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Coal ash ponds pose a significant threat to the environment and human health. Coal ash is a byproduct of the electricity production process, and it contains carcinogens like boron, arsenic, lithium, and mercury. Typically, utility companies store coal ash in ponds located near rivers and lakes. If coal ash is stored in ponds that lack an adequate liner, the coal ash can seep into the groundwater and travel to nearby surface waters, which may serve as a drinking water source for neighboring communities. The EPA has admitted that the majority of America's coal ash ponds are unlined and prone to leaks. Moreover, there have been several instances where coal ash ponds have failed and discharged millions of gallons of coal ash into surrounding surface waters. In an effort to protect citizens' health and the environment, plaintiffs have utilized the Clean Water Act to hold utilities liable when they discharge coal ash pollutants to surface waters via hydrologically connected groundwater. Nevertheless, the Fourth Circuit in Sierra Club v. Virginia Electric and Power Co. determined that coal ash ponds were not point sources under the CWA, and this decision will likely prevent future plaintiffs from bringing claims against utilities under the Act. The holding in Sierra Club will also limit future plaintiffs' ability to hold polluters liable for unpermitted discharges from other types of "containers," which will increase the possibility of an environmental disaster. As a result, the Supreme Court must step in and reverse the Fourth Circuit's decision. More specifically, the Supreme Court must hold that coal ash ponds are point sources under the CWA. To reach this decision, the Supreme Court must first look to the purpose of the CWA, which was designed "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters." Then, the Supreme Court must look to the language of the Act, specifically the CWA's definition of the term "point source." Lastly, the Supreme Court must look to other cases involving "containers" as they indicate that "natural processes" may be part of a point source discharge if the polluter "initially collected" the pollutants. [ABSTRACT FROM AUTHOR]

The residue concentrations and congener profiles of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) were examined in fly ash and bottom ash released from different thermal industrial processes in Vietnam. PCDD/F concentrations and toxic equivalents (TEQs) in the ash samples varied greatly and decreased in the following order: steel making > aluminum recycling > medical waste incinerator > boilers > municipal waste incinerator > tin production > brick production > coal-fired power plant. Both the precursor and de novo synthesis were estimated as possible formation mechanisms of dioxins in the ash, but the latter pathway was more prevalent. The highest emission factors were estimated for the ash released from some steel-making plants, aluminum-recycling facilities, and a medical waste incinerator. The emission factors of PCDD/Fs in ash released from some steel plants of this study were two to six times higher than the UNEP Toolkit default value. The annual emission amount of ash-bound dioxins produced by 15 facilities in our study was estimated to be 26.2 to 28.4 g TEQ year−1, which mainly contributed by 3 steel plants. Health risk related to the dioxin-containing ash was evaluated for workers at the studied facilities, indicating acceptable risk levels for almost all individuals. More comprehensive studies on the occurrence and impacts of dioxins in waste streams from incineration and industrial processes and receiving environments should be conducted, in order to promote effective waste management and health protection scheme for dioxins and related compounds in this rapidly industrializing country. [ABSTRACT FROM AUTHOR]

Biogas residues and coal fly ash composite (CFA/BRC) were first investigated as novel heterogeneous catalysts for strengthening electro-Fenton (EF) of real British gas/Lurgi coal gasification wastewater. The prepared CFA/BRC was characterized by different techniques, i.e., SEM, XRD, BET surface area, XRF, and ICP-AES. The results indicated that CFA/BRC significantly improved performance of pollutant removal in EF across a wide pH range with current density of 10 mA/cm2 and catalyst dosage of 1.0 g/L, and the treated wastewater was more biodegradable than homogeneous EF. Meanwhile, CFA/BRC showed superior stability at successive 2,400-min runs, and leached concentrations of heavy metals were very low without the second pollutant. The change of concentrations of dissolved oxygen and electro-generated H2O2, and fluorescence test indicated that the novel catalyst could enhance H2O2 decomposition into more hydroxyl radicals, which was considered to be mainly responsible for the pollutant removal. And the results offered new insights into sustainable use of waste materials. [ABSTRACT FROM AUTHOR]

The article offers news briefs related to groundwater monitoring and remediation as of July 1, 2018. Topics discussed include the urgency of U.S. Senators to the U.S. Environmental Protection Agency (EPA) to set a legally binding limit for per and polyfluoroalkyl substances (PFAS) in drinking water, public hearing of the Senate Committee on Environment and Public Works regarding groundwater and the regulation proposed by EPA regarding coal ash disposal.

Selenium pollution from the E.W. Brown Electric Generating Station was investigated in Herrington Lake, KY. Coal ash wastewater is discharged as surface water overflow from ash disposal ponds into the lake via a National Pollutant Discharge Elimination System permit issued by the Kentucky Division of Water, but the permit does not restrict or limit the amount of selenium released. Unpermitted discharges occur from seeps and drainage through leaks in ash pond dams. Together, these discharges have resulted in selenium concentrations in water, sediment, benthic macroinvertebrates, and fish that are 2–9 times the level that is toxic for fish reproduction and survival. A large proportion (12.2%, or 25 times background) of juvenile largemouth bass ( Micropterus salmoides , the only species examined) exhibited spinal and/or craniofacial malformations that are consistent with selenium poisoning. Teratogenic Deformity Index values indicated a 3.05% population-level impact on the bass fishery, with total selenium-induced mortality (including pre-swimup mortality) estimated to be in excess of 25% per year. These findings confirm that coal ash discharges into Herrington Lake are contributing selenium to the Lake that is poisoning fish. [ABSTRACT FROM AUTHOR]

