower, J C

2016-05-01

Coarse and fine samples of a Class F fly ash obtained from commercial combustion of Illinois bituminous coal have been exposed to two long-term leaching tests designed to simulate conditions in waste impoundments. ICP-AES analysis indicated that the coarse and fine fly ash samples contained 135 and 171mg/kg Cr, respectively. Measurements by XAFS spectroscopy showed that the ash samples originally contained 5 and 8% of the chromium, respectively, in the hexavalent oxidation state, Cr(VI). After exposure to water for more than four months, the percentage of chromium as Cr(VI) in the fly-ash decreased significantly for the coarse and fine fly-ash in both tests. Combining the XAFS data with ICP-AES data on the concentration of chromium in the leachates indicated that, after the nineteen-week-long, more aggressive, kinetic test on the coarse fly ash, approximately 60% of the Cr(VI) had been leached, 20% had been reduced to Cr(III) and retained in the ash, and 20% remained as Cr(VI) in the ash. In contrast, during the six-month-long baseline test, very little Cr was actually leached from either the coarse or the fine fly-ash (ash was retained in the ash in that form, while the remainder, 34% and 80%, respectively, was reduced and retained in the ash as Cr(III). The results are interpreted as indicating that Cr(VI) present in Class F fly-ash can be reduced to Cr(III) when in contact with water and that such chemical reduction can compete with physical removal of Cr(VI) from the ash by aqueous leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of atomic absorption Spectrophotometry (ashing, non ...

African Journals Online (AJOL)

Three commonly used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and AAS-Non Ashing) and titrimetry (potassium permanganate titration) have been evaluated in this study to determine the calcium content in six food samples whose calcium levels ranged from 0 to more than 250mg/100g ...

Fly ash quality and utilization

Energy Technology Data Exchange (ETDEWEB)

Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

1995-12-01

The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

Collection and preparation of wet and dry stream-sediment samples

International Nuclear Information System (INIS)

Puchlik, K.

1977-03-01

Lawrence Livermore Laboratory is responsible for the Hydrogeochemistry and Stream Sediment Reconnaissance (HSSR) program for uranium in the seven far western states. The work thus far has concentrated on the arid to semi-arid regions of the West and this paper discusses the collection and preparation of sediment samples in the Basin and Range province. The sample collection and preparation procedures described here may not be applicable to other parts of the far western states or other areas. These procedures also differ somewhat from those used by the other three laboratories involved in the HSSR program

Ash fusion temperatures and their association with the transformations of coal ash particles to slag

Energy Technology Data Exchange (ETDEWEB)

Gupta, S.K.; Wall, T.F.; Gupta, R.P. [Cooperative Research Centre for Black Coal Utilisation, Newcastle, NSW (Australia); Creelman, R.A. [Creelman (R.A.) and Associates, Sydney, NSW (Australia)

1997-04-01

Ash deposition on furnace walls in PF (pulverized fuel) furnaces is called slagging when it occurs in the high temperature areas of furnaces directly exposed to flame radiation and fouling in other regions such as tubes in the convection section of the boiler. There are well documented shortcomings of certain approaches relating to their uncertainties as predictive tools for plant performance such as poor repeatability and re-producibility of ash fusion measurements. The nature of physical and chemical changes occurring during melting of coal ash has been investigated in the current study to provide an alternative procedure to the ash fusion test. Shrinkage measurements are frequently used in metallurgy and ceramic science to study the physical properties of materials at high temperatures. The output of this experiment provides three to four `peaks` (maximum rate of shrinkage with temperature) of different intensity and at different temperatures which are related to melting characteristics of the sample. It was concluded that shrinkage extents exceeding 50 percent indicated that the effect of the ash particle size is of secondary importance compared to ash chemistry in determining shrinkage levels, with fine particles giving rapid shrinkage events 10 degrees C lower in temperature. (author). 7 figs., refs.

Impact of sampling strategy on stream load estimates in till landscape of the Midwest

Science.gov (United States)

Vidon, P.; Hubbard, L.E.; Soyeux, E.

2009-01-01

Accurately estimating various solute loads in streams during storms is critical to accurately determine maximum daily loads for regulatory purposes. This study investigates the impact of sampling strategy on solute load estimates in streams in the US Midwest. Three different solute types (nitrate, magnesium, and dissolved organic carbon (DOC)) and three sampling strategies are assessed. Regardless of the method, the average error on nitrate loads is higher than for magnesium or DOC loads, and all three methods generally underestimate DOC loads and overestimate magnesium loads. Increasing sampling frequency only slightly improves the accuracy of solute load estimates but generally improves the precision of load calculations. This type of investigation is critical for water management and environmental assessment so error on solute load calculations can be taken into account by landscape managers, and sampling strategies optimized as a function of monitoring objectives. ?? 2008 Springer Science+Business Media B.V.

Low-level radiation in coals utilized and ashes produced at New York State electric utilities

International Nuclear Information System (INIS)

Hornibrook, C.

1981-01-01

Eight coal-fired power plants in New York State were sampled for coal, fly ash and bottom ash. Samples were analyzed for uranium 238, uranium 235, uranium 234, thorium 232, thorium 230, radium 226, lead 210, polonium 210, radon 222. The leachate of six fly ash samples was analyzed for all of the above except radon 222. Some data on fly ash analysis are included

Trace elements of coal, coal ashes and fly ashes by activation analysis with shor-lived nuclides

International Nuclear Information System (INIS)

Boeck, H.; Sarac, I.; Grass, F.

1981-01-01

On irradiation with neutrons, some of the interesting trace elements in coal, coal ash and fly ash produce short-lived nuclides which may be determined - together with some of the matrix elements - by activation analysis. This enables the characterization of samples. To find out the distribution of elements in the gaseous or aerosol exhaust of fossil-fired power plants, the authors simulated the combustion in a quartz apparatus containing a cold trap, using the combustion temperature (780 deg C) employed for the standard ash determination. High Se values were found in the cold trap deposits of black coal from Poland. Halogens were also found in the deposits. (authors)

Stabilization of ash from combustion of MSW in a fluidised bed boiler

Energy Technology Data Exchange (ETDEWEB)

Steenari, Britt-Marie; Wilewska, Magda [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

2004-06-01

Due to restrictions against the land filling of combustible waste and directives from authorities that favour energy recovery from the waste, combustion of household waste is becoming more common. Even though combustion of MSW reduces the volume of waste to be handled by approximately 90%, it produces ash residues containing most of the metals present in the original fuel and a number of other species carried through the boiler or formed during combustion. The residues can be divided into three categories: 1. Stable, inert ash that can be utilised in, for example, construction applications 2. Ash that is stable enough to be land filled as nonhazardous waste 3. Ash that contains large amounts of soluble components and potentially toxic metal species. The regulations considering leaching of ash components set limits for the release of soluble salts and toxic metals. Some fly ashes show low leachability for metals but gives a salt release that is too close to the limit for total dissolved solids. Since fly ash from FBC boilers represent the largest volume of ash from these boilers there is a need for a simple and cheap treatment method that reduces the amount of soluble salts, i.e. NaCl, KCl etc, in the ash. After stabilisation, the ash is supposed to go into a more stable category. The aim of this project has been to investigate the applicability of a method to wash such an ash with water. The work included laboratory studies of the ash properties, the water washing process, filtration properties of the ash slurry and also tests of the method in pilot scale at a full scale boiler. This work has been concentrated towards the investigation of cyclone ash from a bubbling fluidised bed boiler in Lidkoeping fired with 100% household waste. Elemental composition of ash samples before and after washing/filtration was determined by AAS or ICP after a suitable dissolution of the sample. The mineralogy of ash samples was analysed using X-ray powder diffractometry. This method

Yellow perch larval survival in the Zekiah Swamp watershed (Wicomico River, Maryland) relative to the potential effects of a coal ash storage facility

International Nuclear Information System (INIS)

Burton, W.H.; Pinkney, A.E.

1994-01-01

A coordinated program of in situ and laboratory bioassays supported by water quality analyses was used to evaluate the potential effect of a coal ash storage facility on a yellow perch (Perca flavescens) spawning area. The facility is located in the Zekiah Swamp watershed, a tributary of the Wicomico River, MD. In situ bioassays were conducted in Zekiah Swamp Run and reference locations in 1989 and 1990. Larval mortality was high in non-tidal areas of Zekiah Swamp Run, both at a site upstream and beyond the influence of the facility, and at a site downstream of the facility. Mortality was significantly less at a nearby reference stream and at a station in the tidal area of Zekiah Swamp Run. Analysis of water samples for metals (including inorganic monomeric aluminum), organic contaminants, and pH, as well as measurements of stream flow, did not identify a specific cause for the mortality. The field and laboratory bioassays showed that, although leachate from the ash facility contributed to local contamination of ground water, the facility does not appear to be responsible for the poor survival of larval yellow perch. 16 refs., 4 figs., 6 tabs

Trace and major element pollution originating from coal ash suspension and transport processes

Energy Technology Data Exchange (ETDEWEB)

Popovic, A.; Djordjevic, D.; Polic, P. [University of Belgrade, Belgrade (Yugoslavia). Faculty of Science, Dept. of Chemistry

2001-07-01

Coal ash obtained from Nikola Tesla A power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. It is concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

Norm in coal, fly ash and cement

International Nuclear Information System (INIS)

Kant, K.; Upadhyay, S.B.; Sharma, G.S.

2006-01-01

Coal is technologically important materials being used for power generation and its cinder (fly ash) is used in manufacturing of bricks, sheets, cement, land filling etc. 222 Rn (radon) and its daughters are the most important radioactive and potentially hazardous elements, which are released in the environment from the naturally occurring radioactive material (NORM) present in coal, fly ash and cement. Thus it is very important to carry out radioactivity measurements in coal, fly ash and cement from the health and hygiene point of view. Samples of coal and fly ash from different thermal power stations in northern India and various fly ash using establishments and commercially available cement samples (O.P.C. and P.P.C.) were collected and analyzed for radon concentration and exhalation rates. For the measurements, alpha sensitive LR-115 type II plastic track detectors were used. The radon concentration varied from 147 Bq/m 3 to 443 Bq/m 3 , the radium concentration varied from 1.5 to 4.5 Bq/kg and radon exhalation rate varied from 11.8 mBq.kg -1 .h -1 to 35.7 mBq.kg -1 .h -1 for mass exhalation rate and from 104.5 mBq.m -2 .h -1 to 314.8 mBq.m -2 .h -1 for surface exhalation rate in coal samples. The radon concentration varied from 214 Bq/m 3 to 590 Bq/m 3 , the radium concentration varied from 1.0 to 2.7 Bq/kg and radon exhalation rate varied from 7.8 mBq.kg -1 .h -1 to 21.6 mBq.kg -1 .h -1 for mass exhalation rate and from 138 mBq m -2 h -1 to 380.6 mBq.m -2 .h -1 for surface exhalation rate in fly ash samples. The radon concentration varied from 157.62 Bq/m 3 to 1810.48 Bq/m 3 , the radium concentration varied from 0.76 Bq/kg to 8.73 Bq/kg and radon exhalation rate varied from 6.07 mBq.kg -1 .hr -1 to 69.81 mBq.kg -1 .hr -1 for mass exhalation rate and from 107.10 mBq.m -2 .hr -1 to 1230.21 mBq.m -2 .hr -1 for surface exhalation rate in different cement samples. The values were found higher in P.P.C. samples than in O.P.C. samples. (authors)

Collateral variations between the concentrations of mercury and other water soluble ions in volcanic ash samples and volcanic activity during the 2014-2016 eruptive episodes at Aso volcano, Japan

Science.gov (United States)

Marumoto, Kohji; Sudo, Yasuaki; Nagamatsu, Yoshizumi

2017-07-01

During 2014-2016, the Aso volcano, located in the center of the Kyushu Islands, Japan, erupted and emitted large amounts of volcanic gases and ash. Two episodes of the eruption were observed; firstly Strombolian magmatic eruptive episodes from 25 November 2014 to the middle of May 2015, and secondly phreatomagmatic and phreatic eruptive episodes from September 2015 to February 2016. Bulk chemical analyses on total mercury (Hg) and major ions in water soluble fraction in volcanic ash fall samples were conducted. During the Strombolian magmatic eruptive episodes, total Hg concentrations averaged 1.69 ± 0.87 ng g- 1 (N = 33), with a range from 0.47 to 3.8 ng g- 1. In addition, the temporal variation of total Hg concentrations in volcanic ash varied with the amplitude change of seismic signals. In the Aso volcano, the volcanic tremors are always observed during eruptive stages and quiet interludes, and the amplitudes of tremors increase at eruptive stages. So, the temporal variation of total Hg concentrations could provide an indication of the level of volcanic activity. During the phreatomagmatic and phreatic eruptive episodes, on the other hand, total Hg concentrations in the volcanic ash fall samples averaged 220 ± 88 ng g- 1 (N = 5), corresponding to 100 times higher than those during the Strombolian eruptive episode. Therefore, it is possible that total Hg concentrations in volcanic ash samples are largely varied depending on the eruptive type. In addition, the ash fall amounts were also largely different among the two eruptive episodes. This can be also one of the factors controlling Hg concentrations in volcanic ash.

Interlaboratory Comparison for Digestion Methods, Analytical Methods, and Holding Times for the Analysis of Trace Elements in Biological Samples for the Kingston Fly Ash Recovery Project

Energy Technology Data Exchange (ETDEWEB)

Mathews, Teresa J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rogers, William J [Tennessee Valley Authority (TVA), Knoxville, TN (United States); Vitale, Rock [Environmental Standards, Inc., Knoxville, TN (United States); Smith, John G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peterson, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carriker, Neil [Tennessee Valley Authority (TVA), Knoxville, TN (United States)

2013-05-01

In December 2008, an ash dike at the Tennessee Valley Authority (TVA) Kingston Fossil Plant (KIF) ruptured, releasing over 1 billion gallons of coal ash into the Emory and Clinch Rivers. Coal ash may contain several contaminants of concern; of these, selenium (Se), arsenic (As), and mercury (Hg) have been highlighted in this work because of their toxicity and potential to bioaccumulate in aquatic food chains (Reash et al. 2006, Chapman et al. 2010). To assess the potential impact of the spilled coal ash on humans and the environment, a comprehensive monitoring program was established at the Kingston site, for which resident aquatic organisms (among other sample media) are collected to determine contaminant exposure and evaluate the risk to humans and wildlife.

Protecting black ash from the emerald ash borer

Science.gov (United States)

Les Benedict

2010-01-01

Black ash (Fraxinus nigra) is an important resource for Tribes in the Northeast and Great Lakes regions of the North American continent. Ash in North America is being threatened with widespread destruction as a result of the introduction of emerald ash borer beetle (Agrilus planipennis) in 2002. Measures are being taken to slow the spread of emerald ash borer beetle....

Indirect effects of emerald ash borer-induced ash mortality and canopy gap formation on epigaeic beetles.

Science.gov (United States)

Gandhi, Kamal J K; Smith, Annemarie; Hartzler, Diane M; Herms, Daniel A

2014-06-01

Exotic herbivorous insects have drastically and irreversibly altered forest structure and composition of North American forests. For example, emerald ash borer (Agrilus planipennis Fairmaire) from Asia has caused wide-scale mortality of ash trees (Fraxinus spp.) in eastern United States and Canada. We studied the effects of forest changes resulting from emerald ash borer invasion on epigaeic or ground beetles (Coleoptera: Carabidae) along a gradient of ash dieback and gap sizes in southeastern Michigan. Ground beetles were sampled in hydric, mesic, and xeric habitats in which black (Fraxinus nigra Marshall), green (Fraxinus pennsylvanica Marshall), and white (Fraxinus americana L.) ash were the most common species, respectively. During 2006-2007, we trapped 2,545 adult ground beetles comprising 52 species. There was a negative correlation between percent ash tree mortality in 2006 and catches of all beetles. Catches of Agonum melanarium Dejean (in 2006) and Pterostichus mutus (Say) (in 2006-2007) were negatively correlated with tree mortality and gap size, respectively. However, catches of Pterostichus corvinus Dejean were positively correlated with gap size in 2006. As ash mortality and average gap size increased from 2006 to 2007, catches of all beetles as well as P. mutus and Pterostichus stygicus (Say) increased (1.3-3.9 times), while species diversity decreased, especially in mesic and xeric stands. Cluster analysis revealed that beetle assemblages in hydric and mesic stand diverged (25 and 40%, respectively) in their composition from 2006 to 2007, and that hydric stands had the most unique beetle assemblages. Overall, epigaeic beetle assemblages were altered in ash stands impacted by emerald ash borer; however, these impacts may dissipate as canopy gaps close.

ENVIRONMENTAL EVALUATION FOR UTILIZATION OF ASH IN SOIL STABILIZATION

Energy Technology Data Exchange (ETDEWEB)

David J. Hassett; Loreal V. Heebink

2001-08-01

The Minnesota Pollution Control Agency (MPCA) approved the use of coal ash in soil stabilization, indicating that environmental data needed to be generated. The overall project goal is to evaluate the potential for release of constituents into the environment from ash used in soil stabilization projects. Supporting objectives are: (1) To ensure sample integrity through implementation of a sample collection, preservation, and storage protocol to avoid analyte concentration or loss. (2) To evaluate the potential of each component (ash, soil, water) of the stabilized soil to contribute to environmental release of analytes of interest. (3) To use laboratory leaching methods to evaluate the potential for release of constituents to the environment. (4) To facilitate collection of and to evaluate samples from a field runoff demonstration effort. The results of this study indicated limited mobility of the coal combustion fly ash constituents in laboratory tests and the field runoff samples. The results presented support previous work showing little to negligible impact on water quality. This and past work indicates that soil stabilization is an environmentally beneficial CCB utilization application as encouraged by the U.S. Environmental Protection Agency. This project addressed the regulatory-driven environmental aspect of fly ash use for soil stabilization, but the demonstrated engineering performance and economic advantages also indicate that the use of CCBs in soil stabilization can and should become an accepted engineering option.

The Effect of Volcanic Ash Composition on Ice Nucleation Affinity

Science.gov (United States)

Genareau, K. D.; Cloer, S.; Primm, K.; Woods, T.; Tolbert, M. A.

2017-12-01

Understanding the role that volcanic ash plays in ice nucleation is important for knowledge of lightning generation in both volcanic plumes and in clouds developing downwind from active volcanoes. Volcanic ash has long been suggested to influence heterogeneous ice nucleation following explosive eruptions, but determining precisely how composition and mineralogy affects ice nucleation affinity (INA) is poorly constrained. For the study presented here, volcanic ash samples with different compositions and mineral/glass contents were tested in both the deposition and immersion modes, following the methods presented in Schill et al. (2015). Bulk composition was determined with X-ray fluorescence (XRF), grain size distribution was determined with laser diffraction particle size analysis (LDPSA), and mineralogy was determined with X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results of the deposition-mode experiments reveal that there is no relationship between ice saturation ratios (Sice) and either mineralogy or bulk ash composition, as all samples have similar Sice ratios. In the immersion-mode experiments, frozen fractions were determined from -20 °C to -50 °C using three different amounts of ash (0.5, 1.0, and 2.0 wt% of slurry). Results from the immersion freezing reveal that the rhyolitic samples (73 wt% SiO2) nucleate ice at higher temperatures compared to the basaltic samples (49 wt% SiO2). There is no observed correlation between frozen fractions and mineral content of ash samples, but the two most efficient ice nuclei are rhyolites that contain the greatest proportion of amorphous glass (> 90 %), and are enriched in K2O relative to transition metals (MnO and TiO2), the latter of which show a negative correlation with frozen fraction. Higher ash abundance in water droplets increases the frozen fraction at all temperatures, indicating that ash amount plays the biggest role in ice nucleation. If volcanic ash can reach sufficient abundance (�

Ash and heavy metals in fluidized bed-combustion; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

Energy Technology Data Exchange (ETDEWEB)

Kaessi, T.; Aittoniemi, P. [IVO International, Vantaa (Finland)

1996-12-01

Combustion ashes and submicron fly ash particles were characterized in two industrial boilers (bubbling vs. circulating fluidized bed) burning paper mill deinking sludge and bark or wood as support fuel. Bulk samples from fly ash, circulating ash and bottom ash were analyzed. Fine particles in fly ash were monitored and sampled for microscopic studies. The mass size distribution of fly ash was measured and the chemical composition according to particle size was analyzed. The results showed that ash consists of large and friable clusters formed by sintering of small mineral particles originating from paper fillers. Very few ash particles were fused and they were found only among the smallest particles. No agglomerates of fused particles were found. If the residence time in furnace is long enough sintering may proceed further and ash structure grows more dense. No indication of ash vaporization was detected. These results were similar for bubbling and circulating fluidized bed boilers. (author)

Physical, chemical and mineralogical properties of fly ash

International Nuclear Information System (INIS)

Khairul Nizar Ismail; Kamaruddin Hussin; Mohd Sobri Idris

2007-01-01

Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Fly ash particles are generally spherical in shape and range in size from 2 μm to 10 μm. They consist mostly of silicon dioxide (SiO 2 ), aluminium oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ). Fly ash like soil contains trace concentrations of the following heavy metals: nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F. (Author)

Synthesis of a one-part geopolymer system for soil stabilizer using fly ash and volcanic ash

Directory of Open Access Journals (Sweden)

Tigue April Anne S.

2018-01-01

Full Text Available A novel approach one-part geopolymer was employed to investigate the feasibility of enhancing the strength of in-situ soil for possible structural fill application in the construction industry. Geopolymer precursors such as fly ash and volcanic ash were utilized in this study for soil stabilization. The traditional geopolymer synthesis uses soluble alkali activators unlike in the case of ordinary Portland cement where only water is added to start the hydration process. This kind of synthesis is an impediment to geopolymer soil stabilizer commercial viability. Hence, solid alkali activators such as sodium silicate (SS, sodium hydroxide (SH, and sodium aluminate (SA were explored. The influence of amount of fly ash (15% and 25%, addition of volcanic ash (0% and 12.5%, and ratio of alkali activator SS:SH:SA (50:50:0, 33:33:33, 50:20:30 were investigated. Samples cured for 28 days were tested for unconfined compressive strength (UCS. To evaluate the durability, sample yielding highest UCS was subjected to sulfuric acid resistance test for 28 days. Analytical techniques such as X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDX were performed to examine the elemental composition, mineralogical properties, and microstructure of the precursors and the geopolymer stabilized soil.

Trace and major element pollution originating from coal ash suspension and transport processes.

Science.gov (United States)

Popovic, A; Djordjevic, D; Polic, P

2001-04-01

Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

Coal ash fusion temperatures -- New characterization techniques, and associations with phase equilibria

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Gupta, R.P.; Gupta, S. [Univ. of Newcastle, New South Wales (Australia). Dept. of Chemical Engineering; Creelman, R.A. [R.A. Creelman and Associates, Epping, New South Wales (Australia); Coin, C. [ACIRL Ipswich, Booval, Queensland (Australia); Lowe, A. [Pacific Power, Sydney, New South Wales (Australia)

1996-12-31

The well-documented shortcomings of the standard technique for estimating the fusion temperature of coal ash are its subjective nature and poor accuracy. Alternative measurements based on the shrinkage and electrical conductivity of heating samples are therefore examined with laboratory ash prepared at about 800 C in crucibles, as well as combustion ash sampled from power stations. Sensitive shrinkage measurements indicate temperatures of rapid change which correspond to the formation of liquid phases that can be identified on ternary phase diagrams. The existence and extent of formation of these phases, as quantified by the magnitude of peaks in the test, provide alternative ash fusion temperatures. The peaks from laboratory ashes and corresponding combustion ashes derived from the same coals show clear differences which may be related to the evaporation of potassium during combustion and the reactions of the mineral residues to form combustion ash.

Utilization of coal ash/coal combustion products for mine reclamation

International Nuclear Information System (INIS)

Dolence, R.C.; Giovannitti, E.

1997-01-01

Society's demand for an inexpensive fuel, combined with ignorance of the long term impacts, has left numerous scars on the Pennsylvania landscape. There are over 250,000 acres of abandoned surface mines with dangerous highwalls and water filled pits. About 2,400 miles of streams do not meet water quality standards because of drainage from abandoned mines. There are uncounted households without an adequate water supply due to past mining practices. Mine fires and mine subsidence plague many Pennsylvania communities. The estimated cost to reclaim these past scars is over $15 billion. The beneficial use of coal ash in Pennsylvania for mine reclamation and mine drainage pollution abatement projects increased during the past ten years. The increase is primarily due to procedural and regulatory changes by the Department of Environmental Protection (DEP). Prior to 1986, DEP required a mining permit and a separate waste disposal permit for the use of coal ash in backfilling and reclaiming a surface mine site. In order to eliminate the dual permitting requirements and promote mine reclamation, procedural changes now allow a single permit which authorize both mining and the use of coal ash in reclaiming active and abandoned pits. The actual ash placement, however, must be conducted in accordance with the technical specifications in the solid waste regulations

Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

Directory of Open Access Journals (Sweden)

Francisco Grau

2015-10-01

Full Text Available Biomasses are organic materials that are derived from any living or recently-living structure. Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes. Thus, recycling or treatment of biomass ashes leads to utilizing the natural materials as an economical and environmental alternative. This study is intended to provide an environmental solution for uncontrolled disposal of biomass ashes by way of recycling the biomass ash and replacing the soils in geotechnical engineering projects. Therefore, in this study, characteristic tests of wood and sugarcane bagasse ashes that are considered the most common biomass ashes are conducted. The test of chemical compositions of biomass ashes is conducted using energy dispersive X-ray spectroscopy (EDS, and Scanning Electron Microscope (SEM, and heavy metal analysis is also conducted. Engineering behaviors including hydraulic conductivity, constrained modulus and shear modulus are examined. Also, coal fly ash Class C is used in this study for comparison with biomass ashes, and Ottawa 20/30 sands containing biomass ashes are examined to identify the soil replacement effect of biomass ashes. The results show that the particle sizes of biomass ashes are halfway between coal fly ash Class C and Ottawa 20/30 sand, and biomass ashes consist of a heterogeneous mixture of different particle sizes and shapes. Also, all heavy metal concentrations were found to be below the US Environmental Protection Agency (EPA maximum limit. Hydraulic conductivity values of Ottawa 20/30 sand decrease significantly when replacing them with only 1%–2% of biomass ashes. While both the constrained modulus and shear modulus of biomass ashes are lower than Ottawa 20/30 sand, those of mixtures containing up to 10% biomass ashes are little affected by replacing the soils with biomass ashes.

Analytical investigation of lignite and its ash samples taken from the Afsin-Elbistan coal basin in Turkey

Energy Technology Data Exchange (ETDEWEB)

Kucukonder, Adnan; Paksoy, Emine; Biber, Seyma [Kahramanmaras Suetcue Imam Univ. (Turkey). Dept. of Physics; Durdu, Burhanettin Goeker [Kilis 7 Aralik Univ., Kilis (Turkey). Opticianry Program; Baskaya, H.; Dogru, Mahmut [Bitlis Eren Univ. (Turkey). Dept. of Physics

2014-04-15

Lignite, taken from basin in Afsin-Elbistan region, and ash samples were analyzed according to the qualitative, quantitative and radioactivity properties. An elemental analysis was made by using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique. 59.5 keV photons emitted from a {sup 241}Am source and 5.9 keV photons emitted from a {sup 55}Fe radioactive source were used for excitation. The characteristic K X-rays of the elements were counted with a Si(Li) detector. For the same samples gross alpha, gross beta and radionuclide activities were also measured. (orig.)

Potential for thermochemical conversion of biomass residues from the integrated sugar-ethanol process - Fate of ash and ash-forming elements.

Science.gov (United States)

Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Zevenhoven, Maria; Hupa, Mikko

2017-06-01

In this work, potential for thermochemical conversion of biomass residues from an integrated sugar-ethanol process and the fate of ash and ash-forming elements in the process are presented. Ash, ash-forming elements, and energy flows in the process were determined using mass balances and analyses of eight different biomass samples for ash contents, elemental compositions, and heating values. The results show that the ash content increases from the sugarcane to the final residue, vinasse. The cane straw, which is left in the field, contains one-third of the energy and 25% of the K and Cl while the vinasse contains 2% of the energy and 40% of the K and Cl in the cane. K and Cl in biomass fuels cause corrosion and fouling problems in boilers and gasifiers. Over 85% of these elements in the straw are water soluble indicating that water leaching would improve it for utilization in thermochemical conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acidolysis of coal fly ash by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Torma, A.E.; Singh, A.K. (EG and G Idaho Inc., Idaho Falls, ID (United States). Center for Biological Processing Technology)

1993-12-01

The kinetics of aluminium extraction were investigated, using as-received and calcined fly ash samples and a pure culture of [ital Aspergillus niger]. This fungus metabolized sucrose to citric and oxalic acids, which were involved in the acidolysis of fly ash. Aluminium extraction from as-received fly ash was only 5-8%, whereas from calcined fly ash it was up to 93.5%. The order of reaction and the overall reaction rate constant were determined by the van't Hoff technique with respect to the concentration of calcined fly ash. A linearized form of a modified Monod expression was applied to the experimental data to assess the kinetic constants for the acidolysis process. Statistically designed experiments were carried out with calcined fly ash and synthetic solutions containing citric and oxalic acids to determine the optimum leaching conditions. The acidolysis reaction mechanism is discussed. 28 refs., 6 figs., 3 tabs.

Sensitivity Sampling Over Dynamic Geometric Data Streams with Applications to $k$-Clustering

OpenAIRE

Song, Zhao; Yang, Lin F.; Zhong, Peilin

2018-01-01

Sensitivity based sampling is crucial for constructing nearly-optimal coreset for $k$-means / median clustering. In this paper, we provide a novel data structure that enables sensitivity sampling over a dynamic data stream, where points from a high dimensional discrete Euclidean space can be either inserted or deleted. Based on this data structure, we provide a one-pass coreset construction for $k$-means %and M-estimator clustering using space $\\widetilde{O}(k\\mathrm{poly}(d))$ over $d$-dimen...

Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

Directory of Open Access Journals (Sweden)

Martin Ernesto Kalaw

2016-07-01

Full Text Available Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC, which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1 their technical properties are comparable if not better; (2 they can be produced from industrial wastes; and (3 within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA and coal bottom ash (CBA, and rice hull ash (RHA. The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF for elemental and X-ray diffraction (XRD for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI were determined using thermogravimetric analysis (TGA and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR

Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash.

Science.gov (United States)

Kalaw, Martin Ernesto; Culaba, Alvin; Hinode, Hirofumi; Kurniawan, Winarto; Gallardo, Susan; Promentilla, Michael Angelo

2016-07-15

Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC), which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1) their technical properties are comparable if not better; (2) they can be produced from industrial wastes; and (3) within reasonable constraints, their production requires less energy and emits significantly less CO₂. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC) use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA) and coal bottom ash (CBA), and rice hull ash (RHA). The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF) for elemental and X-ray diffraction (XRD) for mineralogical composition. The raw materials' thermal stability and loss on ignition (LOI) were determined using thermogravimetric analysis (TGA) and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP) analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR), scanning

Characterization and environmental evaluation of Atikokan coal fly ash for environmental applications

Energy Technology Data Exchange (ETDEWEB)

Yeheyis, M.B.; Shang, J.Q.; Yanful, E.K. [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering

2008-09-15

Coal fly ash from thermal power generating stations has become a valuable byproduct in various commercial and environmental applications due to its cementitious, alkaline, and pozzolanic properties. It is used as a raw material in cement production, and also as a replacement for cement in concrete production. This study provided physical, chemical, and mineralogical characterizations of fresh and landfilled coal fly ash from a thermal generation station in Ontario. Fly ash behaviour under various environmental conditions was examined. Tests were conducted to characterize fly ash acid neutralization capacity and heavy metal sorption capacity. The study showed that fresh and landfilled fly ash samples showed significant variations in morphology, mineralogy, and chemical composition. X-ray diffraction studies demonstrated that weathering of the fly ash caused the formation of secondary minerals. The study also showed that the heavy metals from both fresh and landfilled fly ash samples were below leachate criteria set by the provincial government. It was concluded that both fresh and landfilled fly ash are suitable for various environmental and engineering applications. 55 refs., 5 tabs., 11 figs.

