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Rivera NA, Ling FT, Jin Z, Pattammattel A, Yan H, Chu YS, Peters CA, Hsu-Kim H. Nanoscale heterogeneity of arsenic and selenium species in coal fly ash particles: analysis using enhanced spectroscopic imaging and speciation techniques. Environ Sci Nano 2023; 10:1768-1777. [PMID: 37457049 PMCID: PMC10339362 DOI: 10.1039/d2en01056a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/19/2023] [Indexed: 07/18/2023]
Abstract
Coal combustion byproducts are known to be enriched in arsenic (As) and selenium (Se). This enrichment is a concern during the handling, disposal, and reuse of the ash as both elements can be harmful to wildlife and humans if mobilized into water and soils. The leaching potential and bioaccessibility of As and Se in coal fly ash depends on the chemical forms of these elements and their association with the large variety of particles that comprise coal fly ash. The overall goal of this research was to determine nanoscale and microscale solid phase mineral associations and oxidation states of As and Se in fly ash. We utilized nanoscale 2D imaging (30-50 nm spot size) with the Hard X-ray Nanoprobe (HXN) in combination with microprobe X-ray capabilities (∼5 μm resolution) to determine the As and Se elemental associations. Speciation of As and Se was also measured at the nano- to microscale with X-ray absorption spectroscopy. The enhanced resolution of HXN showed As and Se as either diffusely located around or comingled with Ca- and Fe-rich particles. The results also showed nanoparticles of Se attached to the surface of fly ash grains. Overall, a comparison of As and Se species across scales highlights the heterogeneity and complexity of chemical associations for these trace elements of concern in coal fly ash.
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Affiliation(s)
- Nelson A Rivera
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
| | - Florence T Ling
- Department of Civil and Environmental Engineering, Princeton University Princeton New Jersey 08544 USA
- Environmental Science Program, Department of Chemistry and Biochemistry, La Salle University Philadelphia PA 19141 USA
| | - Zehao Jin
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
| | - Ajith Pattammattel
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Hanfei Yan
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Yong S Chu
- National Synchrotron Light Source II, Brookhaven National Laboratory Upton NY 11973 USA
| | - Catherine A Peters
- Department of Civil and Environmental Engineering, Princeton University Princeton New Jersey 08544 USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University Box 90287 Durham North Carolina 27708 USA
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Liu Q, Huang Q, Zhao Y, Liu Y, Wang Q, Khan MA, Che X, Li X, Bai Y, Su X, Lin L, Zhao Y, Chen Y, Wang J. Dissolved organic matter (DOM) was detected in MSWI plant: An investigation of DOM and potential toxic elements variation in the bottom ash and fly ash. Sci Total Environ 2022; 828:154339. [PMID: 35257758 DOI: 10.1016/j.scitotenv.2022.154339] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/22/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
The content of dissolved organic matter (DOM) and potentially toxic elements (PTEs) were investigated in the bottom ash (BA) and fly ash (FA) of different sections of the municipal solid waste incineration (MSWI) plant. BA and FA were collected from the dry (BA1-BA2), burn (BA3-BA4), and burn-out (BA5) sections of the grate incinerator; FA was collected after denitration (DNFA), and from the deacidification tower (FA1) and bag-type dust remover (FA2), respectively. The DOM concentration in BA was higher than that in FA, the highest concentration was in BA3 (556.18 mg/kg), while the lowest concentration was in DNFA (17.53 mg/kg). DOM in BA was mainly composed of protein-like, fulvic-like, tryptophan-like, and humic-like substances, of which humic-like substances accounted for more than 40%. DOM in FA consisted of tryptophan-like and humic-like substances, of which humic-like substances accounted for more than 80%. DOM still existed in BA which may be related to the incomplete combustion, and the influence of microbes, while DOM was increased in FA1, which might be due to the addition of lime slurry. PTEs were analyzed by the Tessier extraction method, Fe-Mn hydroxide-bound fraction of PTEs increased in FA1 in which DOM concentration (137.22 mg/kg) was 7.83 times that in DNFA. The increase of DOM may lead to a higher risk of PTEs in FA. FTIR results indicated that DOM can bond to PTEs in BA and FA. The contents of humus-like substances in DOM were positively correlated with the effective fraction of As, Cu, Pb, Cr, and Cd. This paper investigated the risk of DOM existing in BA and FA in MSWI plant, which can provide a new perspective on how to deal with BA and FA, and reduce their environmental risks.
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Affiliation(s)
- Quan Liu
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Qing Huang
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China.
| | - Youcai Zhao
- The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yin Liu
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Qingqing Wang
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Muhammad Amjad Khan
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Xuyang Che
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China
| | - Xiaohui Li
- Hainan Inspection and Detection Center for Modern Agriculture, Haikou, Hainan 570100, China
| | - Yang Bai
- College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; College of Management and Economics, Tianjin University, Tianjin 300072, China
| | - Xuesong Su
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Linyi Lin
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Yang Zhao
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Ying Chen
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China; Key Laboratory for Environmental Toxicology of Haikou, Hainan University, Haikou, Hainan 570228, China
| | - Junfeng Wang
- Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Haikou 570228, China; College of Ecology and Environment, Hainan University, Haikou, Hainan 570228, China; Center for Eco-Environmental Restoration Engineering of Hainan Province, Haikou 570228, China; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, China
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Fu B, Hower JC, Li S, Huang Y, Zhang Y, Hu H, Liu H, Zhou J, Zhang S, Liu J, Yao H. The key roles of Fe-bearing minerals on arsenic capture and speciation transformation during high-As bituminous coal combustion: Experimental and theoretical investigations. J Hazard Mater 2021; 415:125610. [PMID: 33730644 DOI: 10.1016/j.jhazmat.2021.125610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 02/28/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
The conversion of As vapor released from coal combustion to less hazardous solids is an important process to alleviate As pollution especially for high-As coal burning, but the roles of key ash components are still in debate. Here, we used multiple analytical methods across the micro to bulk scale and density functional theory to provide quantitative information on As speciation in fly ash and clarify the roles of ash components on As retention. Fly ash samples derived from the high-As bituminous coal-fired power plants showed a chemical composition of typical Class F fly ash. In-situ electron probe microanalysis (EPMA) was for the first time used to quantify and distinguish the inter-particle As distribution difference within coal fly ash. The spatial distribution of As was consistent with Fe, O, and sometimes with Ca. Grain-scale distribution of As in coal fly ash was quantified and As concentrations in single ash particles followed the order of Fe-oxides > aluminosilicates > unburned carbon > quartz. Sequential extraction and Wagner chemical plot of As confirmed that Fe minerals rather than Al-/Ca-bearing minerals played a vital role in capturing and oxidizing As3+ into solid phase (As5+). Magnetite content in fly ash well-correlated with the increase ratio of As before and after magnetic separation, suggesting magnetite enhanced As enrichment in fly ash. Density functional theory (DFT) indicated that the bridges O sites of octahedral structure on Fe3O4 (111) surface were likely strong active sites for As2O3 adsorption. This study highlights the importance of magnetite on As transformation during bituminous or high-rank coal combustion in power plants and has great implications for developing effective techniques for As removal.