A proposed coal-fired power plant at Rampal, Bangladesh will produce over 38 million tons of ash during 60 years of operation at 90% electric load generation capacity. The ash disposal pond would be full in twelve years even if half of all fly ash is used in concrete and brick production, leaving at least 20 million tons of ash with a disposal plan that is limited to surface impoundment and unlined fills, which are known to cause groundwater and surface water pollution. At Rampal, probable storm tides of 7.4 meters would breach the ash pond walls during the operational life of the coal plant, potentially resulting in catastrophic failure and massive spills of ash. Seasonal monsoon flooding would cause the ash pond itself to overflow, releasing huge volumes of contaminated water. Ash disposal for the proposed coal-fired power plant at Rampal, Bangladesh, would release toxic heavy metals into the waterways of the Sundarbans Delta and Bay of Bengal, which is a World Heritage Site and includes globally important mangroves, endangered aquatic species, and a fishery that feeds hundreds of thousands of poor people. The economic damage cost of the Rampal Plant could exceed $US 100 million dollars per year. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA) -an industrial solid waste- has tremendous potential to be used as a starting material for development of valuable porous catalysts and adsorbents because of its silicon and aluminum content. Among various products fabricated from CFA by chemical synthesis process, CFA-based porous catalysts have recently gained remarkable interest among researchers. Each CFA–based catalyst has different properties, the most important of which is the ion exchange capability that depends on the chemical composition and structure of the synthesized product. Studies proved that CFA-based compounds can be used as catalysts/photocatalysts in different environmental processes such as degradation of pollutants. Chemical conversion reactions and synthesis of fine chemicals are among other applications, in which CFA is used as substrate for developing different catalysts. In this review paper, CFA-based catalysts have been classified based on their properties and applications. Methods of characterizations including kinetics and isotherm models are discussed. Furthermore, the effect of several parameters including reaction time, reaction temperature, and the ratio of active compounds to CFA substrate on chemical reactions catalyzed by CFA-based catalysts are discussed. This review paper reveals that CFA-based catalysts are highly efficient compounds not only for application in environmental pollution remediation processes, but also in achieving comparable results in chemical conversion reactions for synthesizing fine chemicals. It can be concluded that CFA as a solid waste should be considered as a low-cost source of alumino-silicate that is a promising candidate for developing inexpensive methods of manufacturing highly efficient and eco-friendly porous catalysts for a wide array of applications. [ABSTRACT FROM AUTHOR]

This paper addresses the detailed characterization of coal fly ashes with respect to their utilization in alkali-activated cement systems, thus maximizing the use of fly ashes in the construction industry. A technique was developed to estimate the reactivity of low calcium fly ashes in alkali-activated systems. The technique is based on a K-value which combines three characteristics of a fly ash. Two characteristics – amorphous phase percentage and specific surface area determined through Blaine measurement – are observed quantities. The third characteristic – degree of polymerization of silica in the amorphous phase of fly ash – is a calculated parameter. To take into account the water demand of fly ashes, which will influence the amount of water needed to get a workable mix, the shape factor was used to adjust the Blaine specific surface area. The relationship between the proposed K-value and compressive strength of alkali-activated fly ash pastes is approximated by a linear function. The correlation coefficient of the relationship varied from 0.961 to 0.833 for 1 and 91 days compressive strength respectively. The proposed K-value can firstly be used to rank fly ashes for their suitability to produce high strength alkali-activated materials and secondly when calibrated for a specific activator and curing conditions, to predict the compressive strength of alkali-activated fly ash binders. [ABSTRACT FROM AUTHOR]

Increased concentrations of heavy metals in ash can adversely affect themicrobiological and pedogenetic processes in soil. The aim of this paper is to determine the impact of ash from unburned coal generated in the Kostolac and Gacko coal basins on the quality of soil in the surrounding environment. The investigation included the surface soil layer that was sampled and tested during 2016 and 2017. A total of 30 samples of Kostolac soil and 9 samples of Gacko soil were analyzed for the content of 8 heavy metals: Cu, Pb, Cd, Zn, Hg, As, Cr and Ni. The analyses were carried out by inductively coupled plasma mass spectrometry (ICPMS) technique according to the EPA 6020A method and the following conclusions were made: Kostolac coal ash affects the quality of the surrounding soil in terms of Ni, Cu and Cr as evidenced by the moderately strong correlation of the Ni-Cu pair (k = 0.71), as well as the Cu-Cr pair (k = 0.73) and strong correlation of the Ni-Cr pair (k = 0.82), while the high recorded concentration of Pb, Hg, As and Zn is attributed to other sources of pollution, such as the traffic network and intensive farming activities, and in some cases, its impact is only local. All recorded concentrations of heavy metals are within the remediation values. The effect of ash on soil contamination in the surroundings of the Gacko coal basin is limited to Ni and Cd, with a strong correlation coefficient of this pair (k = 0.82). The recorded overrun of maximum allowed concentration of Cr is evidenced in only 2 samples, and in terms of this element the contamination of the Gacko soil can be considered to be local. It is concluded that prevailing winds play a part in soil pollution. Cluster analysis showed that Ni, Cr and Zn have very similar values in analyzed soil samples from both basins, while a cluster composed of only Hg, in the case of Gacko, indicates lower contamination with Hg compared to the other heavy metals. [ABSTRACT FROM AUTHOR]

A study of near surface sediments from the Dan River (southeastern USA) was conducted to assess the use of magnetic properties as proxies of coal ash after a recent spill. The watershed geology is diverse and potentially contributes magnetic minerals to riverbed sediment from diabase dikes in the Dan River Triassic Basin and from granitic gneiss outside the basin. Coal ash is heterogeneous, including aluminosilicate spheres, amorphous particles and carbonaceous rods and lacy particles. The magnetic fraction of ash from the failed storage pond is up to 17 wt% and is mostly composed of black spheres with maghemite and magnetite. Ash was detected in riverbed sediment from quiet water settings such as inside of meander bends, the confluence of tributary streams and near islands between the spill site and 20 miles downstream in the Schoolfield Reservoir, Danville, VA. The strong magnetic signal is detected above background in riverbed samples and is strongly positively correlated with total ash; elevated low field magnetic susceptibility ( χ ) is evident in samples with ≥ 12% ash content. Anhysteretic remanent magnetization and hysteresis parameters delineate native sediment, ash-bearing sediment, and diabase dikes. Between 20 and 70 miles downstream of the spill site, ash concentrations were either buried or too low due to dilution with native sediment to be detected with χ in riverbed samples. [ABSTRACT FROM AUTHOR]

The storage of coal combustion residue (CCR) in surface water impoundments may have an impact on nearby water quality and aquatic ecosystems. CCR contains leachable trace elements that can enter nearby waters through spills and monitored discharge. It is important, therefore, to understand their environmental fate in affected systems. This experiment examined trace element leachability into freshwater from fly ash (FA), the most common form of CCR. The effects on water quality of FA derived from both high and low sulfur coal sources as well as the influences of two different emergent macrophytes, Juncus effusus and Eleocharis quadrangulata, were evaluated in wetland microcosms. FA leachate dosings increased water electric conductivity (EC), altered pH, and, most notably, elevated the concentrations of boron (B), molybdenum (Mo), and manganese (Mn). The presence of either macrophyte species helped reduce elevated EC, and B, Mo, and Mn concentrations over time, relative to microcosms containing no plants. B and Mo appeared to bioaccumulate in the plant tissue from the water when elevated by FA dosing, while Mn was not higher in plants dosed with FA leachates. The results of this study indicate that emergent macrophytes could help ameliorate downstream water contamination from CCR storage facilities and could potentially be utilized in wetland filtration systems to treat CCR wastewater before discharge. Additionally, measuring elevated B and Mo in aquatic plants may have potential as a monitoring tool for downstream CCR contamination. [ABSTRACT FROM AUTHOR]