Dynamic evaluation of municipal solid waste ash leachate

International Nuclear Information System (INIS)

Theis, T.L.; Gardner, K.H.

1992-01-01

The incineration of municipal solid waste (MSW) produces ashes which are concentrated in many inorganic species. The release of toxic elements from the ash to the aqueous environment is of concern as present methods of ash disposal consist primarily of landfilling. It was the goal of this paper to achieve an understanding of the mechanisms by which elements are transported from the solid ash phase to the aqueous phase. Twelve ash samples were collected from six different incinerators with varying designs and capacities. The leaching experiments were conducted using small (mini) dynamic columns to investigate the variation of leachate chemical characteristics with time. In analyzing the data, a multicomponent chemical equilibrium model was used to determine chemical speciation and component activities. Auxiliary experiments included an array of physical measurements, and aqueous batch leach tests

Microphysical Properties of Alaskan Volcanic Ash

Science.gov (United States)

Puthukkudy, A.; Espinosa, R.; Rocha Lima, A.; Remer, L.; Colarco, P. R.; Whelley, P.; Krotkov, N. A.; Young, K.; Dubovik, O.; Wallace, K.; Martins, J. V.

2017-12-01

Volcanic ash has the potential to cause a variety of severe problems for human health and the environment. Therefore, effective monitoring of the dispersion and fallout from volcanic ash clouds and characterization of the aerosol particle properties are essential. One way to acquire information from volcanic clouds is through satellite remote sensing: such images have greater coverage than ground-based observations and can present a "big picture" perspective. A challenge of remote sensing is that assumptions of certain properties of the target are often a pre-requisite for making accurate and quantitative retrievals. For example, detailed information about size distribution, sphericity, and optical properties of the constituent matter is needed or must be assumed. The same kind of information is also needed for atmospheric transport models to properly simulate the dispersion and fallout of volcanic ash. Presented here is a laboratory method to determine the microphysical and optical properties of volcanic ash samples collected from two Alaskan volcanoes with markedly different compositions. Our method uses a Polarized Imaging Nephelometer (PI-Neph) and a system that re-suspends the particles in an air flow. The PI-Neph measures angular light scattering and polarization of the re-suspended particles from 3o to 175o in scattering angle, with an angular resolution of 1o . Primary measurements include phase function and polarized phase function at three wavelengths (445nm, 532nm, and 661nm). Size distribution, sphericity, and complex refractive index are retrieved indirectly from the PI-Neph measurements using the GRASP (Generalized Retrieval of Aerosol and Surface Properties) inversion algorithm. We report the results of this method applied to samples from the Mt. Okmok (2008) and Mt. Katmai (1912) volcanic eruptions. To our knowledge, this is the first time direct measurements of phase matrix elements of ash from Mt. Okmok and Mt. Katmai have been reported. Retrieved

Ash Utilisation 2012. Ashes in a Sustainable Society. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-11-01

Conference themes: Risk assessment, Fly ash- Road construction, Recycling and Greenhouse gases, Storage of ashes, Fertilizer, Metal Mining, Support and Barriers, Construction Material, Civil Engineering, and MSWI bottom ash.

Ash quality and environmental quality assurance system in co-combustion - Co-combustion of forest industry waste

International Nuclear Information System (INIS)

Laine-Ylijoki, J.; Wahlstroem, M.

2000-01-01

The environmental acceptability and possible utilization of co-combustion ashes will have a significant influence on the wider use of co-combustion in the future. At present the correlation between currently used fuels, their mixture ratios, and quality variations in ashes are not known, which complicates the assessment of possible utilization and environmental acceptability of co-combustion ashes. The composition of ashes has also been found to vary significantly. Effective utilization requires that process variations to alter ash composition and quality variations are known in advance. The aim of the research was to characterize the fly ash from co- combustion of peat, wood and biological paper mill sludge produced under different fuel loadings, especially with and without sludge addition, ant to identify critical parameters influencing on the ash composition. The variations in the leaching properties of ashes collected daily were followed up. The environmental acceptability of the ashes produced under different fuel loadings, especially their suitability for use in road constructions, were evaluated. The project included also the preparation of laboratory reference material from ash material. Guidelines were developed for sampling, sample preparation and analysis, and leaching tests. Furthermore, a quality control system, including sampling strategies, sample analysis and leaching testing, was established

Use of the PISCES Database: power plant aqueous stream compositions

International Nuclear Information System (INIS)

Behrens, G.P.; Orr, D.A.; Wetherold, R.G.; O'Neil, B.T.

1996-01-01

The Power Plant Integrated Systems: Chemical Emissions Studies (PISCES) Database sponsored by the Electric Power Research Institute is a powerful tool for evaluating and comparing the level of trace substances in power plant process streams. In this paper, data are presented on the level of several selected trace metals found in a few of the aqueous streams present in power plants. A brief discussion of other features of the Database is presented. The majority of the data is for coal fired power plants, with only 5% pertaining to oil and gas. Sources of pollution include: ash streams; cooling water; coal pile runoff; FGD liquids; makeup water; and wastewater. 11 refs., 10 figs., 1 tab

Optoelectronic system of online measurements of unburned carbon in coal fly ash

Science.gov (United States)

Golas, Janusz; Jankowski, Henryk; Niewczas, Bogdan; Piechna, Janusz; Skiba, Antoni; Szkutnik, Wojciech; Szkutnik, Zdzislaw P.; Wartak, Ryszarda; Worek, Cezary

2001-08-01

Carbon-in-ash level is an important consideration for combustion efficiency as well as ash marketing. The optoelectronic analyzing system for on-line determination and monitoring of the u burned carbon content of ash samples is presented. The apparatus operates on the principle that carbon content is proportional to the reflectance of IR light. Ash samples are collected iso kinetically from the flue gas duct and placed in a sample tube with a flat glass bottom. The same is then exposed to a light. The reflectance intensity is used by the system's computer to determine residual carbon content from correlation curves. The sample is then air purged back to the duct or to the attached sample canister to enable laboratory check analysis. The total cycle time takes between 5 and 10 minutes. Real time result of carbon content with accuracy 0.3-0.7 percent are reported and can be used for boiler controlling.

Fluidised bed gasification of high-ash South African coals: An experimental and modelling study

CSIR Research Space (South Africa)

Engelbrecht, AS

2011-11-01

Full Text Available model (CeSFaMB). The predictive capability of the model was analysed in terms of the degree of variation between experimental and simulated results for each test. The calibrated model was used to design a 15 MW fluidised bed coal gasifier...-scale BFBG are given in Figure 1 and Table 1. Process description Coal, air, oxygen and steam are the input streams to the process which produce the output streams: gas and char (ash). Coal is fed to the gasifier by means of a screw conveyor at a...

Adding Value to Ash and Digestate (AVAnD). AN Integrated Overview of the Effects of Ash and Digestate Blends on the Soil-Plant System.

Science.gov (United States)

Lag-Brotons, Alfonso; Marshall, Rachel; Herbert, Ben; Hurst, Lois; Ostle, Nick; Dodd, Ian C.; Quinton, John; Surridge, Ben; Aiouache, Farid; Semple, Kirk T.

2017-04-01

Resource recovery from waste could play a central role in strategies tackling current worldwide sustainability problems. Focusing on the agricultural sector, waste streams represent an opportunity to break the cycle of nutrients depletion (exported with crop biomass) and incorporation by non-sustainable means such the use of inorganic fertilisers (either finite and/or highly energy intensive in their production). In this sense, digestate [D], from anaerobic digestion, and biomass ash [A], from incineration, are especially valuable since they supply, amongst other nutrients, nitrogen [N] and phosphorus [P], respectively. Whilst these waste streams could be highly heterogeneous, in general terms they present a complementary nutritional profile which could be exploited for the production of alternative fertilisers. This is precisely the overarching aim of the "Adding Value to Ash and Digestate [AVAnD]" project: the identification of a novel nutrient-recycling pathway to maximise soil quality and crop productivity utilising waste streams derived from bioenergy production. However, the application to land of novel recycled and recovered products entails the assessment of the biological and chemical interactions and the implications for ecosystems, to determine desirable and detrimental effects that might arise. Therefore, we aim to provide an insight on the AVAnD project and briefly describe and discuss some of the findings obtained so far. Experiments were carried out at different scales and under different conditions using two different digestates ([D1], [D2]) and two ash fractions (fly [A1] and bottom [A2]). The main factor considered was fertiliser type including A/D blends, A & D alone, no fertilisation and inorganic fertilisers. Fertilisation target (63/60 kg N/P2O5 per ha) was the same across the different fertiliser materials. Aspects covered included nutrient availability (N-, P- forms), soil properties (DOC, pH, EC), greenhouse gas emissions (CO2, N2O) and

Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

Science.gov (United States)

Bodi, Merche B.; Martin, Deborah; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Cerda, Artemi; Mataix-Solera, Jorge

2014-01-01

Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The homogeneity and thickness of the ash layer can vary substantially in space and time and reported average thicknesses range from close to 0 to 50 mm. Ash is a highly mobile material that, after its deposition, may be incorporated into the soil profile, redistributed or removed from a burned site within days or weeks by wind and water erosion to surface depressions, footslopes, streams, lakes, reservoirs and, potentially, into marine deposits.Research on the composition, properties and effects of ash on the burned ecosystem has been conducted on material collected in the field after wildland and prescribed fires as well as on material produced in the laboratory. At low combustion completeness (typically T  450 °C), most organic carbon is volatized and the remaining mineral ash has elevated pH when in solution. It is composed mainly of calcium, magnesium, sodium, potassium, silicon and phosphorous in the form of inorganic carbonates, whereas at T > 580 °C the most common forms are oxides. Ash produced under lower combustion completeness is usually darker, coarser, and less dense and has a higher saturated hydraulic conductivity than ash with higher combustion completeness, although physical reactions with CO2 and when moistened produce further changes in ash characteristics.As a new

Ultrasonic coal-wash for de-ashing and de-sulfurization. Experimental investigation and mechanistic modeling

Energy Technology Data Exchange (ETDEWEB)

Ambedkar, B. [Indian Institute of Technology Madras, Chennai (India). Dept. of Chemical Engineering

2012-07-01

This study focuses on the physical aspects of ultrasonic de-ashing and de-sulfurization, such as cavitation, streaming and their combined effects. Ambedkar Balraj proposes an ultrasound-assisted coal particle breakage mechanism and explores aqueous and solvent-based ultrasonic techniques for de-ashing and de-sulfurization. Ambedkar designs a Taguchi L-27 fractional-factorial matrix to assess the individual effects of key process variables. In this volume he also describes process optimization and scale-up strategies. The author provides a mechanism-based model for ultrasonic reagent-based coal de-sulfurization, proposes a flow diagram for ultrasonic methods of high-throughput coal-wash and discusses the benefits of ultrasonic coal-wash. Coal will continue to be a major fuel source for the foreseeable future and this study helps improve its use by minimising ash and sulfur impurities.

Effect of Feed Forms on the Results of Melting of Fly Ash by a DC Plasma Arc Furnace

International Nuclear Information System (INIS)

Chen Mingzhou; Meng Yuedong; Shi Jiabiao; Ni Guohua; Jiang Yiman; Yu Xinyao; Zhao Peng

2009-01-01

Fly ash from a municipal solid waste incinerator (MSWI) without preprocessing (original fly ash, OFA) was melted by a direct current (DC) plasma arc furnace to investigate how the feed forms governed the results. Dioxins in flue gas from stack and bag-filter ash (BFA) were detected. The distribution of heavy metals of Pb, Cd, As, and Cr along the flue gas process system was analyzed. Through a comparison of the results for dioxins and heavy metals in this study and previous work, carrying-over of fly ash particles with the flue gas stream can be deduced. Based on the magnetic induction equation and Navier-Stokes equations, a magnetohydrodynamic (MHD) model for the plasma arc was developed to describe the particle-carrying effect. The results indicate that, a. when melted, the feed forms of MSWI fly ash affect the results significantly; b. it is not preferable to melt MSWI fly ash directly, and efforts should be made to limit the mass transfer of OFA from the plasma furnace. (plasma technology)

Effect of Feed Forms on the Results of Melting of Fly Ash by a DC Plasma Arc Furnace

Science.gov (United States)

Chen, Mingzhou; Meng, Yuedong; Shi, Jiabiao; Ni, Guohua; Jiang, Yiman; Yu, Xinyao; ZHAO, Peng

2009-10-01

Fly ash from a municipal solid waste incinerator (MSWI) without preprocessing (original fly ash, OFA) was melted by a direct current (DC) plasma arc furnace to investigate how the feed forms governed the results. Dioxins in flue gas from stack and bag-filter ash (BFA) were detected. The distribution of heavy metals of Pb, Cd, As, and Cr along the flue gas process system was analyzed. Through a comparison of the results for dioxins and heavy metals in this study and previous work, carrying-over of fly ash particles with the flue gas stream can be deduced. Based on the magnetic induction equation and Navier-Stokes equations, a magnetohydrodynamic (MHD) model for the plasma arc was developed to describe the particle-carrying effect. The results indicate that, a. when melted, the feed forms of MSWI fly ash affect the results significantly; b. it is not preferable to melt MSWI fly ash directly, and efforts should be made to limit the mass transfer of OFA from the plasma furnace.

Ash Deposition Trials at Three Power Stations in Denmark

DEFF Research Database (Denmark)

Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

1998-01-01

Six full-scale trials were conducted at three power stations in Denmark: Ensted, Funen, and Vendsyssel power stations. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analyzed with various techniques. On the basis of SEM analyses...

Fundamental study of low-NOx combustion fly ash utilization

International Nuclear Information System (INIS)

Suuberg, Eric M.; Hurt, Robert H.

1998-01-01

This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over fifty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives

Microstructural characterization of ashes from Morinda citrifolia L. (Noni)

International Nuclear Information System (INIS)

Garay, Zoila; Acha De la Cruz, Otilia; Collantes, Ingrit; Olivera, Paula; Santiago, Julio; Universidad Nacional Mayor de San Marcos, Lima

2011-01-01

Noni, Morinda citrifolia Linnaeus, is widely used in traditional medicine due to its antibacterial, antiviral, antiparasitic and antifungal properties, preventing the proliferation of tumors and diabetes. This paper presents a study of the elemental and morphological composition of the ashes from the peels, seeds, pulp and leaves of the noni. These ashes are basically amorphous, except those from the annealing of the leaves. The main compounds that have been identified are the CaCO 3 (seeds and leaves), CaC 2 O 4 (peels and seeds), KHCO 3 (all samples except in leaves), KCl (leaves) and SiO 2 (leaves and pulp). Nanoparticles (20 nm) have been observed in all samples except in the ashes of leaves. (author).

Thermo-mechanical properties and microfabric of fly ash-stabilized gold tailings.

Science.gov (United States)

Lee, Joon Kyu; Shang, Julie Q; Jeong, Sangseom

2014-07-15

This paper studies the changes in thermal conductivity, temperature, and unconfined compressive strength of gold tailings and fly ash mixtures during the curing period of 5 days. The microfabric of the cured mixtures was investigated with mercury intrusion porosimetry (MIP). The mixture samples were prepared at their maximum dry unit weight and optimum moisture content. Effect of adding fly ash to gold tailings (i.e., 0, 20, and 40% of the dry weight of tailings) was examined, and a comparison was made on samples prepared at the same fly ash content by replacing gold tailings with humic acid (i.e., gold tailings and humic acid ratios of 100:0, 90:10, and 80:20 by weight) or by varying pore fluid chemistry (i.e., water and salt solutions of 1M NaCl and CaCl2). The results show that the initial thermal conductivity of the samples is sensitive to the mixture proportion and a declination in the thermal conductivity is observed due to hydration of fly ash and evaporation. Inclusion of fly ash and salts into gold tailings improves the unconfined compressive strength but the presence of humic acid in samples leads to the decrease of the strength. MIP results reveal the pore structure changes associated with the packing states of the samples that reflect the influential factors considered. Copyright © 2014 Elsevier B.V. All rights reserved.

Geotechnical properties of ash deposits near Hilo, Hawaii

Science.gov (United States)

Wieczorek, G.F.; Jibson, R.W.; Wilson, R.C.; Buchanan-Banks, J. M.

1982-01-01

Two holes were hand augered and sampled in ash deposits near Hilo, Hawaii. Color, water content and sensitivity of the ash were measured in the field. The ash alternated between reddish brown and dark reddish brown in color and had water contents as high as 392%. A downhole vane shear device measured sensitivities as high as 6.9. A series of laboratory tests including grain size distribution, Atterberg limits, X-ray diffraction analysis, total carbon determination, vane shear, direct shear and triaxial tests were performed to determine the composition and geotechnical properties of the ash. The ash is very fine grained, highly plastic and composed mostly of gibbsite and amorphous material presumably allophane. The ash has a high angle of internal friction ranging from 40-43? and is classified as medium to very sensitive. A series of different ash layers was distinguished on the basis of plasticity and other geotechnical properties. Sensitivity may be due to a metastable fabric, cementation, leaching, high organic content, and thixotropy. The sensitivity of the volcanic ash deposits near Hilo is consistent with documented slope instability during earthquakes in Hawaii. The high angles of internal friction and cementation permit very steep slopes under static conditions. However, because of high sensitivity of the ash, these slopes are particularly susceptible to seismically-induced landsliding.

Geopolymer obtained from coal ash

International Nuclear Information System (INIS)

Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M.

2011-01-01

Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

Ge extraction from gasification fly ash

Energy Technology Data Exchange (ETDEWEB)

Oriol Font; Xavier Querol; Angel Lopez-Soler; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

2005-08-01

Water-soluble germanium species (GeS{sub 2}, GeS and hexagonal-GeO{sub 2}) are generated during coal gasification and retained in fly ash. This fact together with the high market value of this element and the relatively high contents in the fly ashes of the Puertollano Integrated Gasification in Combined Cycle (IGCC) plant directed our research towards the development of an extraction process for this element. Major objectives of this research was to find a low cost and environmentally suitable process. Several water based extraction tests were carried out using different Puertollano IGCC fly ash samples, under different temperatures, water/fly ash ratios, and extraction times. High Ge extraction yields (up to 84%) were obtained at room temperature (25{sup o}C) but also high proportions of other trace elements (impurities) were simultaneously extracted. Increasing the extraction temperature to 50, 90 and 150{sup o}C, Ge extraction yields were kept at similar levels, while reducing the content of impurities, the water/fly ash ratio and extraction time. The experimental data point out the influence of chloride, calcium and sulphide dissolutions on the Ge extraction. 16 refs., 9 figs., 6 tabs.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets.

Directory of Open Access Journals (Sweden)

T P Mangan

Full Text Available Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets.

Science.gov (United States)

Mangan, T P; Atkinson, J D; Neuberg, J W; O'Sullivan, D; Wilson, T W; Whale, T F; Neve, L; Umo, N S; Malkin, T L; Murray, B J

2017-01-01

Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry.

Fluidized-bed-combustion ash for the solidification and stabilization of a metal-hydroxide sludge.

Science.gov (United States)

Knoll, K L; Behr-Andres, C

1998-01-01

Fluidized-bed-combustion (FBC) ash is a by-product from a developing technology for coal-fired power plants that will economically reduce air emissions to meet requirements of the Clean Air Act. FBC ash has physical and chemical properties similar to Portland cement, but only has moderate success as a pozzolan in concrete applications due to low compressive strengths. However, FBC ash has proven effective for use as a binder for the solidification and stabilization (S/S) of metal-bearing sludges. Physical and chemical characterization procedures were used to analyze FBC ash and a metal-bearing sludge obtained from a hazardous waste treatment facility to develop 12 different S/S mix designs. The mix designs consist of four binder designs to evaluate sludge-to-binder ratios of approximately 0, 0.5, and 1. Portland cement is used as a control binder to compare unconfined compressive strengths and Toxicity Characteristic Leaching Procedure (TCLP) analyses from different ratios of the FBC ash streams: fly ash, char, and spent bed material (SBM). Compressive strengths ranging from 84 lbs per square inch (psi) to 298 psi were obtained from various mix designs containing different sludge-to-ash ratios cured for 28 days. All the mix designs passed the TCLP. Recoveries from leaching for each metal were less than 5% for most mix designs. Results of unconfined compressive strengths, TCLP, and percent recovery calculations indicate that the mix design containing approximately a 1:1 ratio of fly ash to char-and-sludge is the best mix design for the S/S of the metal-bearing sludge.

New mechanism for enhancing ash removal efficiency and reducing tritium inventory

International Nuclear Information System (INIS)

Li Chengyue; Deng Baiquan; Yan Jiancheng

2007-01-01

A new mechanism is suggested to suppress ash particle back streams in the divertor region of our fusion experimental breeder (FEB) reactor for enhancing the ash removal efficiency and reducing the tritium inventory by applications of the nonlinear effect of high power rf ponderomotive force potential which reflects the plate-released and re-ionized He + back to the plate. Meanwhile, the potential does not hinder α particles, which are coming from scraping of the layer, flowing to the target plate. However, it does stop tritium ions flowing to the target. Based on the FEB design parameters, our calculations have shown that the ash removal efficiency can be improved by as much as 40% if the parallel component of rf field 150-200 V/cm is applied to the location at a perpendicular distance L=20 cm apart from the plate and the plate-recycling neutral helium atom energy is about 0.75 eV, at the same time, the tritium inventory can be reduced to some extent. (authors)

Coal ash fusion temperatures - new characterization techniques and implications for slagging and fouling

Energy Technology Data Exchange (ETDEWEB)

Wall, T.F.; Creelman, R.A.; Gupta, R.P.; Gupta, S.K.; Coin, C.; Lowe, A. [University of Newcastle, Newcastle, NSW (Australia). CRC for Black Coal Utilisation

1998-09-01

The ash fusion test (AFT) is the accepted test for the propensity of coal ash to slag in the furnace. The well-documented shortcomings of this technique for estimating the fusion temperature of coal ash are its subjective nature and poor accuracy. Alternative measurements based on the shrinkage and electrical conductivity of heating samples are therefore examined here with laboratory ash prepared at about 800{degree}C in crucibles, as well as combustion ash samples from power stations. Sensitive shrinkage measurements indicate temperatures of rapid change which correspond to the formation of liquid phases that can be identified on ternary phase diagrams. The existence and extent of formation of these phases, as quantified by the magnitude of `peaks` in the test, provide alternative ash fusion temperatures. The peaks from laboratory ashes and corresponding combustion ashes derived from the same coals show clear differences which may be related to the evaporation of potassium during combustion and the reactions of the mineral residues to form combustion ash. A preliminary evaluation of data from nine power stations indicates that shrinkage measurements can provide an alternative approach to characterizing slagging. 15 refs., 9 figs., 2 tabs.

Determination of ash-forming elements in lignite coal

International Nuclear Information System (INIS)

Wischnewski, C.; Werner, G.; Vogt, J.; Just, G.

1990-01-01

The most important methods are discussed suitable for the determination of ash-forming elements in coal. In this connection questions of the concentrations of elements in lignites, of the sample preparation, and of the selection of methods for the determination of ash-forming elements are addressed. Advantages and disadvantages of different analysis techniques are shown using concrete examples. (author)

Predicted mineral melt formation by BCURA Coal Sample Bank coals: Variation with atmosphere and comparison with reported ash fusion test data

Energy Technology Data Exchange (ETDEWEB)

D. Thompson [University of Sheffield (United Kingdom). Department of Engineering Materials

2010-08-15

The thermodynamic equilibrium phases formed under ash fusion test and excess air combustion conditions by 30 coals of the BCURA Coal Sample Bank have been predicted from 1100 to 2000 K using the MTDATA computational suite and the MTOX database for silicate melts and associated phases. Predicted speciation and degree of melting varied widely from coal to coal. Melting under an ash fusion test atmosphere of CO{sub 2}:H{sub 2} 1:1 was essentially the same as under excess air combustion conditions for some coals, and markedly different for others. For those ashes which flowed below the fusion test maximum temperature of 1773 K flow coincided with 75-100% melting in most cases. Flow at low predicted melt formation (46%) for one coal cannot be attributed to any one cause. The difference between predicted fusion behaviours under excess air and fusion test atmospheres becomes greater with decreasing silica and alumina, and increasing iron, calcium and alkali metal content in the coal mineral. 22 refs., 7 figs., 3 tabs.

Separation of ultrafine particles from class F fly ashes

Directory of Open Access Journals (Sweden)

Acar Ilker

2016-01-01

Full Text Available In this study, ultrafine particles were recovered from Çatalağzı (CFA and Sugözü (SFA thermal power plant fly ashes using a specific hydraulic classification technology. Since fly ashes have a high tendency to be flocculated in water, settling experiments were first designed to determine the more effective dispersant and the optimum dosage. Two different types of the superplasticizers (SP polymers based on sulphonate (NSF, Disal and carboxylate (Glenium 7500 were used as the dispersing agents in these settling experiments. Hydraulic classification experiments were then conducted to separate ultrafine fractions from the fly ash samples on the basis of the settling experiments. According to the settling experiments, better results were achieved with the use of Disal for both CFA and SFA. The classification experiments showed that the overflow products with average particle sizes of 5.2 μm for CFA and 4.4 μm for SFA were separated from the respective as-received samples with acceptable yields and high enough recoveries of -5 μm (ultrafine particles. Overall results pointed out that the hydraulic classification technology used provided promising results in the ultrafine particle separations from the fly ash samples.

The Stream-Catchment (StreamCat) and Lake-Catchment ...

Science.gov (United States)

Background/Question/MethodsLake and stream conditions respond to both natural and human-related landscape features. Characterizing these features within contributing areas (i.e., delineated watersheds) of streams and lakes could improve our understanding of how biological conditions vary spatially and improve the use, management, and restoration of these aquatic resources. However, the specialized geospatial techniques required to define and characterize stream and lake watersheds has limited their widespread use in both scientific and management efforts at large spatial scales. We developed the StreamCat and LakeCat Datasets to model, predict, and map the probable biological conditions of streams and lakes across the conterminous US (CONUS). Both StreamCat and LakeCat contain watershed-level characterizations of several hundred natural (e.g., soils, geology, climate, and land cover) and anthropogenic (e.g., urbanization, agriculture, mining, and forest management) landscape features for ca. 2.6 million stream segments and 376,000 lakes across the CONUS, respectively. These datasets can be paired with field samples to provide independent variables for modeling and other analyses. We paired 1,380 stream and 1,073 lake samples from the USEPAs National Aquatic Resource Surveys with StreamCat and LakeCat and used random forest (RF) to model and then map an invertebrate condition index and chlorophyll a concentration, respectively. Results/ConclusionsThe invertebrate

Comparison of active and passive sampling strategies for the monitoring of pesticide contamination in streams

Science.gov (United States)

Assoumani, Azziz; Margoum, Christelle; Guillemain, Céline; Coquery, Marina

2014-05-01

The monitoring of water bodies regarding organic contaminants, and the determination of reliable estimates of concentrations are challenging issues, in particular for the implementation of the Water Framework Directive. Several strategies can be applied to collect water samples for the determination of their contamination level. Grab sampling is fast, easy, and requires little logistical and analytical needs in case of low frequency sampling campaigns. However, this technique lacks of representativeness for streams with high variations of contaminant concentrations, such as pesticides in rivers located in small agricultural watersheds. Increasing the representativeness of this sampling strategy implies greater logistical needs and higher analytical costs. Average automated sampling is therefore a solution as it allows, in a single analysis, the determination of more accurate and more relevant estimates of concentrations. Two types of automatic samplings can be performed: time-related sampling allows the assessment of average concentrations, whereas flow-dependent sampling leads to average flux concentrations. However, the purchase and the maintenance of automatic samplers are quite expensive. Passive sampling has recently been developed as an alternative to grab or average automated sampling, to obtain at lower cost, more realistic estimates of the average concentrations of contaminants in streams. These devices allow the passive accumulation of contaminants from large volumes of water, resulting in ultratrace level detection and smoothed integrative sampling over periods ranging from days to weeks. They allow the determination of time-weighted average (TWA) concentrations of the dissolved fraction of target contaminants, but they need to be calibrated in controlled conditions prior to field applications. In other words, the kinetics of the uptake of the target contaminants into the sampler must be studied in order to determine the corresponding sampling rate

Biomass ash utilization

Energy Technology Data Exchange (ETDEWEB)

Bristol, D.R.; Noel, D.J.; O`Brien, B. [HYDRA-CO Operations, Inc., Syracuse, NY (United States); Parker, B. [US Energy Corp., Fort Fairfield, ME (United States)

1993-12-31

This paper demonstrates that with careful analysis of ash from multiple biomass and waste wood fired power plants that most of the ash can serve a useful purpose. Some applications require higher levels of consistency than others. Examples of ash spreading for agricultural purposes as a lime supplement for soil enhancement in Maine and North Carolina, as well as a roadbase material in Maine are discussed. Use of ash as a horticultural additive is explored, as well as in composting as a filtering media and as cover material for landfills. The ash utilization is evaluated in a framework of environmental responsibility, regulations, handling and cost. Depending on the chemical and physical properties of the biomass derived fly ash and bottom ash, it can be used in one or more applications. Developing a program that utilizes ash produced in biomass facilities is environmentally and socially sound and can be financially attractive.

Evaluation of ash from some tropical plants of Nigeria for the control of Sclerotium rolfsii Sacc. on wheat (Triticum aestivum L.).

Science.gov (United States)

Enikuomehin, O A; Ikotun, T; Ekpo, E J

1998-01-01

Eleven ash samples, from organs of nine tropical plants, were screened for their abilities to inhibit mycelial growth and sclerotial germination of a Nigerian isolate of Sclerotium rolfsii on agar and in the soil. Ten ash samples showed some activity against mycelial growth of S. rolfsii in vitro. Ash samples from Delonix regia stem wood, Mangifera indica leaf and Vernonia amygdalina leaf were most effective as each totally inhibited mycelial growth of S. rolfsii in vitro. Ocimum gratissimum leaf ash, D. regia wood ash and Musa paradisiaca flower bract ash inhibited sclerotial germination on agar. Nine ash samples protected seeds against pre-emergence rot. Ash from M. indica leaf, V. amygdalina leaf and Azadirachta indica leaf protected seedlings against post-emergence infection. Eichornia crassipes ash, which was ineffective in vitro, offered some protection to seeds in soil against pre-emergence rot. The study demonstrates potentials of ash samples from tropical plants in control of S. rolfsii on wheat.

Composition and reactivity of ash from sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Willems, M; Pedersen, B; Jorgensen, S S

1976-01-01

Sewage sludge and sludge ash produced at 450 to 1050/sup 0/C in the laboratory or in a multiple hearth incinerator were analyzed by chemical and X-ray diffraction methods. Among the ash components were 23 to 32 percent calcium and magnesium phosphates and the following percentages of heavy metals: Zn 0.9, Cu 0.2, Pb 0.1, Cr 0.07, Ni 0.02, and Cd 0.006. As shown by EDTA-extraction, the reactivity of heavy metals was higher in ash produced at 450/sup 0/C than in dry sludge, but lower in ash produced above 800/sup 0/C. Phosphate in the 800 to 900/sup 0/C samples was dissolved in citric acid but not in citrate.

Water retention properties of ashes; Vattenretentionsegenskaper hos aska

Energy Technology Data Exchange (ETDEWEB)

Hemstroem, Kristian; Ezziyani, Samir; Bendz, David

2009-05-15

The water holding properties of a material can be described with a water retention curve (also called pF curve or characteristic curve). The importance of this material property has until now been neglected in waste and rest products contexts. There is an eminent need for knowledge of the water holding properties of ash and rest products in order to improve the possibility to perform i) assessment of leaching from rest product used in constructions, ii) dimensioning of covers built with rest products and iii) assessment of long term properties of land fill waste concerning leaching, especially for stabilized ash with a monolithic characteristics. The aim of this project was to increase the knowledge of the water holding properties of ashes by determining water retention curves with laboratory methods on four ash materials with the potential to be used in constructions. In the project, four ashes has been studied; one MSWI bottom ash from SYSAV, one aged MSWI bottom ash from Gaerstadverket and two fly ashes from incineration of biofuels; one from SCA Ortviken and one from Jaemtkraft AB. For comparison, data from a silt soil studied in another SGI project is presented. When determining a water retention curve for a specific material water from the examined, beforehand water saturated, sample is eliminated under controlled circumstances in a pressure plate extractor. The sample is exposed to a pressure, with increasing degree, squeezing excess water out of the material. The excess water is measured for each increased pressure step and the remaining volumetric water content in the material can be calculated. The results from such measurements are presented in water retention curves, in which the volumetric water content is plotted as a function of the capillary pressure. The water retention curves shows how various materials differ in water content at the same pressure. The results from the study showed that ashes have great water holding capacity. The study also

Study on cement mortar and concrete made with sewage sludge ash.

