Pulverized bituminous coal was burned in a 10W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28, 32, and 36%). Experiments were designed to produce flames with practically relevant stoichiometric ratios (SR=1.2-1.4) and constant residence times (2.3s). Size-classified fly ash samples were collected, and measurements focused on the soot, elemental carbon (EC), and organic carbon (OC) composition of the total and ultrafine (<0.6μm) fly ash. Results indicate that although the total fly ash carbon, as measured by loss on ignition, was always acceptably low (<2%) with all three oxycombustion conditions lower than air-combustion, the ultrafine fly ash for both air-fired and oxy-fired combustion conditions consists primarily of carbonaceous material (50-95%). Carbonaceous components on particles <0.6μm measured by a thermal optical method showed that large fractions (52-93%) consisted of OC rather than EC, as expected. This observation was supported by thermogravimetric analysis indicating that for the air, 28% oxy, and 32% oxy conditions, 14-71% of this material may be OC volatilizing between 100 and 550°C with the remaining 29-86% being EC/soot. However, for the 36% oxy condition, OC may comprise over 90% of the ultrafine carbon with a much smaller EC/soot contribution. These data were interpreted by considering the effects of oxy-combustion on flame attachment, ignition delay, and soot oxidation of a bituminous coal, and the effects of these processes on OC and EC emissions. Flame aerodynamics and inlet oxidant composition may influence emissions of organic hazardous air pollutants (HAPs) from a bituminous coal. During oxy-coal combustion, judicious control of inlet oxygen concentration and placement may be used to minimize organic HAP and soot emissions.
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http://dx.doi.org/10.1016/j.proci.2016.08.073 | DOI Listing |
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School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, People's Republic of China; Key Laboratory of Advanced Plasma Catalysis Engineering for China Petrochemical Industry, Jiangsu 213164, China. Electronic address:
Photochemistry plays a significant role in the atmospheric aging processes of soot. However, the physicochemical properties and changes in environmental and health effects of soot particles from sacrificial sources after photochemical aging remain unclear. The reaction mechanisms of soot under different irradiation wavelengths require further investigation.
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Instituto Nacional de Pesquisas Espaciais (INPE), Centro de Previsão de Tempo e Estudos Climáticos (CPTEC), Rodovia Presidente Dutra, Km 40, 12630-000 Cachoeira Paulista, SP, Brazil.
Pantanal fires have a significant impact on the environment. Anthropogenic emissions of residual gases have changed the tropospheric composition in this region due to burning. This study aims to analyze the spatial patterns of atmospheric pollutants (including carbon monoxide (CO), nitrogen dioxide (NO2), black carbon (BC), organic carbon (OC) and sulfur dioxide (SO2) and aerosol optical depth, along with fire outbreaks across the Pantanal biome from 2016 to 2021.
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December 2024
Meteorological Medical Research Center, Panzhihua Central Hospital, No.34 Yikang Street, East District, Panzhihua, 617067, China; Dali University, No.2 Hongsheng Road, Ancient City, Dali, 671000, China; Department of Pharmacy, Panzhihua Central Hospital, No.34 Yikang Street, East District, Panzhihua, 617067, China. Electronic address:
Limited epidemiological information exists on the relationships between fine particulate matter (PM) components and glaucoma risk. Moreover, the potential mediation effect of serum uric acid (UA) levels remains unexplored. Data from the China Health and Retirement Longitudinal Survey (CHARLS) spanning 2011-2020 were analyzed.
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Six Geological Team of Hubei Geological Bureau, Xiaogan 432000, China; Hubei Key Laboratory of Resources and Eco-Environment Geology, Xiaogan 432000, China.
Due to rapid urbanization and industrialization, combined pollution caused by BTEX (benzene, toluene, ethylbenzene, and xylene) and heavy metals has become ubiquitous in soils, which would pose serious health risks to humans. However, the effects of heavy metals on the sorption and desorption behaviors of BTEX have not been fully elucidated. In this study, the effects of Cu and Pb ions on the sorption and desorption of benzene onto humic acids and black carbons were investigated.
View Article and Find Full Text PDFBiotechnol Lett
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Department of Chemistry, Boğaziçi University, Bebek, 34342, İstanbul, Türkiye.
Microbial fuel cells (MFCs) utilize the metabolic activities of microorganisms, through which the chemical energy is directly converted into electrical energy. Bacteria produce electrons by means of oxidation of organic/inorganic substrates within the MFCs. Metal organic frameworks (MOFs) that are porous coordination polymers have gained much interest in the field of efficient catalysts due to their unique characteristics.
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