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Affiliation(s)
- Biao Fu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - James C Hower
- University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, United States; University of Kentucky, Department of Earth & Environmental Sciences, Lexington, KY 40506, United States
| | - Shuai Li
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yongda Huang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yue Zhang
- School of Energy and Power Engineering, North China Electric Power University, Baoding, Hebei 071003, China
| | - Hongyun Hu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Huimin Liu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shiding Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jingjing Liu
- State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Xuzhou), China
| | - Hong Yao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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Li GK, Fischer WW, Lamb MP, West AJ, Zhang T, Galy V, Wang XT, Li S, Qiu H, Li G, Zhao L, Chen J, Ji J. Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin. Proc Natl Acad Sci U S A 2021; 118:e1921544118. [PMID: 34001595 DOI: 10.1073/pnas.1921544118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fly ash-the residuum of coal burning-contains a considerable amount of fossilized particulate organic carbon (FOCash) that remains after high-temperature combustion. Fly ash leaks into natural environments and participates in the contemporary carbon cycle, but its reactivity and flux remained poorly understood. We characterized FOCash in the Chang Jiang (Yangtze River) basin, China, and quantified the riverine FOCash fluxes. Using Raman spectral analysis, ramped pyrolysis oxidation, and chemical oxidation, we found that FOCash is highly recalcitrant and unreactive, whereas shale-derived FOC (FOCrock) was much more labile and easily oxidized. By combining mass balance calculations and other estimates of fly ash input to rivers, we estimated that the flux of FOCash carried by the Chang Jiang was 0.21 to 0.42 Mt C⋅y-1 in 2007 to 2008-an amount equivalent to 37 to 72% of the total riverine FOC export. We attributed such high flux to the combination of increasing coal combustion that enhances FOCash production and the massive construction of dams in the basin that reduces the flux of FOCrock eroded from upstream mountainous areas. Using global ash data, a first-order estimate suggests that FOCash makes up to 16% of the present-day global riverine FOC flux to the oceans. This reflects a substantial impact of anthropogenic activities on the fluxes and burial of fossil organic carbon that has been made less reactive than the rocks from which it was derived.
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Alam J, Yadav VK, Yadav KK, Cabral-pinto MM, Tavker N, Choudhary N, Shukla AK, Ali FAA, Alhoshan M, Hamid AA. Recent Advances in Methods for the Recovery of Carbon Nanominerals and Polyaromatic Hydrocarbons from Coal Fly Ash and Their Emerging Applications. Crystals 2021; 11:88. [DOI: 10.3390/cryst11020088] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Coal fly ash is found to be one of the key pollutants worldwide due to its toxic heavy metal content. However, due to advancements in technology, coal fly ash has gained importance in various emerging fields. They are rich sources of carbonaceous particles which remain unburnt during burning of various coals in thermal power plants (TPPs). Various carbonaceous nanoparticles in the form of fullerenes, soot, and carbon nanotubes could be recovered from coal fly ash by applying trending techniques. Moreover, coal fly ash is comprised of rich sources of organic carbons such as polycyclic and polyaromatic hydrocarbons that are used in various industries for the development of carbon-derived value-added materials and nanocomposites. Here, we focus on all the types of carbon nanominerals from coal fly ash with the latest techniques applied. Moreover, we also emphasize the recovery of organic carbons in polyaromatic (PAHs) and polycyclic hydrocarbons (PCHs) from coal fly ash (CFA). Finally, we try to elucidate the latest applications of such carbon particle in the industry.
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Akinyemi SA, Gitari WM, Petrik LF, Nyakuma BB, Hower JC, Ward CR, Oliveira MLS, Silva LFO. Environmental evaluation and nano-mineralogical study of fresh and unsaturated weathered coal fly ashes. Sci Total Environ 2019; 663:177-188. [PMID: 30711584 DOI: 10.1016/j.scitotenv.2019.01.308] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 01/20/2019] [Accepted: 01/24/2019] [Indexed: 06/09/2023]
Abstract
Coal combustion and the disposal of combustion wastes emit enormous quantities of nano-sized particles that pose significant health concerns on exposure, particularly in unindustrialized countries. Samples of fresh and weathered class F fly ash were analysed through various techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), field-emission gun scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM) coupled with energy dispersive x-ray spectroscopy (EDS), and Raman Spectroscopy. The imaging techniques showed that the fresh and weathered coal fly ash nanoparticles (CFA-NPs) are mostly spherical shaped. The crystalline phases detected were quartz, mullite, ettringite, calcite, maghemite, hematite, gypsum, magnetite, clay residues, and sulphides. The most abundant crystalline phases were quartz mixed with Al-Fe-Si-K-Ti-O-amorphous phases whereas mullite was detected in several amorphous phases of Al, Fe, Ca, Si, O, K, Mg, Mn, and P. The analyses revealed that CFA-NPs are 5-500 nm in diameter and encapsulate several potentially hazardous elements (PHEs). The carbon species were detected as 5-50 nm carbon nanoballs of graphitic layers and massive fullerenes. Lastly, the aspects of health risks related to exposure to some detected ambient nanoparticles are also discussed.
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Affiliation(s)
- Segun A Akinyemi
- Environmental Remediation and Geopollution Group, Department of Geology, Faculty of Science, Ekiti State University, Ado Ekiti, P.M.B. 5363, Ado Ekiti, Nigeria; Environmental Remediation and Water Pollution Chemistry Group, Department of Ecology and Resources Management, School of Environmental Studies, University of Venda, Private Bag, X5050, Thohoyandou, 0950, South Africa.
| | - Wilson M Gitari
- Environmental Remediation and Water Pollution Chemistry Group, Department of Ecology and Resources Management, School of Environmental Studies, University of Venda, Private Bag, X5050, Thohoyandou, 0950, South Africa
| | - Leslie F Petrik
- Environmental and Nano Sciences Group, Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
| | - Bemgba B Nyakuma
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia
| | - James C Hower
- University of Kentucky Centre for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, United States of America
| | - Colin R Ward
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Marcos L S Oliveira
- Department of Civil and Environmental, Universidad de la Costa, CUC, Calle 58 # 55-66, Barranquilla, Atlantico, Colombia; Universidade do Vale do Rio do Sinos, Av. Unisinos, 950-Cristo Rei, RS 93022-000, Brazil; Faculdade Meridional IMED, 304-Passo Fundo, RS, 99070-220, Brazil
| | - Luis F O Silva
- Department of Civil and Environmental, Universidad de la Costa, CUC, Calle 58 # 55-66, Barranquilla, Atlantico, Colombia.