Larval gray tree frogs ( Hyla chrysoscelis) were exposed to inorganic Se (SeO) added to the diet (10.2 and 86.3 ug/g dw) and monitored for accumulation and effect. Background concentrations of Hg were also measured in food and carcasses to assess possible effects of Se on Hg accumulation. Selenium was accumulated in a dose dependent manner, and life stages did not differ. No effects of Se exposure were observed on survival, growth, or time to metamorphosis. Mercury concentrations in carcasses, resulting from background concentrations in food, were significantly affected by the presence of Se. In the high Se treatment, Hg concentrations were significantly decreased relative to those in the low Se treatment and the control. Our study suggests that exposure to inorganic Se as SeO at the concentrations tested do not elicit adverse biological effects, but exposure to relatively high concentrations of Se may reduce accumulation of Hg from food. [ABSTRACT FROM AUTHOR]

The article presents the results of a hydrogeological survey aimed to substantiate the engineering recultivation of accumulation ponds of lignin mud by inwashing it with coal ash. The ash bed causes compression consolidation of lignin bed, leading to an increase in the pond seal margin. The mass exchange between the ash and the lignin mud is accompanied by changes in the hydrogeochemical conditions: the mineralization of the liquid phase of technogenic soils increases by a factor of up to 8, and the concentration of microcomplex increases to very high values. The analysis of the qualitative state of groundwater showed it to be tolerant to the effect of accumulation ponds. The moderate deviation from the local natural background is due to other pollution sources. The applied recultivation technology is effective and environmentally safe, though it needs modernization. The alternative technology, proposed by OOO VEB-Inzhiniiring, i.e., grouting the pond content, is extremely hazardous, and the implementation of the project involves considerable environmental risk because of the possible loss of pond containment. [ABSTRACT FROM AUTHOR]

Nakashita, S.; Nakamoto, K.; Koshikawa, Y.; Kim, K.-H., and Hibino, T., 2017. Evaluation of granulated coal ash as artificial seabed for eelgrass. In: Lee, J.L.; Griffiths, T.; Lotan, A.; Suh, K.-S., and Lee, J. (eds.), The 2nd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 79, pp. 40-44. Coconut Creek (Florida), ISSN 0749-0208. Granulated coal ash (GCA) is a by-product of coal-fired thermoelectric power stations. In this study, GCA was used to create a functional artificial seabed for eelgrass. Moreover, the capability of GCA for the growth of eelgrass in an indoor experiment was examined to elucidate the ability of eelgrass to establish itself and grow in a GCA artificial seabed created in an actual marine environment. The eelgrass in the GCA artificial seabed branched and adapted similar to that on sandy ground. A stable eelgrass community was established in one year in an actual marine environment. Furthermore, five years after transplantation, the eelgrass community was maintained. For the GCA artificial seabed, the oxidation-reduction potential of the bottom sediments was approximately 100 mV higher than that of the surrounding ground, and the amount of sulfide decreased to approximately one third of that of the surrounding ground. Even five years after construction, a stable environment was preserved. Therefore, it is concluded that GCA is an effective material for an eelgrass seabed. [ABSTRACT FROM AUTHOR]

ABSTRACT The present crippling crude oil price worldwide demands a new strategy and cost-effective technology that will promote additional oil recovery in mature oilfields. Herein, crosslinked polyacrylamide (PAM) gels reinforced with coal fly ash (CFA) were investigated for water reduction purpose during enhanced oil recovery. Polyethyleneimine (PEI) is chosen as the crosslinker. Neat PAM/PEI gel and PAM/PEI composite gels filled with various CFA concentrations (0.5 to 2 wt%) were developed and characterized by aging, gravimetric, hybrid rheometer, thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) instruments. Gelation performance of these gels was conducted at 90 °C, and results show that increase in CFA in PAM/PEI gels causes a delay in the gelation time. This indicates that CFA can act as a retarder in polymer gels applied for water control in mature oilfields. Moreover, the PAM/PEI composite gels containing CFA displayed improved viscoelastic properties as compared to the neat PAM/PEI gel at various gelation behaviors that were tested. Additionally, TGA analysis revealed that PAM/PEI gels infused with different CFA amounts possessed high resistance to thermal decomposition. The presence of alumina and silica in high concentrations in CFA induced a strong bond within these polymer gels, which resulted in improved thermal stability. Further, owing to the fact that CFA only absorbed a small amount of water through the hydroxyl and amine groups, its presence decreased the swelling ability of these composite gels. Morphological and structural analysis demonstrated by these gels affirmed the consistency of viscoelastic, thermal and swelling kinetic results. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Fine particles are agglomerated by calcium-based solution in wet flue gas desulphurisation (WFGD) system. Surfactant, polymeric flocculant and vapour condensation are usual ways to strengthen the wet agglomeration. There are different theories without adhesion force to explain these ways. The adhesion force is not the quantitative research emphasis in wet agglomeration, especially in WFGD. But the adhesion force is the key factor in wet agglomeration. We used saturated solutions of CaSO4, CaSO3 and CaCO3, respectively, as bridging liquids. A nano-sized atomic force microscope tip and a micro-sized coal ash particle were as experimental substances. The study results show that the adhesion forces of saturated solutions with surfactants are lower than the pure saturated solutions. The adhesion forces of saturated solutions with surfactants and polymeric flocculants are not necessarily higher than the pure or surfactants added solutions. The theoretical results are in accordance with the experiment datum. [ABSTRACT FROM AUTHOR]