Science.gov (United States)

Chang, F C; Lin, J D; Tsai, C C; Wang, K S

2010-01-01

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

[Near-infrared reflectance spectroscopy predicts protein, moisture and ash in beans].

Science.gov (United States)

Gao, Huiyu; Wang, Guodong; Men, Jianhua; Wang, Zhu

2017-05-01

To explore the potential of near-infrared reflectance( NIR)spectroscopy to determine macronutrient contents in beans. NIR spectra and analytical measurements of protein, moisture and ash were collected from 70 kinds of beans. Reference methods were used to analyze all the ground beans samples. NIR spectra on intact and ground beans samples were registered. Partial least-squares( PLS)regression models were developed with principal components analysis( PCA) to assign 49 bean accessions to a calibration data set and 21 accessions to an external validation set. For intact beans, the relative predictive determinant( RPD) values for protein and ash( 3. 67 and 3. 97, respectively) were good for screening. RPD value for moisture was only 1. 39, which was not recommended. For ground beans, the RPD values for protein, moisture and ash( 6. 63, 5. 25 and 3. 57, respectively) were good enough for screening. The protein, moisture and ash levels for intact and ground beans were all significantly correlated( P beans with no or easy sample preparation.

Electrodialytic remediation of fly ash from co-combustion of wood and straw

International Nuclear Information System (INIS)

Chen, Wan; Jensen, Pernille E.; Ottosen, Lisbeth M.; Kirkelund, Gunvor M.

2015-01-01

The heavy metal content in fly ash from biomass combustion, such as straw, wood and sludge, often needs reducing before the ash can be used as fertilizer for agricultural land or as a component in the production of construction materials. In this study, fly ash from a boiler fueled with wood chips and straw was treated either by electrodialytic remediation (EDR) directly or by a combination of EDR and pre-wash with distilled water to investigate the possibilities of reducing the heavy metal content and reusing nutrients as fertilizer and bulk material in construction materials. Different experimental set-ups were tested for EDR treatment primarily of Cd and Pb as well as of Cu and Zn. Elemental contents such as K, P and Ni were compared in ash samples before and after treatment. The results showed that pre-washing caused an increase in total concentrations of most heavy metals because the highly soluble fraction, mainly KCl and K 2 SO 4 , was removed. After EDR treatment, the Cd concentration was reduced to below 2 mg kg −1 in all ash samples with high and stable average removal of above 95%, no matter how high the initial concentration was. The amount of Pb removed varied from 12% to 67%. Even though Pb was extracted from the ash samples, its concentrations in the treated ash samples were elevated due to the ash dissolution, except in the case of pre-washed ash treated in a two-compartment EDR cell, where the mass of Pb removed was the highest with a final concentration of about 100 mg kg −1 . The two-compartment EDR cell probably performed better due to a fast acidification process. In addition, this process was less energy-consuming. However, the fast acidification did in turn affect the leaching property of the treated ash, such as As and Ni, exceeding the limiting concentrations. The EDR/pre-wash-EDR treated ash mainly contained quartz, and the X-ray diffraction (XRD) peaks of K salts had disappeared. This shows that the potassium fertilizer potential was

Radiobiological waste treatment-ashing treatment and immobilization with cement

Energy Technology Data Exchange (ETDEWEB)

Shengtao, Feng; Li, Gong; Li, Cheng; Benli, Wang; Lihong, Wang [China Inst. for Radiation Protection, Taiyuan, Shanxi (China)

1997-02-01

This report describes the results of the study on the treatment of radioactive biological waste in the China Institute for Radiation Protection (CIRP). The possibility of radiobiological waste treatment was investigated by using a RAF-3 type rapid ashing apparatus together with the immobilization of the resulted ash. This rapid ashing apparatus, developed by CIRP, is usually used for pretreatment of samples prior to chemical analysis and physical measurements. The results show that it can ash 3 kg of animal carcasses a batch, the ashing time is 5-7 h and the ash content is less than 4 wt%. The ashing temperature not exceeding 450 deg. C was used without any risk of high losses of radionuclides. The ash from the rapid ashing apparatus was demonstrated to be immobilized with ordinary silicate cement. The optimum cement/ash/water formulation of the cemented waste form was 35 {+-} 5 wt% cement, 29 {+-} 2 wt% water, and 36 {+-} 6 wt% ash. The performance of the waste form was in compliance with the technical requirements except for impact resistance. Mixing additives in immobilization formulations can improve the performance of the cemented ash waste form. The additives chosen were DH{sub 4A} flow promoter as a cement additive and vermiculite or zeolite as a supplement. The recommended formulation, i.e. an improved formulation of the cemented ash waste form is that additives DH{sub 4A} flow promoter and vermiculite (or zeolite) are added on the ground of optimum cement/ash/water formulation of the cemented waste form, the dosage of water, DH{sub 4A} and vermiculite (or zeolite) is 70 wt%, 0.5 wt% and {<=} 5 wt% of the cement dosage, respectively. The cemented ash waste forms obtained meet all the requirements for disposal. (author). 12 refs, 7 figs, 13 tabs.

Radiobiological waste treatment-ashing treatment and immobilization with cement

International Nuclear Information System (INIS)

Feng Shengtao; Gong Li; Cheng Li; Wang Benli; Wang Lihong

1997-01-01

This report describes the results of the study on the treatment of radioactive biological waste in the China Institute for Radiation Protection (CIRP). The possibility of radiobiological waste treatment was investigated by using a RAF-3 type rapid ashing apparatus together with the immobilization of the resulted ash. This rapid ashing apparatus, developed by CIRP, is usually used for pretreatment of samples prior to chemical analysis and physical measurements. The results show that it can ash 3 kg of animal carcasses a batch, the ashing time is 5-7 h and the ash content is less than 4 wt%. The ashing temperature not exceeding 450 deg. C was used without any risk of high losses of radionuclides. The ash from the rapid ashing apparatus was demonstrated to be immobilized with ordinary silicate cement. The optimum cement/ash/water formulation of the cemented waste form was 35 ± 5 wt% cement, 29 ± 2 wt% water, and 36 ± 6 wt% ash. The performance of the waste form was in compliance with the technical requirements except for impact resistance. Mixing additives in immobilization formulations can improve the performance of the cemented ash waste form. The additives chosen were DH 4A flow promoter as a cement additive and vermiculite or zeolite as a supplement. The recommended formulation, i.e. an improved formulation of the cemented ash waste form is that additives DH 4A flow promoter and vermiculite (or zeolite) are added on the ground of optimum cement/ash/water formulation of the cemented waste form, the dosage of water, DH 4A and vermiculite (or zeolite) is 70 wt%, 0.5 wt% and ≤ 5 wt% of the cement dosage, respectively. The cemented ash waste forms obtained meet all the requirements for disposal. (author). 12 refs, 7 figs, 13 tabs

Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

Science.gov (United States)

Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

2014-01-01

The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

Leaching for recovery of copper from municipal solid waste incineration fly ash: influence of ash properties and metal speciation.

Science.gov (United States)

Lassesson, Henric; Fedje, Karin Karlfeldt; Steenari, Britt-Marie

2014-08-01

Recovery of metals occurring in significant amounts in municipal solid waste incineration fly ash, such as copper, could offer several advantages: a decreased amount of potentially mobile metal compounds going to landfill, saving of natural resources and a monetary value. A combination of leaching and solvent extraction may constitute a feasible recovery path for metals from municipal solid waste incineration fly ash. However, it has been shown that the initial dissolution and leaching is a limiting step in such a recovery process. The work described in this article was focused on elucidating physical and chemical differences between two ash samples with the aim of explaining the differences in copper release from these samples in two leaching methods. The results showed that the chemical speciation is an important factor affecting the release of copper. The occurrence of copper as phosphate or silicate will hinder leaching, while sulphate and chloride will facilitate leaching. © The Author(s) 2014.

MICROSTRUCTURE, MINERALOGY AND PHYSICAL PROPERTIES OF GROUND FLY ASH BASED GEOPOLYMERS

Directory of Open Access Journals (Sweden)

Ferenc Madai

2015-03-01

Full Text Available This paper is focused on the utilization of deposited fly ash as a main component of geopolymer. After determination of particle size distribution, moisture content, real and bulk density and specific surface area of the raw fly ash, mechanical activation was performed by laboratory scale ball mill. This step is introduced for improving the reactivity of raw material. Then test specimens were produced by geopoliomerisation using a caustic spent liquor (NaOH. Compressive strength was determined on cilindrical specimens. Finally, samples of the ground fly ash based geopolymer specimens were analyzed by X-ray diffraction, optical and scanning electron microscopy. Results prove that geopolymer production with proper strength from the investigated F-type deposited fly ash is possible. The uniaxial compressive strength of obtained composites strongly depends on the fineness of the ground fly ash. XRD results show that comparing the crystalline components for different geopolymer samples, zeolite-A appears and its amount increases gradually from 0T sample till 30T and then decreases for 60T sample. The same trend holds for sodalite type structure phases, however its amount is much lower than for zeolite-A. SEM+EDS investigation revealed that Na-content is elevated in the interstitial fine-grained matrix, especially for the 30T sample when highest strength was observed. Si and Al are abundant mainly in anhedral and spherical grains and in rarely occurring grains resembling some crystal shape.

Development of novel ash hybrids to introgress resistance to emerald ash borer into north American ash species

Science.gov (United States)

Jennifer L. Koch; David W. Carey; Mary E. Mason

2008-01-01

Currently, there is no evidence that any of the native North American ash species have any resistance to the emerald ash borer (EAB). This means that the entire ash resource of the eastern United States and Canada is at risk of loss due to EAB. In contrast, outbreaks of EAB in Asian ash species are rare and appear to be isolated responses to stress (Bauer et al. 2005,...

Evaluation of the mechanical properties of class-F fly ash

Energy Technology Data Exchange (ETDEWEB)

Kim, B.; Prezzi, M. [Purdue University, West Lafayette, IN (United States)

2008-07-01

Coal-burning power plants in the United States (US) generate more than 70 million tons of fly ash as a by-product annually. Recycling large volumes of fly ash in geotechnical applications may offer an attractive alternative to the disposal problem as most of it is currently dumped in ponds or landfills. Class-F fly ash, resulting from burning of bituminous or anthracite coals, is the most common type of fly ash in the US. In the present study, the mechanical characteristics (compaction response, compressibility, and shear strength) of class-F fly ash were investigated by performing various laboratory tests (compaction test, one-dimensional compression test, direct shear test and consolidated-drained triaxial compression test) on fly ash samples collected from three power plants in the state of Indiana (US). Test results have shown that despite some morphological differences, class-F fly ash exhibits mechanical properties that are, in general, comparable to those observed in natural sandy soils.

Assessing pesticide concentrations and fluxes in the stream of a small vineyard catchment - Effect of sampling frequency

International Nuclear Information System (INIS)

Rabiet, M.; Margoum, C.; Gouy, V.; Carluer, N.; Coquery, M.

2010-01-01

This study reports on the occurrence and behaviour of six pesticides and one metabolite in a small stream draining a vineyard catchment. Base flow and flood events were monitored in order to assess the variability of pesticide concentrations according to the season and to evaluate the role of sampling frequency on the evaluation of fluxes estimates. Results showed that dissolved pesticide concentrations displayed a strong temporal and spatial variability. A large mobilisation of pesticides was observed during floods, with total dissolved pesticide fluxes per event ranging from 5.7 x 10 -3 g/Ha to 0.34 g/Ha. These results highlight the major role of floods in the transport of pesticides in this small stream which contributed to more than 89% of the total load of diuron during August 2007. The evaluation of pesticide loads using different sampling strategies and method calculation, showed that grab sampling largely underestimated pesticide concentrations and fluxes transiting through the stream. - This work brings new insights about the fluxes of pesticides in surface water of a vineyard catchment, notably during flood events.

Assessing pesticide concentrations and fluxes in the stream of a small vineyard catchment - Effect of sampling frequency

Energy Technology Data Exchange (ETDEWEB)

Rabiet, M., E-mail: marion.rabiet@unilim.f [Cemagref, UR QELY, 3bis quai Chauveau, CP 220, F-69336 Lyon (France); Margoum, C.; Gouy, V.; Carluer, N.; Coquery, M. [Cemagref, UR QELY, 3bis quai Chauveau, CP 220, F-69336 Lyon (France)

2010-03-15

This study reports on the occurrence and behaviour of six pesticides and one metabolite in a small stream draining a vineyard catchment. Base flow and flood events were monitored in order to assess the variability of pesticide concentrations according to the season and to evaluate the role of sampling frequency on the evaluation of fluxes estimates. Results showed that dissolved pesticide concentrations displayed a strong temporal and spatial variability. A large mobilisation of pesticides was observed during floods, with total dissolved pesticide fluxes per event ranging from 5.7 x 10{sup -3} g/Ha to 0.34 g/Ha. These results highlight the major role of floods in the transport of pesticides in this small stream which contributed to more than 89% of the total load of diuron during August 2007. The evaluation of pesticide loads using different sampling strategies and method calculation, showed that grab sampling largely underestimated pesticide concentrations and fluxes transiting through the stream. - This work brings new insights about the fluxes of pesticides in surface water of a vineyard catchment, notably during flood events.

Silica from Ash

Indian Academy of Sciences (India)

management, polymer composites and chemical process design. Figure 1 Difference in color of the ash ... The selection of ash is important as the quality of ash determines the total amount as well as quality of silica recoverable Ash which has undergone maximum extent of combustion is highly desirable as it contains ...

Estimation of river and stream temperature trends under haphazard sampling

Science.gov (United States)

Gray, Brian R.; Lyubchich, Vyacheslav; Gel, Yulia R.; Rogala, James T.; Robertson, Dale M.; Wei, Xiaoqiao

2015-01-01

Long-term temporal trends in water temperature in rivers and streams are typically estimated under the assumption of evenly-spaced space-time measurements. However, sampling times and dates associated with historical water temperature datasets and some sampling designs may be haphazard. As a result, trends in temperature may be confounded with trends in time or space of sampling which, in turn, may yield biased trend estimators and thus unreliable conclusions. We address this concern using multilevel (hierarchical) linear models, where time effects are allowed to vary randomly by day and date effects by year. We evaluate the proposed approach by Monte Carlo simulations with imbalance, sparse data and confounding by trend in time and date of sampling. Simulation results indicate unbiased trend estimators while results from a case study of temperature data from the Illinois River, USA conform to river thermal assumptions. We also propose a new nonparametric bootstrap inference on multilevel models that allows for a relatively flexible and distribution-free quantification of uncertainties. The proposed multilevel modeling approach may be elaborated to accommodate nonlinearities within days and years when sampling times or dates typically span temperature extremes.

Characterization of North American lignite fly ashes. II. XRD Mineralogy

International Nuclear Information System (INIS)

McCarthy, G.J.; Johansen, D.M.; Thedchanamoorthy, A.; Steinwand, S.J.; Swanson, K.D.

1988-01-01

X-ray powder diffraction has been used to determine the crystalline phase mineralogy in samples of fly ash from each of the lignite mining areas of North America. The characteristic phases of North Dakota lignite fly ashes were periclase, lime, merwinite and the sulfate phases anhydrite, thenardite and a sodalite-structure phase. Mullite was absent in these low-Al/sub 2/O/sub 3/ ashes. Montana lignite ash mineralogy had characteristics of ND lignite and MT subbituminous coal fly ashes; mullite and C/sub 3/A were present and the alkali sulfates were absent. Texas and Louisiana lignite fly ashes had the characteristic mineralogy of bituminous coal fly ash: quartz, mullite, ferrite-spinel (magnetite) and minor hematite. Even though their analytical CaO contents were 7-14%, all but one lacked crystalline CaO-containing phases. Lignite fly ashes from Saskatchewan were generally the least crystalline of those studied and had a mineralogy consisting of quartz, mullite, ferrite spinel and periclase. Quantitative XRD data were obtained. The position of the diffuse scattering maximum in the x-ray diffractograms was indicative of the glass composition of the lignite fly ash

Performance evaluation of clay fly ash brick masonry

Energy Technology Data Exchange (ETDEWEB)

Kute, S.; Deodhar, S.V. [K.K. Wagh College of Engineering, Panchavati (India). Dept. of Civil Engineering

2003-07-01

Despite inexorable trends of automation in manufacturing industry throughout the world, the conventional brick manufacturing practices have remained largely unchanged since the dawn of civilization in India. This has imposed restrictions on quality of bricks in general. The paper highlights the results derived from an extensive experimental work on performance evaluation of brick masonry. Four types of bricks, three values of joint thickness and fineness modulus of sand, and two grades of mortar with four different proportions were used as samples. Fly ash was from Nashik Thermal Power Station in Maharashtra, India. The results show that the brick masonry of 40% fly ash bricks and mortar with 20% fly ash as replacement to cement with 1:4 and 1:6 proportion gives optimum strength and advocates use of fly ash for this combination. 8 tabs.

Analysis of radioactivity in coal, cinders, fly ash and discharges from the stack

International Nuclear Information System (INIS)

Meide, A.

1985-01-01

Gamma measurements of coal samples originating from several supplying countries proved that the South African coal has about double U-238 and Ra-226 concentration and about treble Th-232 concentration compared to coal from the other countries. Gamma measurements of coal, cinders and fly ash samples from five coal-fueled plants indicate somewhat higher concentrations of Th-232 in cinders and U-238 and Th-232 in fly ashes than those described in literature. The ratio Po-210/Pb-210 was about 2 for fly ash particulates <35μ. A positive correlation between ash percentage and radioactivity of coal might be assumed. (EG)

Arsenic and mercury partitioning in fly ash at a Kentucky power plant

Energy Technology Data Exchange (ETDEWEB)

Tanaporn Sakulpitakphon; James C. Hower; Alan S. Trimble; William H. Schram; Gerald A. Thomas [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

2003-08-01

Coal and fly ash samples were collected from a 500-MW unit at a Kentucky power plant, with the objective of studying the distribution of arsenic, mercury, and other trace elements in fly ash. The coal feed was low-sulfur, high volatile A bituminous central West Virginia coal. The plant produced a relatively low-carbon fly ash. In contrast to power plants with high-mercury feed coal, the fly ashes from the lower-mercury feed coal had low mercury values, generally not exceeding 0.01 ppm Hg. Mercury capture by fly ash varies with both the amount and type of carbon and the collection temperature; mercury capture is more efficient at lower temperatures. Arsenic in the feed coal and in the flue gas is of concern to the utility, because of the potential for catalyst poisoning in the selective catalytic reduction system (in the planning stage at the time of the sampling). Arsenic is captured in the fly ash, increasing in concentration in the more-distant (from the boiler) reaches of the electrostatic precipitator system. 16 refs., 2 figs., 5 tabs.

Phase 2 Sampling Plan for Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1992-08-01

CDM Federal Programs Corporation (CDM Federal) was contracted by Martin Marietta Energy Systems, Inc. to prepare a Phase H Sampling Plan to describe field investigation work necessary to address regulatory agency review comments on the Remedial Investigation of Filled Coal Ash Pond (FCAP)/Upper McCoy Branch, Chestnut Ridge Operable Unit 2 at the Y-12 Plant, conducted by CH2M Hill in 1990. The scope and approach of the field investigation described in this plan specifically focus on deficiencies noted by the regulators in discussions at the comment resolution meeting of May 8, 1992, in Oak Ridge, Tennessee. This Phase II Sampling Plan includes a field sampling plan, a field and laboratory quality assurance project plan, a health and safety plan, a waste management plan, and appendixes providing an update to applicable or relevant and appropriate requirements for this site and field and laboratory testing methods and procedures. To address deficiencies noted by the regulators, the following activities will be conducted: Background surface soil and surface water/sediment samples will be collected based on statistical considerations for comparison to site data. Existing and new data to be collected will be used to support a human health risk assessment that includes the future homesteader scenario. Biological surveys, samples, and measurements will be collected/conducted to augment existing data and support an ecological risk assessment. Another round of groundwater sampling will be conducted, including on-site wells and the wells on Chestnut Ridge downgradient of the Security Pits. Borings will be completed in the FCAP to collect samples from below the surface depth to describe the chemical characteristics and volume of the ash. The volume of ash associated with sluice channel on Chestnut Ridge will be determined. Soil samples will be corrected below the coal ash in the FCAP and adjacent to sluice channel to evaluate soil contamination and migration of contaminants

Influence of several experimental parameters on As and Se leaching from coal fly ash samples

International Nuclear Information System (INIS)

Otero-Rey, Jose R.; Mato-Fernandez, Maria J.; Moreda-Pineiro, Jorge; Alonso-Rodriguez, Elia; Muniategui-Lorenzo, Soledad; Lopez-Mahia, Purificacion; Prada-Rodriguez, Dario

2005-01-01

Coal fly ash leaching process for As and Se is studied. Environmental parameters such as pH, temperature, solid-liquid ratio, particle size and leaching time are taken into account in order to simulate As and Se leaching process for disposal coal fly ash. Analysis of reference materials was carried out by using of hydride generation coupled to atomic fluorescence spectrometry. Plackett-Burman experimental design is used to know the significative parameters, and Box-Behnken experimental design is used to refine the results obtained for these significative parameters. pH and temperature shown a hardly influence in leaching process. Furthermore, leaching time was also significative. According our results, it may be assumed that percentage of As and Se leaching in experimental conditions tested is relatively low for acidic fly ashes

On-conveyor belt determination of ash in coal

International Nuclear Information System (INIS)

Sowerby, B.; Lim, C.S.; Abernethy, D.A.; Liu, Y.; Maguire, P.A.

1997-01-01

A laboratory feasibility study has been carried out on new and advanced neutron and gamma-ray analysis systems for the direct on-conveyor belt analysis of ash in coal without the need for sample by-lines. Such an analysis system could deliver the combined advantages of a direct on-conveyor configuration with new and accurate analysis techniques. An industry survey of 18 coal companies carried out in early 1996 indicated that accurate on-belt ash analysis is of the highest priority. Subsequent laboratory work has focussed on the investigation of methods with the potential for improving the accuracy of ash content measurement relative to existing on-belt ash analysers, the most widely-used of which are based on dual energy gamma-ray transmission (DUET), which is sensitive to variations in ash composition. The current work indicates that on-belt neutron/gamma-ray techniques combined with advanced spectral analysis techniques show promise for development into an on-belt ash analysis system which is significantly less sensitive to composition changes than DUET and which analyses a much larger proportion of coal on the belt, thus eliminating some key sources of analysis error

Bio fuel ash in a road construction: impact on soil solution chemistry.

Science.gov (United States)

Thurdin, R T; van Hees, P A W; Bylund, D; Lundström, U S

2006-01-01

Limited natural resources and landfill space, as well as increasing amounts of ash produced from incineration of bio fuel and municipal solid waste, have created a demand for useful applications of ash, of which road construction is one application. Along national road 90, situated about 20 km west of Sollefteå in the middle of Sweden, an experiment road was constructed with a 40 cm bio fuel ash layer. The environmental impact of the ash layer was evaluated from soil solutions obtained by centrifugation of soil samples taken on four occasions during 2001-2003. Soil samples were taken in the ash layer, below the ash layer at two depths in the road and in the ditch. In the soil solutions, pH, conductivity, dissolved organic carbon (DOC) and the total concentration of cations (metals) and anions were determined. Two years after the application of the ash layers in the test road, the concentrations in the ash layer of K, SO4, Zn, and Hg had increased significantly while the concentration of Se, Mo and Cd had decreased significantly. Below the ash layer in the road an initial increase of pH was observed and the concentrations of K, SO4, Se, Mo and Cd increased significantly, while the concentrations of Cu and Hg decreased significantly in the road and also in the ditch. Cd was the element showing a potential risk of contamination of the groundwater. The concentrations of Ca in the ash layer indicated an ongoing hardening, which is important for the leaching rate and the strength of the road construction.

The Complex Refractive Index of Volcanic Ash Aerosol Retrieved From Spectral Mass Extinction

Science.gov (United States)

Reed, Benjamin E.; Peters, Daniel M.; McPheat, Robert; Grainger, R. G.

2018-01-01

The complex refractive indices of eight volcanic ash samples, chosen to have a representative range of SiO2 contents, were retrieved from simultaneous measurements of their spectral mass extinction coefficient and size distribution. The mass extinction coefficients, at 0.33-19 μm, were measured using two optical systems: a Fourier transform spectrometer in the infrared and two diffraction grating spectrometers covering visible and ultraviolet wavelengths. The particle size distribution was measured using a scanning mobility particle sizer and an optical particle counter; values for the effective radius of ash particles measured in this study varied from 0.574 to 1.16 μm. Verification retrievals on high-purity silica aerosol demonstrated that the Rayleigh continuous distribution of ellipsoids (CDEs) scattering model significantly outperformed Mie theory in retrieving the complex refractive index, when compared to literature values. Assuming the silica particles provided a good analogue of volcanic ash, the CDE scattering model was applied to retrieve the complex refractive index of the eight ash samples. The Lorentz formulation of the complex refractive index was used within the retrievals as a convenient way to ensure consistency with the Kramers-Kronig relation. The short-wavelength limit of the electric susceptibility was constrained by using independently measured reference values of the complex refractive index of the ash samples at a visible wavelength. The retrieved values of the complex refractive indices of the ash samples showed considerable variation, highlighting the importance of using accurate refractive index data in ash cloud radiative transfer models.

Encapsulation of mixed radioactive and hazardous waste contaminated incinerator ash in modified sulfur cement

International Nuclear Information System (INIS)

Kalb, P.D.; Heiser, J.H. III; Colombo, P.

1990-01-01

Some of the process waste streams incinerated at various Department of Energy (DOE) facilities contain traces of both low-level radioactive (LLW) and hazardous constituents, thus yielding ash residues that are classified as mixed waste. Work is currently being performed at Brookhaven National Laboratory (BNL) to develop new and innovative materials for encapsulation of DOE mixed wastes including incinerator ash. One such material under investigation is modified sulfur cement, a thermoplastic developed by the US Bureau of Mines. Monolithic waste forms containing as much as 55 wt % incinerator fly ash from Idaho national Engineering Laboratory (INEL) have been formulated with modified sulfur cement, whereas maximum waste loading for this waste in hydraulic cement is 16 wt %. Compressive strength of these waste forms exceeded 27.6 MPa. Wet chemical and solid phase waste characterization analyses performed on this fly ash revealed high concentrations of soluble metal salts including Pb and Cd, identified by the Environmental Protection Agency (EPA) as toxic metals. Leach testing of the ash according to the EPA Toxicity Characteristic Leaching Procedure (TCLP) resulted in concentrations of Pb and Cd above allowable limits. Encapsulation of INEL fly ash in modified sulfur cement with a small quantity of sodium sulfide added to enhance retention of soluble metal salts reduced TCLP leachate concentrations of Pb and Cd well below EPA concentration criteria for delisting as a toxic hazardous waste. 12 refs., 4 figs., 2 tabs

Bioassessment tools in novel habitats: an evaluation of indices and sampling methods in low-gradient streams in California.

Science.gov (United States)

Mazor, Raphael D; Schiff, Kenneth; Ritter, Kerry; Rehn, Andy; Ode, Peter

2010-08-01

Biomonitoring programs are often required to assess streams for which assessment tools have not been developed. For example, low-gradient streams (slopeindices in the state were developed in high-gradient systems. This study evaluated the performance of three sampling methods [targeted riffle composite (TRC), reach-wide benthos (RWB), and the margin-center-margin modification of RWB (MCM)] and two indices [the Southern California Index of Biotic Integrity (SCIBI) and the ratio of observed to expected taxa (O/E)] in low-gradient streams in California for application in this habitat type. Performance was evaluated in terms of efficacy (i.e., ability to collect enough individuals for index calculation), comparability (i.e., similarity of assemblages and index scores), sensitivity (i.e., responsiveness to disturbance), and precision (i.e., ability to detect small differences in index scores). The sampling methods varied in the degree to which they targeted macroinvertebrate-rich microhabitats, such as riffles and vegetated margins, which may be naturally scarce in low-gradient streams. The RWB method failed to collect sufficient numbers of individuals (i.e., >or=450) to calculate the SCIBI in 28 of 45 samples and often collected fewer than 100 individuals, suggesting it is inappropriate for low-gradient streams in California; failures for the other methods were less common (TRC, 16 samples; MCM, 11 samples). Within-site precision, measured as the minimum detectable difference (MDD) was poor but similar across methods for the SCIBI (ranging from 19 to 22). However, RWB had the lowest MDD for O/E scores (0.20 versus 0.24 and 0.28 for MCM and TRC, respectively). Mantel correlations showed that assemblages were more similar within sites among methods than within methods among sites, suggesting that the sampling methods were collecting similar assemblages of organisms. Statistically significant disagreements among methods were not detected, although O/E scores were higher

Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

OpenAIRE

T. D. Gunneswara Rao; Mudimby Andal

2014-01-01

Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

Science.gov (United States)

In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

Influence of fly-ashes on properties of ordinary concretes

Directory of Open Access Journals (Sweden)

Rutkowska Gabriela

2016-03-01

Full Text Available Influence of fly-ashes on properties of ordinary concretes. Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. The construction and building materials industry has the greatest potential for reuse of waste. The article presents the results of investigations of selected properties (consistency, water absorbability, compressive strength and tensile strength after 28 and 56 days of curing, depth of penetration of ordinary concretes and concretes containing fly-ashes - calcareous and siliceous ash − in their composition. To make the samples, the Portland cement CEM I 42.5 R and natural aggregate with graining of 0-16 mm were used. The concrete with siliceous and calcareous admixtures was made in three lots where the ash was added in the quantity of 15, 20 and 30% of the cement mass. After the tests, it was stated that the fly-ash admixture does not increase the air content in the mix, it increases the compressive strength in time and the siliceous ash improves the splitting tensile strength.

Technique for determining cesium-137 in milk excluding ashing

International Nuclear Information System (INIS)

Antonova, V.A.; Prokof'ev, O.N.

1984-01-01

For the purpose of simplification of the method of milk sample preparation for the radiochemical analysis for 137 Cs in laboratory sanitary and higienic investigations rapid analysis technique excluding sample ashing is developed. The technique comprises sample mixing with silica gel during an hour, 137 Cs desorption from silica gel into the 1N solution of hydrochloric acid, radiochemical analysis of hydrochloric solution for determining 137 Cs. The comparison of the results obtained by the above method and that with ashing provides perfect agreement. For taking into account the incompleteness of 137 Cs adsorption by silica gel a correction factor is applied in calculation formulae

Potential of oil palm empty fruit bunch ash for remediation of crude ...

African Journals Online (AJOL)

The potential of oil palm empty fruit bunch ash for remediation of crude oil polluted soil was investigated. Three levels (100 g, 200 g and 300 g) of ash treatments in 2 kg of soil were set up alongside a control (nil ash) after pollution with100 ml of crude oil. Composite soil samples were collected and analyzed at intervals of ...