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Fu B, Hower JC, Dai S, Mardon SM, Liu G. Determination of Chemical Speciation of Arsenic and Selenium in High-As Coal Combustion Ash by X-ray Photoelectron Spectroscopy: Examples from a Kentucky Stoker Ash. ACS Omega 2018; 3:17637-17645. [PMID: 31458363 PMCID: PMC6643703 DOI: 10.1021/acsomega.8b02929] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/05/2018] [Indexed: 05/14/2023]
Abstract
Knowledge of the chemical speciation of arsenic and selenium in coal fly ash is essential in the evaluation of the environmental behavior of fly ash disposed in a landfill in a natural environment. In this study, a series of high-As coal fly ash from stoker boilers were collected to determine the chemical forms of arsenic and selenium. The ash surface chemical characteristics and the speciation of arsenic and selenium were characterized by X-ray photoelectron spectroscopy and X-ray-induced Auger electron spectroscopy. The results indicate that the surface enrichment ratio for selenium (63.3-309.5) is higher than that of arsenic (1.2-21.2). The Wagner chemical-state plot of arsenic indicates that As is mainly present as As(V) bonded to oxygen ligands, that is, the [AsO4]3- anion; Se is found predominantly as elemental Se (62.0-83.3%), followed by selenite (16.7-38%). The extreme enrichment of both arsenic and selenium arsenic is controlled by iron oxides in the coal fly ash.
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Affiliation(s)
- Biao Fu
- CAS
Key Laboratory of Crust-Mantle Materials and Environment, School of
Earth and Space Sciences, University of
Science and Technology of China, Hefei, Anhui 230026, China
| | - James C. Hower
- Center
for Applied Energy Research, University
of Kentucky, 2540 Research Park Drive, Lexington, Kentucky 40511, United States
- E-mail: (J.C.H.)
| | - Shifeng Dai
- State
Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, China, Beijing 100083, China
| | - Sarah M. Mardon
- Office
of Philanthropy, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Guijian Liu
- CAS
Key Laboratory of Crust-Mantle Materials and Environment, School of
Earth and Space Sciences, University of
Science and Technology of China, Hefei, Anhui 230026, China
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Fu B, Liu G, Sun M, Hower JC, Mian MM, Wu D, Wang R, Hu G. Emission and transformation behavior of minerals and hazardous trace elements (HTEs) during coal combustion in a circulating fluidized bed boiler. Environ Pollut 2018; 242:1950-1960. [PMID: 30072220 DOI: 10.1016/j.envpol.2018.07.066] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/11/2018] [Accepted: 07/15/2018] [Indexed: 05/27/2023]
Abstract
Emission of hazardous trace elements (HTEs) from energy production is receiving much attention due to concerns about the toxicity to the ecosystem and human health. This study presented new field measurement data on the HTEs partitioning behavior and size-segregated elemental compositions of gaseous particular matter (PM) generated from a commercial circulating fluidized bed (CFB) power plant. Mineralogical and morphological characteristics of combustion ash and PM2.5 (particle diameter less than 2.5 μm) were determined by X-ray diffractometer (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). Functional groups alteration during CFB combustion was characterized by Fourier transform infrared spectroscopy (FTIR). The presence of aliphatic hydrogen at 2910 cm-1 and 2847 cm-1 in the PM2.5 suggested that the aliphatic carbon-rich volatiles were absorbed on the fine particles with large surface area. Fine fly ash (PM2.5) occurred as irregular glass particles or/and as unburned carbon. The typical irregular particles were mainly composed of Al-Si-Ca or Al-Si-Fe phases. The enrichment behavior of HTEs was determined for the airborne size-segregated particular matter. Elemental occurrences, combustion temperature, unburnt carbon, and limestone additives during CFB combustion were critical in the transformation behavior of HTEs. The total potentially mobile pollutants that exit the CFB power plant every year were estimated as follows: 0.22 tons of Cr, 0.12 tons of Co, 0.73 tons of Ni, 0.04 tons of As, 0.07 tons of Se, 3.95 kg of Cd, and 3.34 kg of Sb.
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Affiliation(s)
- Biao Fu
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China
| | - Guijian Liu
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China.
| | - Mei Sun
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - James C Hower
- University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY, 40511, United States
| | - Md Manik Mian
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Dun Wu
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; Exploration Research Institute, Anhui Provincial Bureau of Coal Geology, Hefei, Anhui, 23008, China
| | - Ruwei Wang
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Guangqing Hu
- CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; Exploration Research Institute, Anhui Provincial Bureau of Coal Geology, Hefei, Anhui, 23008, China
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Deonarine A, Kolker A, Foster AL, Doughten MW, Holland JT, Bailoo JD. Arsenic Speciation in Bituminous Coal Fly Ash and Transformations in Response to Redox Conditions. Environ Sci Technol 2016; 50:6099-106. [PMID: 27186791 DOI: 10.1021/acs.est.6b00957] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The risk of the mobilization of coal ash into the environment has highlighted the need for the assessment of the environmental behavior of coal ash, particularly with respect to toxic trace elements such as arsenic (As). Here, we examined As speciation in coal fly ash samples and transformations in response to aquatic redox conditions. X-ray absorption spectroscopy indicated that 92-97% of total As occurred as As(V), with the remainder present as As(III). Major As-bearing hosts in unamended ashes were glass, iron (oxyhydr)oxides, and calcium arsenate. Oxic leaching resulted in immediate As mobilization to the aqueous phase, reprecipitation of As-iron ferrihydrite, and As adsorption to mineral surfaces. Under anoxic conditions, the (reductive) dissolution of As-bearing phases such as iron ferrihydrite resulted in increased dissolved As compared to oxic conditions and reprecipitation of iron arsenate. Overall, As in coal ash is not environmentally stable and can participate in local biogeochemical cycles.