Dry magnetic separation of different sizes of Yiluo fine coal was carried out to purify deleterious elements. It was found that dry magnetic separation can effectively reduce a variety of harmful trace elements in raw coal. Regardless of coal particle size, the rejection efficiency of Cd, Hg, As, and Mn is 39.07%–57.16%, 33.89%–49.94%, 30.49%–47.52%, and 27.10%–52.28%, respectively. Relatively high removal efficiency of Pb, Cu, and Se is obtained, which is 26.23%–35.32%, 27.25%–39.41%, and 25.05%–32.84%, respectively. Moreover, the results show that sulfur rejection of 33.87% and reductions in ash of 41.19% are obtained with particle size of 80–120 mesh, while the combustible recovery reaches 83.68%. [ABSTRACT FROM PUBLISHER]

The stability of the ashes taken from the three heat-power plants showed that each day of storage in wet landfill causes transformation in their physical and chemical composition. At low temperatures, the spherical grains become brittle and consequently undergo cracking. The studies with a laser diffractometer have shown changes in particle size distribution during the experiment. The pozzolanic activity of the studied ashes significantly decreased under the weathering impact. [ABSTRACT FROM PUBLISHER]

With increased environmental awareness, utilization of bottom ash has become an attractive alternative to disposal. The objective of the present work was to study the environmental impact of bottom ash and to explore the possibility of its potential utilization. Comprehensive characterization of four bottom ash samples collected from different thermal power plants was investigated. Particle size distribution, bulk density, settling characteristics, specific gravity, porosity, permeability, and water-holding capacity etc. were determined for all bottom ash samples. A series of leaching tests was also performed to determine the tracing metal characterization of bottom ash. It is observed that Mn, Mg, Cr, Zn, Ni, and Cu were the most abundant elements while Pb, Mo, Fe, and Co were the least abundant elements. According to the mineral characterization, it is observed that silica (SiO2) and alumina (Al2O3) are primarily present in all samples. Quartz, mullite, and hematite were identified as the mineral phases. The properties of bottom ash give useful information about the utilization of its end use. [ABSTRACT FROM PUBLISHER]

The investigations integrate thermo and hydrometallurgical methods for fly ash treatment collected from thermal power Plants (TPP) in Bulgaria. The first stage of the autoclave treatment of the proposed process using sulfuric acid with concentration 20 and 30 mass % at thermal treatment temperature of 100, 120 and 140°C and time of 60, 90, 120, 240, 360 and 480 min, was studied. In the second stage, the obtained samples were dissolved with water at constant temperature and time. Based on the results from chemical analyses the extent of extraction of 12 elements was determined. The data obtained show that the method used can be considered successful for extraction efficiency of 88.8 % for Al, 88.5 % for Fe, over 80 % for Ca, Cu and Mn, over 70 % for Mg, Cr, Mo and nearly 100 % for other elements - Na, Zn and Ni. The extraction behaviour depends on all studied parameters. [ABSTRACT FROM AUTHOR]

As is the case in many other countries around the world, India's main source of electricity is coal‐fired power plants. In addition to providing energy, the burning of coal also results in large amounts of coal combustion products (CCP), the incombustible material, such as fly ash, left after the coal is burned. These materials are produced in large volume, and if they are not managed or utilized properly, they can pose a danger to the environment. This article discusses the uses of CCP, with a special emphasis on fly ash, and the role that it is currently playing and can continue to play as a mine filler for India's depleted opencast and underground coal mines. [ABSTRACT FROM AUTHOR]

ABSTRACT Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35 000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future. Integr Environ Assess Manag 2016;12:353-363. © 2015 SETAC [ABSTRACT FROM AUTHOR]

The article focuses on the enforceability of the Disposal of Coal Combustion Residuals from Electric Utilities (DCCREU), coal ash regulation by the U.S. Environmental Protection Agency (EPA), and its refusal to classify coal ash as hazardous waste impacts environmental and public health concerns.

Humans are exposed to different stress factors that are responsible for over-production of reactive oxygen species. Exposure to heavy metals is one of these factors. The aim of the study was to analyze the effect of chronic exposure to heavy metals through coal flying ash on the efficiency of antioxidative defensive mechanisms, represented by the activity of superoxide dismutase, glutathione peroxidase and ascorbic acid. Nonessential elements such as arsenic and mercury levels showed a significant increase ( p > 0.001) in the power plant workers rather than in the control subjects. There were no significant differences of blood cadmium between power plant workers and control subjects. We found a significant positive correlation ( p < 0.05) between BAs/SZn ( r = 0.211), BAs/BSe ( r = 0.287), BCd/SCu ( r = 0.32) and BHg/BSe ( r = 0.263) in the plant workers. Red blood cell antioxidant enzymes and plasma ascorbic acid were significantly lower in power plants workers than in the control group ( p < 0.002). We can conclude that levels of mercury, arsenic and cadmium in blood, despite their concentration within the reference values, significantly affect plasma ascorbic acid concentration, superoxide dismutase and glutathione peroxidase activity, which are able to increase the risk of oxidative stress. [ABSTRACT FROM AUTHOR]

Coal power plants are producing huge amounts of coal ash that may be applied to a variety of secondary uses. Class F fly ash may act as an excellent scrubber and fixation reagent for highly acidic wastes, which might also contain several toxic trace elements. This paper evaluates the potential of using Class F fly ashes (<20% CaO), in combination with excessive fines from the limestone quarry industry as a fixation reagent. The analysis included leaching experiments (EN12457-2) and several analytical techniques (ICP, SEM, XRD, etc.), which were used in order to investigate the fixation procedure. The fine sludge is used as a partial substitute in concrete that can be used in civil engineering projects, as it an environmentally safe product. [ABSTRACT FROM AUTHOR]

This study investigates the potential of incorporating inorganic amendments such as coal and bagasse ashes in different composting mixes. 10 different composting mixes were assessed as follows: A-20% bagasse ash (BA) with unsorted municipal solid wastes (UMSW); B-40% BA with UMSW; C-UMSW; D-20% BA with sorted municipal solid wastes (SMSW); E-40% BA with SMSW; F-SMSW; G-20% coal ash (CA) with UMSW; H-40% CA with UMSW; I-20% CA with SMSW and J-40% CA with SMSW. The composting processes were carried out in rotary drum composters. Composting mixes D, F, G and I achieved a temperature above 55 °C for at least 3 days, with the following peak temperatures: D-62 °C, F-57 °C, G-62 °C and I-58 °C. D resulted in the highest average net Volatile solids (VS) degradation of 68.6% and yielded the highest average volume reduction of 66.0%. The final compost from D, G, I, C and F were within range for electrical conductivities (EC) (794–1770 μS/cm) and pH (6.69–7.12). The ashes also helped in maintaining high average water holding capacities within the range of 183–217%. The C/N ratio of sorted wastes was improved by the addition of 20% coal ash and bagasse ash. Higher germination indices, above 0.8 were obtained for the ash-amended compost (D, G, I), indicating the feasibility and enhancement of using bagasse and coal ash as inorganic amendment in the composting process. Regarding heavy metals content, the chromium concentration for the composting mix G was found to be the highest whereas mixes D and I showed compliance with the MS (Mauritian Standards) 164 standards. [ABSTRACT FROM AUTHOR]