The durability of fired brick incorporating textile factory waste ash and basaltic pumice

Energy Technology Data Exchange (ETDEWEB)

Binici, Hanifi [Kahramanmaras Sutcu Imam Univ., Kahramanmaras (Turkey). Dept. of Civil Engineering; Yardim, Yavuz [Epoka Univ., Tirana (Albania). Dept. of Civil Engineering

2012-07-15

This study investigates the durability of fired brick produced with additives of textile factories' waste ash and basaltic pumice. The effects of incorporating waste ash and basaltic pumice on durability and mechanical properties of the clay bricks were studied. Samples were produced with different ratios of the textile factories' waste ash and basaltic pumice added and at different fire temperatures of 700, 900, and 1 050 C for 8 h. The bricks with additives were produced by adding equal amounts of textile factories' waste ash and basaltic pumice, separately and together, with rates of 5, 10 and 20 wt.%. The produced samples were kept one year in sodium sulphate and sodium nitrate and tested under freezing - unfreezing and drying - wetting conditions. Then compression strength and mass loss of the samples with and without additives were investigated. The test results were compared with standards and results obtained from control specimens. The results showed that incorporations up to 10 wt.% of textile factories' waste ash and basaltic pumice is beneficial to the fired brick. Both textile factories' waste ash and basaltic pumice were suitable additives and could be used for more durable clay brick production at 900 C fire temperature. (orig.)

Preliminary Evaluation of Potassium Extraction from Bamboo Ash

Directory of Open Access Journals (Sweden)

Samadhi Tjokorde W.

2018-01-01

Full Text Available Bamboo is a potentially economical fuel crop that has not been utilized at a substantial extent for energy generation in Indonesia. As a thermal conversion waste, bamboo ash is particularly interesting due to its high potassium content. This paper discusses the determination of several key parameters of a simple batchwise extraction process to recover potassium in the form of weak solution from bamboo ash. To produce the ash, black bamboo (Gigantochloa atroviolaceae is charred in a fixed bed combustor. The bamboo char is ground and ashed at 500 °C in an electric furnace. The ash yield is 3.3 %-mass relative to as-received ash, with an ash K2O content of 12.9 %-mass. The ash is ground until passing 100-mesh standard sieve, and extracted by deionized water on a 2-stage laboratory-scale batchwise extractor battery. Process variables include extractror battery configuration (counter-current and co-current, temperature (nominal setting at 45-80 °C, and contact period of 1-6 hours. The concentration of extracted K2O increases asymptotically with temperature and contact time. Counter-current extraction yields more than twice the extract K2O concentration compared to cross-current extraction. The optimum conditions for the counter-current extraction is identified as a temperature of 78 °C and contact time of 4 hours, resulting in a 0.70 %-mass K2O solution concentration. Spot sampling of commercial liquid fertilizer products in Indonesia indicates an equivalent K2O content of 0.08-13.6 %-mass, suggesting the potential of the bamboo ash extract as an intermediate for fertilizer product.

Stabilisation of clayey soils with high calcium fly ash and cement

Energy Technology Data Exchange (ETDEWEB)

S. Kolias; V. Kasselouri-Rigopoulou; A. Karahalios [National Technical University of Athens, Athens (Greece)

2005-02-01

The effectiveness of using high calcium fly ash and cement in stabilising fine-grained clayey soils (CL,CH) was investigated in the laboratory. Strength tests in uniaxial compression, in indirect (splitting) tension and flexure were carried out on samples to which various percentages of fly ash and cement had been added. Modulus of elasticity was determined at 90 days with different types of load application and 90-day soaked CBR values are also reported. Pavement structures incorporating subgrades improved by in situ stabilisation with fly ash and cement were analyzed for construction traffic and for operating traffic. These pavements are compared with conventional flexible pavements without improved subgrades and the results clearly show the technical benefits of stabilising clayey soils with fly ash and cement. In addition TG-SDTA and XRD tests were carried out on certain samples in order to study the hydraulic compounds, which were formed.

The reaction of acid mine drainage with fly ash from coal combustion

International Nuclear Information System (INIS)

Kim, A.G.

1999-01-01

The placement of alkaline fly ash in abandoned, reclaimed or active surface coal mines is intended to reduce the amount of acid mine drainage (AMD) produced at such sites by neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion. A continuing concern with this application is the potential release of trace elements from the fly ash when it is placed in contact with AMD. To investigate the possible release of antimony, arsenic, barium, boron, cadmium, chromium, cobalt, copper, lead, nickel, selenium, and zinc from fly ash, a series of column leaching tests were conducted. A one kg fly ash sample, placed in a 5-cm by 1 m acrylic columns, was leached at a nominal rate of 250 mL/d for between 30 and 60 days. The leachant solutions were deionized water, and dilute solutions of sulfuric acid and ferric chloride. Leaching tests have been completed on 28 fly ash samples. leachate data, analyzed as the mass extracted with respect to the concentration in the solid, indicate that the release of trace elements is variable, with only barium and zinc extracted at greater than 50 pct of the amount present in the original sample. As a comparison, water quality changes have been monitored at three sites where fly ash grout was injected after reclamation to control AMD. When compared before and after grouting, small increases in pH and decreases in acidity at discharge points were observed. Concentrations of trace metals were found to be comparable in treated and untreated areas. When grouted and ungrouted areas were compared, the effect of the fly ash was shown to be localized in the areas of injection. These studies indicated that when fly ash is used as a reagent to control of AMD, the release of trace elements is relatively small

Characterization of Montserrat volcanic ash for the assessment of respiratory health hazards

International Nuclear Information System (INIS)

Horwell, Claire Judith

2002-01-01

Volcanic ash, generated in the long-lived eruption of the Soufriere Hills volcano, Montserrat, is shown to contain respirable (sub-4 μm) particles and the crystalline silica polymorph, cristobalite. Respirable particles of cristobalite can cause silicosis, raising the possibility that volcanic ash is a respiratory health hazard. This study considers some of the main factors that affect human exposure to volcanic particles: the composition, proportions and surface reactivity of respirable ash and the composition and concentrations of re-worked and airborne suspended particulates. Dome-collapse ash-fall deposits are significantly richer in respirable particles (12 weight %) than the other tephra samples, in particular the matrices of dome-collapse pyroclastic-flow deposits (3 weight %). Within the respirable fraction, dome-collapse ash contains the highest proportion of crystalline silica particles (20-27 number %, of which 97 % is cristobalite), compared with other primary tephra types (0.4-5.6 number %). The results are explained by significant fractionation during fragmentation of pyroclastic flows due to the size and strength of particles and the selective elutriation of fines into the lofting ash plume. This result in a fines-depleted dome-collapse matrix and a fines-rich dome-collapse ash deposit. For all sample types, the sub-4 μm fraction comprises 45-55 weight % of the sub-10 μm fraction. Re-worked and airborne samples show enrichment of crystalline silica in the respirable fraction (10-18 number %) but have low proportions of respirable ash (∼ 3 weight %) compared to primary ash samples. The concentration of ash particles re-suspended by road vehicles on Montserrat is found to decrease exponentially with height above the ground, indicating higher exposure for children compared with adults: PM 4 concentration at 0.9 m (height of two year old child) is three times that at 1.8m (adult height). Surface- and free-radical production has been closely linked

Characterization of Montserrat volcanic ash for the assessment of respiratory health hazards

Energy Technology Data Exchange (ETDEWEB)

Horwell, Claire Judith

2002-07-01

Volcanic ash, generated in the long-lived eruption of the Soufriere Hills volcano, Montserrat, is shown to contain respirable (sub-4 {mu}m) particles and the crystalline silica polymorph, cristobalite. Respirable particles of cristobalite can cause silicosis, raising the possibility that volcanic ash is a respiratory health hazard. This study considers some of the main factors that affect human exposure to volcanic particles: the composition, proportions and surface reactivity of respirable ash and the composition and concentrations of re-worked and airborne suspended particulates. Dome-collapse ash-fall deposits are significantly richer in respirable particles (12 weight %) than the other tephra samples, in particular the matrices of dome-collapse pyroclastic-flow deposits (3 weight %). Within the respirable fraction, dome-collapse ash contains the highest proportion of crystalline silica particles (20-27 number %, of which 97 % is cristobalite), compared with other primary tephra types (0.4-5.6 number %). The results are explained by significant fractionation during fragmentation of pyroclastic flows due to the size and strength of particles and the selective elutriation of fines into the lofting ash plume. This result in a fines-depleted dome-collapse matrix and a fines-rich dome-collapse ash deposit. For all sample types, the sub-4 {mu}m fraction comprises 45-55 weight % of the sub-10 {mu}m fraction. Re-worked and airborne samples show enrichment of crystalline silica in the respirable fraction (10-18 number %) but have low proportions of respirable ash ({approx} 3 weight %) compared to primary ash samples. The concentration of ash particles re-suspended by road vehicles on Montserrat is found to decrease exponentially with height above the ground, indicating higher exposure for children compared with adults: PM{sub 4} concentration at 0.9 m (height of two year old child) is three times that at 1.8m (adult height). Surface- and free-radical production has been

Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

Energy Technology Data Exchange (ETDEWEB)

Flyhammar, Peter [Lund Univ. (Sweden). Dept. of Engineering Geology

2006-04-15

In Sweden several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm (HG) presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. A quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by the Sysav company. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate: pH, availability and leached amount and the connection between these variables; the possibilities to use pH or the availability to assess both short-term and long term leaching properties; how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements; how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish incineration plants indicates that the availability of elements such as Cd, Cu, Cr, Ni, Pb and Zn in bottom ash usually is below Sysav's target values. Extreme values

Design Study of an Incinerator Ash Conveyor Counting System - 13323

International Nuclear Information System (INIS)

Jaederstroem, Henrik; Bronson, Frazier

2013-01-01

A design study has been performed for a system that should measure the Cs-137 activity in ash from an incinerator. Radioactive ash, expected to consist of both Cs-134 and Cs-137, will be transported on a conveyor belt at 0.1 m/s. The objective of the counting system is to determine the Cs-137 activity and direct the ash to the correct stream after a diverter. The decision levels are ranging from 8000 to 400000 Bq/kg and the decision error should be as low as possible. The decision error depends on the total measurement uncertainty which depends on the counting statistics and the uncertainty in the efficiency of the geometry. For the low activity decision it is necessary to know the efficiency to be able to determine if the signal from the Cs-137 is above the minimum detectable activity and that it generates enough counts to reach the desired precision. For the higher activity decision the uncertainty of the efficiency needs to be understood to minimize decision errors. The total efficiency of the detector is needed to be able to determine if the detector will be able operate at the count rate at the highest expected activity. The design study that is presented in this paper describes how the objectives of the monitoring systems were obtained, the choice of detector was made and how ISOCS (In Situ Object Counting System) mathematical modeling was used to calculate the efficiency. The ISOCS uncertainty estimator (IUE) was used to determine which parameters of the ash was important to know accurately in order to minimize the uncertainty of the efficiency. The examined parameters include the height of the ash on the conveyor belt, the matrix composition and density and relative efficiency of the detector. (authors)

Design Study of an Incinerator Ash Conveyor Counting System - 13323

Energy Technology Data Exchange (ETDEWEB)

Jaederstroem, Henrik; Bronson, Frazier [Canberra Industries Inc., 800 Research Parkway Meriden CT 06450 (United States)

2013-07-01

A design study has been performed for a system that should measure the Cs-137 activity in ash from an incinerator. Radioactive ash, expected to consist of both Cs-134 and Cs-137, will be transported on a conveyor belt at 0.1 m/s. The objective of the counting system is to determine the Cs-137 activity and direct the ash to the correct stream after a diverter. The decision levels are ranging from 8000 to 400000 Bq/kg and the decision error should be as low as possible. The decision error depends on the total measurement uncertainty which depends on the counting statistics and the uncertainty in the efficiency of the geometry. For the low activity decision it is necessary to know the efficiency to be able to determine if the signal from the Cs-137 is above the minimum detectable activity and that it generates enough counts to reach the desired precision. For the higher activity decision the uncertainty of the efficiency needs to be understood to minimize decision errors. The total efficiency of the detector is needed to be able to determine if the detector will be able operate at the count rate at the highest expected activity. The design study that is presented in this paper describes how the objectives of the monitoring systems were obtained, the choice of detector was made and how ISOCS (In Situ Object Counting System) mathematical modeling was used to calculate the efficiency. The ISOCS uncertainty estimator (IUE) was used to determine which parameters of the ash was important to know accurately in order to minimize the uncertainty of the efficiency. The examined parameters include the height of the ash on the conveyor belt, the matrix composition and density and relative efficiency of the detector. (authors)

A robust method to forecast volcanic ash clouds

Science.gov (United States)

Denlinger, Roger P.; Pavolonis, Mike; Sieglaff, Justin

2012-01-01

Ash clouds emanating from volcanic eruption columns often form trails of ash extending thousands of kilometers through the Earth's atmosphere, disrupting air traffic and posing a significant hazard to air travel. To mitigate such hazards, the community charged with reducing flight risk must accurately assess risk of ash ingestion for any flight path and provide robust forecasts of volcanic ash dispersal. In response to this need, a number of different transport models have been developed for this purpose and applied to recent eruptions, providing a means to assess uncertainty in forecasts. Here we provide a framework for optimal forecasts and their uncertainties given any model and any observational data. This involves random sampling of the probability distributions of input (source) parameters to a transport model and iteratively running the model with different inputs, each time assessing the predictions that the model makes about ash dispersal by direct comparison with satellite data. The results of these comparisons are embodied in a likelihood function whose maximum corresponds to the minimum misfit between model output and observations. Bayes theorem is then used to determine a normalized posterior probability distribution and from that a forecast of future uncertainty in ash dispersal. The nature of ash clouds in heterogeneous wind fields creates a strong maximum likelihood estimate in which most of the probability is localized to narrow ranges of model source parameters. This property is used here to accelerate probability assessment, producing a method to rapidly generate a prediction of future ash concentrations and their distribution based upon assimilation of satellite data as well as model and data uncertainties. Applying this method to the recent eruption of Eyjafjallajökull in Iceland, we show that the 3 and 6 h forecasts of ash cloud location probability encompassed the location of observed satellite-determined ash cloud loads, providing an

Mutagenicity and genotoxicity of coal fly ash water leachate.

Science.gov (United States)

Chakraborty, Rajarshi; Mukherjee, Anita

2009-03-01

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals-sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significant (Ppercentage (%), tail length (mum), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

Size distribution of rare earth elements in coal ash

Science.gov (United States)

Scott, Clinton T.; Deonarine, Amrika; Kolker, Allan; Adams, Monique; Holland, James F.

2015-01-01

Rare earth elements (REEs) are utilized in various applications that are vital to the automotive, petrochemical, medical, and information technology industries. As world demand for REEs increases, critical shortages are expected. Due to the retention of REEs during coal combustion, coal fly ash is increasingly considered a potential resource. Previous studies have demonstrated that coal fly ash is variably enriched in REEs relative to feed coal (e.g, Seredin and Dai, 2012) and that enrichment increases with decreasing size fractions (Blissett et al., 2014). In order to further explore the REE resource potential of coal ash, and determine the partitioning behavior of REE as a function of grain size, we studied whole coal and fly ash size-fractions collected from three U.S commercial-scale coal-fired generating stations burning Appalachian or Powder River Basin coal. Whole fly ash was separated into , 5 um, to 5 to 10 um and 10 to 100 um particle size fractions by mechanical shaking using trace-metal clean procedures. In these samples REE enrichments in whole fly ash ranges 5.6 to 18.5 times that of feedcoals. Partitioning results for size separates relative to whole coal and whole fly ash will also be reported. 

Mercury removal from coal combustion flue gas by fly ash

Energy Technology Data Exchange (ETDEWEB)

Kuang, Junyan [Chinese Academy of Sciences, Beijing (China). Research Center for Process Pollution Control; Chinese Academy of Sciences, Beijing (China). Graduate Univ.; Xu, Wenqing; Zhu, Tingyu; Jing, Pengfei [Chinese Academy of Sciences, Beijing (China). Research Center for Process Pollution Control

2013-07-01

The effect of physicochemical properties on the mercury adsorption performance of three fly ash samples has been investigated. The samples were tested for mercury adsorption using a fixed-bed with a simulated gas. X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy and other methods were used to characterize the samples. The results indicate that mercury adsorption on fly ash is mainly physisorption and chemisorption. Uncompleted burned carbon is an important factor for the improvement of mercury removal efficiency, especially, the C-M bond may improve the oxidation of mercury, which formed via the reaction of C and Ti, Si and other elements. The higher specific surface areas and smaller pore diameter are all beneficial for the high mercury removal efficiency. The presence of O{sub 2} plays a positive role on Hg adsorption of modified fly ash, while SO{sub 2} has double role of inhibition because of competitive adsorption and promotion to chemisorption. In addition, sample modified with FeCl{sub 3} has a great performance in Hg removal.

Simulating intracrater ash recycling during mid-intensity explosive activity: high temperature laboratory experiments on natural basaltic ash

Science.gov (United States)

D'Oriano, Claudia; Pompilio, Massimo; Bertagnini, Antonella; Cioni, Raffaello; Pichavant, Michel

2010-05-01

Direct observations of mid-intensity eruptions, in which a huge amount of ash is generated, indicate that ash recycling is quite common. The recognition of juvenile vs. recycled fragments is not straightforward, and no unequivocal, widely accepted criteria exist to support this. The presence of recycled glassy fragments can hide primary magmatic information, introducing bias in the interpretations of the ongoing magmatic and volcanic activity. High temperature experiments were performed at atmospheric pressure on natural samples to investigate the effects of reheating on morphology, texture and composition of volcanic ash. Experiments simulate the transformation of juvenile glassy fragments that, falling into the crater or in the upper part of the conduit, are recycled by following explosions. Textural and compositional modifications obtained in laboratory are compared with similar features observed in natural samples in order to identify some main general criteria to be used for the discrimination of recycled material. Experiments were carried out on tephra produced during Strombolian activity, fire fountains and continuous ash emission at Etna, Stromboli and Vesuvius. Coarse glassy clasts were crushed in a nylon mortar in order to create an artificial ash, and then sieved to select the size interval of 1-0.71 mm. Ash shards were put in a sealed or open quartz tube, in order to prevent or to reproduce effects of air oxidation. The tube was suspended in a HT furnace at INGV-Pisa and kept at different temperatures (up to to 1110°C) for increasing time (0.5-12 hours). Preliminary experiments were also performed under gas flux conditions. Optical and electron microscope observations indicate that high temperature and exposure to the air induce large modifications on clast surface, ranging from change in color, to incipient plastic deformation till complete sintering. Significant change in color of clasts is strictly related to the presence of air, irrespective of

Radiochemical studies on Bikini ashes

Energy Technology Data Exchange (ETDEWEB)

Shiokawa, T

1954-01-01

Decay characteristics of the ashes which were brought back by the crew of the Fukuryu Maru No. 5 were: untreated ash I = ct/sup -1/ /sup 81/, water soluble part t/sup -2/ /sup 71/, insoluble part t/sup -1/ /sup 68/. Radioactive species separated by chemical method with carrier or collector were: nuclide, activity of nuclide (counts/min)/activity of original sample (counts/min), and the date of separation, /sup 89/Sr 6000/80 X 10/sup 4/, April 24; /sup 95/Zr, 280/80 x 10/sup 4/, -; /sup 111/Ag, 200/200 x 10/sup 4/, April 14; /sup 103/Ru, 2.300/25 x 10/sup 4/, etc.

Recent results of the investigation of a micro-fluidic sampling chip and sampling system for hot cell aqueous processing streams

International Nuclear Information System (INIS)

Tripp, J.; Smith, T.; Law, J.

2013-01-01

A Fuel Cycle Research and Development project has investigated an innovative sampling method that could evolve into the next generation sampling and analysis system for metallic elements present in aqueous processing streams. Initially sampling technologies were evaluated and micro-fluidic sampling chip technology was selected and tested. A conceptual design for a fully automated microcapillary-based system was completed and a robotic automated sampling system was fabricated. The mechanical and sampling operation of the completed sampling system was investigated. Different sampling volumes have been tested. It appears that the 10 μl volume has produced data that had much smaller relative standard deviations than the 2 μl volume. In addition, the production of a less expensive, mass produced sampling chip was investigated to avoid chip reuse thus increasing sampling reproducibility/accuracy. The micro-fluidic-based robotic sampling system's mechanical elements were tested to ensure analytical reproducibility and the optimum robotic handling of micro-fluidic sampling chips. (authors)

Solubility and transport of arsenic coal ash

International Nuclear Information System (INIS)

Iturbe, R.; Cruickshank, C.; Vega, E.; Silva, A.E.

1996-01-01

An experimental method combined with a numerical model allows a comparison of two methods for the disposal of ash that contains arsenic, from the Rio Escondido coal-fired power plant. The calculation yields significant differences in aquifer migration times for the site. The wet disposal method gave 10 years time and the dry method gave 22 years. Experiments were performed on the rate of dissolution of the arsenic from ash samples; and these results indicate a first order kinetics reaction. 8 refs., 8 figs., 8 tabs

Fly ash carbon passivation

Science.gov (United States)

La Count, Robert B; Baltrus, John P; Kern, Douglas G

2013-05-14

A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

Ashes to ashes: Large Fraxinus germplasm collections and their fates

Science.gov (United States)

Kim C. Steiner; Paul. Lupo

2010-01-01

As the emerald ash borer (EAB) threatens the survival of our ash species, measures should be taken to preserve their genetic variability in the event that we discover a way to restore populations destroyed by the beetle. As it happens, large germplasm collections exist for our most important and widely distributed eastern species of the genus, white ash (...

Simultaneous speciation of arsenic, selenium, and chromium: Species stability, sample preservation, and analysis of ash and soil leachates

Science.gov (United States)

Wolf, R.E.; Morman, S.A.; Hageman, P.L.; Hoefen, T.M.; Plumlee, G.S.

2011-01-01

An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10 ??C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present

Simultaneous speciation of arsenic, selenium, and chromium: species, stability, sample preservation, and analysis of ash and soil leachates

Science.gov (United States)

Wolf, Ruth E.; Morman, Suzette A.; Hageman, Philip L.; Hoefen, Todd M.; Plumlee, Geoffrey S.

2011-01-01

An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10° C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present

Simultaneous speciation of arsenic, selenium, and chromium: species stability, sample preservation, and analysis of ash and soil leachates

Energy Technology Data Exchange (ETDEWEB)

Wolf, Ruth E.; Morman, Suzette A.; Hageman, Philip L.; Hoefen, Todd M.; Plumlee, Geoffrey S. [Denver Federal Center, US Geological Survey, Denver, CO (United States)

2011-11-15

An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10 C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present, but

Fire severity effects on ash extractable Total Phosphorous

Science.gov (United States)

Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

2010-05-01

Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher

Technical note - the incorporation of ash content into gas content

Energy Technology Data Exchange (ETDEWEB)

Creech, M.; Mahoney, M. [Powercoal Pty. Ltd., Budgewoi, NSW (Australia)

1995-12-31

For gas content analysis in recent years, it has been standard procedure to report results on a `dry ash free` (daf) basis, under the assumption that gas only adsorbs onto coaly material. In order to test the relationship between ash and gas content, samples of various rock types were taken from two drillholes in the Newcastle Coalfield. The results of this study confirmed the correlation between gas content and ash, providing an accurate means of relating gas contents for all carbonaceous rock types. 4 refs., 5 figs., 1 tab.

Trace elements in coal ash

Science.gov (United States)

Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

2015-01-01

Coal ash is a residual waste product primarily produced by coal combustion for electric power generation. Coal ash includes fly ash, bottom ash, and flue-gas desulfurization products (at powerplants equipped with flue-gas desulfurization systems). Fly ash, the most common form of coal ash, is used in a range of products, especially construction materials. A new Environmental Protection Agency ruling upholds designation of coal ash as a non-hazardous waste under Subtitle D of the Resource Conservation and Recovery Act, allowing for the continued beneficial use of coal ash and also designating procedures and requirements for its storage.

On-stream chemical element monitor

International Nuclear Information System (INIS)

Averitt, O.R.; Dorsch, R.R.

1979-01-01

An apparatus and method for on-stream chemical element monitoring are described wherein a multiplicity of sample streams are flowed continuously through individual analytical cells and fluorescence analyses are performed on the sample streams in sequence, together with a method of controlling the time duration of each analysis as a function of the concomitant radiation exposure of a preselected perforate reference material interposed in the sample-radiation source path

Mercury release from fly ashes and hydrated fly ash cement pastes

Science.gov (United States)

Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

2018-04-01

The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

Suitability of untreated wood ash for recycling; Qualitaet und Verwertungsmoeglichkeiten von Holzaschen aus naturbelassenen Hoelzern

Energy Technology Data Exchange (ETDEWEB)

Stahl, E. [Fraunhofer-Inst. fuer Umwelt-, Sicherheits- und Energietechnik, UMSICHT, Oberhausen (Germany); Doetsch, P. [RWTH Aachen (Germany). Lehr- und Forschungsgebiet Abfallwirtschaft

2008-10-15

Background, aim and scope: The increasing use of wood for generating heat and electricity requires that more and more fuels be obtained directly or indirectly from the forest. Sound, sustainable recycling management calls for the return of any generated wood ash back to the forest to make use of the nutrients it contains. Similarly, recycling this ash in other locations such as agricultural land or private gardens can serve equally well as fertilizer. At the same time, it is critical that no accumulated pollutants be introduced into the nutrient loop. Wood ash that is heavily laden with such pollutants must not be considered for recycling. As part of this research project, commissioned by the Ministry for the Environment and Conservation, Agriculture and Consumer Protection of the State of North Rhine-Westphalia in Germany (MUNLV), ash samples of 209 woodfired appliances generating between 10 and 4000 kW of heat performance were taken from throughout the federal state of North Rhine-Westphalia. Untreated wood, either forested or scrap, was used as the sole fuel for these appliances. Materials and methods: All course ash and fly ash samples were analyzed to determine their composition of main nutrients, heavy metals, and the elements Fe, Cl, Si, Al and Na. The purpose of this analysis was to evaluate the suitability of this wood ash for reintroduction to forest soils or as fertilizer in other types of soil. Results: The majority of the wood ash samples in this study contained sufficiently high amounts of nutrients to match the requirement for stand-alone fertilizers (PK-fertilizer, potash fertilizer). However, the heavy metal content was highly variable, with a mean content high enough to prohibit them from being classified per se as PK- or potash fertilizer for agricultural land. Due to the high quantities of cadmium, application of this ash to garden soils would likewise be ill-advised. Discussion: On forest soils German law permits application of a mixture of

Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

Science.gov (United States)

Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

2013-12-17

Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (1-5 μm, exceptionally 13 μm), rarely engine wear and escape into the atmosphere.

Fly ash aggregates. Vliegaskunstgrind

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A study has been carried out into artificial aggregates made from fly ash, 'fly ash aggregates'. Attention has been drawn to the production of fly ash aggregates in the Netherlands as a way to obviate the need of disposal of fly ash. Typical process steps for the manufacturing of fly ash aggregates are the agglomeration and the bonding of fly ash particles. Agglomeration techniques are subdivided into agitation and compaction, bonding methods into sintering, hydrothermal and 'cold' bonding. In sintering no bonding agent is used. The fly ash particles are more or less welded together. Sintering in general is performed at a temperature higher than 900 deg C. In hydrothermal processes lime reacts with fly ash to a crystalline hydrate at temperatures between 100 and 250 deg C at saturated steam pressure. As a lime source not only lime as such, but also portland cement can be used. Cold bonding processes rely on reaction of fly ash with lime or cement at temperatures between 0 and 100 deg C. The pozzolanic properties of fly ash are used. Where cement is applied, this bonding agent itself contributes also to the strength development of the artificial aggregate. Besides the use of lime and cement, several processes are known which make use of lime containing wastes such as spray dry absorption desulfurization residues or fluid bed coal combustion residues. (In Dutch)

EFFECT OF PALM EMPTY BUNCH ASH ON TRANSESTERIFICATION OF PALM OIL INTO BIODIESEL

Directory of Open Access Journals (Sweden)

Johan Sibarani

2010-06-01

Full Text Available Biodiesel conversion from transesterification reaction palm oil with methanol was studied by using an ash of palm empty bunch as a base catalyst. Atomic absorption spectroscopy (AAS and indicator titration analysis were used as tools for characterization of ash sample. Chemical structure of biodiesel was analyzed by GC-MS. The effects of ash sample weight (5, 10, 15, 20 and 25 g immersed in 75 mL methanol and the methanol-palm oil mol ratio (3:1; 6:1; 9:1 and 12:1 toward the conversion of biodiesel were investigated. Biodiesel was prepared by refluxing palm oil and methanol containing ash sample. The reflux was done at room temperature for 2 h. Ester layer was distillated at 74 oC, extracted with aquadest and then dried using Na2SO4 anhydrous. The product was characterized by GC-MS, ASTM D 1298 (specific gravity 60/60 °F, ASTM D 97 (pour point, ASTM D 2500 (cloud point, ASTM D 93 (flash point, ASTM D 445 (kinematics viscosity 40 °C and ASTM D 482 (ash content. The result of GC-MS analysis showed that methyl palmitate is primary content of biodiesel product. A 15 g weight of ash sample gave the maximum biodiesel conversion. By increasing methanol mole quantity, biodiesel conversion increased progressively and maximum at 9:1 methanol-palm oil ratio (84.12 % and decreased on 12:1 ratio (75.58 %. Most of the biodiesel products were similar to those of the diesel physical characters.   Keywords: Biodiesel conversion, transesterification, palm oil, palm empty bunch

Radiological assessment of the utilization of fly ash in concrete for building construction and the parameters affecting radon-222 emanation from fly ash concrete

International Nuclear Information System (INIS)

Hwang, J.G.

1986-01-01

In this study, the Rn-222 area exhalation rates and the maximum area exhalations for concrete containing fly ash or Ra-226 water were measured. Various concrete samples were fabricated with fly ash of known radium content as a cement substitute. Other samples were prepared with one of three concentrations of Ra-226 water solution added into the concrete mix. A newly designed Indoor/Outdoor Emanation Chamber. The Ra-225 concentrations for the fly ash used ranged from 3.42 pCi/g to 7.55 pCi/g depending upon the source of the ash and the particle size. Doses were calculated for occupants of a hypothetical house built with concrete of the type studied. Doses to the basal cells of the bronchial epithelium and the mean dose to the lung were 2.10 rad/yr and 0.37 rad/yr for standard concrete, up to 4.28 rad/yr and 0.76 rad/yr for fly ash concrete, and 3.26 rad/yr and 0.58 rad/yr for the concrete made with 25 pCI/L radium-226 water. The risk associated with utilization of standard concrete in an unventilated house was estimated to range from 560 to 1316 fatal cancers in million population. Utilization of fly ash as a cement substitute could increase the number of fatal lung cancers up to 2680. Introducing 25 pCi/L Ra-226 water into concrete will increase the fatal cancer rate up to 2042 in a million population

Hydration of fly ash cement and microstructure of fly ash cement pastes

Energy Technology Data Exchange (ETDEWEB)

Shiyuan, H.

1981-01-01

The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

Influence of the Chernobyl accident on radioactivity of fuel peat and peat ash in Finland

International Nuclear Information System (INIS)

Mustonen, R.; Salonen, S.; Itkonen, A.

1988-04-01

The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were measured in relative high concentrations in fuel peat and especially in peat ash. The radionuclide concentrations were measured at six peat-fired power plants in different parts of Finland throughout the heating season 1986-87. Also evaporation of different radionuclides in peat combustion and their condensation on fly ash particles were studied at four power plants. The 137 Cs-concentrations in compiled peat samples varied between 30 and 3600 Bq kg -1 dry weight and in ash samples between 600 and 68000 Bq kg -1 . Differences in radionuclide concentrations between the power plants were great and also the radionuclide composition in fuel peat varied regionally. The 137 Cs-concentrations of the fly ash after the ash precipitators varied between 12000 and 120000 Bq kg -1 and fly ash emissions varied from 17 to 1100 mg m -3 , depending on the power plant and the load of the boiler. High radioactivity concentrations in precipitator ash caused some restrictions to the utilization of peat ash for various purposes

Analysis of Content of Selected Critical Elements in Fly Ash

Directory of Open Access Journals (Sweden)

Makowska Dorota

2016-03-01

Full Text Available Pursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

Identification and quantification of radionuclides in coal ash. Final report

International Nuclear Information System (INIS)

Alleman, J.E.; Clikeman, F.M.; Skronski, T.