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Affiliation(s)
- Amrika Deonarine
- US Geological Survey , 12201 Sunrise Valley Drive, Reston, Virginia 20192, United States
| | - Allan Kolker
- US Geological Survey , 12201 Sunrise Valley Drive, Reston, Virginia 20192, United States
| | - Andrea L Foster
- US Geological Survey , 345 Middlefield Road, Menlo Park, California 94025, United States
| | - Michael W Doughten
- US Geological Survey , 12201 Sunrise Valley Drive, Reston, Virginia 20192, United States
| | - James T Holland
- US Geological Survey , 12201 Sunrise Valley Drive, Reston, Virginia 20192, United States
| | - Jeremy D Bailoo
- US Geological Survey , 12201 Sunrise Valley Drive, Reston, Virginia 20192, United States
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Civeira MS, Pinheiro RN, Gredilla A, de Vallejuelo SFO, Oliveira MLS, Ramos CG, Taffarel SR, Kautzmann RM, Madariaga JM, Silva LFO. The properties of the nano-minerals and hazardous elements: Potential environmental impacts of Brazilian coal waste fire. Sci Total Environ 2016; 544:892-900. [PMID: 26706762 DOI: 10.1016/j.scitotenv.2015.12.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 11/20/2015] [Accepted: 12/05/2015] [Indexed: 06/05/2023]
Abstract
Brazilian coal area (South Brazil) impacted the environment by means of a large number of coal waste piles emplaced over the old mine sites and the adjacent areas of the Criciúma, Urussanga, and Siderópolis cities. The area studied here was abandoned and after almost 30 years (smokeless visual) some companies use the actual minerals derived from burning coal cleaning rejects (BCCRs) complied in the mentioned area for industry tiles or refractory bricks. Mineralogical and geochemical similarities between the BCCRs and non-anthropogenic geological environments are outlined here. Although no visible flames were observed, this study revealed that auto-combustion existed in the studied area for many years. The presence of amorphous phases, mullite, hematite and other Fe-minerals formed by high temperature was found. There is also pyrite, Fe-sulphates (eg. jarosite) and unburnt coal present, which are useful for comparison purposes. Bad disposal of coal-dump wastes represents significant environmental concerns due to their potential influence on atmosphere, river sediments, soils and as well as on the surface and groundwater in the surroundings of these areas. The present study using advanced analytical techniques were performed to provide an improved understanding of the complex processes related with sulphide-rich coal waste oxidation, spontaneous combustion and mineral formation. It is reporting huge numbers of rare minerals with alunite, montmorillonite, szomolnokite, halotrichite, coquimbite and copiapite at the BCCRs. The data showed the presence of abundant amorphous Si-Al-Fe-Ti as (oxy-)hydroxides and Fe-hydro/oxides with goethite and hematite with various degrees of crystallinity, containing hazardous elements, such as Cu, Cr, Hf, Hg, Mo, Ni, Se, Pb, Th, U, Zr, and others. By Principal Component Analysis (PCA), the mineralogical composition was related with the range of elemental concentration of each sample. Most of the nano-minerals and ultra-fine particles found in the burned coal-dump wastes are the same as those commonly associated with coal cleaning rejects, in which oxidation of sulphides plays an important role to environment and human health.
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Affiliation(s)
- Matheus S Civeira
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Rafael N Pinheiro
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Ainara Gredilla
- University of the Basque Country (UPV/EHU), Faculty of Science and Technology, Department of Analytical Chemistry, P.O. Box 644, 48080 Bilbao, Spain
| | - Silvia Fdez Ortiz de Vallejuelo
- University of the Basque Country (UPV/EHU), Faculty of Science and Technology, Department of Analytical Chemistry, P.O. Box 644, 48080 Bilbao, Spain
| | - Marcos L S Oliveira
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Claudete G Ramos
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Silvio R Taffarel
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Rubens M Kautzmann
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
| | - Juan Manuel Madariaga
- University of the Basque Country (UPV/EHU), Faculty of Science and Technology, Department of Analytical Chemistry, P.O. Box 644, 48080 Bilbao, Spain
| | - Luis F O Silva
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
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Ntwampe IO, Waanders FB, Bunt JR. Destabilization dynamics of clay and acid-free polymers of ferric and magnesium salts in AMD without pH adjustment. Water Sci Technol 2016; 74:861-875. [PMID: 27533861 DOI: 10.2166/wst.2016.259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The physicochemical treatment was employed to treat acid mine drainage (AMD) in the removal of turbid materials using clay only (exp A) and a combination of clay, FeCl3 and Mg(OH)2 (exp B) to form a polymer. A 5 g sample of clay (bentonite) was added to 1.2 L of AMD and treated in a jar test at 250 rpm for 2 min and reduced to 100 rpm for 10 min. A 200 mL sub-sample from the 1.2 L mother liquor was poured into five 500 mL glass beakers, and 20 mL dosages of a polymer of 0.1 M Fe(3+) in (FeCl3) and 0.1 M Mg(2+) in (Mg(OH)2) was added to the beakers. The samples were allowed to settle for 1 h, after which the supernatant was analyzed for pH, total suspended solids (TSS), dissolved oxygen (DO) and oxidation-reduction potential (ORP) (exp A). A similar set of experiments was conducted where 200 mL of the AMD sample was poured into 500 mL glass beakers and (20-60 mL) dosages of a combination of 5 g clay, 0.1 M Fe(3+) (FeCl3) and Mg(2+) (Mg(OH)2) polymer was added and similar mixing, settling time and measurements were conducted (exp B). The polymers used in exp A exhibited TSS removal efficiency (E%) which was slightly lower compared with the polymer used in exp B, above 90%. Clay has a high TSS removal efficiency in the treatment of the AMD, indicating that adsorption was a predominant process in exps A and B. The scanning electron microscope (SEM) micrographs of the AMD sludge of both exps A and B, with a rigid and compacted structure consisting of dense flocs surrounded by the smaller flocs bound together, corroborate the fact that adsorption is a predominant process.
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Affiliation(s)
- I O Ntwampe
- School of Chemical and Minerals Engineering, North West University, Faculty of Engineering, North West Province, Potchefstroom Campus, South Africa E-mail:
| | - F B Waanders
- School of Chemical and Minerals Engineering, North West University, Faculty of Engineering, North West Province, Potchefstroom Campus, South Africa E-mail:
| | - J R Bunt
- School of Chemical and Minerals Engineering, North West University, Faculty of Engineering, North West Province, Potchefstroom Campus, South Africa E-mail:
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van der Merwe E, Mathebula C, Prinsloo L. Characterization of the surface and physical properties of South African coal fly ash modified by sodium lauryl sulphate (SLS) for applications in PVC composites. POWDER TECHNOL 2014; 266:70-8. [DOI: 10.1016/j.powtec.2014.06.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Martinello K, Oliveira MLS, Molossi FA, Ramos CG, Teixeira EC, Kautzmann RM, Silva LFO. Direct identification of hazardous elements in ultra-fine and nanominerals from coal fly ash produced during diesel co-firing. Sci Total Environ 2014; 470-471:444-452. [PMID: 24157478 DOI: 10.1016/j.scitotenv.2013.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 09/29/2013] [Accepted: 10/01/2013] [Indexed: 06/02/2023]
Abstract
This study has provided an initial assessment of the environmental impacts and potential health effects associated with coal fly ash produced during diesel co-firing. Many hazardous elements that are typically detected by multifaceted chemical characterization by XRD, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS in ultra-fine compounds and nanominerals from the co-fired coal fly ashes (CFAs). It provided an in-depth understanding of coal ash produced during diesel co-firing. Several of the neoformed ultra-fine compounds and nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of aluminosilicates, carbonates, sulphides and phosphates.