A coal ash spill that occurred from an ash impoundment pond into the Dan River, North Carolina, provided a unique opportunity to study the significance and role of naturally occurring and incidental nanomaterials associated with contaminant distribution from a large-scale, acute aquatic contamination event. Besides traditional measurements of bulk watercolumn and sediment metal concentrations, the nanoparticle (NP) analyses are based on cross-flow ultrafiltration (CFUF) and advanced transmission electron microscopy (TEM) techniques. A drain pipe fed by coal ash impoundment seepage showed a high level of arsenic, with concentrations many times over the EPA limit. The majority of the arsenic was found sorbed to large aggregates dominated by incidental iron oxyhydroxide (ferrihydrite) NPs, while the remainder of the arsenic was truly dissolved. These ferrihydrites were probably formed in situ where Fe(II) was leached through subsurface flowpaths into an aerobic environment, and further act as a significant contributor to the elevated As concentrations in downstream sediments after the spill. In addition, we discovered and describe a photocatalytic nano-TiO2 phase (anatase) present in the coal ash impacted river water that was also carrying/transporting transition metals (Cu, Fe), which may also have environmental consequences. [ABSTRACT FROM AUTHOR]

Nikola Tesla B power plant (TENT-B), located on the Sava River in Obrenovac, 52 km west from the Serbian's capital, Belgrade, is the second largest coal-fired power plant in the country, consisting of two blocks of 620 MW each. Samples of fresh coal ash obtained by coal combustion in TENT-B, as well as coal ash samples from the surface and 1-m depth of active, currently filled, and passive, previously filled and not currently used, cassettes, were taken from the coal ash dump. Ultrasonic extracts of the samples were analyzed using gas chromatography with mass selective detection (GC/MSD) in order to identify and quantify 16 priority polycyclic aromatic hydrocarbons (PAHs). Two PAH extraction mechanisms during coal ash dumping and storage processes are discussed and significant differences between them were established. PAH concentrations in the ash samples were compared statistically. Correlations between samples and sampling points were established, and leaching potential of samples was examined. Concentrations of PAHs can be reduced in coal ash sediments by environmental influences only after long time periods, and PAHs with two six-membered rings pose danger to underground waters, while PAHs with three rings pose danger to soil sediments. [ABSTRACT FROM AUTHOR]

Fly ash, a coal combustion residue of thermal power plants and a source of multiple pollutants, has been recognized as an environmental hazard all over the world. Although it is known that fly ash effluent affects density, diversity and distribution of rotifers in drainage systems and receiving water bodies, the effect of fly ash effluent on the distributions of highly similar rotifer species remains unknown. In this study, the mtDNA COI genes of 90 individuals in Brachionus calyciflorus complex from Lake Hui (as a fly ash discharge water pond) and other two neighboring lakes (Lake Fengming and Lake Tingtang) were sequenced and analyzed, and the responses in selected life table demographic parameters (life expectancy at hatching, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring) of different rotifer populations to fly ash effluent were investigated. Overall, 72 mtDNA haplotypes were defined, and were split into two clades by the phylogenetic trees. The divergence of COI gene sequences between the two clades ranged from 11.8% to17.8%, indicating the occurrence of two sibling species (sibling species I and sibling species II). Sibling species I distributed in all the three lakes, showing strong capabilities for dispersal and colonization, which were supported by its higher level of gene flow (2.60–4.04) between the populations from Lake Hui and each of the other two lakes, longer life expectancy at hatching (101.6–148.2 h), and higher net reproductive rate (4.4–16.4 offspring/female) and intrinsic rate of population increase (0.60–0.98/d) when cultured in aerated tap water and fly ash effluent. Sibling species II distributed in both Lake Tingtang and Lake Fengming, showing that its dispersal existed between the two lakes. Considering that the distance between Lake Hui and Lake Fengming is shorter than that between Lake Tingtang and Lake Fengming, sibling species II is able to disperse at least from Lake Fengming to Lake Hui. The restricted distribution of sibling species II in Lake Hui might be attributed to its lower intrinsic rate of population increase (0.34–0.39/d) when cultured in aerated tap water and fiy ash effluent, which might be further lowered by the lower algal food level and quality in Lake Hui. [ABSTRACT FROM AUTHOR]

In order to evaluate the ability of granulated coal ash (GCA), a byproduct of coal thermal electric power stations, to remove hydrogen sulfide from organically enriched sediments, a pilot study was carried out at oyster farming sites, where sediments were enriched with oyster feces and dead oysters. Concentration of hydrogen sulfide in the interstitial water of the sediment decreased to nearly zero in both experimental sites, whereas it remained over 0.2 mg/l in the control site. Concentration of acid volatile sulfide (AVS) in the sediment also decreased significantly in both experimental sites, while remained over 0.4 mg/g in the control site. Increases were observed in both the number of benthic microalgae species and the individual number of benthic animals in the surface sediments. This may have been due to the decrease in hydrogen sulfide. [ABSTRACT FROM AUTHOR]

ABSTRACT Coal-fly ash was released in unprecedented amounts (4.1 × 106 m3) into the Emory River from the Tennessee Valley Authority Kingston Fossil Plant on Watts Bar Reservoir in Tennessee. Tree swallows were exposed to ash-related constituents at the ash release via their diet of emergent aquatic insects, whose larval forms can accumulate constituents from submerged river sediments. Reproduction of tree swallow colonies was assessed over a 2-year period by evaluating whether 1) ash constituent concentrations were elevated in egg, eggshell, and nestling tissues at colonies near ash-impacted river reaches compared to reference colonies, 2) production of fledglings per nesting female was significantly lower in ash-impacted colonies versus reference colonies, and 3) ash constituent concentrations or diet concentrations were correlated with nest productivity measures (clutch size, hatching success, and nestling survival, and fledglings produced per nest). Of the 26 ash constituents evaluated, 4 (Se, Sr, Cu, and Hg) were significantly elevated in tissues potentially from the ash, and 3 (Se, Sr, and Cu) in tissues or in swallow diet items were weakly correlated to at least one nest-productivity measure or egg weight. Tree swallow hatching success was significantly reduced by 12%, but fledgling production per nest was unaffected due to larger clutch sizes in the impacted than reference colonies. Bioconcentration from the ash to insects in the diet to tree swallow eggs appears to be low. Overall, adverse impacts of the ash on tree swallow reproduction were not observed, but monitoring is continuing to further ensure Se from the residual ash does not adversely affect tree swallow reproduction over time. Integr Environ Assess Manag 2015;11:56-66. © 2014 SETAC [ABSTRACT FROM AUTHOR]