1998-01-01

One of the important environmental issues raised recently in regard to coal ash reuse for highway construction purposes (e.g., embankment development) is that of worker, and public, exposure to radiation which might possibly be emitted by these types of residues. This research project subsequently addressed the associated issue of radiation emission by coal ash residuals generated within the State of Indiana, covering both fly ash and bottom ash materials. Samples were obtained at sixteen different coal-fired power generating facilities within Indiana and subjected to quantitative analysis of their associated gamma-ray emission levels. After identifying the responsible radionuclides, a conservative approximation was then developed for the worst-case potential occupational exposure with construction employees working on this type of high-volume, coal ash embankment. In turn, these potential emissions levels were compared to those of other traditional construction materials and other common sources

Ash properties of some dominant Greek forest species

International Nuclear Information System (INIS)

Liodakis, S.; Katsigiannis, G.; Kakali, G.

2005-01-01

The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

Ash properties of some dominant Greek forest species

Energy Technology Data Exchange (ETDEWEB)

Liodakis, S. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)]. E-mail: liodakis@central.ntua.gr; Katsigiannis, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece); Kakali, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)

2005-10-15

The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

Quality assurance of MSWI bottom ash. Environmental properties; Kvalitetssaekring av slaggrus. Miljoemaessiga egenskaper

Energy Technology Data Exchange (ETDEWEB)

Flyhammar, Peter [Lund Univ. (Sweden). Engineering Geology

2006-04-15

In Sweden, several hundred tonnes of MSWI bottom ash are generated annually at 29 incineration plants for municipal solid waste. So far bottom ash has mainly been disposed in to landfills or used as cover material in landfills or in other construction works at landfills. A few applications of bottom ash in construction works outside landfills have been reported. A large problem for the market of bottom ash and other secondary materials outside Swedish waste treatment plants is the lack of roles and regulations for a non-polluting use. During 2002 Hartlen and Groenholm presented a proposal to a system to assure the quality of bottom ash after homogenization and stabilization. They notice that the leaching of salts and metals to ground water constitutes the largest risk for the environment during use of bottom ash. Therefore, a quality assurance of environmental properties should be based on leaching tests. The aim of this project was to study how the control of environmental properties of bottom ash (at first hand leaching properties) earlier described in e.g. a product information sheet should be worked out. The starting-point has been a control system for bottom ash developed by Sysav. Different leaching tests illustrate however different aspects of the environmental properties, e.g. short-term and long-term leaching. Limit and target values for different variables could affect both the possibilities to use bottom ash as well as the sampling from storage heaps. We have chosen to investigate pH, availability and leached amount and the connection between these variables. the possibilities to use pH or the availability to assess both short-term and longterm leaching properties. how the number of subsamples that should be collected from a storage heap is affected by different control variables and quality requirements. how bottom ash is stabilized by today's storage technology and how the technology could be improved. Our sample test of bottom ash from Swedish

Glass-ceramic from mixtures of bottom ash and fly ash.

Science.gov (United States)

Vu, Dinh Hieu; Wang, Kuen-Sheng; Chen, Jung-Hsing; Nam, Bui Xuan; Bac, Bui Hoang

2012-12-01

Along with the gradually increasing yield of the residues, appropriate management and treatment of the residues have become an urgent environmental protection problem. This work investigated the preparation of a glass-ceramic from a mixture of bottom ash and fly ash by petrurgic method. The nucleation and crystallization kinetics of the new glass-ceramic can be obtained by melting the mixture of 80% bottom ash and 20% fly ash at 950 °C, which was then cooled in the furnace for 1h. Major minerals forming in the glass-ceramics mainly are gehlenite (Ca(2)Al(2)SiO(7)) & akermanite (Ca(2)MgSiO(7)) and wollastonite (CaSiO(3)). In addition, regarding chemical/mechanical properties, the chemical resistance showing durability, and the leaching concentration of heavy metals confirmed the possibility of engineering and construction applications of the most superior glass-ceramic product. Finally, petrurgic method of a mixture of bottom ash and fly ash at 950 °C represents a simple, inexpensive, and energy saving method compared with the conventional heat treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Academic Self-Concepts in Ability Streams: Considering Domain Specificity and Same-Stream Peers

Science.gov (United States)

Liem, Gregory Arief D.; McInerney, Dennis M.; Yeung, Alexander S.

2015-01-01

The study examined the relations between academic achievement and self-concepts in a sample of 1,067 seventh-grade students from 3 core ability streams in Singapore secondary education. Although between-stream differences in achievement were large, between-stream differences in academic self-concepts were negligible. Within each stream, levels of…

Arsenic, chromium and mercury removal using mussel shell ash or a sludge/ashes waste mixture.

Science.gov (United States)

Seco-Reigosa, Natalia; Peña-Rodríguez, Susana; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel; Fernández-Sanjurjo, María J; Alvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino

2013-04-01

Different batches of valued mussel shell and waste mussel shell ash are characterised. Shell ash has pH > 12 and high electrical conductivities (between 16.01 and 27.27 dS m(-1)), while calcined shell shows pH values up to 10.7 and electrical conductivities between 1.19 and 3.55 dS m(-1). X-ray fluorescence, nitric acid digestion and water extractions show higher concentrations in shell ash for most parameters. Calcite is the dominant crystalline compound in this ash (95.6%), followed by aragonite. Adsorption/desorption trials were performed for mussel shell ash and for a waste mixture including shell ash, sewage sludge and wood ash, showing the following percentage adsorptions: Hg(II) >94%, As(V) >96% and Cr(VI) between 11 and 30% for shell ash; Hg(II) >98%, As(V) >88% and Cr(VI) between 30 and 88% for the waste mixture. Hg and As desorption was ash and the waste mixture, while Cr desorption was between 92 and 45% for shell ash, and between 19 and 0% for the mixture. In view of that, mussel shell ash and the mixture including shell ash, sewage sludge and wood ash could be useful for Hg(II) and As(V) removal.

Determination of ash content of coal by mass absorption coefficient measurements at two X-ray energies

International Nuclear Information System (INIS)

Fookes, R.A.; Gravitis, V.L.; Watt, J.S.

1977-01-01

A method for determining the ash content of coal is proposed. It involves measurements proportional to mass absorption coefficients of coal at two X-ray energies. These measurements can be made using X-ray transmission or scatter techniques. Calculations based on transmission of narrow beams of X-rays have shown that ash can be determined to about 1wt%(1 sigma) in coal of widely varying ash content and composition. Experimentally, ash content was determined to 0.67wt% by transmission techniques and 1.0wt% by backscatter techniques in coal samples from the Bulli seam, NSW, Australia, having ash in the range 11-34wt%. For samples with a much wider range of coal composition (7-53wt% ash and 0-25wt% iron in the ash), ash content was determined by backscatter measurements to 1.62wt%. The method produced ash determinations at least as accurate as those produced by the established technique which compensates for variation in iron content of the ash by X-ray fluorescence analysis for iron. Compared with the established technique, it has the advantage of averaging analysis over much larger volumes of coal, but the disadvantage that much more precise measurements of X-ray intensities are required. (author)

Exploring the molecular and biochemical basis of ash resistance to emerald ash borer

Science.gov (United States)

Justin G.A. Whitehill; Daniel A. Herms; Pierluigi. Bonello

2010-01-01

Larvae of the emerald ash borer (EAB) (Agrilus planipennis) feed on phloem of ash (Fraxinus spp.) trees. It is hypothesized that the resistance of Asian species of ash (e.g., Manchurian ash, F. mandshurica) to EAB is due to endogenous defenses present in phloem tissues in the form of defensive proteins and/or...

Analytical data and sample locality map for aqua-regia leachates of stream sediments analyzed by ICP, and emission spectrographic and ICP results for many NURE stream sediments from the Killik River Quadrangle, Alaska

International Nuclear Information System (INIS)

Motooka, J.M.; Adrian, B.M.; Church, S.E.; McDougal, C.M.; Fife, J.B.

1989-01-01

A U.S. Geological Survey report is presented giving analytical data and sample locality map for aqua-regia leachates of stream sediments analyzed by ICP, and emission spectrographic and ICP results for many NURE stream sediments from the Killik River Quadrangle, Alaska

On-stream analysis of coal by prompt neutron activation analysis

International Nuclear Information System (INIS)

Barker, D.

1981-01-01

The need for rapid continuous on-stream analysis of coal was recognised in 1975. Analytical systems capable of determining some of the most important compositional properties of coal have been developed. The research programme has produced a series of analysers suitable for on-stream, batch, slurry and laboratory analytical determination of coal. This series of analysers is marketed under the name of 'Nucoalyzer'. The Nucoalyzer - CONAC (Continuous On-line Nuclear Analyzer for Coal) offers real-time, continuous determination of calorific value, percentage ash, percentage moisture, percentage sulphur, boiler fouling and slagging indices. The CONAC model is described in this article. The analytical principle employed in the various Nucoalyzer systems is based on prompt neutron activation analysis

Effect of ash components on the ignition and burnout of high ash coals

Energy Technology Data Exchange (ETDEWEB)

Feng, B.; Yan, R.; Zheng, C.G. [Huazhong University of Science and Technology, Wuhan (China). National Laboratory of Coal Combustion

1998-11-01

The effect of the ash components on the ignition and burnout of four Chinese high ash coals were studied by thermogravimetric analysis. To investigate the influence of the ash components, comparative experiments were carried out with original, deashed and impregnated coals. Eleven types of ash components, such as SiO{sub 2}, CaCO{sub 3}, MgO, Na{sub 2}CO{sub 3}, K{sub 2}CO{sub 3}, Al{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, FeS{sub 2}, NH{sub 4}Fe(SO{sub 4}){sub 2}{center_dot}12H{sub 2}O and FeSO{sub 4},(NH{sub 4}){center_dot}6H{sub 2}O were used in the present study. It was found that most of the ash components have negative effects. The strong influence of some ash components suggests that the combustion characteristics of high ash coal may be determined by the ash composition. 5 refs., 2 figs., 2 tabs.

Impact of sugar industry fly ash emissions on environment

International Nuclear Information System (INIS)

Memom, A.R.; Ansari, A.K.

2001-01-01

This work was conducted in 1992 to find out the effects and causes of environmental problems due to sugar mills of Sindh. Most of the complaints were received from Nawabshah, Tando Mohammed Khan residential areas where following mills are located, emitting large amounts of fly ash from their chimneys into the atmosphere: (i) Habib Sugar Mills, Nawabshah, (II) Fauji Sugar Mills, Tando Mohammed Khan. Environmental survey of above localities was carried out which reveals that eye-allergy and asthma are the major health effects of fly ash besides the aesthetic problems. Sieve analysis of two fly ash samples viz Fauji Sugar Mills (Old Plant) and Sanghar Sugar Mills (New Plant) showed that the particle size of over 50% of fly ash was above 300 mu m. These large size black particles were unburned carbon particles, which on burning in air gave a weight loss of over 87% at 1000 centi grade. The fly ash analytical results showed that combustion of bagasse in sugar mills was not complete at all and this was not only polluting the atmosphere but also causing energy losses. (author)

Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Coloado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino Counties, California

Science.gov (United States)

King, Harley D.; Chaffee, Maurice A.

2000-01-01

INTRODUCTION In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management's (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM's Coordinated Management Plan for the area. This report presents analytical data from this study. To provide comprehensive coverage of the NECD, we compiled and examined all available geochemical data, in digital form, from previous studies in the area, and made sample-site plots to aid in determining where sample-site coverage and analyses were sufficient, which samples should be re-analyzed, and where additional sampling was needed. Previous investigations conducted in parts of the current study area included the National Uranium Resource Evaluation (NURE) program studies of the Needles and Salton Sea 1? x 2? quadrangles; USGS studies of 12 BLM Wilderness Study Areas (WSAs) (Big Maria Mountains, Chemehuevi Mountains, Chuckwalla Mountains, Coxcomb Mountains, Mecca Hills, Orocopia Mountains, Palen-McCoy, Picacho Peak, Riverside Mountains, Sheephole Valley (also known as Sheep Hole/Cadiz), Turtle Mountains, and Whipple Mountains); and USGS studies in the Needles and El Centro 1? x 2? quadrangles done during the early 1990s as part of a project to identify the regional geochemistry of southern California. Areas where we did new sampling of rocks and stream sediments are mainly in the Chocolate Mountain Aerial Gunnery Range and in Joshua Tree National Park, which extends into the west-central part of the NECD, as shown in figure 1 and figure 2. This report contains analytical data for 132 rock samples and 1,245 stream-sediment samples collected by the USGS, and 362 stream-sediment samples and 189 soil samples collected during the NURE program. All samples are from the Northern and Eastern Colorado

Shedding of ash deposits

DEFF Research Database (Denmark)

Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt

2009-01-01

Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

Pengaruh Kombinasi Fly Ash dan Bottom Ash sebagai Bahan Substitusi pada Campuran Beton terhadap Sifat Mekanis

OpenAIRE

Yahya, Tengku Tantoni; Kurniawandy, Alex; Djauhari, Zulfikar

2017-01-01

Fly ash and bottom ash were waste that generated from the power plant burning coal process. Fly ash and bottom ash has the potential to be developed as a basic ingredient in concrete composites. This research aimed to obtain the properties of fresh concrete and hard concrete of the combined effect of fly ash and bottom ash as a substitute ingredient in composite concrete. This research has examined the influence of a combination of waste fly ash and bottom ash to the compressive strength of a...

Utilization of stabilized municipal waste combustion ash residues as construction material

International Nuclear Information System (INIS)

Shieh, C.S.

1992-01-01

Stabilized municipal waste combustion (MWC) ash residues were investigated for their potential as construction material that can be beneficially used in terrestrial and marine environments. End-use products, such as patio stones, brick pavers, solid blocks, and reef units, were fabricated and tested for their engineering and chemical characteristics. engineering feasibility and environmental acceptability of using stabilized ash residues as construction material are discussed in this paper. Ash samples were collected from two mass-burn facilities and one refuse derived fuel (RDF) facility in Florida

Radioactivity of Yatagan lignites and their ash

International Nuclear Information System (INIS)

Cicek, F.; Mustafaev, I.; Aliyev, C.

2004-01-01

Full text: One of harmful factor of Environmental impact of coal combustion is radiation pollution of Environment. The natural radioisotopes - uranium, thorium and potassium and products of their radioactive destruction contains of radionuclides. These radionuclides in composition of fly ash are thrown to atmosphere from coal combustion furnaces. The concentration of radioisotopes in composition of coals changes in the wide ranges: from 3 up to 520 Becquerel per kilogram (Bq/kg) for Uranium-238 and from 3 up to 320 Bq/kg for thorium-232. The radioactive pollution degree of environment depends on radioisotopes content of initial fuels. In this connection at the estimation of outlook and exploitation of coal mines it is necessary to determine of radioisotopes concentration in coals. That is why investigation of radioisotopes concentration of Turkish lignites has great importance. In this work the radionuclide content of Yatagan lignites and their ash, taken from Gekova thermal Electro station have been studied. The total radiation background generated by these samples was investigated by using of dosimeters 8P-5, CRP-88H, PYB-OIP. Radionuclides content of samples was determined in the Institute of Geology Azerbaijan national Academy of Sciences by using of highly sensitivity gamma-spectrometer CAPU-2, designed by Special Constructor Buro G eophysika . The plant allows to determine the radioisotopes content of solid and liquid samples with highly reliability. It has been established that in sample of lignite uranium content (on the radium equivalent) is 68 Bq/kg, potassium-149 Bq/kg and thorium is absent. The total radioactivity of lignite sample is 79,7 Bq/kg. In the ash sample uranium content is 266 Bq/kg, potassium-188 Bq/kg, and total activity reach to 300 Bq/kg. The possibility of application of purification erection for radionuclides from smoke gases of coal combustion is discussed

Evaluation and Treatment of Coal Fly Ash for Adsorption Application

Directory of Open Access Journals (Sweden)

Samson Oluwaseyi BADA

Full Text Available Many researchers had investigated fly ash as an adsorbent for the uptake of organic compounds from petrochemical waste effluents. The availability, inexpensive and its adsorption characteristic had made it an alternative media for the removal of organic compounds from aqueous solution. The physical property of South African Coal Fly Ash (SACFA was investigated to determine its adsorption capability and how it can be improved. Chemical treatment using 1M HCl solution in the ratio of (1 g fly ash to (2 ml of acid was used and compared with untreated heat-treated samples. The chemically treated fly ash has a higher specific surface area of 5.4116 m2/g than the heat-treated fly ash with 2.9969 m2/g. More attention had to be given to the utilization of SACFA for the treatment of wastewaters containing organic compounds through the application of Liquid phase adsorption process that was considered as an inexpensive and environmentally friendly technology.

Melting and Sintering of Ashes

DEFF Research Database (Denmark)

Hansen, Lone Aslaug

1997-01-01

-1300°C, and a trend of higher fusion temperatures with increasing contents of Al-silicates and quartz was found.c) Fly ashes, bottom ashes and deposits from coal/straw co-firing were all found to consist mainly of metal-alumina and alumina-silicates. These ashes all melt in the temperature range 1000......The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction......, the biggest deviations being found for salt rich (i.e. straw derived) ashes.A simple model assuming proportionality between fly ash fusion and deposit formation was found to be capable of ranking deposition rates for the different straw derived fly ashes, whereas for the fly ashes from coal/straw co-firing...

pH-dependent leaching of dump coal ash - retrospective environmental analysis

Energy Technology Data Exchange (ETDEWEB)

Popovic, A.; Djordjevic, D. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

2009-07-01

Trace and major elements in coal ash particles from dump of 'Nikola Tesla A' power plant in Obrenovac near Belgrade (Serbia) can cause pollution, due to leaching by atmospheric and surface waters. In order to assess this leaching potential, dump ash samples were subjected to extraction with solutions of decreasing pH values (8.50, 7.00, 5.50, and 4.00), imitating the reactions of the alkaline ash particles with the possible alkaline, neutral, and acidic (e.g., acid rain) waters. The most recently deposited ash represents the greatest environmental threat, while 'aged' ash, because of permanent leaching on the dump, was shown to have already lost this pollution potential. On the basis of the determined leachability, it was possible to perform an estimation of the acidity of the regional rainfalls in the last decades.

Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

Directory of Open Access Journals (Sweden)

Antoni

2017-01-01

Full Text Available Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash.

Aircraft and Volcanic Ash a Key Focus of EGU Meeting

Science.gov (United States)

Showstack, Randy

2010-05-01

The erupting Eyjafjallajökull volcano in southern Iceland, which has intermittently disrupted European air traffic since 14 April, provided a dramatic backdrop for the recent European Geosciences Union (EGU) General Assembly in Vienna, Austria, about 2700 kilometers to the east. EGU organized several last-minute conference sessions about the eruption, and a number of scientists, including some from Iceland, discussed the latest situation, monitoring and assessment needs, and new guidance about flying through volcanic ash, which volcanologist and incoming EGU president-elect Donald Dingwell of the University of Munich, Germany, called “one of the ugliest cocktails nature throws up.” Although the eruption was small compared with those at Mount St. Helens in 1980 or Mount Pinatubo in 1991, the event produced an estimated 0.1 ± 0.05 cubic kilometer of tephra between 14 and 16 April, according to preliminary numbers from the Institute of Earth Sciences in Reykjavik, Iceland (see the related news item in this issue). An enormous amount of ash from the eruption got lofted into the jet stream toward the United Kingdom and the European mainland. European air traffic controllers, operating under the best guidance and guidelines available at that time—which indicated no flying in ash—shut down European air space to avoid a potential catastrophe if ash clogged up an aircraft's engines.

Mercury in coals and fly ashes from Republika and Bobov dol thermoelectric power plants

Science.gov (United States)

Kostova, I.; Vassileva, C.; Hower, J.; Mastalerz, Maria; Vassilev, S.; Nikolova, N.

2011-01-01

Feed coal and y ash samples were collected at Republika and Bobov Dol thermoelectric power plants (TPPs). The y ashes (FAs) were collected fromthree rows of the hot-side electrostatic precipitators (ESPs) array. Each sam- ple was wet-screened at 100, 200, 325 and 500 mesh. The coals and y ashes were characterized with regard to their petrological and chemical composition (including mercury content) and to their surface area properties. The calculated enrichment factor (EF) shows that the Hg concentrations in the bulk coal samples from Republika and Bobov Dol TPPs are 2.19 and 1.41, respectively. In some coal size fractions the EF can be up to 4 times higher than the Clarke value. The calculated EF for fly ashes shows that the Hg concentrations in the bulk samples studied are lower (between 0.03 and 0.32) than the Clarke value. The most enriched in Hg are the fly ashes from the 3rd ESP row of Republika TPP. The Hg distribution in bulk FAs taken from dierent rows of the electrostatic precipitators of both TPPs studied shows well established tendency of gradual increase in the Hg content from the 1st to the 2nd and 3rd ESP rows. The correlation between Hg content and surface area, mesopore and micropore volume of y ashes was also done in the present investigation.

The stability of clay using mount Sinabung ash with unconfined compression test (uct) value

Science.gov (United States)

Puji Hastuty, Ika; Roesyanto; Hutauruk, Ronny; Simanjuntak, Oberlyn

2018-03-01

The soil has a important role as a highway’s embankment material (sub grade). Soil conditions are very different in each location because the scientifically soil is a very complex and varied material and the located on the field is very loose or very soft, so it is not suitable for construction, then the soil should be stabilized. The additive material commonly used for soil stabilization includes cement, lime, fly ash, rice husk ash, and others. This experiment is using the addition of volcanic ash. The purpose of this study was to determine the Index Properties and Compressive Strength maximum value with Unconfined Compression Test due to the addition of volcanic ash as a stabilizing agent along with optimum levels of the addition. The result showed that the original soil sample has Water Content of 14.52%; the Specific Weight of 2.64%; Liquid limit of 48.64% and Plasticity Index of 29.82%. Then, the Compressive Strength value is 1.40 kg/cm2. According to USCS classification, the soil samples categorized as the (CL) type while based on AASHTO classification, the soil samples are including as the type of A-7-6. After the soil is stabilized with a variety of volcanic ash, can be concluded that the maximum value occurs at mixture variation of 11% Volcanic Ash with Unconfined Compressive Strength value of 2.32 kg/cm2.

Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

International Nuclear Information System (INIS)

Motlep, Riho; Sild, Terje; Puura, Erik; Kirsimaee, Kalle

2010-01-01

Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

Energy Technology Data Exchange (ETDEWEB)

Motlep, Riho, E-mail: riho.motlep@ut.ee [Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu (Estonia); Sild, Terje, E-mail: terje.sild@maaamet.ee [Estonian Land Board, Mustamaee tee 51, 10621 Tallinn (Estonia); Puura, Erik, E-mail: erik.puura@ut.ee [Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu (Estonia); Kirsimaee, Kalle, E-mail: kalle.kirsimae@ut.ee [Department of Geology, University of Tartu, Ravila 14A, 50411 Tartu (Estonia)

2010-12-15

Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

Apparatus and method for direct measurement of coal ash sintering and fusion properties at elevated temperatures and pressures

Science.gov (United States)

Khan, M. Rashid

1990-01-01

A high-pressure microdilatometer is provided for measuring the sintering and fusion properties of various coal ashes under the influence of elevated pressures and temperatures in various atmospheres. Electrical resistivity measurements across a sample of coal ash provide a measurement of the onset of the sintering and fusion of the ash particulates while the contraction of the sample during sintering is measured with a linear variable displacement transducer for detecting the initiation of sintering. These measurements of sintering in coal ash at different pressures provide a mechanism by which deleterious problems due to the sintering and fusion of ash in various combustion systems can be minimized or obviated.

Release of microspherolites and metals extraction from energetical fly ashes by Bacillus isolates

Directory of Open Access Journals (Sweden)

Štyriaková Iveta

2000-09-01

Full Text Available The amorphous secondary silicate mineral components formed in the process of coal combustion dominate in the composition of energy fly-ash. Depending on the composition of coal concentrate, this secondary raw material source also contains the industrially interesting components, e.g. titanium (eventually iron and aluminium and can be considered as a non-metallic material suitable for the construction industry.The main secondary mineral components of the energy fly-ash formed during the coal combustion were studied using SEM (scanning electronic microscope. They can be divided into four groups:1. Amorphous spherical alumocilicate particles in allotriomorphic aluminosilicate grains – they represent a main mineral component of fly-ash, which is formed from the accompanying rocks of coal containing silicate minerals,2. Quartz – which formed a substantial component of accompanying rocks of coal or accompanying accessory mineral of coal together with kaolinite and mica, was transformed into tridymite at the temperature exceeding 870°C and into cristobalite at the temperature exceeding 1470°C. The spherical particles are products of reaction between cristobalite and aluminosilicate, which is a frequent phenomenon occurring during the formation of volcanic rocks. These particles form together a main amorphous phase of fly-ash.3. Mullite – represents a secondary component of fly-ash, which is formed from accompanying clay minerals of coal (kaolinite, mica together with cristobalite under the effect of temperature exceeding 1150°C,4. Non-combusted residue – consists of organic substance, represents a non-combusted ratio of coal as a secondary component of fly-ash.Heterotrophic bacteria of Bacillus genus are capable to remove 66 % of titanium and 33 % of iron from non-deposited fly-ash from Opatovice after 35 days of leaching of samples. The content of solid phase in fly-ash influences the extraction of elements, mainly iron and titatnium, because

Potential use of fly ash to soil treatment in the Morava region

Science.gov (United States)

Bulíková, Lucia; Kresta, František; Rochovanský, Martin

2017-09-01

Soil treatment by binders is a standard technology and leads to optimal utilization of excavated soils in road constructions. Soil treatment is controlled in the Czech Republic by EN 14227-15 and Technical Requirement TP 94. Soil treatment using fly ash has not been performed in the Czech Republic, although there is a sufficient normative base. Fly ash produced by burning of hard coal in the Moravian region was tested as a potential binder. Fly ash samples were mixed with loess loams (CI). Tested siliceous fly ash of class F (ASTM C618) did not showed hydraulic properties but it showed positive effect on reducing maximum dry density of mixtures, increasing the IBI value (Immediate bearing index) and decreasing tendency to volume changes when the amount of fly ash was increased. The results of laboratory tests demonstrate the possibility of using fly ashes as a binder for soil treatment.

Levels and patterns of polycyclic aromatic hydrocarbons in fly ash generated in Coal-fired power plant

International Nuclear Information System (INIS)

Ajmal, P.Y.; Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.

2005-01-01

The burning of pulverized coal to produce energy for generation of electricity in thermal power plants results in huge quantity of coal ash of varying properties. Because of the increase in electricity production, the amount of ash produced will increase proportionally. A large percentage of coal fly ash is comprised of relatively inert materials, such as silica and other trace and toxic elements. The coal ash also contain organic constituents of potential environmental concern. So far, very few studies on characterization of organic constituents in fly ash have been reported in the literature. In the present study, the fly ashes generated from the power stations are investigated regarding the distribution of 14 PAHs. The total amount of PAHs in the fly ash samples varied between 45.8 ng/g and 257.7 ng/g. Lower molecular weight (MW) PAHs, were found to be predominant in the fly ash samples. The concentration of Benzo(a)pyrene, which is the most potent carcinogenic PAH was found to vary between 0.8 ng/g to 6.3 ng/g with a mean concentration of 2.5 ng/g. (author)

Enhancing the compressive strength of landfill soil using cement and bagasse ash

Science.gov (United States)

Azim, M. A. M.; Azhar, A. T. S.; Tarmizi, A. K. A.; Shahidan, S.; Nabila, A. T. A.

2017-11-01

The stabilisation of contaminated soil with cement and agricultural waste is a widely applied method which contributes to the sustainability of the environment. Soil may be stabilised to increase strength and durability or to prevent erosion and other geotechnical failure. This study was carried out to evaluate the compressive strength of ex-landfill soil when cement and bagasse ash (BA) are added to it. Different proportions of cement (5%, 10%, 15% and 20%) was added to sample weights without BA. On the other hand, the cement in a different batch of sample weights was replaced by 2.5%, 5%, 7.5% and 10% of BA. All samples were allowed to harden and were cured at room temperature for 7, 14 and 28 days respectively. The strength of the contaminated soil was assessed using an unconfined compressive strength test (UCS). The laboratory tests also included the index properties of soil, cement and bagasse ash in raw form. The results indicated that the samples with cement achieved the highest compressive strength measuring 4.39 MPa. However, this study revealed that the use of bagasse ash produced low quality products with a reduction in strength. For example, when 5% of cement was replaced with 5% ash, the compressive strength decreased by about 54% from 0.72 MPa to 0.33 MPa. Similarly, the compressive strength of each sample after a curing period of 28 days was higher compared to samples cured for 7 and 14 days respectively. This is proved that a longer curing period is needed to increase the compressive strength of the samples.

Regional geochemical maps of the Tonopah 1 degree by 2 degrees Quadrangle, Nevada, based on samples of stream sediment and nonmagnetic heavy-mineral concentrate

Science.gov (United States)

Nash, J.T.; Siems, D.F.

1988-01-01

This report is part of a series of geologic, geochemical, and geophysical maps of the Tonopah 1° x 2° quadrangle, Nevada, prepared during studies of the area for the Conterminous United States Mineral Assessment Program (CUSMAP). Included here are 21 maps showing the distributions of selected elements or combinations of elements. These regional geochemical maps are based on chemical analyses of the minus-60 mesh (0.25 mm) fraction of stream-sediment samples and the nonmagnetic heavy-mineral concentrate derived from stream sediment. Stream sediments were collected at 1,217 sites. Our geochemical studies of mineralized rock samples provide a framework for evaluating the results from stream sediments.

Hydrogeochemical and stream sediment reconnaissance basic data report for Winnemucca NTMS Quadrangle, Nevada

International Nuclear Information System (INIS)

Puchlik, K.P.

1978-05-01

Results are presented of the geochemical reconnaissance sampling in the Winnemucca 1 0 x 2 0 quadrangle of the National Topographic Map Series (NTMS). Wet and dry sediment samples were collected throughout the 18,770-km 2 arid to semi-arid area and water samples at available streams, springs and wells. Results of neutron activation analyses are presented of uranium and trace elements and other measurements made in the field and laboratory in tabular hardcopy and microfiche format. The report includes 5 full-size overlays for use with the Winnemucca NTMS 1:250,000 quadrangle. Water sampling sites, water-sample uranium and thorium concentrations, sediment sampling sites, and sediment-sample total uranium and thorium concentrations are shown on the separate overlays. General geological and structural descriptions of the area are given and the 12 known uranium occurrences are described. The results indicate that the uranium geochemistry of the area is diverse. High concentrations (greater than 5 ppM) of uranium in sediments are associated mainly with rhyolitic ash falls and flows and silicic intrusives. In defining areas of interest the ratio of relatively insoluble thorium to uranium was considered. The anomalies as defined are then the sediment samples containing low Th/U and high uranium concentrations. These areas consist mainly of fluvial-lacustrine units. Most known uranium occurrences were also identified by this technique. The main Humboldt River shows an irregular increase in uranium concentration downstream which may be related to agricultural modification of the stream flow. U/Cl ratios were used to evaluate the effects of evaporative concentration. Of interest are spring and tributary waters containing high U/Cl and high uranium values. These waters mainly drain acid intrusives, silicic volcanic rocks and related sediments. One such area is the Shoshone and Cortez Mountains

Passive sampling of bioavailable organic chemicals in Perry County, Missouri cave streams.

Science.gov (United States)

Fox, J Tyler; Adams, Ginny; Sharum, Martin; Steelman, Karen L

2010-12-01

Two types of passive samplers--semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCIS)--were deployed in spring 2008 to assess bioavailable concentrations of aquatic contaminants in five cave streams and resurgences in Perry County, Missouri. Study sites represent areas of high cave biodiversity and the only known habitat for grotto sculpin (Cottus carolinae). Time-weighted average (TWA) water concentrations were calculated for 20 compounds (n = 9 SPMDs; n = 11 POCIS) originating primarily from agricultural sources, including two organochlorine insecticides, dieldrin and heptachlor epoxide, which were found at levels exceeding U.S. EPA criteria for the protection of aquatic life. GIS data were used to quantify and map sinkhole distribution and density within the study area. Infiltration of storm runoff and its influence on contaminant transport were also evaluated using land cover and hydrological data. This work provides evidence of cave stream contamination by a mix of organic chemicals and demonstrates the applicability of passive samplers for monitoring water quality in dynamic karst environments where rapid transmission of storm runoff makes instantaneous water sampling difficult.