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Affiliation(s)
- Kátia Martinello
- Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina, Brazil
| | - Marcos L S Oliveira
- Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina, Brazil; Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil
| | - Fernando A Molossi
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil
| | - Claudete G Ramos
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil
| | - Elba C Teixeira
- Fundação Estadual de Proteção Ambiental Henrique Luis Roessler/RS, Fundação Estadual de Proteção Ambiental Henrique Luis Roessler-RS, Rua Carlos Chagas 55/802, Centro 90030-020 - Porto Alegre, RS, Brazil
| | - Rubens M Kautzmann
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil
| | - Luis F O Silva
- Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina, Brazil; Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil.
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Oliveira MLS, Marostega F, Taffarel SR, Saikia BK, Waanders FB, DaBoit K, Baruah BP, Silva LFO. Nano-mineralogical investigation of coal and fly ashes from coal-based captive power plant (India): an introduction of occupational health hazards. Sci Total Environ 2014; 468-469:1128-1137. [PMID: 24121564 DOI: 10.1016/j.scitotenv.2013.09.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 08/21/2013] [Accepted: 09/13/2013] [Indexed: 06/02/2023]
Abstract
Coal derived nano-particles has been received much concern recently around the world for their adverse effects on human health and the environment during their utilization. In this investigation the mineral matter present in some industrially important Indian coals and their ash samples are addressed. Coal and fly ash samples from the coal-based captive power plant in Meghalaya (India) were collected for different characterization and nano-mineralogy studies. An integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS analysis, and Mössbauer spectroscopy were used to know their extent of risks to the human health when present in coal and fly ash. The study has revealed that the coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals in lesser quantities were found to be present in the coal fly ash. Fly ash carbons were present as chars. Indian coal fly ash also found to contain nanominerals and ultrafine particles. The coal-fired power plants are observed to be the largest anthropogenic source of Hg emitted to the atmosphere and expected to increase its production in near future years. The Multi Walled Carbon Nano-Tubes (MWCNTs) are detected in our fly ashes, which contains residual carbonaceous matter responsible for the Hg capture/encapsulation. This detailed investigation on the inter-relationship between the minerals present in the samples and their ash components will also be useful for fulfilling the clean coal technology principles.
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Affiliation(s)
- Marcos L S Oliveira
- Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS, Brazil; Development Department of Touristic Opportunities, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina, Brazil
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Gasparotto J, Somensi N, Caregnato FF, Rabelo TK, DaBoit K, Oliveira MLS, Moreira JCF, Gelain DP. Coal and tire burning mixtures containing ultrafine and nanoparticulate materials induce oxidative stress and inflammatory activation in macrophages. Sci Total Environ 2013; 463-464:743-753. [PMID: 23856402 DOI: 10.1016/j.scitotenv.2013.06.086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 06/02/2023]
Abstract
Ultra-fine and nano-particulate materials resulting from mixtures of coal and non-coal fuels combustion for power generation release to the air components with toxic potential. We evaluated toxicological and inflammatory effects at cellular level that could be induced by ultrafine/nanoparticles-containing ashes from burning mixtures of coal and tires from an American power plant. Coal fly ashes (CFA) samples from the combustion of high-S coal and tire-derived fuel, the latter about 2-3% of the total fuel feed, in a 100-MW cyclone utility boiler, were suspended in the cell culture medium of RAW 264.7 macrophages. Cell viability, assessed by MTT reduction, SRB incorporation and contrast-phase microscopy analysis demonstrated that CFA did not induce acute toxicity. However, CFA at 1mg/mL induced an increase of approximately 338% in intracellular TNF-α, while release of this proinflammatory cytokine was increased by 1.6-fold. The expression of the inflammatory mediator CD40 receptor was enhanced by 2-fold, the receptor for advanced glycation endproducts (RAGE) had a 5.7-fold increase and the stress response protein HSP70 was increased nearly 12-fold by CFA at 1mg/mL. Although CFA did not induce cell death, parameters of oxidative stress and reactive species production were found to be altered at several degrees, such as nitrite accumulation (22% increase), DCFH oxidation (3.5-fold increase), catalase (5-fold increase) and superoxide dismutase (35% inhibition) activities, lipoperoxidation (4.2 fold-increase) and sulfhydryl oxidation (40% decrease in free SH groups). The present results suggest that CFA containing ultra-fine and nano-particulate materials from coal and tire combustion may induce sub-chronic cell damage, as they alter inflammatory and oxidative stress parameters at the molecular and cellular levels, but do not induce acute cell death.
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Affiliation(s)
- Juciano Gasparotto
- Center of Oxidative Stress Research, Tuiskon Dick Department of Biochemistry, Institute of Health Basic Sciences, Federal University of Rio Grande do Sul (UFRGS) Brazil.
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Bhattacharjee A, Mandal H, Roy M, Kusz J, Hofmeister W. Comparative study of the microstructural and magnetic properties of fly ashes obtained from different thermal power plants in West Bengal, India. Environ Monit Assess 2013; 185:8673-8683. [PMID: 23612769 DOI: 10.1007/s10661-013-3203-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 04/09/2013] [Indexed: 06/02/2023]
Abstract
This paper deals with the physical nature of the fly ashes obtained from two thermal power plants, situated in West Bengal, India. The fly ash samples are characterized by using comprehensive techniques with an emphasis on their ultrafine nature. The particle sizes of the samples are estimated using scanning electron microcopy (SEM) and found to lie within 0.18-5.90 μm. For morphology and compositional analysis, we also use SEM coupled with energy dispersive X-ray spectrometry. From X-ray study of the fly ashes the nature of conglomeration is seen to be crystalline, and the major components are mullite (Al6Si2O13) and quartz (SiO2). The magnetic measurement of the fly ash samples was carried out by SQUID magnetometer. (57)Fe Mössbauer spectra are obtained using a conventional constant-acceleration spectrometer with a (57)Co/Rh Mössbauer source. The hyperfine parameters obtained, in general, support the findings as made from XRD analysis and provide a quantitative measure of different iron ions present in the samples. The paper presents experimental data on the physical aspects of the fly ash samples of the thermal power plants which comprise coarse, fine, and ultrafine magnetic particulate materials and attempts to provide an exhaustive analysis.
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Kronbauer MA, Izquierdo M, Dai S, Waanders FB, Wagner NJ, Mastalerz M, Hower JC, Oliveira MLS, Taffarel SR, Bizani D, Silva LFO. Geochemistry of ultra-fine and nano-compounds in coal gasification ashes: a synoptic view. Sci Total Environ 2013; 456-457:95-103. [PMID: 23584038 DOI: 10.1016/j.scitotenv.2013.02.066] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 02/22/2013] [Accepted: 02/23/2013] [Indexed: 06/02/2023]
Abstract
The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO₃ versus Al₂O₃ determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates.