ABSTRACT A baseline ecological risk assessment (BERA) was performed for residual ash in the Watts Bar Reservoir following a release of fly ash from the Tennessee Valley Authority (TVA) Kingston Fossil Plant. The site consists of parts of 3 rivers in eastern Tennessee comprising over 32 river kilometers. The purpose of the assessment was to determine if residual ash negatively impacts maintenance and reproduction of balanced communities or populations of potentially exposed ecological receptor groups in these rivers. This introductory article summarizes the site and environmental setting, assessment and measurement endpoints, risk characterization methods, and the study approach. Subsequent articles describe ecological risks to fish, benthic invertebrates, aquatic- and riparian-feeding wildlife, and aerial-feeding insectivores; and the role ecological risk characterization played in determining the most effective management of the residual ash, setting project remediation objectives and targets, and designing long-term monitoring to measure the effectiveness of the selected removal action. Integr Environ Assess Manag 2015;11:32-42. © 2014 SETAC [ABSTRACT FROM AUTHOR]

ABSTRACT Extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This article describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs and larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. This study demonstrates that a thorough and detailed investigation using multiple measurement endpoints is needed to properly evaluate ecological effects. Integr Environ Assess Manag 2015;11:88-101. © 2014 SETAC [ABSTRACT FROM AUTHOR]

ABSTRACT Current scientific advances in metal and metalloid risk assessment were applied to evaluate risk to aquatic and riparian wildlife species potentially impacted by residual coal fly ash after cleanup of an unprecedented large ash release into an aquatic environment-the first assessment of its kind. Risk was evaluated using multiple lines of evidence (LOE), including 1) tissue-based risk assessment of inorganic concentrations in piscivorous and insectivorous bird eggs and raccoon organs, 2) deterministic and probabilistic diet-based risk estimates for 10 receptors species, 3) raccoon health metrics, and 4) tree swallow nest productivity measures. Innovative approaches included use of tissue-based toxicity reference values (TRVs), adjustment of bioavailability in the dietary uptake models (using sequential metal extractions in sediment), partitioning chemical species into uptake compartments (e.g., prey gut, nongut, sediment), incorporating uncertainty in both modeled dose and dietary TRVs, matching TRVs to chemical forms of constituents, and pairing these LOEs with reproductive success or health status of sensitive receptor species. The weight of evidence revealed that risk to wildlife from residual ash was low and that risk, though low, was most pronounced for insectivorous birds from exposure to Se and As. This information contributes to the debate surrounding coal combustion residue regulations prompted by this ash release. Because of the responsible party's proactive approach of applying state-of-the-art methods to assess risk using several LOEs that produced consistent results, and because of their inclusion of the regulating agencies in decisions at every step of the process, the risk assessment results were accepted, and an effective approach toward cleanup protective of the environment was quickly implemented. This study highlights the value of using multiple LOEs and the latest scientific advances to assist in timely decision making to obtain an effective remedy for an emergency spill. Integr Environ Assess Manag 2015;11:67-79. © 2014 SETAC [ABSTRACT FROM AUTHOR]

ABSTRACT Benthic invertebrate communities were assessed after the December 2008 release of approximately 4.1 million m3 coal fly ash from a disposal dredge cell at the Tennessee Valley Authority (TVA) Kingston Fossil Plant on Watts Bar Reservoir in Roane County, Tennessee, USA. Released ash filled the adjacent embayments and the main channel of the Emory River, migrating into reaches of the Emory, Clinch, and Tennessee Rivers. Dredging was completed in summer 2010, and the benthic community sampling was conducted in December 2010. This study is part of a series that supported an Ecological Risk Assessment for the Kingston site. Benthic invertebrate communities were sampled at transects spread across approximately 20 miles of river that includes both riverine and reservoirlike conditions. Community composition was assessed on a grab sample and transect basis across multiple cross-channel transects to gain an understanding of the response of the benthic community to a fly ash release of this magnitude. This assessment used invertebrate community metrics, similarity analysis, geospatial statistics, and correlations with sediment chemistry and habitat. The community composition was reflective of a reservoir system, with dominant taxa being insect larva, bivalves, and aquatic worms. Most community metric results were similar for ash-impacted areas and upstream reference areas. Variation in the benthic community was correlated more with habitat than with sediment chemistry or residual ash. Other studies have reported that a benthic community can take several years to a decade to recover from ash or ash-related constituents. Although released ash undoubtedly had some initial impacts on the benthic community in this study, the severity of these effects appears to be limited to the initial smothering of the organisms followed by a rapid response and the initial start of recovery postdredging. Integr Environ Assess Manag 2015;11:43-55. © 2014 SETAC [ABSTRACT FROM AUTHOR]

ABSTRACT Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. This brief communication describes a broad range of toxicity studies conducted for the Tennessee Valley Authority (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash. Integr Environ Assess Manag 2015;11:5-9. © 2014 SETAC [ABSTRACT FROM AUTHOR]

The Permian-Triassic boundary extinction event was the largest biological crisis of the Phanerozoic. One of the principle triggers for the mass extinction is thought to be greenhouse warming resulting from the release of CH4 from basalt-coal interaction during the extensive Siberian Traps (Russia) eruptions. Observations of organic matter interpreted to be coal combustion products (fly ash) in latest Permian marine sediments have been used to support this hypothesis. However, this interpretation is dependent upon vesicular chars being fly ash (coal combustion derived) and not formed by alternative mechanisms. Here we present reflectance microscopy images of vesicular chars from Russian Permian coals, and chars from modern tundra, peatland, and boreal forest fires, to demonstrate that despite a difference in precursor fuels, wildfires are capable of generating vesicular chars that are morphologically comparable to end-Permian fly ash. These observations, coupled with extensive global evidence of wildfires during this time interval, call into question the contribution of coal combustion to the end-Permian extinction event. [ABSTRACT FROM AUTHOR]