The Coupling Effect Research of Ash Deposition and Condensation in Low Temperature Flue Gas

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Lei Ma

2016-01-01

Full Text Available Ash deposition is a key factor that deteriorates the heat transfer performance and leads to higher energy consumption of low pressure economizer working in low temperature flue gas. In order to study the ash deposition of heat exchange tubes in low temperature flue gas, two experiments are carried out with different types of heat exchange tubes in different flue gas environments. In this paper, Nusselt Number Nu and fouling factor ε are calculated to describe the heat transfer characteristics so as to study the ash deposition condition. The scanning electron microscope (SEM is used for the analysis of ash samples obtained from the outer wall of heat exchange tubes. The dynamic process of ash deposition is studied under different temperatures of outer wall. The results showed that ash deposition of heat exchanger will achieve a stable state in constant flue gas environment. According to the condition of condensation of acid vapor and water vapor, the process of ash deposition can be distinguished as mere ash deposition, acid-ash coupling deposition, and acid-water-ash coupling deposition.

Steam hydration-reactivation of FBC ashes for enhanced in situ desulphurization

Energy Technology Data Exchange (ETDEWEB)

Fabio Montagnaro; Marianna Nobili; Antonio Telesca; Gian Lorenz Valenti; Edward J. Anthony; Piero Salatino [Universita degli Studi di Napoli Federico II, Napoli (Italy). Dipartimento di Chimica

2009-06-15

Bed and fly ashes originating from industrial-scale fluidized bed combustors (FBCs) were steam hydrated to produce sorbents suitable for further in situ desulphurization. Samples of the hydrated ash were characterized by X-ray diffraction analysis, scanning electron microscopy and porosimetry. Bed ashes were hydrated in a pressure bomb for 30 and 60 min at 200{sup o}C and 250{sup o}C. Fly ash was hydrated in an electrically heated tubular reactor for 10 and 60 min at 200{sup o}C and 300{sup o}C. The results were interpreted by considering the hydration process and the related development of accessible porosity suitable for resulphation. The performance of the reactivated bed ash as sulphur sorbent improved with a decrease of both the hydration temperature and time. For reactivated fly ash, more favourable porosimetric features were observed at longer treatment times and lower hydration temperatures. Finally, it was shown that an ashing treatment (at 850{sup o}C for 20 min) promoted a speeding up of the hydration process and an increase in the accessible porosity. 36 refs., 6 figs., 2 tabs.

Long-term leaching of nutrients and contaminants from wood combustion ashes

DEFF Research Database (Denmark)

Maresca, Alberto; Hyks, J.; Astrup, Thomas Fruergaard

2018-01-01

With increasing amounts of woody biomass being combusted for energy purposes worldwide, more wood ash is being generated and needs management. As an alternative to landfilling, residues may be utilised for liming and fertilising purposes on forest soils. Comprehensive evaluations of long-term lea......With increasing amounts of woody biomass being combusted for energy purposes worldwide, more wood ash is being generated and needs management. As an alternative to landfilling, residues may be utilised for liming and fertilising purposes on forest soils. Comprehensive evaluations of long......-term leaching from these residues are needed in order to assess potential environmental impacts associated with their utilisation. Two Danish wood ash samples, one fly ash and one mixed ash (a combination of fly ash and bottom ash), were evaluated in long-term percolation column tests (up to L/S ∼2000 L....../kg), in order to quantify the release of major, minor and trace metal(loid)s. While columns of three different lengths were used, the leaching of individual elements could be described as a function of the L/S ratio – irrespective of the column length. At L/S 1000 L/kg, the cumulative releases of K, S, Na, Ca...

Promoting effect of various biomass ashes on the steam gasification of low-rank coal

International Nuclear Information System (INIS)

Rizkiana, Jenny; Guan, Guoqing; Widayatno, Wahyu Bambang; Hao, Xiaogang; Li, Xiumin; Huang, Wei; Abudula, Abuliti

2014-01-01

Highlights: • Biomass ash was utilized to promote gasification of low rank coal. • Promoting effect of biomass ash highly depended on AAEM content in the ash. • Stability of the ash could be improved by maintaining AAEM amount in the ash. • Different biomass ash could have completely different catalytic activity. - Abstract: Application of biomass ash as a catalyst to improve gasification rate is a promising way for the effective utilization of waste ash as well as for the reduction of cost. Investigation on the catalytic activity of biomass ash to the gasification of low rank coal was performed in details in the present study. Ashes from 3 kinds of biomass, i.e. brown seaweed/BS, eel grass/EG, and rice straw/RS, were separately mixed with coal sample and gasified in a fixed bed downdraft reactor using steam as the gasifying agent. BS and EG ashes enhanced the gas production rate greater than RS ash. Higher catalytic activity of BS or EG ash was mainly attributed to the higher content of alkali and alkaline earth metal (AAEM) and lower content of silica in it. Higher content of silica in the RS ash was identified to have inhibiting effect for the steam gasification of coal. Stable catalytic activity was remained when the amount of AAEM in the regenerated ash was maintained as that of the original one

Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

Science.gov (United States)

Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

2011-01-01

The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

Naturally occurring radionuclides of paper ashes and their effect in the environment

International Nuclear Information System (INIS)

Kobashi, Asaya

2011-01-01

The concentrations of naturally occurring radionuclides ( 226 Ra, 228 Ra, 228 Th, and 40 K) in ashes of papers such as magazines and newspapers were determined from the nuclide concentrations in the papers and the ash contents of the papers. The average 226 Ra, 228 Ra, 228 Th, and 40 K concentrations in the 34 ashes were respectively 27, 68, 75, and 75Bq kg -1 . The radium equivalent activities of the ashes were calculated to evaluate the hazard of γ-ray radiation from the ashes in the environment. A copying paper sample showed a high radium equivalent activity of 602Bq kg -1 . However, the average radium equivalent activity was 140Bq kg -1 and was lower than the level that causes an environmental health problem. (author)

Mineral conversion and microstructure change in the melting process of Shenmu coal ash

Energy Technology Data Exchange (ETDEWEB)

Yang Jianguo; Deng Furong; Zhao Hong; Cen Kefa [Zhejiang University, Hangzhou (China). State Key Laboratory of Clean Energy Utilization

2007-05-15

China has rich reserves of Shenmu coal, which has the typical characteristic of low-melting-point ash. If used in the pulverized-coal boiler of a power plant, Shenmu coal would cause serious slagging. In order to solve the slagging problem of Shenmu coal, the melting mechanism of Shenmu coal ash was studied. One of the Shenmu coals - Wenjialiang coal - was selected for the study. Using thermogravimetry-differential scanning colorimetry (TG-DSC) methods, the change of the coal ash's physicochemistry with temperature was studied. The typical temperature points in the melting process were obtained. Ash samples of the different temperature points were prepared in a high-temperature furnace with parameters similar to those used in the TG-DSC test, and were then cooled quickly in water. Later, the ash samples were analyzed using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) methods in detail. Wenjialiang coal ash started to melt at 980{sup o}C. The ash was found to melt to a great extent at 1200{sup o}C and formed a multiform microstructure. At 1260{sup o}C, it was found to melt into a dense body with many pores, and formed a piece of vitreous body at 1340{sup o}C. Anorthite and gehlenite are the intermediate products that exist between 980 and 1340{sup o}C. They may be the main cause of the ash having low melting points, so that they could convert into a eutectic at low temperatures.

In vitro toxicology of respirable Montserrat volcanic ash.

Science.gov (United States)

Wilson, M R; Stone, V; Cullen, R T; Searl, A; Maynard, R L; Donaldson, K

2000-11-01

In July 1995 the Soufriere Hills volcano on the island of Montserrat began to erupt. Preliminary reports showed that the ash contained a substantial respirable component and a large percentage of the toxic silica polymorph, cristobalite. In this study the cytotoxicity of three respirable Montserrat volcanic ash (MVA) samples was investigated: M1 from a single explosive event, M2 accumulated ash predominantly derived from pyroclastic flows, and M3 from a single pyroclastic flow. These were compared with the relatively inert dust TiO(2) and the known toxic quartz dust, DQ12. Surface area of the particles was measured with the Brunauer, Emmet, and Teller (BET) adsorption method and cristobalite content of MVA was determined by x ray diffraction (XRD). After exposure to particles, the metabolic competence of the epithelial cell line A549 was assessed to determine cytotoxic effects. The ability of the particles to induce sheep blood erythrocyte haemolysis was used to assess surface reactivity. Treatment with either MVA, quartz, or titanium dioxide decreased A549 epithelial cell metabolic competence as measured by ability to reduce 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). On addition of mannitol, the cytotoxic effect was significantly less with M1, quartz, and TiO(2). All MVA samples induced a dose dependent increase in haemolysis, which, although less than the haemolysis induced by quartz, was significantly greater than that induced by TiO(2). Addition of mannitol and superoxide dismutase (SOD) significantly reduced the haemolytic activity only of M1, but not M2 or M3, the samples derived from predominantly pyroclastic flow events. Neither the cristobalite content nor the surface area of the MVA samples correlated with observed in vitro reactivity. A role for reactive oxygen species could only be shown in the cytotoxicity of M1, which was the only sample derived from a purely explosive event. These results suggest that in general the

Physical and Chemical Character of Fly Ash of Coal Fired Power Plant in Java

Science.gov (United States)

Triwulan; Priadana, K. A.; Ekaputri, J. J.; Bayuaji, R.

2017-11-01

Quality of fly ash is varying widely in the field, it depends on the combustion process and the quality of the basic ingredients, namely coal. It will affect the physical and mechanical properties of the concrete mixtures used. This study used 12 samples of fly ash. The physical and chemical properties and finesse modulus were analyzed. The fly ash was mixed with OPC (Ordinary Portland Cement) with the proportion of 20% fly ash and 80% OPC. The specimens were form with mortar dimension of 5cm x 5 cm. The test was affected by the correlation of fly ash fineness modulus to compressive strength, correlation density of fly ash to compressive strength, and correlation of carbon content to the compressive strength.

Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site.

Science.gov (United States)

Adama, M; Esena, R; Fosu-Mensah, B; Yirenya-Tawiah, D

2016-01-01

Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

Influence of ash on the fiber composition of dried dairy manures

International Nuclear Information System (INIS)

Reeves, J.B.; Van Kessel, J.A.S.

2002-01-01

The ash content of dried dairy manures is a significant source of error in the determination of their fiber composition. - The objective of this work was to examine the role of ash in the compositional analysis of dried dairy manures. Ninety-nine dairy manures obtained from Connecticut, Maryland, New York, Pennsylvania and Virginia were dried at 60 deg. C, and ground to 20 mesh. Samples were analyzed for neutral and acid detergent fiber, acid detergent lignin, total carbon, total nitrogen, and ash. In addition, cellulose and hemicellulose were computed by difference. Results indicated that high ash contents (8-52% of dry matter) can dramatically and unpredictably alter various measures of fiber composition and are a significant source of error in the determination of manure composition and how it relates to mineralization or other compositional influenced factors. Also, while the ash content of the dried intact manure can easily be determined, it is difficult to estimate the ash contribution to the individual fiber determinations, especially if sequential assays are performed

Comparing two periphyton collection methods commonly used for stream bioassessment and the development of numeric nutrient standards.

Science.gov (United States)

Rodman, Ashley R; Scott, J Thad

2017-07-01

Periphyton is an important component of stream bioassessment, yet methods for quantifying periphyton biomass can differ substantially. A case study within the Arkansas Ozarks is presented to demonstrate the potential for linking chlorophyll-a (chl-a) and ash-free dry mass (AFDM) data sets amassed using two frequently used periphyton sampling protocols. Method A involved collecting periphyton from a known area on the top surface of variably sized rocks gathered from relatively swift-velocity riffles without discerning canopy cover. Method B involved collecting periphyton from the entire top surface of cobbles systematically gathered from riffle-run habitat where canopy cover was intentionally avoided. Chl-a and AFDM measurements were not different between methods (p = 0.123 and p = 0.550, respectively), and there was no interaction between method and time in the repeated measures structure of the study. However, significantly different seasonal distinctions were observed for chl-a and AFDM from all streams when data from the methods were combined (p methods may effectively be used together with some minor considerations due to potential confounding factors. This study provides motivation for the continued investigation of combining data sets derived from multiple methods of data collection, which could be useful in stream bioassessment and particularly important for the development of regional stream nutrient criteria for the southern Ozarks.

Aluminium alloys in municipal solid waste incineration bottom ash.

Science.gov (United States)

Hu, Yanjun; Rem, Peter

2009-05-01

With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

Get immersed and black in fire ash world. Field Wildgeographers experience.

Science.gov (United States)

Pereira, Paulo; Cerdà, Artemi; Misiune, Ieva; Jordan, Antonio

2015-04-01

Ash is the footprint left by the fire. This residue is very important to landscape recover and is an important source of soil protection after the fire. Get immersed in fire ash world is the same thing of get dirty and do not be recognizable in a fire affected area. To measure ash in the field we have to be careful where to step, how to do the experimental design, collect samples and find with accuracy the places measured before. A good methodology is needed in design field experiments, collect ash samples and monitoring ash evolution (Cerdà and Doerr, 2008; Bodi et al., 2014; Pereira and Ubeda, 2010; Pereira et al. 2011; 2012, 2013, 2014, 2015). The objective of this work is to share with the Avatar world the methodologies used when wildgeographers get immersed in fire ash world, including: 1) Identify the best study area 2) Experimental design 3) Sample collection 4) Get dirty and have fun in the field 5) Laboratory, Statistical and spatial analysis Acknoledgements The author are thankful for the support of the projects POSTFIRE (Soil quality, erosion control and plant cover recovery under different post-fire management scenarios, CGL2013-47862-C2-1-R) funded by the Spanish Ministry of Economy and Competitiveness; GL2008-02879/BTE, LEDDRA 243857, RECARE (Preventing and Remediating Degradation of Soils in Europe Through Land Care, FP7-ENV-2013-TWO STAGE), funded by the European Commission; and for the COST action ES1306 (Connecteur: Connecting European Connectivity Research), FUEGORED (Spanish Network of Forest Fire Effects on Soils, http://grupo.us.es/fuegored/) and to Comissionat per a Universitats i Recerca del DIUE de la Generalitat de Catalunya. References Bodi, M., Martin, D.A., Santin, C., Balfour, V., Doerr, S.H., Pereira, P., Cerda, A., Mataix-Solera, J. (2014) Wildland fire ash: production, composition and eco-hydro-geomorphic effects. Earth-Science Reviews, 130, 103-127. Cerdà, A. y Doerr, S.H. 2008. The effect of ash and needle cover on surface

Survey for tolerance to emerald ash borer within North American ash species

Science.gov (United States)

Jennifer L. Koch; Mary E. Mason; David W. Carey; Kathleen Knight; Therese Poland; Daniel A. Herms

2010-01-01

Since the discovery of the emerald ash borer (EAB) near Detroit, MI, in 2002, more than 40 million ash trees have been killed and another 7.5 billion are at risk in the United States. When the EAB outbreak was initially discovered, our native ash species appeared to have no resistance to the pest.

Mapping ash properties using principal components analysis

Science.gov (United States)

Pereira, Paulo; Brevik, Eric; Cerda, Artemi; Ubeda, Xavier; Novara, Agata; Francos, Marcos; Rodrigo-Comino, Jesus; Bogunovic, Igor; Khaledian, Yones

2017-04-01

In post-fire environments ash has important benefits for soils, such as protection and source of nutrients, crucial for vegetation recuperation (Jordan et al., 2016; Pereira et al., 2015a; 2016a,b). The thickness and distribution of ash are fundamental aspects for soil protection (Cerdà and Doerr, 2008; Pereira et al., 2015b) and the severity at which was produced is important for the type and amount of elements that is released in soil solution (Bodi et al., 2014). Ash is very mobile material, and it is important were it will be deposited. Until the first rainfalls are is very mobile. After it, bind in the soil surface and is harder to erode. Mapping ash properties in the immediate period after fire is complex, since it is constantly moving (Pereira et al., 2015b). However, is an important task, since according the amount and type of ash produced we can identify the degree of soil protection and the nutrients that will be dissolved. The objective of this work is to apply to map ash properties (CaCO3, pH, and select extractable elements) using a principal component analysis (PCA) in the immediate period after the fire. Four days after the fire we established a grid in a 9x27 m area and took ash samples every 3 meters for a total of 40 sampling points (Pereira et al., 2017). The PCA identified 5 different factors. Factor 1 identified high loadings in electrical conductivity, calcium, and magnesium and negative with aluminum and iron, while Factor 3 had high positive loadings in total phosphorous and silica. Factor 3 showed high positive loadings in sodium and potassium, factor 4 high negative loadings in CaCO3 and pH, and factor 5 high loadings in sodium and potassium. The experimental variograms of the extracted factors showed that the Gaussian model was the most precise to model factor 1, the linear to model factor 2 and the wave hole effect to model factor 3, 4 and 5. The maps produced confirm the patternd observed in the experimental variograms. Factor 1 and 2

Cast-concrete products made with FBC ash and wet-collected coal-ash

Energy Technology Data Exchange (ETDEWEB)

Naik, T.R.; Kraus, R.N.; Chun, Y.M.; Botha, F.D. [University of Wisconsin, Milwaukee, WI (United States)

2005-12-01

Cast-concrete hollow blocks, solid blocks, and paving stones were produced at a manufacturing plant by replacing up to 45% (by mass) of portland cement with fluidized bed combustion (FBC) coal ash and up to 9% of natural aggregates with wet-collected, low-lime, coarse coal-ash (WA). Cast-concrete product specimens of all three types exceeded the compressive strength requirements of ASTM from early ages, with the exception of one paving-stone mixture, which fell short of the requirement by less than 10%. The cast-concrete products made by replacing up to 40% of cement with FBC ash were equivalent in strength (89-113% of control) to the products without ash. The abrasion resistance of paving stones was equivalent for up to 34% FBC ash content. Partial replacement of aggregates with WA decreased strength of the products. The resistance of hollow blocks and paving stones to freezing and thawing decreased appreciably with increasing ash contents. The cast-concrete products could be used indoors in regions where freezing and thawing is a concern, and outdoors in a moderate climate.

On-line nuclear ash gauge for coal based on gamma-ray transmission techniques

International Nuclear Information System (INIS)

Rizk, R.A.M.; El-Kateb, A.H.; Abdul-Kader, A.M.

1999-01-01

Developments and applications of on-line nuclear gauges in the coal industry are highly requested. A nuclear ash gauge for coal, based on γ-ray transmission techniques is developed. Single and dual energy γ-ray beams are used to determine the ash content of coal. The percentage ash content as a function of the γ-ray intensities transmitted through coal samples is measured and sensitivity curves are obtained. An empirical formulation relating the ash content values to the γ-ray intensities is derived. Preliminary results show that both single and dual energy γ-ray transmission techniques can be used to give a rapid on-line estimation of the ash concentration values in coal with low cost and reasonable accuracy, but the dual one is much preferable. (author)

Can ash clog soil pores?

Science.gov (United States)

Stoof, Cathelijne; Stoof, Cathelijne; Gevaert, Anouk; Gevaert, Anouk; Baver, Christine; Baver, Christine; Hassanpour, Bahareh; Hassanpour, Bahareh; Morales, Veronica; Morales, Veronica; Zhang, Wei; Zhang, Wei; Martin, Deborah; Martin, Deborah; Steenhuis, Tammo; Steenhuis, Tammo

2015-04-01

Wildfire can greatly increase a landscape's vulnerability to flooding and erosion events, and ash is thought to play a large role in controlling runoff and erosion processes after wildfire. Although ash can store rainfall and thereby reduce runoff and erosion for a limited period after wildfires, it has also been hypothesized to clog soil pores and reduce infiltration. Several researchers have attributed the commonly observed increase in runoff and erosion after fire to the potential pore-clogging effect of ash. Evidence is however incomplete, as to date, research has solely focused on identifying the presence of ash in the soil, with the actual flow processes associated with the infiltration and pore-clogging of ash remaining a major unknown. In several laboratory experiments, we tested the hypothesis that ash causes pore clogging to the point that infiltration is hampered and ponding occurs. We first visualized and quantified pore-scale infiltration of water and ash in sand of a range of textures and at various infiltration rates, using a digital bright field microscope capturing both photo and video. While these visualization experiments confirm field and lab observation of ash washing into soil pores, we did not observe any clogging of pores, and have not been able to create conditions for which this does occur. Additional electrochemical analysis and measurement of saturated hydraulic conductivity indicate that pore clogging by ash is not plausible. Electrochemical analysis showed that ash and sand are both negatively charged, showing that attachment of ash to sand and any resulting clogging is unlikely. Ash also had quite high saturated conductivity, and systems where ash was mixed in or lying on top of sand had similarly high hydraulic conductivity. Based on these various experiments, we cannot confirm the hypothesis that pore clogging by ash contributes to the frequently observed increase in post-fire runoff, at least for the medium to coarse sands

Slags and ashes from municipal waste incineration in Poland - mineralogical and chemical composition

Science.gov (United States)

Kowalski, Piotr; Michalik, Marek

2013-04-01

In the next few years there will be a large change in the waste management system in Poland. Its primary aim will be reduction of the amount of landfilled waste by enhancing level of recycling, waste segregation, composting of biomass and incineration. The biggest investment during this transformation is construction of nine incinerators with assumed slags production around 200 thousand tons per year. Slag production is accompanied by fly ash generating. This ash can be a valuable raw material as fly ash from the power industry. Waste management system transformation will cause big increase in slag production in comparison to the present amount and will require taking necessary steps to ensure environmental safety. For this purpose, studies of slags and fly ashes in terms of environmental risk and potential impact on human health are significant. The object of the study are fly ashes and slags produced in the biggest municipal waste incineration power plant in Poland. Two series of samples obtained in municipal waste incineration process were studied in order to characterize mineralogical and chemical composition and to determine the concentrations of heavy metals and their possible negative environmental impact. Characteristics of these materials will be the basis for determining their value in application, for example in building industry. Mineralogical characteristic of slags was based on X-ray diffraction. Characteristic of structures and forms of occurrence of mineral phases was based on the optical microscopy and SEM imaging coupled with EDS analysis. Chemical analysis were performed using ICP-MS/ICP-AES methods. They allowed to follow variability between studied samples and gave basic information about metals. Metals in samples of slag and ashes are present as component of mineral phases and in the form of metallic inclusions in glass or minerals. Potentially hazardous concentrations for environment are observed for copper (330-4900ppm), zinc (1500-8100ppm

ECOLOGICAL AND TECHNOLOGYCAL ASPECTS OF ASH AND SLAG WASTES UTILIZATION

Directory of Open Access Journals (Sweden)

Tatyana Aleksandrova

2017-07-01

Full Text Available The article presents the results of investigation focused on the utilization of ash and slag wastes (ASW in Russia including investigation of chemical and physical properties of ASW and processing products. Many factors influence the technological properties of ash and slag materials: naturals, processes and environments. The integrated treatment of ash and slag wastes of both stored and re-formed types will allow obtaining the following commercial products: coal concentrate, iron concentrate, aluminosilicate cenospheres, aluminosilicate product. In this study we have analyzed the methods for separation of ASW iron-containing part using the different types of the magnetic separation from the ash and slag material from one of the combined heat and power plant (CHPP in the Russian Far East Federal District. The greatest interest is the dry magnetic separation with travelling electromagnetic field. The subject of research was a sample taken from one of ash dump of CHPP in the Far East. In the study iron concentrate containing Fetotal = 64% was obtained recovery 68% in the low intensity (up to 5 kOe travelling magnetic field.

Natural radioisotopes in lignite of the Ptolemais region (Greece) and in their ashes

International Nuclear Information System (INIS)

Simopoulos, S.E.; Angelopoulos, M.G.

1987-01-01

Samples of lignite, fly ash and bottom ash of a power plant, located in the Ptolemais region, were examined by gamma spectroscopy and their concentrations in Ra-226, Ra-228 and K-40 have been determined. These samples were prepared from samples taken daily for a period of one month. The brown coal samples are taken from the front of the brown coal field supplying one of the units. They show a flutuation of the concentrations of the same radionuclides in the brown coal seams and in the intermediate layers. Further samples taken from 3 small private mines of the Ptolemais region were also examined. (author)

Emerald ash borer genetics: an update

Science.gov (United States)

Alicia M. Bray; Leah S. Bauer; Robert A. Haack; Therese Poland; James J. Smith

2008-01-01

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, samples were collected from introduced sites in Michigan, Ohio, Indiana, Pennsylvania, Illinois, and Ontario, Canada, as well as native sites in China, Japan, and South Korea with the help of a network of collaborators. The beetles were analyzed using DNA sequences from mitochondrial cytochrome...

Elemental analysis of bottom ash from municipal incinerator by neutron activation analysis

International Nuclear Information System (INIS)

Kim, S. H.; Jang, S. H.; Moon, J. H.; Jung, Y. S.; Kim, Y. J.

2003-01-01

Elemental analysis of bottom ash generated from municipal solid waste incinerator was performed by neutron activation analysis. For this study, ash samples monthly collected from incinerator in D city were sieved with 5 mm mesh size, dried, pulverized by agate mortar and finally re-sieved with 200μ mesh size. Prepared samples were irradiated by neutrons using NAA No.1 irradiation hole in Korea Atomic Energy Research Institute. Activated samples were measured by gamma-ray spectrometer according to the relevant nuclear properties of target nuclides and the concentration of 33 elements were determined from the collected ash samples. Quality control was conducted by comparative analysis with two NIST standard reference materials simultaneously. Mean values and standard deviations of hazardous elements such as As, Cr, Cu, Fe, Mn, Sb and Zn among the determined elements were 3.8±6.9mg/kg, 620±0.12 %, 4.76±0.37 %, 0.26±0.10 %, 115±29 mg/kg and 0.71±0.19 %, respectively

Accumulation of metals in vegetation established in ash constructions; Ackumulering av metaller i vegetation paa geotekniska askkonstruktioner

Energy Technology Data Exchange (ETDEWEB)

Hemstroem, Kristian; Wik, Ola (SGI, Statens geotekniska institut (Sweden)); Bramryd, Torleif; Johansson, Michael (Lunds Universitet, Miljoestrategi (Sweden)); Jaegerbrand, Annika (VTI, Statens Vaeg och transportforskningsinstitut (Sweden))

2012-02-15

The overall aim of this study was to investigate how the use of ash in a long-term perspective affects the surrounding flora and fauna with regard to the accumulation of metals in the ecosystem through plant uptake and exposure to grazing animals. The study included a field study and a cultivation experiment. In the field study, the accumulation of metals and metalloids in leaves of trees and shrubs that had self established and grown in lysimeters with aged MSWI bottom ash and aged biofuel ash was determined. In the cultivation experiment, the accumulation of metals and metalloids from the studied materials in ryegrass was determined. Reference materials in the cultivation experiment were two conventional geotechnical materials, crushed rock and excavated soil. Leaves from trees and bushes in the vicinity of the ash lysimeters were used as reference materials in the field study. Contamination of plant samples with particles, through splashing during rain, dusting, or in connection with sampling, proved to have had a major impact on the measured metal and metalloid concentrations in several grass samples in the cultivation experiment. The results also indicate that contamination of plant samples with particles occurred in the field study. In this case, probably due to atmospheric deposition. The particle contamination complicated the evaluation of some of the results in the project since the intention was to study accumulation by roots from the studied ash materials, but, on the other hand, the particle contamination showed the importance of taking into account the spreading of contaminants through particles as an exposure route for grazing animals. In the field study, only Cd and Zn in aspen, willow and birch exhibited elevated levels in the leaves due to root uptake from MSWI bottom ash compared to the reference samples. In addition, elevated levels of As was observed in leaves from trees in the biofuel ash. The total content of As was similar in all studied

Recent developments in nucleonic control systems and on-stream analysers for the mineral and coal industries

International Nuclear Information System (INIS)

Mathew, P.J.

1994-01-01

Some recent developments in industrial nuclear gauging in Australia are briefly reviewed. Quality control, process control and automation in the mineral and coal industries are based on measurements of the composition and flows of critical process stream. Australia's vast mineral wealth and its importance to the national economy has resulted in CSIRO (Commonwealth Scientific and Industrial Research Organisation) successfully developing and commercializing a variety of nucleonic gauges to meet the needs of the mineral and coal industries. These include gauges for on-line determination of the ash content of coal on conveyor belts, the ash content of solids of weight fraction of coal in slurries, on-stream determination of iron, alumina and manganese in iron ore, bulk analysis of raw feed limestone in the cement industry, and gauges for the measurement of level, moisture, and interfaces. A variety of gauges based on natural radioactivity have also been developed. Instruments based on natural gamma radiation are relatively inexpensive, and free of artificial radiation sources. An on-stream analyser based on natural gamma ray activity has been developed for monitoring the soil content of sugar cane. Significant benefits accrued to industry in using nucleonic gauges are briefly discussed. (author). 18 refs., 8 figs

Ash study for biogas purification

International Nuclear Information System (INIS)

Juarez V, R. I.

2016-01-01

This work evaluates the ashes generated from the wood and coal combustion process of the thermoelectric plant in Petacalco, Guerrero (Mexico) in order to determine its viability as a filter in the biogas purification process. The ash is constituted by particles of morphology and different chemical properties, so it required a characterization of the same by different analytical techniques: as was scanning electron microscopy and X-ray diffraction, in order to observe the microstructure and determine the elemental chemical composition of the particles. Prior to the analysis, a set of sieves was selected to classify as a function of particle size. Four different types of ashes were evaluated: one generated by the wood combustion (wood ash) and three more of the Petacalco thermoelectric generated by the coal combustion (wet fly ash, dry fly ash and dry bottom ash). (Author)

Lunar ash flows - Isothermal approximation.

Science.gov (United States)

Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

1972-01-01

Suggestion of the ash flow mechanism as one of the major processes required to account for some features of lunar soil. First the observational background and the gardening hypothesis are reviewed, and the shortcomings of the gardening hypothesis are shown. Then a general description of the lunar ash flow is given, and a simple mathematical model of the isothermal lunar ash flow is worked out with numerical examples to show the differences between the lunar and the terrestrial ash flow. The important parameters of the ash flow process are isolated and analyzed. It appears that the lunar surface layer in the maria is not a residual mantle rock (regolith) but a series of ash flows due, at least in part, to great meteorite impacts. The possibility of a volcanic contribution is not excluded. Some further analytic research on lunar ash flows is recommended.

StreamMap: Smooth Dynamic Visualization of High-Density Streaming Points.

Science.gov (United States)

Li, Chenhui; Baciu, George; Han, Yu

2018-03-01

Interactive visualization of streaming points for real-time scatterplots and linear blending of correlation patterns is increasingly becoming the dominant mode of visual analytics for both big data and streaming data from active sensors and broadcasting media. To better visualize and interact with inter-stream patterns, it is generally necessary to smooth out gaps or distortions in the streaming data. Previous approaches either animate the points directly or present a sampled static heat-map. We propose a new approach, called StreamMap, to smoothly blend high-density streaming points and create a visual flow that emphasizes the density pattern distributions. In essence, we present three new contributions for the visualization of high-density streaming points. The first contribution is a density-based method called super kernel density estimation that aggregates streaming points using an adaptive kernel to solve the overlapping problem. The second contribution is a robust density morphing algorithm that generates several smooth intermediate frames for a given pair of frames. The third contribution is a trend representation design that can help convey the flow directions of the streaming points. The experimental results on three datasets demonstrate the effectiveness of StreamMap when dynamic visualization and visual analysis of trend patterns on streaming points are required.

[Correlation of Persistent Free Radicals, PCDD/Fs and Metals in Waste Incineration Fly Ash].