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Affiliation(s)
- Marcio A Kronbauer
- Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil
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Ribeiro J, DaBoit K, Flores D, Kronbauer MA, Silva LFO. Extensive FE-SEM/EDS, HR-TEM/EDS and ToF-SIMS studies of micron- to nano-particles in anthracite fly ash. Sci Total Environ 2013; 452-453:98-107. [PMID: 23500403 DOI: 10.1016/j.scitotenv.2013.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 02/04/2013] [Accepted: 02/05/2013] [Indexed: 06/01/2023]
Abstract
The generation of anthropogenic carbonaceous matter and mixed crystalline/amorphous mineral ultrafine/nano-particles in the 1 to 100 nm size range by worldwide coal power plants represents serious environmental problems due to their potential hazards. Coal fly ash (CFA) that resulted from anthracite combustion in a Portuguese thermal power plant was studied in this work. The physico-chemical characterization of ultrafine/nano-particles present in the CFA samples and their interaction with environment are the aim of this study. The methodologies applied for this work were field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy (HR-TEM/EDS) and time of flight secondary ion mass spectrometry (ToF-SIMS). Some hazardous volatile elements, C, N, S and Hg contents were also determined in the studied samples. Generally, the CFA samples comprise carbonaceous, glassy and metallic solid spheres with some containing mixed amorphous/crystalline phases. The EDS analysis coupled with the FE-SEM and HR-TEM observations of the fly ash particles with 100 to 0.1 nm demonstrates that these materials contain a small but significant proportion of encapsulated HVEs. In addition, the presence of abundant multi-walled carbon nanotubes (MWCNTs) and amorphous carbon particles, both containing hazardous volatile elements (HVEs), was also evidenced by the FE-SEM/EDS and HR-TEM/EDS analysis. A wide range of organic and inorganic compounds was determined by chemical maps obtained in ToF-SIMS analysis.
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Affiliation(s)
- Joana Ribeiro
- Centro de Geologia, Universidade do Porto, Porto, Portugal
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Oliveira MLS, Ward CR, Izquierdo M, Sampaio CH, de Brum IAS, Kautzmann RM, Sabedot S, Querol X, Silva LFO. Chemical composition and minerals in pyrite ash of an abandoned sulphuric acid production plant. Sci Total Environ 2012; 430:34-47. [PMID: 22613465 DOI: 10.1016/j.scitotenv.2012.04.046] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 04/16/2012] [Accepted: 04/17/2012] [Indexed: 06/01/2023]
Abstract
The extraction of sulphur produces a hematite-rich waste, known as roasted pyrite ash, which contains significant amounts of environmentally sensitive elements in variable concentrations and modes of occurrence. Whilst the mineralogy of roasted pyrite ash associated with iron or copper mining has been studied, as this is the main source of sulphur worldwide, the mineralogy, and more importantly, the characterization of submicron, ultrafine and nanoparticles, in coal-derived roasted pyrite ash remain to be resolved. In this work we provide essential data on the chemical composition and nanomineralogical assemblage of roasted pyrite ash. XRD, HR-TEM and FE-SEM were used to identify a large variety of minerals of anthropogenic origin. These phases result from highly complex chemical reactions occurring during the processing of coal pyrite of southern Brazil for sulphur extraction and further manufacture of sulphuric acid. Iron-rich submicron, ultrafine and nanoparticles within the ash may contain high proportions of toxic elements such as As, Se, U, among others. A number of elements, such as As, Cr, Cu, Co, La, Mn, Ni, Pb, Sb, Se, Sr, Ti, Zn, and Zr, were found to be present in individual nanoparticles and submicron, ultrafine and nanominerals (e.g. oxides, sulphates, clays) in concentrations of up to 5%. The study of nanominerals in roasted pyrite ash from coal rejects is important to develop an understanding on the nature of this by-product, and to assess the interaction between emitted nanominerals, ultra-fine particles, and atmospheric gases, rain or body fluids, and thus to evaluate the environmental and health impacts of pyrite ash materials.
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Affiliation(s)
- Marcos L S Oliveira
- Development Department of Touristic Opportunities, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina, Brazil
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El Badawy AM, Scheckel KG, Suidan M, Tolaymat T. The impact of stabilization mechanism on the aggregation kinetics of silver nanoparticles. Sci Total Environ 2012; 429:325-31. [PMID: 22578844 DOI: 10.1016/j.scitotenv.2012.03.041] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 03/14/2012] [Accepted: 03/15/2012] [Indexed: 05/21/2023]
Abstract
The use of silver nanoparticles (AgNPs) for various applications is growing drastically. The increase in use will eventually lead to their release into the environment. The tendency of AgNPs to aggregate and the kinetics of aggregation are major factors that govern their fate in the environment. Dynamic light scattering (DLS) was utilized to investigate the electrolyte-induced aggregation kinetics (NaNO₃, NaCl and Ca(NO₃)₂) of coated and uncoated AgNPs which are electrostatically (H₂-AgNPs and Citrate-AgNPs), sterically (polyvinylpyrrolidone (PVP)-AgNPs) and electrosterically (branched polyethyleneimine (BPEI)-AgNPs) stabilized. The aggregation kinetics of the electrostatically stabilized AgNPs was in agreement with the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the AgNPs exhibited both reaction-limited and diffusion-limited regimes. The H₂-AgNPs had critical coagulation concentrations (CCC) of 25, 30 and 3mM in the presence of NaNO₃, NaCl and Ca(NO₃)₂ salts, respectively. The Citrate-AgNPs had CCC of 70, 70 and 5 mM in the presence of NaNO₃, NaCl and Ca(NO₃)₂ salts, respectively. The values of the Hamaker constant for the electrostatically stabilized AgNPs were also determined and the values were in agreement with the reported values for metallic particles. The aggregation kinetics for both the sterically and electrosterically stabilized AgNPs (PVP-AgNPs and BPEI-AgNPs) was not in agreement with the DLVO theory and the particles were resistant to aggregation even at high ionic strength and electrolyte valence. The PVP-AgNPs and the BPEI-AgNPs had no critical aggregation concentration value at the investigated ionic strength values.
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Affiliation(s)
- Amro M El Badawy
- Dept. of Environmental Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, USA
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22
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Silva LFO, Jasper A, Andrade ML, Sampaio CH, Dai S, Li X, Li T, Chen W, Wang X, Liu H, Zhao L, Hopps SG, Jewell RF, Hower JC. Applied investigation on the interaction of hazardous elements binding on ultrafine and nanoparticles in Chinese anthracite-derived fly ash. Sci Total Environ 2012; 419:250-264. [PMID: 22297247 DOI: 10.1016/j.scitotenv.2011.12.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/31/2011] [Accepted: 12/31/2011] [Indexed: 05/31/2023]
Abstract
A multifaceted instrumental approach was employed to determine the chemistry and mineralogy of pulverized-coal-combustion fly ashes from two Chinese power plants. Techniques included traditional optical microscopy, X-ray diffraction, and chemical analysis along with a variety of electron beam methods. The aim is to demonstrate and bring together the wide variety of procedures dealing with F as the key element of concern, and determining its location in the mineral nanoparticles. The Hg content of the Anwen (Songzao coalfield) fly ashes is higher than that of the Diandong (East Yunnan) fly ashes, possibly owing to the greater C and Cl in the Anwen fly ashes. Both fly ash sources contain a variety of amorphous and nano-crystalline trace-element-bearing particles, both associated with multi-walled carbon nanotubes and as particles independent of carbons.