Overload of coal ash (CA) generated from several coal fired plants poses acute problems of disposal and contamination of soil and water resources. Since CA generated from tea factories has not yet been characterized from environmental viewpoints, we attempted to critically characterize the agro-ecological compatibility of CA samples (CA1, CA2, CA3, and CA4) collected from four distantly located tea factories. Among these samples, we found CA3 and CA4 to have low pH and high metal content. Accordingly, we restricted our study to predict the solubility pattern of non-metal and metal ions in CAs by adopting a geochemical model (Visual MINTEQ). Various fractions of metals like Fe, Mn, Cu, Zn, Cr, Ni, and Pb were studied to figure out the mobility pattern of metals in the environment. The results clearly indicate that tea industry derived CA substantially differs from thermal power plant CA as regards several physico-chemical properties, for example, sandy texture, low pH and high nutrient content. Risk evaluation of human exposure to trace elements and the metal fractionation study led us to conclude that CA1 and CA2 are highly compatible with agricultural use. [ABSTRACT FROM AUTHOR]

In order to investigate the mechanism of adsorption of reactive dyes from the textile industry on ash from heating plant produced by brown coal combustion, some characteristic sorption constants are determined using Langergren adsorption equations for pseudo-fi rst and pseudo-second order. Combined kinetic models of pseudo-first order and pseudo-second order can provide a simple but satisfactory explanation of the adsorption process for a reactive dye. According to the characteristic diagrams and results of adsorption kinetic parameters of reactive dyes on ashes, for the applied amounts of the adsorbents and different initial dye concentrations, it can be concluded that the rate of sorption is fully functionally described by second order adsorption model. According to the results, the rate constant of pseudo-second order decreases with increasing initial dye concentration and increases with increasing amount of adsorbent - ash. [ABSTRACT FROM AUTHOR]

For Gorj County, heavy ash from thermal power plants (bottom ash) is an industrial waste that causes major effects of soil pollution by large landfill areas (over 570 hectares) covered by historical and present deposits. This is a consequence of bottom ash transport and disposal through hydro-mixture process from the installations for energy coal (lignite) combustion of steam generators of Turceni Power Plant (Valea Ceplea deposits) and Rovinari (deposits from Balta Uncheaşului and Cicani - Beterega). The main physical-chemical characteristics of ash of these deposits allow to be classified as light granular aggregates (bulk density, dryied 0.8 - 1.0 g/cm3), the potential for use being provided also by the relatively high chemical inertness, generated also by origin supplying technology (solid oxide residue, heated at over 1100°C). Based on these considerations, within the activities of LIFE 10 ENV/RO/729 research project, financed by European funds, have been studied the possibilities of manufacturing of some concrete in the composition of which bottom ash represents the granular aggregate, exclusively or combined with other lightweight aggregate, such as expanded perlite, concrete from which can be manufactured prefabricated components with high thermal and sound insulation properties. This article presents the results of the experiments carried out, to justify the opportunity of considering this type of industrial waste as alternative interest raw material for the production of building materials. [ABSTRACT FROM AUTHOR]

The results of environmental assessment of ash ponds of thermal power plants in Vladivostok and Khabarovsk are given. High radioactivity of coal in the Russian Far East is responsible for the accumulation of radionuclides in the fly and bottom ashes, which leads to pollution of atmosphere, lithosphere, biosphere, and hydrosphere with toxic and radioactive elements. Runoff carries these elements to the Ussuri Bay of the Sea of Japan. Harmful effect of these wastes on human health is noted, and possible ways of their utilization have been recommended. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a bioaccumulative constituent of coal fly-ash that can disrupt reproduction of oviparous wildlife. In food webs, the greatest enrichment of Se occurs at the lowest trophic levels, making it readily bioavailable to higher consumers. However, subsequent enrichment at higher trophic levels is less pronounced, leading to mixed tendencies for Se to biomagnify. We used stable isotopes (1 5N and 13C) in claws to infer relative trophic positions and relative carbon sources, respectively, of seven turtle species near the site of a recently-remediated coal fly-ash spill. We then tested whether Se concentrations differed with relative trophic position or relative carbon source. We did not observe a strong relationship between δ15N and Se concentration. Instead, selenium concentrations decreased with increasing δ13C among species. Therefore, in an assemblage of closely-related aquatic vertebrates, relative carbon source was a better predictor of Se bioaccumulation than was relative trophic position. [Copyright &y& Elsevier]

The co-combustion characteristics and the NO emission characteristics of pulverized coal/biomass blends at constant temperature were studied using a newly designed experimental system that can obtain the sample weight and the NO concentration at the same time. In particular, the effect of blending ratio, coal type, biomass type and temperature on the co-combustion characteristics and the NO emission characteristics were investigated. The results show that with the increase of blending biomass ratio, the burnout time moves forward and the NO emission ratio reduces. Blending biomass has an obvious effect on the combustion characteristics of nonflammable coal, but has little effect on the NO emission characteristics of coal with high ash content. At the initial stage of combustion process, the influence of biomass types on the combustion characteristics is not high. During the co-combustion process, the effect of blending biomass with high ash content on the combustion characteristics decreases gradually. The reduction of NO emission rate is significant when coal blends with high nitrogen content biomass. However, if the biomass has similar nitrogen content, the more ash content, the more the reduction of NO emission rate. The effect of temperature can be negligible at the initial stage of combustion process, but become obvious at the end of combustion process. In the temperature range of the experiments, with the increase of temperature, the NO emission rate increases gradually. [ABSTRACT FROM AUTHOR]

Environmental justice movements often contest environmental knowledge by engaging in scientific debates, which implies accepting the predominance of scientific discourses over alternative forms of knowledge. Using Bourdieu's concept of symbolic violence, this paper warns that the engagement with hegemonic forms of knowledge production may reproduce, rather than challenge, existing social and environmental inequalities. The argument is developed with reference to a case study of coal ash pollution in Tuzla, Bosnia and Herzegovina. The case study shows that the construction of knowledge in a scientific project led to the exclusion of local definitions of the situation and the dismissal of their observations of environmental pollution. The case suggests that the capacity of different actors to put forward their interpretation of an environmental issue depends on the forms of symbolic violence that emerge within hegemonic discourses of the environment. [ABSTRACT FROM AUTHOR]