Science.gov (United States)

Wang, Tian-jiao; Chen, Tong; Zhan, Ming-xiu; Guo, Ying; Li, Xiao-dong

2016-03-15

Environmentally persistent free radicals (EPFRs) are relatively highly stable and found in the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Recent studies have concentrated on model dioxin formation reactions and there are few studies on actual waste incineration fly ash. In order to study EPFRs and the correlation with dioxins and heavy metals in waste incineration fly ash, the spins of EPFRs, concentration of PCDD/Fs and metals in samples from 6 different waste incinerators were detected. The medical waste incineration fly ash from Tianjin, municipal solid waste incineration fly ash from Jiangxi Province, black carbon and slag from municipal solid waste incinerator in Lanxi, Zhejiang Province, all contained EPFRs. Above all the signal in Tianjin sample was the strongest. Hydroxyl radicals, carbon-center radicals and semiquinone radicals were detected. Compared with other samples, Jiangxi fly ash had the highest toxic equivalent quantity (TEQ) of dioxins, up to 7.229 4 ng · g⁻¹. However, the dioxin concentration in the Tianjin sample containing the strongest EPFR signals was only 0.092 8 ng · g⁻¹. There was perhaps little direct numeric link between EPFRs and PCDD/Fs. But the spins of EPFRs in samples presented an increasing trend as the metal contents increased, especially with Al, Fe, Zn. The signal strength of radicals was purposed to be related to the metal contents. The concentration of Zn (0.813 7% ) in the Tianjin sample was the highest and this sample contained much more spins of oxygen-center radicals. We could presume the metal Zn had a greater effect on the formation of EPFRs, and was easier to induce the formation of radicals with a longer half-life period.

Regular Recycling of Wood Ash to Prevent Waste Production (RecAsh). Technical Final Report

Energy Technology Data Exchange (ETDEWEB)

Andersson, Lars E-mail: lars.t.andersson@skogsstyreslen.se

2007-03-15

At present, the extraction of harvest residues is predicted to increase in Sweden and Finland. As an effect of the intensified harvesting, the export of nutrients and acid buffering substances from the growth site is also increased. Wood ash could be used to compensate forest soils for such losses. Most wood fuel ash is today often deposited in landfills. If the wood ash is recycled, wood energy is produced without any significant waste production. Ash recycling would therefore contribute to decreasing the production of waste, and to maintaining the chemical quality of forest waters and biological productivity of forest soils in the long term. The project has developed, analysed and demonstrated two regular ash-recycling systems. It has also distributed knowledge gathered about motives for ash recycling as well as technical and administrative solutions through a range of media (handbooks, workshops, field demonstrations, reports, web page and information videos). Hopefully, the project will contribute to decreasing waste problems related to bio-energy production in the EU at large. The project has been organised as a separate structure at the beneficiary and divided in four geographically defined subprojects, one in Finland and three in Sweden (Central Sweden, Northern Sweden, and South-western Sweden). The work in each subproject has been lead by a subproject leader. Each subproject has organised a regional reference group. A project steering committee has been established consisting of senior officials from all concerned partners. The project had nine main tasks with the following main expected deliverables and output: 1. Development of two complete full-scale ash-recycling systems; 2. Production of handbooks of the ash recycling system; 3. Ash classification study to support national actions for recommendations; 4. Organise regional demonstrations of various technical options for ash treatment and spreading; 5. Organise national seminars and demonstrations of

Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

2003-01-01

Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied...... in lab scale, and the results were discussed in relation to the expected heavy metal speciation in the ashes. In initial leaching experiments the pH-dependent desorption characteristics of the heavy metals Cd, Pb, Zn and Cu were analogous in the two MSWI ashes, and thus it was expected......-moval efficiencies were observed, especially for Pb and Zn. Cd, the sole heavy metal of environmental concern in the wood ash, was found more tightly bonded in this ash than in the two MSWI ashes. It was suggested that complex Cd-silicates are likely phases in the wood ash whereas more soluble, condensed phases...

Utilization of Yatagan Power Plant Fly Ash in Production of Building Bricks

Science.gov (United States)

Önel, Öznur; Tanriverdi, Mehmet; Cicek, Tayfun

2017-12-01

Fly ash is a by-product of coal combustion, which accumulates in large quantities near the coal-fired power plants as waste material. Fly ash causes serious operational and environmental problems. In this study, fly ash from Yatağgan thermal power plant was used to produce light-weight building bricks. The study aimed to reduce the problems related to fly ash by creating a new area for their use. The optimum process parameters were determined for the production of real size bricks to be used in construction industry. The commercial size bricks (200 × 200 × 90-110 mm) were manufactured using pilot size equipment. Mechanical properties, thermal conductivity coefficients, freezing and thawing strengths, water absorption rates, and unit volume weights of the bricks were determined. Etringite (Ca6Al2 (SO4)3 (OH)12 25(H2O)) and Calcium Silicate Hydrate (2CaO.SiO2.4H2O) were identified as the binding phases in the real size brick samples after 2 days of pre-curing and 28 days curing at 50° C and 95% relative moisture. The water absorption rate was found to be 27.7 % in terms of mass. The mechanical and bending strength of the brick samples with unit volume weight of 1.29 g.cm-3 were determined as 6.75 MPa and 1,56 MPa respectively. The thermal conductivity of the fly ash bricks was measured in average as 0,340 W m-1 K-1. The fly ash sample produced was subjected to toxic leaching tests (Toxic Property Leaching Procedure (EPA-TCLP 1311), Single-step BATCH Test and Method-A Disintegration Procedure (ASTM)). The results of these tests suggested that the materials could be classified as non-hazardous wastes / materials.

Field trial of a pair production gauge for the on-line determination of ash in coal on a conveyor belt

International Nuclear Information System (INIS)

Millen, M.J.; Sowerby, B.D.; Rafter, P.T.; Ellis, W.K.; Gravitis, V.L.; Howells, E.; McLennan, T.D.; Muldoon, L.J.

1984-01-01

The ash content of coal can be determined by a method based on pair production. Coal is irradiated with high energy γ-rays and the resulting 0.511 MeV annihilation and Compton scattered γ-rays are measured. The pair production (PP) technique has been previously proved in the laboratory on static bulk samples and in the field on high-throughput sample by-lines. In the present paper, a plant test to assess the PP gauge for direct on-line conveyor belt analysis is described. This test was undertaken on the recirculating coal facility at the pilot plant coal washery at the BHP Steel Works, Newcastle, New South Wales. Seven Hunter Valley coals with ash in the range 7.5-33 wt% were circulated around the conveyor loop, and scanned by both PP and low energy γ-ray transmission (LET) gauges. Samples were measured on-belt as a function of sample depth, compaction, moisture and particle size. The mass per unit area of coal on the belt was varied in the range 40-210 kg m -2 . The r.m.s. deviation between PP gauge ash and chemical laboratory ash was 1.07 wt% ash for 370 individual on-belt measurements on coal of mass per unit area greater than 60 kg m -2 ad 0.45 wt% ash for the mean ash of each sample. (author)

TECHNOLOGY AND EFFICIENCY OF PEAT ASH USAGE IN CEMENT CONCRETE

Directory of Open Access Journals (Sweden)

G. D. Liakhevich

2015-01-01

Full Text Available One of the main ways to improve physical and mechanical properties of cement concrete is an introduction of ash obtained due to burning of fossil fuels into concrete mix. The concrete mixes with ash are characterized by high cohesion, less water gain and disintegration. At the same time the concrete has high strength, density, water resistance, resistance to sulfate corrosion. The aim of this paper is to explore the possibility to use peat ash and slag of peat enterprises of the Republic of Belarus in the concrete for improvement of its physical and mechanical properties and characteristics of peat ash, slag, micro-silica, cement, superplasticizing agent. Compositions and technology for preparation of concrete mixes have been developed and concrete samples have been have been fabricated and tested in the paper. It has been shown that the concrete containing ash, slag obtained due to burning of peat in the industrial installations of the Usiazhsky and Lidsky Peat Briquette Plants and also MK-85-grade micro-silica NSPKSAUsF-1-grade superplasticizing agent have concrete tensile strength within 78–134 MPa under axial compression and 53 MPa – for the control composition. This index is 1.5–2.5 times more than for the sample containing no additives.The usage of peat ash, slag together with MK-85-grade micro-silica and NSPKSAUsF-1-grade superplasticizing agent for fabrication of concrete and reinforced bridge and tunnel structures will provide the following advantages: reduction of cross-sectional area of structures while maintaining their bearing capacity due to higher value of tensile strength in case of axial compression; higher density, waterand gas tightness due to low water cement ratio; high resistance to aggressive environment due to lower content of capillary pores that ensures bridge structure longevity; achievement of environmental and social impacts.

Evaluation of Changes in Index Properties of Lateritic Soil Stabilized with Fly Ash

Directory of Open Access Journals (Sweden)

Agapitus AMADI

2010-12-01

Full Text Available For soils to be suitable in civil engineering projects, they must meet existing local requirements for index properties in addition to certain strength criteria. Typically, specifications limit these properties to some threshold values which in most cases are project specific. Some lateritic soils in their natural state need some treatment/modification to meet these specification requirements. The objective of this study was to evaluate changes in the index properties (i.e., particle size distribution, Atterberg limits and compaction characteristics of a residually derived lateritic soil following fly ash application. Lateritic soil – fly ash mixtures with up to 20% fly ash by dry weight of soil were tested and specimens for compaction characteristics were prepared at different compaction states (optimum, dry and wet of optimum moisture content and compacted using British Standard Light (BSL compactive effort. While soil – fly ash mixtures containing up to 15% fly ash classify as CL according to USCS classification system and plotted above A-line in the plasticity chart, it was observed that changes in the gradation characteristics of soil sample treated with 20% fly ash resulted in the alteration of its classification to ML as well as the crossing of the A- line to the silty region. The liquid limit (LL varied from 42.2 to 29.53% representing 70% reduction while the plasticity index (PI of specimen treated with 20% fly ash was 16% lower than that of natural soil. The optimum moisture content (OMC ranged from 17.36% for the natural soil to 18.34% for soil mixtures containing 20% fly ash which yielded dry unit weight of 17.2kN/m3 for the natural soil and 16.1kN/m3 for samples treated with 20% fly ash. From the study, useful data were obtained showing substantial and desirable changes in the properties of lateritic soil as a civil engineering material on application of fly ash.

Applying the GNSS Volcanic Ash Plume Detection Technique to Consumer Navigation Receivers

Science.gov (United States)

Rainville, N.; Palo, S.; Larson, K. M.

2017-12-01

Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS) rely on predictably structured and constant power RF signals to fulfill their primary use for navigation and timing. When the received strength of GNSS signals deviates from the expected baseline, it is typically due to a change in the local environment. This can occur when signal reflections from the ground are modified by changes in snow or soil moisture content, as well as by attenuation of the signal from volcanic ash. This effect allows GNSS signals to be used as a source for passive remote sensing. Larson et al. (2017) have developed a detection technique for volcanic ash plumes based on the attenuation seen at existing geodetic GNSS sites. Since these existing networks are relatively sparse, this technique has been extended to use lower cost consumer GNSS receiver chips to enable higher density measurements of volcanic ash. These low-cost receiver chips have been integrated into a fully stand-alone sensor, with independent power, communications, and logging capabilities as part of a Volcanic Ash Plume Receiver (VAPR) network. A mesh network of these sensors transmits data to a local base-station which then streams the data real-time to a web accessible server. Initial testing of this sensor network has uncovered that a different detection approach is necessary when using consumer GNSS receivers and antennas. The techniques to filter and process the lower quality data from consumer receivers will be discussed and will be applied to initial results from a functioning VAPR network installation.

Study on uranium leaching behavior from coal fly ash samples

International Nuclear Information System (INIS)

Police, S.; Maity, S.; Chaudhary, D.K.; Sahu, S.K.; Pandit, G.G.

2017-01-01

Leachability of trace and toxic metals from coal fly ash (FA) poses significant environmental problems especially ground and surface water contamination. In the present study, leachability of U using batch leaching tests (i.e., at various leachate pH values) and using TCLP was studied. Results of pH variation study indicate that, U has higher leachability in acidic medium as compared to slightly alkaline medium. The leachable U concentrations observed in pH variation study are well below the WHO safety limits. In TCLP leachates, the leachable U concentrations are found to be higher than that observed in pH variation study. (author)

Increased sensitivity in thick-target particle induced X-ray emission analyses using dry ashing for preconcentration

International Nuclear Information System (INIS)

Lill, J.-O.; Harju, L.; Saarela, K.-E.; Lindroos, A.; Heselius, S.-J.

1999-01-01

The sensitivity in thick-target particle induced X-ray emission (PIXE) analyses of biological materials can be enhanced by dry ashing. The gain depends mainly on the mass reduction factor and the composition of the residual ash. The enhancement factor was 7 for the certified reference material Pine Needles and the limits of detection (LODs) were below 0.2 μg/g for Zn, Cu, Rb and Sr. When ashing biological materials with low ash contents such as wood of pine or spruce (0.3% of dry weight) and honey (0.1% of wet weight) the gain was far greater. The LODs for these materials were 30 ng/g for wood and below 10 ng/g for honey. In addition, the ashed samples were more homogenous and more resistant to changes during the irradiation than the original biological samples. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Phenolic acids as bioindicators of fly ash deposit revegetation.

Science.gov (United States)

Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

2006-05-01

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

First international ash marketing and technology conference

Energy Technology Data Exchange (ETDEWEB)

1978-01-01

A total of 42 papers were presented in sessions with the following headings: production and disposal of ash - an international review; environmental, health, safety, and legal aspects of ash handling; marketing of ash; development of new uses for ash; cementitious use of ash; ash in manufactured products; and geotechnical uses of ash.

Heavy metal content in ash of energy crops growing in sewage-contaminated natural wetlands: Potential applications in agriculture and forestry?

International Nuclear Information System (INIS)

Bonanno, Giuseppe; Cirelli, Giuseppe Luigi; Toscano, Attilio; Giudice, Rosa Lo; Pavone, Pietro

2013-01-01

One of the greatest current challenges is to find cost-effective and eco-friendly solutions to the ever increasing needs of modern society. Some plant species are suitable for a multitude of biotechnological applications such as bioenergy production and phytoremediation. A sustainable practice is to use energy crops to clean up polluted lands or to treat wastewater in constructed wetlands without claiming further arable land for biofuel production. However, the disposal of combustion by-products may add significant costs to the whole process, especially when it deals with toxic waste. This study aimed to investigate the possibility of recycling ash from energy biomass as a fertilizer for agriculture and forestry. In particular, the concentrations of Cd, Cr, Cu, Mn, Pb and Zn were analyzed in the plant tissues and corresponding ash of the grasses Phragmites australis and Arundo donax, collected in an urban stream affected by domestic sewage. Results showed that the metal concentration in ash is 1.5–3 times as high as the values in plant tissues. However, metal enriched ash showed much lower element concentrations than the legal limits for ash reutilization in agriculture and forestry. This study found that biomass ash from constructed wetlands may be considered as a potential fertilizer rather than hazardous waste. Energy from biomass can be a really sustainable and clean option not only through the reduction of greenhouse gas emissions, but also through ash recycling for beneficial purposes, thus minimizing the negative impacts of disposal. - Highlights: • Metal content in ash reflects the element concentrations in Phragmites australis and Arundo donax. • Metal enriched ash of both species may be recycled as fertilizers in agriculture and forestry. • Constructed wetlands may produce a large amount of plant ash-based fertilizers from P. australis and A. donax

Heavy metal content in ash of energy crops growing in sewage-contaminated natural wetlands: Potential applications in agriculture and forestry?

Energy Technology Data Exchange (ETDEWEB)

Bonanno, Giuseppe, E-mail: bonanno.giuseppe@unict.it [Department of Biological, Geological and Environmental Sciences, University of Catania, Via Longo 19, 95125, Catania (Italy); Cirelli, Giuseppe Luigi; Toscano, Attilio [Department of Agri-Food and Environmental Systems Management, University of Catania, Via Santa Sofia 100, 95123, Catania (Italy); Giudice, Rosa Lo; Pavone, Pietro [Department of Biological, Geological and Environmental Sciences, University of Catania, Via Longo 19, 95125, Catania (Italy)

2013-05-01

One of the greatest current challenges is to find cost-effective and eco-friendly solutions to the ever increasing needs of modern society. Some plant species are suitable for a multitude of biotechnological applications such as bioenergy production and phytoremediation. A sustainable practice is to use energy crops to clean up polluted lands or to treat wastewater in constructed wetlands without claiming further arable land for biofuel production. However, the disposal of combustion by-products may add significant costs to the whole process, especially when it deals with toxic waste. This study aimed to investigate the possibility of recycling ash from energy biomass as a fertilizer for agriculture and forestry. In particular, the concentrations of Cd, Cr, Cu, Mn, Pb and Zn were analyzed in the plant tissues and corresponding ash of the grasses Phragmites australis and Arundo donax, collected in an urban stream affected by domestic sewage. Results showed that the metal concentration in ash is 1.5–3 times as high as the values in plant tissues. However, metal enriched ash showed much lower element concentrations than the legal limits for ash reutilization in agriculture and forestry. This study found that biomass ash from constructed wetlands may be considered as a potential fertilizer rather than hazardous waste. Energy from biomass can be a really sustainable and clean option not only through the reduction of greenhouse gas emissions, but also through ash recycling for beneficial purposes, thus minimizing the negative impacts of disposal. - Highlights: • Metal content in ash reflects the element concentrations in Phragmites australis and Arundo donax. • Metal enriched ash of both species may be recycled as fertilizers in agriculture and forestry. • Constructed wetlands may produce a large amount of plant ash-based fertilizers from P. australis and A. donax.

Long-range volcanic ash transport and fallout during the 2008 eruption of Chaiten volcano, Chile

Science.gov (United States)

Durant, A. J.; Prata, A. J.; Villarosa, G.; Rose, W. I.; Delmelle, P.; Viramonte, J.

2012-04-01

The May 2008 eruption of Chaitén volcano, Chile, provided a rare opportunity to measure the long-range transport of volcanic emissions and characteristics of a widely-dispersed terrestrial ash deposit. Airborne ash mass, quantified using thermal infrared satellite remote sensing, ranged between 0.2-0.4 Tg during the period 3-7 May 2008. A high level of spatiotemporal correspondence was observed between cloud trajectories and changes in surface reflectivity, which was inferred to indicate ash deposition. The evolution of the deposit was mapped for the first time using satellite-based observations of surface reflectivity. The distal (>80 km) ash deposit was poorly sorted and fine grained, and mean particle size varied very little beyond a distance >300 km. There were 3 consistent particle size subpopulations in fallout at distances >300 km which suggests that aggregation influenced particle settling. Discrete temporal sampling and characterisation of fallout demonstrated contributions from specific eruptive phases. Some evidence for winnowing was identified through comparison of samples collected at the time of deposition to bulk samples collected months after deposition. X-Ray Photoelectron Spectroscopy (XPS) analyses revealed surface enrichments in Ca, Na and Fe and the presence of coatings of mixed Ca-, Na- and Fe-rich salts on ash particles prior to deposition. XPS analyses revealed strong surface Fe enrichments (in contrast to the results from bulk leachate analyses), which indicates that surface analysis techniques should be applied to investigate potential influences on ocean productivity in response to volcanic ash fallout over oceans. Low S:Cl ratios in leachates indicate that the eruption had a low S content, and high Cl:F ratios imply gas-ash interaction within a Cl-rich environment. We estimate that ash fallout had potential to scavenge ~42 % of total S released into the atmosphere prior to deposition.

Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

Directory of Open Access Journals (Sweden)

M. Adama

2016-01-01

Full Text Available Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (Igeo and pollution load indices (PLI were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69, Pb (143.80, Cr (99.30, and Cd (7.54 in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

Science.gov (United States)

Adama, M.; Esena, R.; Fosu-Mensah, B.; Yirenya-Tawiah, D.

2016-01-01

Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites. PMID:27034685

Re-Meandering of Lowland Streams

DEFF Research Database (Denmark)

Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

2014-01-01

We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats...... and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled...... along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored...

Identifying fly ash at a distance from fossil fuel power stations

International Nuclear Information System (INIS)

Flanders, P.J.

1999-01-01

A method has been developed to identify fly ash originating at fossil fuel power stations, even at a distance where the ash level is lower by a factor of 1000 from that close to a source. Until now such detection has been difficult and uncertain. The technique combines collection of particles, measurement of magnetization and coercive field, and microscopy. The analysis depends on the fact that ash from iron sulfide in fossil fuels is in the form of spherical magnetite. These particles have a relatively high coercive field H c , near 135 Oe, compared with airborne particulates from soil erosion which have an H c of ∼35 Oe. The coercive field of any sample therefore gives an indication for the percentage of fly ash relative to the total amount of magnetic material that is airborne. The concentration of ash from a large, isolated coal burning power station is found to fall off with the distance from the source, approximately as D -1 . As D increases there is a drop in H c , associated with the reduced amount of fly ash relative to the airborne particulates from soil erosion

POLA RASIO KEUANGAN PADA SAAT UP STREAM DAN DOWN STREAM DI INDUSTRI REALESTAT YANG GO PUBLIC

Directory of Open Access Journals (Sweden)

David Sukardi Kodrat

2006-01-01

Full Text Available This research has purpose to explain differences on indicator financial ratio in up and down stream condition. This research uses real estate industries listed on Jakarta Stock Exchange as a sample. Sample selection is performed based on purposive sampling method with object to gain sample according to the research aim. Based on those criteria, there are 18 companies, which have fulfilling the conditions needed, starting from 1994 until 2002. The classification of business cycle on up and down stream conditions to used stock pricing indexes of property and real estate which calculated by arithmatic mean method. Based on those criteria, the classifications from 1994 until 1997 are represented by up stream condition and from 1998 until 2002 are represented by down stream condition. The result shows indicators: profitability ratios, gross margin ratios, capital turnover ratios, asset to equity ratios, growth ratios, liquidity ratios, leverage ratios, and cash flow ratios are different in up and down stream conditions, both simultaneously and partially. Simultaneously, there is a significant difference between up and down stream condition with wilks lambda of 0,346 and p value of 0,000. This research shows financial ratio indicator has differences on business cycle. Abstract in Bahasa Indonesia : Penelitan ini mempunyai tujuan untuk mengetahui perbedaan indikator rasio keuangan pada kondisi up stream dan down stream. Penelitian ini menggunakan sampel pada industri di sektor properti yang terdaftar di Bursa Efek Jakarta. Pemilihan sampel dalam penelitian ini menggunakan Purposive Sampling yaitu sampel diambil berdasarkan kriteria-kriteria tertentu yang sesuai dengan tujuan penelitian ini. Berdasarkan kriteria tersebut, terdapat 18 perusahaan yang dapat dijadikan sampel mulai tahun 1994 sampai dengan 2002. Untuk menentukan perubahan business cycle pada kondisi up stream dan down stream dilakukan dengan menggunakan indeks harga saham di sektor properti

Determining ash content in flotation wastes by means of the MPOF optical ash meter. [Poland

Energy Technology Data Exchange (ETDEWEB)

Sikora, T; Sliwa, J

1982-03-01

The paper evaluates an experimental unit of the MPOF optical ash meter, developed by the EMAG Research and Production Center for Electrical Engineering and Mining Automation. The MPOF, which is being tested at the coal preparation plant of the 30 lecia PRL mine, is the first system for continuous determination of ash content in flotation tailings developed in Poland. A block scheme of the system is given. It consists of a measuring head and electronic system which processes data supplied by the measuring head and calculates ash content. System operation is based on the principle of determining ash content in a mixture of coal and mineral wastes by measuring mixture reflectivity. Determining ash content in the mixture is possible as reflectivity coefficients for coal and ash are constant. Performance of the MPOF optical ash meter is evaluated; the results are shown in a table and a scheme. Measurement accuracy is satisfactory.

Magnesiothermic reduction of rice husk ash for electromagnetic wave adsorption

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu-Ting; Yan, Kang-kang; Zhang, Yuan hu; Jin, Shi-di; Ye, Ying; Chen, Xue-Gang, E-mail: chenxg83@zju.edu.cn

2015-11-15

The increase in electromagnetic pollution due to the extensive exploitation of electromagnetic (EM) waves in modern technology creates correspondingly urgent need for developing effective EM wave absorbers. In this study, we carried out the magnesiothermic reduced the rice husk ash under different temperatures (400–800 °C) and investigated the electromagnetic wave adsorption of the products. The EM absorbing for all samples are mainly depend on the dielectric loss, which is ascribed to the carbon and silicon carbide content. RA samples (raw rice husk ashed in air and was magesiothermic reduced in different temperatures) exhibit poor dielectric properties, whereas RN samples (raw rice husk ashed in nitrogen and was magesiothermic reduced in different temperatures) with higher content of carbon and silicon carbide display considerable higher dielectric loss values and broader bandwidth for RL<−5 dB and −10 dB. For RN samples, the maximum bandwidth for −5 dB and −10 dB decrease with carbon contents, while the optimum thickness decrease with increasing SiC content. The optimum thickness of RN400–800 for EM absorption is 1.5–2.0 mm, with maximum RL of between −28.9 and −68.4 dB, bandwidth of 6.7–13 GHz for RL<−5 dB and 3.2–6.2 GHz for RL<−10 dB. The magnesiothermic reduction will enhance the potential application of rice husk ash in EM wave absorption and the samples benefited from low bulk density and low thickness. With the advantages of light-weight, high EM wave absorption, low cost, RN400–800 could be promising candidates for light-weight EM wave absorption materials over many conventional EM wave absorbers. - Highlights: • RN400–800 samples are potential light-weight electromagnetic absorbers. • Carbon and SiC are considered as dominating contributions for the dielectric loss. • Magnesiumothermic reduction extends the EM wave absorption potential of RHN.

INFLUENCE OF SILICEOUS AND CALCAREOUS FLY-ASHES ON PROPERTIES OF CEMENT MORTARS

Directory of Open Access Journals (Sweden)

Gabriela Monika Rutkowska

2016-09-01

Full Text Available Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. Construction and building industries have the greatest potential for reuse of waste. The article presents the results of investigations of cement mortars – tests of compressive and tensile strength after 28 and 56 days of curing – for normative mortars and mortars containing fly ashes – calcareous and siliceous ash – in their composition. To make the samples, the Portland cement CEM I 32,5 R, 42,5R and natural aggregate with graining of 0–2 mm were used. Concrete with siliceous and calcareous admixtures was made in six lots where the ash was added in the quantity of 2%, 5%, 10% of the cement mass or the 2%, 5%, 10% of cement was replaced by ashes. After the tests, it was stated that the siliceous fly-ash admixture increases the compressive and bending strength in comparison to the mortars with the calcareous ash admixtures.

Wet-dry cycles effect on ash water repellency. A laboratory experiment.

Science.gov (United States)

Pereira, Paulo; Cerdà, Artemi; Oliva, Marc; Mataix, Jorge; Jordán, Antonio

2014-05-01

In the immediate period after the fire, the ash layer has a strong influence on soil hydrological processes, as runoff, infiltration and erosion. Ash is very dynamic in the space and time. Until the first rainfall periods, ash is (re)distributed by the wind. After it can cover the soil surface, infiltrate or transported to other areas by water transport (Pereira et al., 2013a, b). This will have strong implications on nutrient redistribution and vegetation recovery. Ash layer may affect soil water repellency in different ways, depending on fire severity, soil properties and vegetation. Ash produced at low temperatures after low-severity burning is usually hydrophobic (Bodi et al., 2011, 2012). Wet-dry cycles have implications on ash physical and chemical properties, changing their effects in space and time. The aim of this study is to analyse the effects of fire temperature and severity on ash water repellency. Pinus sylvestris needles were collected in a Lithuania forest in Dzukija National Park (53º 54' N and 24º 22' E), transported to laboratory and washed with deionized water to remove soil particles and other residues. Needle samples were dried during 24 hours and exposed to different temperatures: 200, 300, 400 and 500 ºC, during 2 hours. Ash colour was analysed according to the Munsell Soil Color charts. Ash was black (10 YR 2/1) at 200 ºC, very dark grey (10YR 3/1) at 300 ºC, gray (10YR 5/1) at 400 ºC and light gray (10YR 7/1) at 500 ºC. Ten samples of ash released after each treatment were placed in plastic dishes (50 mm in diameter) in an amount enough to form a 5 mm thick layer, and ash water repellency was measured according to the Water Drop Penetration Test. Later, ash was carefully wetted with 15 ml of deionized water and placed in an oven during 4 days (96 hours), as in Bodí et al. (2012). This procedure was repeated 5 times in order to observe the effects of wet-dry cycles in ash water repellency. The results showed significant differences

Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

Science.gov (United States)

Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

2017-06-01

Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor.

Science.gov (United States)

Lapa, N; Barbosa, R; Lopes, M H; Mendes, B; Abelha, P; Boavida, D; Gulyurtlu, I; Oliveira, J Santos

2007-08-17

In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub-products of such type

Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

Energy Technology Data Exchange (ETDEWEB)

Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

2007-08-17

In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

International Nuclear Information System (INIS)

Lapa, N.; Barbosa, R.; Lopes, M.H.; Mendes, B.; Abelha, P.; Gulyurtlu, I.; Santos Oliveira, J.

2007-01-01

In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

Ash Properties of Alternative Biomass

DEFF Research Database (Denmark)

Capablo, Joaquin; Jensen, Peter Arendt; Pedersen, Kim Hougaard

2009-01-01

analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence...... on ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion....

Characterization of a stream sediment matrix material for sampling behavior in order to use it as a CRM

International Nuclear Information System (INIS)

Huang Donghui; Xiao Caijin; Ni Bangfa; Tian Weizhi; Zhang Yuanxun; Wang Pingsheng; Liu Cunxiong; Zhang Guiying

2010-01-01

Sampling behavior of multielements in a stream sediment matrix was studied with sample sizes in a range of 9 orders of magnitude by a combination of INAA, PIXE and SR-XRF. For accurately weighable sample sizes (>1 mg), sampling uncertainties for 16 elements are better than 1% by INAA. For sample sizes that cannot be accurately weighed (<1 mg), PIXE and SR-XRF were used and the effective sample sizes were estimated. Sampling uncertainties for seven elements are better than 1% at sample sizes of tenth mg level, and that for three elements are better than 10% on ng levels.

The aggregation efficiency of very fine volcanic ash

Science.gov (United States)

Del Bello, E.; Taddeucci, J.; Scarlato, P.

2013-12-01

Explosive volcanic eruptions can discharge large amounts of very small sized pyroclasts (under 0.090 mm) into the atmosphere that may cause problems to people, infrastructures and environment. The transport and deposition of fine ash are ruled by aggregation that causes premature settling of fine ash and, as consequence, significantly reduces the concentration of airborne material over long distances. Parameterizing the aggregation potential of fine ash is then needed to provide accurate modelling of ash transport and deposition from volcanic plumes. Here we present the first results of laboratory experiments investigating the aggregation efficiency of very fine volcanic particles. Previous laboratory experiments have shown that collision kinetic and relative humidity provide the strongest effect on aggregation behaviour but were only limited to particles with size > 0.125 mm. In our work, we focus on natural volcanic ash at ambient humidity with particles size aggregation potential. Two types of ash were used in our experiments: fresh ash, collected during fall-out from a recent plume-forming eruption at Sakurajima (Japan -July 2013) and old ash, collected from fall-out tephra deposits at Campi Flegrei (Italy, ca. 10 ka), to account for the different chemical composition and morphoscopic effects of altered ash on aggregation efficiency. Total samples were hand sieved to obtain three classes with unimodal grain size distributions (sieved from the top of a transparent tank where a fan, placed at the bottom, allows turbulent dispersion of particles. Collision and sticking of particles on a vertical glass slide were filmed with a high speed cameras at 6000 fps. Our lenses arrangement provide high image resolution allowing to capture particles down to 0.005 mm in diameter. Video sequences of particles motion and collision were then processed with image analysis and particle tracking tools to determine i) the particle number density and ii) the grain size distribution

Hydrogeochemical and stream sediment reconnaissance basic data for Emory Peak NTMS Quadrangle, Texas. Uranium Resource Evaluation Project

International Nuclear Information System (INIS)

1978-01-01

Results of a reconnaissance geochemical survey of the Emory Peak Quadrangle, Texas, are reported. Field and laboratory data are presented for 193 groundwater samples and 491 stream sediment samples. Statistical and areal distributions of uranium and other possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and the pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. In groundwater, uranium concentrations above the 85th percentile outline an area in the northwest portion of the quadrangle which is dominated by tertiary tuffaceous ash beds which disconformably overlie cretaceous units. The relationship between uranium and related variables indicates this area appears to have the best potential for uranium mineralization within the quadrangle. Stream sediment data indicate four areas that appear to be favorable for potential uranium mineralization: the Upper Green Valley-Paradise Valley region, the Terlingua Creek-Solitario region, an area in the vicinity of Big Bend National Park, and an area east of long. 102 0 15' W. In the first three of the preceding areas, soluble uranium is associated with tertiary igneous rocks. In the fourth area, soluble uranium is present in carbonate-dominant cretaceous strata

Surface chemical properties of novel high surface area solids synthesized from coal fly ash

CSIR Research Space (South Africa)

Pretorius, PJ

2003-07-23

Full Text Available The zeolite, Na-P1, was synthesized from fly ash samples originating from coal-fired power stations in South Africa by hydrothermal treatment of the raw ash with concentrated aqueous NaOH solutions. The zeolite was then further modified by acid...