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Affiliation(s)
- Luis F O Silva
- Centro Universitário Univates, Programa de Pós Graduação Ambiente e Desenvolvimento, Rua Avelino Tallini, 171, Universitário, 95900-000 Lajeado, RS, Brazil.
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23
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Silva LFO, DaBoit K, Sampaio CH, Jasper A, Andrade ML, Kostova IJ, Waanders FB, Henke KR, Hower JC. The occurrence of hazardous volatile elements and nanoparticles in Bulgarian coal fly ashes and the effect on human health exposure. Sci Total Environ 2012; 416:513-526. [PMID: 22200375 DOI: 10.1016/j.scitotenv.2011.11.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/26/2011] [Accepted: 11/03/2011] [Indexed: 05/31/2023]
Abstract
Low-rank, high-mineral matter Bulgarian coals were studied using a variety of chemical, optical, and electron beam methods. The larger fly ash carbon phases include charred carbons in contrast to coked carbons present in the fly ashes of bituminous-coal-derived fly ashes. Nanoscale carbons include multi-walled carbon nanotubes (MWCNTs) encapsulating Hg, Se, and As, among other elements. In addition to the glass which dominates the fly ash, relatively coarse 'rock fragments', consisting of an unmelted to partially melted core surrounded by a glassy rim, are present in the fly ash. Nano-scale minerals can contain hazardous elements and, along with metal-bearing multiwalled nanotubes, can be a path for the entry of hazardous particles into the lungs and other organs.
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Affiliation(s)
- Luis F O Silva
- Centro Universitário Univates, Pró Reitoria de Pesquisa Estensão e Pós Graduação, Programa de Pós Graduação Ambiente e Desenvolvimento, Brazil.
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24
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Bohnsack JP, Assemi S, Miller JD, Furgeson DY. The primacy of physicochemical characterization of nanomaterials for reliable toxicity assessment: a review of the zebrafish nanotoxicology model. Methods Mol Biol 2012; 926:261-316. [PMID: 22975971 DOI: 10.1007/978-1-62703-002-1_19] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Engineered nanomaterials (ENMs) have become increasingly prevalent in the past two decades in academic, medical, commercial, and industrial settings. The unique properties imbued with nanoparticles, as the physiochemical properties change from the bulk material to the surface atoms, present unique and often challenging characteristics that larger macromolecules do not possess. While nanoparticle characteristics are indeed exciting for unique chemistries, surface properties, and diverse applications, reports of toxicity and environmental impacts have tempered this enthusiasm and given cause for an exponential increase for concomitant nanotoxicology assessment. Currently, nanotoxicology is a steadily growing with new literature and studies being published more frequently than ever before; however, the literature reveals clear, inconsistent trends in nanotoxicological assessment. At the heart of this issue are several key problems including the lack of validated testing protocols and models, further compounded by inadequate physicochemical characterization of the nanomaterials in question and the seminal feedback loop of chemistry to biology back to chemistry. Zebrafish (Danio rerio) are emerging as a strong nanotoxicity model of choice for ease of use, optical transparency, cost, and high degree of genomic homology to humans. This review attempts to amass all contemporary nanotoxicology studies done with the zebrafish and present as much relevant information on physicochemical characteristics as possible. While this report is primarily a physicochemical summary of nanotoxicity studies, we wish to strongly emphasize that for the proper evolution of nanotoxicology, there must be a strong marriage between the physical and biological sciences. More often than not, nanotoxicology studies are reported by groups dominated by one discipline or the other. Regardless of the starting point, nanotoxicology must be seen as an iterative process between chemistry and biology. It is our sincere hope that the future will introduce a paradigm shift in the approach to nanotoxicology with multidisciplinary groups for data analysis to produce predictive and correlative models for the end goal of rapid preclinical development of new therapeutics into the clinic or insertion into environmental protection.
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Affiliation(s)
- John P Bohnsack
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, USA
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25
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Silva LFO, da Boit KM. Nanominerals and nanoparticles in feed coal and bottom ash: implications for human health effects. Environ Monit Assess 2011; 174:187-197. [PMID: 20422282 DOI: 10.1007/s10661-010-1449-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 04/06/2010] [Indexed: 05/29/2023]
Abstract
Environmental and human health risk assessments of nanoparticle effects from coal and bottom ash require thorough characterisation of nanoparticles and their aggregates. In this manuscript, we expand the study of human exposure to nanosized particles from coal combustion sources (typically <100 nm in size), characterising the complex micromineralogy of these airborne combustion-derived nanomaterials. Our study focuses on bottom ash generated in the Santa Catarina power station (Brazil) which uses coal enriched in ashes, many potential elements (e.g. Cr and Ni) and pyrite. Transmission electron microscope data reveal nanoscale C deposits juxtaposed with and overgrown by slightly larger aluminosilicate (Al-Si) glassy spheres, oxides, silicates, carbonated, phosphates and sulphates. Iron oxides (mainly hematite and magnetite) are the main bottom ash products of the oxidation of pyrite, sometimes via intermediate pyrrhotite formation. The presence of iron oxide nanocrystals mixed with silicate glass particles emphasises the complexity of coal and bottom ash micromineralogy. Given the potentially bioreactive nature of such transition metal-bearing materials, there is likely to be an increased health risk associated with their inhalation.
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Affiliation(s)
- Luis F O Silva
- Catarinense Institut of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina, Brazil.
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26
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Ruhl L, Vengosh A, Dwyer GS, Hsu-Kim H, Deonarine A. Environmental impacts of the coal ash spill in Kingston, Tennessee: an 18-month survey. Environ Sci Technol 2010; 44:9272-8. [PMID: 21105737 DOI: 10.1021/es1026739] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
An 18 month investigation of the environmental impacts of the Tennessee Valley Authority (TVA) coal ash spill in Kingston, Tennessee combined with leaching experiments on the spilled TVA coal ash have revealed that leachable coal ash contaminants (LCACs), particularly arsenic, selenium, boron, strontium, and barium, have different effects on the quality of impacted environments. While LCACs levels in the downstream river water are relatively low and below the EPA drinking water and ecological thresholds, elevated levels were found in surface water with restricted water exchange and in pore water extracted from the river sediments downstream from the spill. The high concentration of arsenic (up to 2000 μg/L) is associated with some degree of anoxic conditions and predominance of the reduced arsenic species (arsenite) in the pore waters. Laboratory leaching simulations show that the pH and ash/water ratio control the LCACs' abundance and geochemical composition of the impacted water. These results have important implications for the prediction of the fate and migration of LCACs in the environment, particularly for the storage of coal combustion residues (CCRs) in holding ponds and landfills, and any potential CCRs effluents leakage into lakes, rivers, and other aquatic systems.