The experimental results performed after the application of one single-stage treatment by sorption onto coal fly ash are evaluated in order to decolorize a real textile effluent of a private company specializing in manufacturing of cotton fabrics (i.e., sorption performance applied for a real textile effluent collected after the fabric dyeing, rinsing, and final finishing steps). The experiments are focused on studying the effect of initial textile effluent pH, adsorbent dose, temperature and adsorption time, considered as operating parameters of sorption process for high pollutant removals (e.g., organic pollutants as dyes, phenols, polymeric, and degradation compounds), and decoloration. The results indicate high values of decoloration degree (55.42-83.00 %) and COD removal (44.44-61.11 %) when it is worked at pH ≤2 with coal ash dose of 12-40 g/L, temperature higher than 20-25 °C, and continuous static operating regime (with an initial agitation step of 3-5 min). The treated textile effluent fulfills the quality demand, and is recyclable, inside reused or discharged after a stage of neutralization (standard pH of 6.5-8.5 for all textile effluent discharges). Also, the final effluent is able to follow the common path to the central biological treatment plant (i.e., a centralized treatment plant for all companies acting in the industrial site area with mechanical-biological steps for wastewater treatment) or may be directly discharged in the nearly watercourse. [ABSTRACT FROM AUTHOR]

The Tennessee Valley Authority Kingston coal ash spill in December 2008 deposited approximately 4.1 million m3 of fly ash and bottom ash into the Emory and Clinch River system (Harriman, Tennessee, U.S.A.). The objective of this study was to investigate the impact of the ash on surface water and sediment quality over an eighteen month period after the spill, with a specific focus on mercury and methylmercury in sediments. Our results indicated that surface water quality was not impaired with respect to total mercury concentrations. However, in the sediments of the Emory River near the coal ash spill, total mercury concentrations were 3- to 4-times greater than sediments several miles upstream of the ash spill. Similarly, methylmercury content in the Emory and Clinch River sediments near the ash spill were slightly elevated (up to a factor of 3) at certain locations compared to upstream sediments. Up to 2% of the total mercury in sediments containing coal ash was present as methylmercury. Mercury isotope composition and sediment geochemical data suggested that elevated methylmercury concentrations occurred in regions where native sediments were mixed with coal ash (e.g., less than 28% as coal ash in the Emory River). This coal ash may have provided substrates (such as sulfate) that stimulated biomethylation of mercury. The production of methylmercury in these areas is a concern because this neurotoxic organomercury compound can be highly bioaccumulative. Future risk assessments of coal ash spills should consider not only the leaching potential of mercury from the wastes but also the potential for methylmercury production in receiving waters. [ABSTRACT FROM AUTHOR]

Mercury stable isotope abundances were used to trace transport of Hg-impacted river sediment near a coal ash spill at Harriman, Tennessee, USA. δ202Hg values for Kingston coal ash released into the Emory River in 2008 are significantly negative (-1.78 ± 0.35‰), whereas sediments of the Clinch River, into which the Emory River flows, are contaminated by an additional Hg source (potentially from the Y-12 complex near Oak Ridge, Tennessee) with near-zero values (-0.23 ± 0.16‰). Nominally uncontaminated Emory River sediments (12 miles upstream from the Emory-Clinch confluence) have intermediate values (-1.17 ± 0.13‰) and contain lower Hg concentrations. Emory River mile 10 sediments, possibly impacted by an old paper mill has δ202Hg values of -0.47 ± 0.04‰. A mixing model, using δ202Hg values and Hg concentrations, yielded estimates of the relative contributions of coal ash, Clinch River, and Emory River sediments for a suite of 71 sediment samples taken over a 30 month time period from 13 locations. Emory River samples, with two exceptions, are unaffected by Clinch River sediment, despite occasional upstream flow from the Clinch River. As expected, Clinch River sediment below its confluence with the Emory River are affected by Kingston coal ash; however, the relative contribution of the coal ash varies among sampling sites [ABSTRACT FROM AUTHOR]

On December 22, 2008 a dike containing coal fly ash from the Tennessee Valley Authority Kingston Fossil Plant near Kingston Tennessee USA failed and resulted in the largest coal ash spill in U.S. history. Coal ash, a by-product of coal combustion, is known to contain multiple contaminants of concern, including arsenic and selenium. The purpose of this study was to investigate species differences in the bioaccumulation of arsenic and selenium and potential factors contributing to these differences (i.e., trophic dynamics and gut pH) in the vicinity of the Kingston coal ash spill. Elevated levels of arsenic and selenium were observed in various tissues of largemouth bass, white crappie, bluegill and redear sunfish from sites associated with the Kingston coal ash spill. Highest concentrations of selenium were found in redear sunfish with liver concentrations as high as 24.83mg/kg dry weight and ovary concentrations up to 10.40mg/kg dry weight at coal ash-associated sites. Investigations into the gut pH and trophic dynamics of redear sunfish and bluegill demonstrated a large difference in the gut physiology between these two species. Redear sunfish stomach and intestinal pH was found to be 1.1 and 0.16 pH units higher than in bluegill, respectively. In addition, fish from coal ash-associated sites showed enrichment differences (15N and 13C) compared to no ash sites, indicating differences in food web dynamics between sites. These results imply the incorporation of coal ash-associated compounds into local food webs and/or a shift in diet at ash sites compared to the no ash reference sites. Based on these results, further investigation into a broader food web at ash-associated sites is warranted. [Copyright &y& Elsevier]

Abstract: The optimized BCR sequential extraction procedure was applied to washing aggregate sludge and fly ash, the raw materials used to produce artificial lightweight aggregates (LWAs) in a previous study. The mixtures of the raw materials and the two types of LWAs obtained have also undergone this procedure. As a result, it has been possible to evaluate the effects of the heating process on the extraction behaviour of twenty-eight elements. The thermal process reduces the availability of all the studied heavy metals, with the exception of Mo. The availability of the other elements is also reduced, with the exceptions of As and Sb, which increase in the non-residual fractions. [Copyright &y& Elsevier]

The article discusses the need for the U.S. Federal Government to recognize coal ash as a hazardous waste considering its adverse affects on public health and environment. It informs that coal ash waste poses health risks to human as it consists of carcinogenic and neurotoxic chemicals such as arsenic, lead and cadmium. It analyzes different coal ash regulations enforced to restrict the hazards of coal ash.