A closed coal ash impoundment case study characterized the effects of field redox conditions on arsenic and selenium partitioning through monitoring of porewater and subsurface gas in conjunction with geochemical speciation modeling. When disposed coal ash materials and porewater were recovered for testing, oxidation led to lower arsenic and higher selenium concentrations in leaching test extracts compared to porewater measurements. Multiple lines of evidence suggest multiple mechanisms of arsenic retention are plausible and the concurrent presence of several redox processes and conditions (e.g., methanogenesis, sulfate reduction, and Fe(III)-reduction) controlled by spatial gradients and dis-equilibrium. Geochemical speciation modeling indicated that, under reducing field conditions, selenium was immobilized through the formation of insoluble precipitates Se(0) or FeSe while arsenic partitioning was affected by a progression of reactions including changes in arsenic speciation, reduction in adsorption due to dissolution and recrystallization of hydrous ferric oxides, and precipitation of arsenic sulfide minerals.
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http://dx.doi.org/10.1016/j.jhazmat.2022.128255 | DOI Listing |
Anal Chim Acta
February 2025
School of Electric Power Engineering, South China University of Technology, Guangzhou, Guangdong, 510641, China; Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization, Guangzhou, Guangdong, 510641, China. Electronic address:
Background: Rapid and accurate detection of the biomass potassium (K) content in biomass is crucial for mitigating ash deposition and fouling issues in biomass fuel combustion processes. Laser-induced breakdown spectroscopy (LIBS) offers a promising approach for rapid analysis of biomass elemental. However, the accuracy of LIBS detection is susceptible to chemical matrix effects.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China.
Gasification slag is the solid waste produced in the process of coal gasification. China produces approximately 30 million tons of gasification slag every year, which urgently needs to be recycled in an efficient and sustainable way. This paper discusses the feasibility of using gasification slag as a supplementary cementitious material (SCM).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Civil Engineering, College of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, 603203, India.
Fly ash (FA) is a consequence of burning coal and is widely used in construction because of its pozzolanic qualities, which increase the strength and longevity of materials. Graphene oxide (GO) is a functionalized version of graphene with low electrical conductivity, high mechanical strength, and a large surface area. By examining the behavior of fly ash and GO composites at high temperatures, new materials with improved mechanical and functional qualities that are appropriate for a range of industrial uses can be created.
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December 2024
State Key Laboratory of Coal Resources and Safe Mining & College of Geosciences and Surveying Engineering, China University of Mining and Technology, Beijing 100083, China.
Xuanwei and the neighboring Fuyuan (XF) counties in Yunnan Province have the highest lung cancer incidence rates in China. Previous studies suggest that the nano-minerals released during the combustion of locally sourced "smoky" (bituminous) coal are the primary contributors to these elevated cancer rates. The coal ash generated during combustion predominantly consists of nano-minerals, which can be resuspended into the atmosphere during routine ash-handling activities.
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December 2024
Faculty of Non-Ferrous Metals, AGH University of Krakow, Al. Mickiewicza 30, 30-059 Krakow, Poland.
Gallium, a critical and strategic material for advanced technologies, is anomalously enriched in certain coal deposits and coal by-products. Recovering gallium from solid residues generated during coal production and utilization can yield economic benefits and positive environmental gains through more efficient waste processing. This systematic literature review focuses on gallium concentrations in coal and its combustion or gasification by-products, modes of occurrence, gallium-hosting phases, and hydrometallurgical recovery methods, including pretreatment procedures that facilitate metal release from inert aluminosilicate minerals.
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