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Affiliation(s)
- Laura Ruhl
- Division of Earth and Ocean Sciences, Nicholas School of Environment, 205 Old Chemistry Building, Box 90227, Duke University, Durham, North Carolina 27708, United States
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Silva LFO, Hower JC, Izquierdo M, Querol X. Complex nanominerals and ultrafine particles assemblages in phosphogypsum of the fertilizer industry and implications on human exposure. Sci Total Environ 2010; 408:5117-5122. [PMID: 20701953 DOI: 10.1016/j.scitotenv.2010.07.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 06/18/2010] [Accepted: 07/07/2010] [Indexed: 05/29/2023]
Abstract
Phosphogypsum (CaSO(4).2H(2)O), a by-product of phosphate-rock processing, contains high amounts of impurities such P(2)O(5), F, radioactive elements, organic substances, secondary nanominerals, and ultrafine particles (UFP) enriched in metals and metalloids. In this study, we examine phosphogypsum (PG) collected from abandoned fertilizer industry facility in south Brazil (Santa Catarina state). The fragile nature of nanominerals and UFP assemblages from fertilizer industry systems required novel techniques and experimental approaches. The investigation of the geochemistry of complex nanominerals and UFP assemblages was a prerequisite to accurately assess the environmental and human health risks of contaminants and cost-effective chemical and biogeological remediation strategies. Particular emphasis was placed on the study and characterization of the complex mixed nanominerals and UFP containing potentially toxic elements. Nanometer-sized phases in PG were characterized using energy-dispersive X-ray spectrometer (EDS), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) images. The chemical composition and possible correlations with morphology of nanominerals and UFP, as well as aspects of nanominerals and UFP, are discussed in the context of human health exposure, as well as in relation to management of the nanominerals and UFP in PG environments.
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Affiliation(s)
- Luis F O Silva
- Catarinense Institute of Environmental Research and Human Development-IPADHC, Capivari de Baixo, Santa Catarina, Brazil.
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Hower JC, Senior CL, Suuberg EM, Hurt RH, Wilcox JL, Olson ES. Mercury capture by native fly ash carbons in coal-fired power plants. Prog Energy Combust Sci 2010; 36:10.1016/j.pecs.2009.12.003. [PMID: 24223466 PMCID: PMC3820115 DOI: 10.1016/j.pecs.2009.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The control of mercury in the air emissions from coal-fired power plants is an on-going challenge. The native unburned carbons in fly ash can capture varying amounts of Hg depending upon the temperature and composition of the flue gas at the air pollution control device, with Hg capture increasing with a decrease in temperature; the amount of carbon in the fly ash, with Hg capture increasing with an increase in carbon; and the form of the carbon and the consequent surface area of the carbon, with Hg capture increasing with an increase in surface area. The latter is influenced by the rank of the feed coal, with carbons derived from the combustion of low-rank coals having a greater surface area than carbons from bituminous- and anthracite-rank coals. The chemistry of the feed coal and the resulting composition of the flue gas enhances Hg capture by fly ash carbons. This is particularly evident in the correlation of feed coal Cl content to Hg oxidation to HgCl2, enhancing Hg capture. Acid gases, including HCl and H2SO4 and the combination of HCl and NO2, in the flue gas can enhance the oxidation of Hg. In this presentation, we discuss the transport of Hg through the boiler and pollution control systems, the mechanisms of Hg oxidation, and the parameters controlling Hg capture by coal-derived fly ash carbons.
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Affiliation(s)
- James C Hower
- University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (1+859-257-0261; )
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Silva LFO, Moreno T, Querol X. An introductory TEM study of Fe-nanominerals within coal fly ash. Sci Total Environ 2009; 407:4972-4974. [PMID: 19525000 DOI: 10.1016/j.scitotenv.2009.05.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 05/25/2009] [Accepted: 05/26/2009] [Indexed: 05/27/2023]
Abstract
The investigation presented here was conducted during a wider experiment on the technical feasibility and environmental impacts of tire combustion in a Brazilian coal-fired power station. Nanometric-sized crystalline phases in fly ash were characterised using energy-dispersive X-ray spectrometer (EDS) and high-resolution transmission electron microscopy (HR-TEM) images. The nanoparticles, which register abundance peaks at 10 nm and 100 nm, include iron-rich oxide (e.g. hematite), Fe-sulphate (e.g., yavapaiite: KFe(SO4)2), and Fe-aluminumsilicate glass. Individual metalliferous nanoparticles have a heterogeneous microstructure in which elements such as iron, aluminum and silicon are not uniformly distributed. HR-TEM offers a powerful analytical technique in the study of fly ash nanoparticles, providing a better understanding of the detailed chemistry of this potentially strongly bioreactive component of atmospheric particulate matter.
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Affiliation(s)
- L F O Silva
- Catarinense Institut of Environmental Research and Human Development-GPADHC, Capivari de Baixo, Santa Catarina, Brazil.
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30
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Ruhl L, Vengosh A, Dwyer GS, Hsu-Kim H, Deonarine A, Bergin M, Kravchenko J. Survey of the potential environmental and health impacts in the immediate aftermath of the coal ash spill in Kingston, Tennessee. Environ Sci Technol 2009; 43:6326-33. [PMID: 19746733 DOI: 10.1021/es900714p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An investigation of the potential environmental and health impacts in the immediate aftermath of one of the largest coal ash spills in U.S. history at the Tennessee Valley Authority (TVA) Kingston coal-burning power plant has revealed three major findings. First the surface release of coal ash with high levels of toxic elements (As = 75 mg/kg; Hg = 150 microg/kg) and radioactivity (226Ra + 228Ra = 8 pCi/g) to the environment has the potential to generate resuspended ambient fine particles (< 10 microm) containing these toxics into the atmosphere that may pose a health risk to local communities. Second, leaching of contaminants from the coal ash caused contamination of surface waters in areas of restricted water exchange, but only trace levels were found in the downstream Emory and Clinch Rivers due to river dilution. Third, the accumulation of Hg- and As-rich coal ash in river sediments has the potential to have an impact on the ecological system in the downstream rivers by fish poisoning and methylmercury formation in anaerobic river sediments.
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Affiliation(s)
- Laura Ruhl
- Division of Earth and Ocean Sciences, Nicholas School of the Environment, 205 Old Chemistry Building, Box 90227, Duke University, Durham, North Carolina 27708, USA
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