Natural radioactivity in volcanic ash from Mt. Pinatubo eruption

International Nuclear Information System (INIS)

Duran, E.B.; De Vera, C.M.; Garcia, T.Y.; Dela Cruz, F.M.; Esguerra, L.V.; Castaneda, S.S.

1992-01-01

Last June 15, 1991, a major pyroclastic eruption occurred from Mt. Pinatubo volcano located in Zambales, Central Luzon. The radiological impact of this eruption was assessed based on the concentrations of the principal naturally occurring radionuclides observed in volcanic ash. The volcanic ash samples were collected from locations which are within 50-km radius of Mt. Pinatubo at various times after the eruption. The mean activity concentrations in Bq/kg wet weight of the natural radionuclides in volcanic ash were as follows: 12.6 for 238 U, 14.0 for 232 Th and 330 for 40 K. These values are significantly higher than the mean activity concentrations of these radionuclides observed in topsoil in the same provinces before the eruption. This suggests that with the deposition of large quantities of volcanic ash and lahar in Central Luzon and concomitant topographic changes, the distribution and quantities of radionuclides which gave rise to terrestrial radiation may have also changed. Outdoor radon concentrations measured three days and later after the eruption were within normal background values. (auth.). 4 refs.; 5 tabs.; 1 fig

Studies on rheological and leaching characteristics of heavy metals through selective additive in high concentration ash slurry.

Science.gov (United States)

Senapati, P K; Mohapatra, R; Pani, G K; Mishra, B K

2012-08-30

The generation and disposal level of thermal power plant ash in India is a challenging task. The conventional mode of dilute phase ash slurry (10-20% solids by weight) transport through pipelines being practiced in majority of these plants not only consumes huge amount of precious water and pumping energy but also causes serious environmental problem at the disposal site. The present study investigates the rheological and leaching characteristics of an Indian ash samples at high solids concentrations (>50% by weight) using sodium silicate as an additive. The flow behaviour of ash slurry in the concentration range of 50-60% by weight is described by a Bingham-plastic model. It was indicated that the addition of sodium silicate (0.2-0.6% of the total solids) could able to reduce both the slurry viscosity and the yield stress. The analysis of the ash samples for the presence of heavy metals such as Fe, Cd, Ni, Pb, Zn, Cu, Co, As and Hg were carried out following Hansen and Fisher procedure. The addition of sodium silicate affected the leaching characteristics of the ash samples over a period of 300 days resulting in the reduction of leaching of heavy metals. Copyright © 2012 Elsevier B.V. All rights reserved.

Immersion freezing induced by different kinds of coal fly ash: Comparing particle generation methods and measurement techniques

Science.gov (United States)

Grawe, Sarah; Augustin-Bauditz, Stefanie; Clemen, Hans-Christian; Eriksen-Hammer, Stine; Lubitz, Jasmin; Schneider, Johannes; Stratmann, Frank; Wex, Heike

2017-04-01

To date, a lot of effort has been put into the identification and characterization of atmospheric ice nucleating particles (INPs), which may influence both weather and climate. The majority of studies focuses on INPs from natural origin such as biological particles or mineral dust particles (Hoose and Möhler 2012, Murray et al. 2012). Combustion ashes, being possible sources of anthropogenic INPs, have rarely been investigated in the past. Ash particles may be emitted into the atmosphere either by the action of wind from ash deposits on the ground (bottom ash), or during the combustion process (fly ash). Two recent studies (Umo et al., 2015; Grawe et al., 2016) identified fly ash from coal combustion as the most efficient of the investigated samples (including also bottom ashes from wood and coal combustion). These results motivate the here presented study in which we investigated the immersion freezing behavior of four coal fly ash samples taken from the filters of different coal-fired power plants in Germany. A combination of two instruments was used to capture the temperature range from 0 °C to the homogeneous freezing limit at around -38 °C. Firstly, the new Leipzig Ice Nucleation Array (LINA) was used, where droplets from an ash-water suspension are pipetted onto a cooled plate. Secondly, we used the Leipzig Aerosol Cloud Interaction Simulator (LACIS; Hartmann et al., 2011), a laminar flow tube in which every droplet contains a single size-segregated ash particle. Here, it was possible to study the effect of different kinds of particle generation, i.e., atomization of an ash-water suspension, and aerosolization of dry ash material. The composition of the ash particles was investigated by means of single particle aerosol mass spectrometry and particles were sampled on filters for environmental scanning electron microscope analysis. Our measurements show that all four fly ash samples feature a similar immersion freezing behavior (ice fractions vary by a

Effect of wood ash and K-fertilization on {sup 137}Cs uptake by selected forest plants

Energy Technology Data Exchange (ETDEWEB)

Mandro, Yrii N. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Rosen, Klas [Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden); Vinichuk, Mykhailo M. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden)

2014-07-01

Accumulation {sup 137}Cs by different forest plants and trees after fertilization of soil with potassium and wood ash ({sup 137}Cs-contaminated and non-contaminated) in forest ecosystems of Ukraine contaminated by radionuclides after Chernobyl accident in 1986 was studied. Experiment is performed in Bazar forestry, Zhytomyr region, Ukraine, located about 70 km (51 deg. 5'35'' N, 29 deg. 18'56'' E) from Chernobyl NPP. Potassium fertilizer (KCl, wooden ash (Ash), and {sup 137}Cs-contaminated ash ({sup 137}CsAsh) in different combinations) were spread on the forest floor in April 2012 at a rate corresponding 100 kg/ha potassium. The experiment layout was as follows: 1- Control (no fertilizers were applied), 2- KCl, 3- Ash + KCl, 4- Ash + {sup 137}CsAsh, 5- Ash, 6- {sup 137}CsAsh + KCl. Samples (leaves and annual shoots) of blueberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea), rowan (Sorbus aucuparia), birch (Betula), buckthorn (Frangula) and oak (Quercus robur) and also mushrooms (fruit bodies of Russula, Lactarius, Cantharellus, Collybia etc.) and berries (blueberry and cowberry) were taken monthly from each treatment. Samples were measured for {sup 137}Cs with calibrated HPGe detectors. The results of the first year studies show variation of Transfer Factors (TF) for different plants and for the same plants on different treatments. The effect of fertilization was found for blueberry on Ash-applicated (TF = 0.0085 ± 0.0025), {sup 137}CsAsh + KCl-applicated (TF = 0.0105 ± 0.0060) and Ash + KCl-applicated (TF = 0.0123 ± 0.0058) treatments compared to Control (TF = 0.0163 ± 0.0092). Also good effect for rowan on Ash + KCl-applicated treatment (TF = 0.0067 ± 0.0024) compared to Control (TF = 0.0100 ± 0.0064). Effect was less obvious for birch on Ash + KCl-applicated treatment and for cowberry on Ash + KCl-applicated treatment. There was not found an obvious effect of fertilization for buckthorn. Positive effect of

Effect of CaCO_3 addition on ash sintering behaviour during K_2CO_3 catalysed steam gasification of a Chinese lignite

International Nuclear Information System (INIS)

Zhang, Jiguang; Li, Jianbo; Mao, Yandong; Bi, Jicheng; Zhu, Mingming; Zhang, Zhezi; Zhang, Li; Zhang, Dongke

2017-01-01

Highlights: • K_2CO_3 decreased ash sintering temperature and enhanced ash melting in gasification. • CaCO_3 addition enhanced ash melting and lowered ash sintering temperatures. • CaCO_3 reacted with SiO_2 to form fluxing phases and amorphous materials. • CaCO_3 addition inhibited the potassium aluminium silicate formation. • CaCO_3 addition preserved the catalytic activity of potassium. - Abstract: The ash sintering behaviour of a Chinese lignite (LLI) with different amounts of CaCO_3 addition during K_2CO_3-catalysed gasification was investigated. 0–10 wt% K_2CO_3 was doped into the lignite for catalytic gasification, and CaCO_3 was added into the K_2CO_3-doped samples, varying in the range of 0–20 wt% relative to the lignite, for understanding its impact on ash sintering and catalytic gasification activity. Ash samples were prepared by completely gasifying the lignite samples with steam in a fixed-bed catalytic gasification system operating at 1073 K and atmospheric pressure. Sintering temperature, mineralogy and morphology of the ash samples thus obtained were determined using a pressure-drop sintering device, XRD and SEM-EDS, respectively. The results showed that the ash sintering temperature decreased as the K_2CO_3 addition increased, indicating that K_2CO_3 as the catalyst for gasification would promote ash sintering. SEM imaging analysis showed that all the ash samples from LLI with K_2CO_3 addition were composed of agglomerated particles with smooth surfaces, indicating the ashes had incurred partial melting. The degree of melting became more apparent as the K_2CO_3 addition ratio increased. These molten phases were identified as K-bearing arcanite and kaliophilite, which contributed to the formation of liquid phases at lower temperatures, resulting in lowered ash sintering temperatures. It was also revealed that the addition of CaCO_3 decreased the sintering temperatures of ash samples, indicating that the ash sintering was further

Immobilization of Radioactive Waste in Different Fly Ash Zeolite Cement Blends

International Nuclear Information System (INIS)

Sami, N.M.

2013-01-01

The problem of radioactive waste management has been raised from the beginning use of nuclear energy for different purposes. The rad waste streams produced were sufficient to cause dangerous effects to man and its environment. The ordinary portland cement is the material more extensively used in the technologies of solidification and immobilization of the toxic wastes, low and medium level radioactive wastes. The production of portland cement is one of the most energy-intensive and polluting. The use of high energy in the production causes high emission due to the nature and processes of raw materials. The cement industry is responsible for 7% of the total CO 2 emission. Thus, the cement industry has a crucial role in the global warming. The formation of alite (Ca 3 SiO 5 ), which is the main component of the Portland cement clinker, produces a greater amount of CO 2 emission than the formation of belite (Ca 2 SiO 4 ). The proportion of alite to belite is about 3 in ordinary Portland clinker. Therefore, by decreasing this proportion less CO 2 would be emitted. Furthermore, if industrial byproducts such as fly ash from thermal power station or from incineration of municipal solid wastes have the potential to reduce CO 2 used as raw materials and alternative hydrothermal calcination routes are employed for belite clinker production, CO 2 emission can be strongly reduced or even totally avoided. The availability of fly ash will help in reducing the CO 2 emissions and will also help in resolving, to a great extent, the fly ash disposal problem. This thesis is based on focusing on the possibility of using fly ash as raw materials to prepare low cost innovation matrices for immobilization of radioactive wastes by synthesizing new kind of cement of low consuming energy. The synthesis process is based on the hydrothermal-calcination route of the fly ash without extra additions.

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

Science.gov (United States)

Chen, Yigen; Poland, Therese M

2009-12-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

Studying the melting behavior of coal, biomass, and coal/biomass ash using viscosity and heated stage XRD data

DEFF Research Database (Denmark)

Arvelakis, Stelios; Folkedahl, B.; Dam-Johansen, Kim

2006-01-01

by the cocombustion tests appeared to be somewhat different compared to that of the laboratory-prepared ash samples. The heated stage XRD data provide useful information regarding the reactions among the various ash compounds and the phase transformations during the heating and cooling of the ash samples and helped...... a high-temperature rotational viscometer and a hot stage XRD. The produced data were used to calculate the operating temperature of a pilot-scale entrained flow reactor during the cocombustion of biomass/ coal samples in order to ensure the slag flow and to avoid corrosion of the walls due to liquid slag...

10 Risk to Ash from Emerald Ash Borer: Can Biological Control Prevent the Loss of Ash Stands

Science.gov (United States)

Ash trees were once relatively free of serious, major diseases and insect pests in North America until the arrival of EAB, which was first detected in North America in Michigan in 2002. As of February 2014, EAB had been detected in 22 U.S. states and two Canadian provinces, killing millions of ash ...

Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

OpenAIRE

Antoni; Sulistio Aldi Vincent; Wahjudi Samuel; Hardjito Djwantoro; Hardjito Djwantoro

2017-01-01

Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment includi...

Particle dispersion at road building using fly ash - model review, investigation of influence of humidity content for dust emission and fly ash particle characterisation; Partikelspriding vid byggnation av vaeg med aska - modelloeversikt, undersoekning av fuktighetsgradens betydelse foer damning och karaktaerisering av partiklar fraan flygaska

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Mats; Wik, Ola; Frogner-Kockum, Paul

2009-03-15

Ashes from incineration may have very good properties, such as building materials in roads. This use assumes that the ashes do not have serious environmental and health effects. Since ash might generate large amounts of dust in handling the issue on the extent of dusting and dust properties has proved to be important to assess the risks of environmental impacts during use. Inhalable particles in the ambient air are a problem that has attracted much attention and is regarded as one of the most serious health related air pollutants. The present project has aimed to: describe appropriate models for calculating the emission and dispersion of dust in the air during the construction of ash containing roads, evaluate a new method to examine the importance of moisture for dusting from fly ash and investigate the properties of fly ash, making it possible to identify ash in samples of airborne particles. The target audience is ash manufacturers, contractors and consultants with a need for knowledge of ash dusting. Project modules have included: a literature review to identify appropriate modelling tools to describe the emission and dispersion of dust from road building with ash a method study in which a piece of equipment called Duster, have been evaluated for assessing the significance of the ash humidity to dusting, and an electron microscope study where morphology and composition of some ashes, cement and Merit have been studied to find ways to identify ash particles in dust samples. The results show that there is a lack of overall model tools that can describe the emissions from all the management operations of ashes at road building and that existing models sometimes lack key variables. Also, because of high silt content of ashes, some models are deemed inferior compared to when used for ordinary mineral material. Furthermore, attempts with the Duster shows that the method works, but with limited precision, and that dusting from the ash samples was reduced significantly

Ash characteristics and plant nutrients in some aquatic biomasses

Science.gov (United States)

Masto, Reginald; Pandit, Ankita; George, Joshy; Mukhopadhyay, Sangeeta; Selvi, Vetrivel; Ram, Lal

2016-04-01

Aquatic biomasses are explored as potential fuel source for direct combustion because of their faster growth and no land requirement. The energy density and the ash characteristics of the aquatic biomasses are to be evaluated for their suitability for energy extraction. In the study, four aquatic plant samples namely Eichornia crassipes, Hydrilla verticilleta, Lemna minor, Spirogyra spp were collected from a pond in Digwadih Campus of Central Institute of Mining and Fuel Research, Dhanbad. The biomasses were air dried, powdered and ashed at different temperatures. Volatile C was relatively lower in Spirogyra and Hydrilla (53 %) than Eichornia (62.6 %) or Lemna (59.7 %), whereas fixed C was higher for Eichornia and Lemna (about 10 %) and lower for Hydrilla (1 %). Ultimate analysis showed that the carbon content was in the order Eichornia > Lemna > Spirogyra > Hydrilla. The IR spectra of each raw biomass is compared to their respective ashes obtained at different temperatures (500-900°C). With increase in ashing temperature from 500-900°C there is gradual breakdown of the cellulosic structure hence, peaks around 2900-2800cm-1 caused by aliphatic C-H vibration tends to disappear slowly in ash. More number of peaks appears at lower wavenumbers in ashes of all the biomass samples indicating towards increased percentage of inorganic ion species. Considerable enrichment of SiO2 is validated with prominent peaks at 1100-900 cm-1 in all the ashes. Lemna and Spirogyra has a similar ash composition (Si > Al > Ca > K), whereas, Ca was higher in Hydrilla (Si > Ca > K > Al). Eichornia (Si > K > Ca > Al) has higher K and Ca than Al. SiO2 and Al2O3 were higher in Spirogyra, while SiO2 and CaO in Eichornia and Hydrilla. K first increased from 500-700/800⁰C, and then decreased from 800-900⁰C. Cl is lost slowly in ash from 500-700/800⁰C and then by a drastic reduction from 800-900⁰C. S is enhanced in ash at all temperatures although the change is quite small. Most of the Cl

Utilisation of different types of coal fly ash in the production of ceramic tiles

OpenAIRE

KocKal, N. U.

2012-01-01

The influence of varying proportions of different types of fly ash (used in place of feldspar) and different sintering temperatures on the sintered properties of ceramic tile bodies was evaluated. The results indicated that sintering ceramic tiles with a high fly ash content at a high temperature caused a decrease in the properties because of bloating. The ceramic samples containing a higher amount of fly ash that were sintered at low temperature exhibited lower water absorption, larger shrin...

Wildland fire ash: future research directions

Science.gov (United States)

Bodí, Merche B.; Martins, Deborah A.; Cerdà, Artemi; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Mataix-Solera, Jorge

2014-05-01

Ash is a key component of the forest fires affected land (Cerdà, 1998; Bodí et al., 2011; Pereira et al., 2013a). Ash controls the hydrological processes and determines the water repellency (Dlapa et al., 2012) and the infiltration rates (Cerdà and Doerr, 2008;). Moreover, ash is the key factor on runoff initiation and then on the soil erosion. Little is known about the impact of ash in different ecosystems, but during the last decade a substantial increase in the papers that show the role of ash in the Earth and Soil System were published (Bodí et al., 2012; Pereira et al., 2013b).. Ash is being found as the key component of the post-fire pedological, geomorphological and hydrological response after forest fires (Fernández et al., 2012; Martín et al., 2012; Bodí et al., 2013; Guénon et al., 2013; Pereira et al., 2013c). A recent State-of-the-Art review about wildland fire ash (Bodí et al., 2014) compiles the knowledge regarding the production, composition and eco-hydro-geomorphic effects of wildland fire ash. In the present paper we indicate the knowledge gaps detected and suggest topics that need more research effort concerning: i) data collection and analysis techniques: a) To develop standardized sampling techniques that allow cross comparison among sites and avoid inclusion of the underlying soil unless the burned surface soil forms part of the ash layer, b) To develop standardized methods to define and characterize ash, including its color, physical properties such as particle size distribution or density, proportion of pyrogenic C, chemical and biological reactivity and persistence in the environment, c) To validate, calibrate and test measurements collected through remote sensing with on-the-ground measurements. ii) ash production, deposition redistribution and fate: d) To untangle the significance of the effects of maximum temperature reached during combustion versus the duration of heating, e) To understand the production of ash by measuring its

Characterization of metals released from coal fly ash during dredging at the Kingston ash recovery project.

Science.gov (United States)

Bednar, A J; Averett, D E; Seiter, J M; Lafferty, B; Jones, W T; Hayes, C A; Chappell, M A; Clarke, J U; Steevens, J A

2013-09-01

A storage-pond dike failure occurred on December 22, 2008 at the Tennessee Valley Authority Kingston Fossil Plant resulting in the release of over 4million cubic meters (5million cubic yards) of fly ash. Approximately half of the released ash was deposited in the main channel of the Emory River, Tennessee, USA. Remediation efforts of the Emory River focused on hydraulic dredging, as well as mechanical excavation in targeted areas. However, agitation of the submerged fly ash during hydraulic dredging introduces river water into the fly ash material, which could promote dissolution and desorption of metals from the solid fly ash material. Furthermore, aeration of the dredge slurry could alter the redox state of metals in the fly ash material and thereby change their sorption, mobility, and toxicity properties. The research presented here focuses on the concentrations and speciation of metals during the fly ash recovery from the Emory River. Our results indicate that arsenite [As(III)] released from the fly ash material during dredging was slowly oxidized to arsenate [As(V)] in the slurry recovery system with subsequent removal through precipitation or sorption reactions with suspended fly ash material. Concentrations of other dissolved metals, including iron and manganese, also generally decreased in the ash recovery system prior to water discharge back to the river. Published by Elsevier Ltd.

Prospects for ash pond reclamation

Energy Technology Data Exchange (ETDEWEB)

Shyyam, A.K.; Shukla, K.S.; Agrawal, D. (National Thermal Power Corporation Ltd., New Delhi (India))

1993-01-01

A typical modern coal fired station in India burns 0.7 t/MWh of coal and consequently generates ash at 0.245 t/MWh. The physical nature of ash, low available concentrations of certain plant nutrients and the presence of phytotoxic trace elements render fly ash marginally adequate for plant growth. As fly ash itself was thought to be an inappropriate growth medium for plants, regulators decided that a soil cover is mandatory. There is ample data to suggest that the attributes of fly ash detrimental to plant growth can be ameliorated, allowing the establishment of vegetation directly on fly ash surfaces. The natural revegetation of fly ash disposal sites has been reported in the world. The natural vegetation pioneered by Cynodon at different stages of ecological succession and comprising of species such as [ital Calotropis gigantea], [ital Lippia nodiflora], [ital Ipomea, cornea], [ital Xanthium parviflorum] has been noted at one of the NTPC projects, in Badarpur Thermal Power Station. Since natural reclamation is a time-consuming process, experimental trials of growing some species over the temporary ash lagoon directly (without soil cover) were carried out at Ramagundam Super Thermal Power Project (RSTPP) of NTPC, in South India to achieve faster results than the natural process. 6 refs., 8 figs.

Effect of interfacial properties on mechanical stability of ash deposit

Directory of Open Access Journals (Sweden)

A. Ontiveros-Ortega

2016-04-01

Full Text Available The paper presents a study on the cohesion of volcanic ash particles using surface free energy determination and zeta potential analyses. This is a subject of great interest in physical volcanology, as many researches on volcanic particle aggregation are frequently reported. In this case, special attention is paid to the role of structural or hydration forces between hydrophilic surfaces, which are a consequence of the electron-donor/electron-acceptor character of the interface. From this point of view, the results are potentially interesting as they could give valuable insights into this process. The results are presented in terms of the total energy of interaction between dispersed particles, computed from the extended DLVO theory. Contributions to the total free energy of interaction were determined from the zeta potential and surface free energy of ash, measured under different experimental conditions. Two samples of basaltic volcanic ash (black and white with silica contents of 44% and 63% respectively are studied. The surface free energy and zeta potential were analysed for ashes immersed in different electrolytes (NaCl, CaCl2, FeCl3. The presence of electrolytes changes the surface properties of the solid materials. The analysis of total interaction energy between the ash particles in aqueous medium shows that soil cohesion strongly depends on ash surface properties, chemical nature, the adsorbed cation on the surface, and pH value.

Radioisotope conveyor ash meter

International Nuclear Information System (INIS)

Savelov, V.D.

1994-01-01

Radioisotope conveyor ash meter realizes persistent measuring of ashiness of coal and products of its enrichment on the belt conveyor without contact. The principle of ash meter acting is based on functional dependence of the gamma radiation flows backscattering intensity of radioisotope sources from the ash volume content in the controlled fuel. Facility consists from the ashiness transducer and the processing and control device

Influence of fly ash added to a ceramic body on its thermophysical properties

Directory of Open Access Journals (Sweden)

Kováč Jozef

2016-01-01

Full Text Available We study thermal expansion, mass changes, heat capacity, and thermal diffusivity and conductivity for a ceramic body with 20 mass% and without fly ash content, using the TDA, TG, DTA, DSC, and flash method. The measurements were performed (a for green samples either isothermally or by a linear heating up to a temperature 600°C, 1050°C, or 1100°C, depending on the measurement method; (b at the room temperature for samples preheated at 100°C, 200°C, ..., 1100°C. In case (a addition of fly ash changes the final contraction only above ~900°C, while the thermal properties remain almost unchanged. In case (b the final contraction of samples at 1100°C is the same. The thermal diffusivity is nearly identical up to 700°C, and fly ash causes the diffusivity to stay almost constant up to 1000°C.

Hydrogeochemical and Stream Sediment Reconnaissance Program in central United States. Semiannual progress report, October 1, 1978--March 31, 1979

International Nuclear Information System (INIS)

Arendt, J.W.

1979-01-01

Basic data reports were open filed for eight NTMS quadrangles during the reporting period: Sherman, Houston, Ardmore, Emory Peak, Presidio, Enid, Austin, and Lawton. Basic data reports, which have been prepared and are in the process of being open filed, include Wichita, St. Cloud, Ashland, and Clinton. Results indicate that the most favorable areas for the occurrence of uranium mineralization in the open filed quadrangles are as follows: (1) Austin Quadrangle - Whitsett, Catahoula, Oakville, and Fleming Formations (Tertiary). (2) Lawton Quadrangle - Hennessey and Clearfork Groups, Garber Sandstone, and Post Oak Conglomerate (Lower Permian); and El Reno Group (Upper Permian). (3) Emory Peak Quadrangle - Tertiary tuffaceous ash beds and other igneous rocks, carbonate-dominant Cretaceous strata. During the period, approximately 13,886 samples of groundwater and stream sediments were collected by the URE Project. Approximately 20,738 samples were analyzed by the URE Laboratory

Bioleaching of trace metals from coal ash using local isolate from coal ash ponds

Directory of Open Access Journals (Sweden)

Pangayao Denvert

2018-01-01

Full Text Available Bioleaching of chromium, copper, manganese and zinc from coal ash were investigated using isolates from coal ash ponds particularly Psuedomonas spp. Six (6 different coal ash ponds were examined however, after initial screening Psuedomonas spp. were only present in three (3 coal ash ponds. Among the three coal ash ponds, results showed that eight (8 putative Pseudomonas spp. isolates were present that were identified using the Polymerase Chain Reaction (PCR. Using the eight putative Pseudomonas spp. for bioleaching at optimum conditions and 15 days, the pH value ranges from 8.26 to 8.84 which was basic in nature. Moreover, the maximum metal leached were 8.04% Cr, 12.05% Cu, 4.34% Mn and 10.63% Zn.

Determination of Total Solids and Ash in Algal Biomass: Laboratory Analytical Procedure (LAP)

Energy Technology Data Exchange (ETDEWEB)

Van Wychen, Stefanie; Laurens, Lieve M. L.

2016-01-13

This procedure describes the methods used to determine the amount of moisture or total solids present in a freeze-dried algal biomass sample, as well as the ash content. A traditional convection oven drying procedure is covered for total solids content, and a dry oxidation method at 575 deg. C is covered for ash content.

Fly ash dynamics in soil-water systems

International Nuclear Information System (INIS)

Sharma, S.; Fulekar, M.H.; Jayalakshmi, C.P.

1989-01-01

Studies regarding the effluents and coal ashes (or fly ash) resulting from coal burning are numerous, but their disposal and interactions with the soil and water systems and their detailed environmental impact assessment with concrete status reports on a global scale are scanty. Fly ash dynamics in soil and water systems are reviewed. After detailing the physical composition of fly ash, physicochemical changes in soil properties due to fly ash amendment are summarized. Areas covered include texture and bulk density, moisture retention, change in chemical equilibria, and effects of fly ash on soil microorganisms. Plant growth in amended soils is discussed, as well as plant uptake and accumulation of trace elements. In order to analyze the effect of fly ash on the physicochemical properties of water, several factors must be considered, including surface morphology of fly ash, pH of the ash sluice water, pH adjustments, leachability and solubility, and suspended ash and settling. The dynamics of fly ash in water systems is important due to pollution of groundwater resources from toxic components such as trace metals. Other factors summarized are bioaccumulation and biomagnification, human health effects of contaminants, and the impact of radionuclides in fly ash. Future research needs should focus on reduction of the environmental impact of fly ash and increasing utilization of fly ash as a soil amendment. 110 refs., 2 figs., 10 tabs

Ash cloud aviation advisories

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

1992-06-25

During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

Local Geomorphology as a Determinant of Macrofaunal Production in a Mountain Stream.

Science.gov (United States)

Huryn, Alexander D; Wallace, J Bruce

1987-12-01

By comparing distributions of functional group production among different habitats in an Appalachian mountain stream, the influence of site-specific geomorphology upon the overall functional group composition of the animal community was demonstrated. By replicated monthly sampling, substrate particle size distributions, current velocity, standing crops of benthic organic matter, and production of macrofauna were measured in each of three principal habitats: bedrock-outcrop, riffle, and pool. Samples were taken at randomly assigned locations and the relative number of samples taken from each habitat was assumed to be proportional to the area of the habitat within the stream. These proportions were used to weight production measured in each habitat and the resulting values were summed to obtain production per unit area of average stream bed. The bedrock-outcrop habitat was characterized by high material entertainment and export as indicated by significantly higher current velocities and lower standing crops of detritus compared to the riffle and pool habitats. Pools were sites of low entertainment and high retention of organic matter as demonstrated by significantly lower current velocities and higher accumulations of detritus than other habitats. The riffle habitat was intermediate to the bedrock-outcrop and pool habitats in all parameters measured. Annual production of collector-filterers was highest in the bedrock-outcrop (ash-free dry mass 1920 mg/m 2 ), followed by riffle (278 mg/m 2 ) and pool (32 mg/m 2 ). Although constituting only 19% of the stream area, the bedrock-outcrop habitat contributed 68% of the habitat-weighted collector-filterer production. Annual production of shredders was highest in pools (2616 mg/m 2 ), followed by riffles (1657 mg/m 2 ) and bedrock-outcrop (579 mg/m 2 ). The pool habitat, constituting 23% of stream area, contributed 36% of shredder production. Annual production of scrapers was highest in the riffle habitat (905 mg/m 2

Identifying glass compositions in fly ash

Directory of Open Access Journals (Sweden)

Katherine eAughenbaugh

2016-01-01

Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration after Invasion

Science.gov (United States)

Emerald ash borer (EAB) is an invasive Asian beetle that is destroying ash in forests over much of eastern North America because of the high susceptibility of our native ash and a lack of effective natural enemies. To increase mortality of EAB larvae and eggs, the USDA (FS, ARS and APHIS) is carryin...

The distribution of copper in stream sediments in an anomalous stream near Steinkopf, Namaqualand

International Nuclear Information System (INIS)

De Bruin, D.

1987-01-01

Anomalous copper concentrations detected by the regional stream-sediment programme of the Geological Survey was investigated in a stream near Steinkopf, Namaqualand. A follow-up disclosed the presence of malachite mineralization. However, additional stream-sediment samples collected from the 'anomalous' stream revealed an erratic distribution of copper and also that the malachite mineralization had no direct effect on the copper distribution in the stream sediments. Low partial-extraction yields, together with X-ray diffraction analyses, indicated that dispersion is mainly mechanical and that the copper occurs as cations in the lattice of the biotite fraction of the stream sediments. (author). 8 refs., 5 figs., 1 tab

The distribution of copper in stream sediments in an anomalous stream near Steinkopf, Namaqualand

Energy Technology Data Exchange (ETDEWEB)

De Bruin, D

1987-01-01

Anomalous copper concentrations detected by the regional stream-sediment programme of the Geological Survey was investigated in a stream near Steinkopf, Namaqualand. A follow-up disclosed the presence of malachite mineralization. However, additional stream-sediment samples collected from the 'anomalous' stream revealed an erratic distribution of copper and also that the malachite mineralization had no direct effect on the copper distribution in the stream sediments. Low partial-extraction yields, together with X-ray diffraction analyses, indicated that dispersion is mainly mechanical and that the copper occurs as cations in the lattice of the biotite fraction of the stream sediments. (author). 8 refs., 5 figs., 1 tab.