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Du Y, Shi T, Guo S, Li H, Qin Y, Wang Y, He C, Wei Y. Unraveling the intrinsic mechanism behind the retention of arsenic in the co-gasification of coal and sewage sludge: Focus on the role of Ca and Fe compounds. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134211. [PMID: 38598878 DOI: 10.1016/j.jhazmat.2024.134211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/27/2024] [Accepted: 04/02/2024] [Indexed: 04/12/2024]
Abstract
Minimizing the emission of arsenic (As) is one of the urgent problems during co-gasification of Shenmu coal (SM) and sewage sludge (SS). The intrinsic mechanism of As retention was obtained by analyzing the effect of different SM addition ratios on the As form transformation during co-gasification at 1000 °C under CO2 atmosphere. The results showed that the addition of SM effectively promoted the enrichment of As in the co-gasified residues. Especially, the best As retention rate of 65.71% was achieved with the 70 wt% addition ratio of SM. The addition of SM promoted the adsorption and chemical oxidation of As(III) to the less toxic As(V) through the coupling of Ca and Fe compounds in the co-gasified residues. XRD and XPS results indicated that Fe2O3 adsorbed As2O3(g) after partial conversion to Fe3O4 by the Boudouard reaction, while part of As2O3 was oxidized to As2O5 by lattice oxygen. Finally, the generated As2O5 was successively trapped by CaO and Fe2O3 to form stable Ca3(AsO4)2 and FeAsO4. HRTEM and TEM analysis comprehensively proved that As(III) was stabilized by the lattice cage of CaAl2Si2O8. In conclusion, the co-oxidation of Ca and Fe compounds and lattice stabilization simultaneously played a crucial role in the retention of As2O3(g) during co-gasification.
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Affiliation(s)
- Yujia Du
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
| | - Tingrui Shi
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
| | - Shugang Guo
- Shanxi Provincial Center for Disease Control and Prevention, 8 Xiaonanguan Street, Taiyuan 030012, PR China
| | - Hugang Li
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China; Laboratory of Ecology-based Solutions, College of Ecology, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
| | - Yuhong Qin
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China.
| | - Yuefeng Wang
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
| | - Chong He
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
| | - Yuexing Wei
- College of Environmental Science and Engineering, Taiyuan University of Technology, No. 79 Yingze West Street, Taiyuan 030024, PR China
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Zhang H, Ouyang Z, Li M, Wen B, Zhuang S, Zhao X, Jiang P. Spatial distribution and main drivers of soil selenium in Taihu Lake Basin, Southeast China. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133091. [PMID: 38056274 DOI: 10.1016/j.jhazmat.2023.133091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/13/2023] [Accepted: 11/23/2023] [Indexed: 12/08/2023]
Abstract
Selenium (Se) is an essential micronutrient that is both hazardous and beneficial to living organisms. However, few studies have examined soil Se distribution and its driving mechanisms on a large basin scale. Thus, multivariate statistics, geostatistics, boosted regression trees, and structural equation models were used to investigate the spatial distribution, driving factors, and multivariate interactions of soil Se based on 1753 topsoil samples (0-20 cm) from the Taihu Lake Basin. The results indicated that the soil Se concentration ranged from 0.12 to 57.26 mg kg-1, with a mean value of 0.90 mg kg-1. Overall, the spatial pattern of soil Se gradually decreased from south to north with approximately 1.06% of the soil contaminated with Se. Moisture index (MI), soil moisture (SM), and ≥ 0 ℃ accumulative temperature (AAT0) were the main determinants of soil Se accumulation. Additionally, the substantial effect of SM∩AAT0 on soil Se concentrations demonstrated that climate-soil interactions largely governed the spatial pattern of soil Se. The Se-enriched and Se-contaminated soils occurred mainly in regions with high precipitation, MI, SM, AAT0, and soil organic matter. This study provides a theoretical basis and practical guidance for the remediation of soil Se contamination and the sustainable development of Se-enriched agriculture.
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Affiliation(s)
- Han Zhang
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing 210023, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China
| | - Zhencheng Ouyang
- Ganzhou Institute of Agricultural Sciences, Gannan Academy of Sciences, Ganzhou 341000, China
| | - Manchun Li
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Key Laboratory of Coastal Zone Exploitation and Protection, Ministry of Natural Resources, Nanjing 210023, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China.
| | - Boqing Wen
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China
| | - Sudan Zhuang
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China
| | - Xiaomin Zhao
- Key Laboratory of Poyang Lake Basin Agricultural Resources and Ecology of Ministry of Agriculture and Rural Affairs in China, Jiangxi Agricultural University, Nanchang 330045, China
| | - Penghui Jiang
- College of Public Administration, Nanjing Agricultural University, Nanjing 210095, China; Observation Research Station of Land Ecology and Land Use in the Yangtze River Delta, MNR, Nanjing 210017, China; China Resources & Environment and Development Academy (REDA), Nanjing Agricultural University, Nanjing 210095, China.
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Chen H, Li Z, Zhan L, Zheng S, Wu H, Yang L. The fate of selenium in the desulfurization wastewater evaporation process: Migration mechanisms and risk analysis. CHEMOSPHERE 2023; 325:138310. [PMID: 36889481 DOI: 10.1016/j.chemosphere.2023.138310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Owing to the implementation of the zero wastewater discharge policy in China, stricter supervision and technical requirements have been imposed. Hot flue gas evaporation technology exhibits significant advantages in desulfurization wastewater treatment. However, volatile constituents (such as selenium, Se) present in wastewater may be released, thus disrupting the power plant's original Se balance. In this study, the evaporation of three desulfurization wastewater plants is performed. The release of Se mainly begins from the threshold at which wastewater is evaporated to dryness, and Se release rates of 21.5, 25.1, and 35.6% are detected. Furthermore, the key components and properties of wastewater for Se migration are identified through experiments and density functional theory calculations. Lower pH values and Cl- contents are not conducive to Se stability, and this tendency is more pronounced in selenite. The suspended solid content temporarily traps the Se in the initial evaporation process, as confirmed via a decrease in the Se release rate and a high binding energy (-307.7 kJ/mol). Moreover, results of risk assessment reveal that wastewater evaporation results in a negligible increase in Se concentration. This study evaluates the risk of Se release during wastewater evaporation and provides a basis for Se emission control strategies.
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Affiliation(s)
- Heng Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Zhihao Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Lingxiao Zhan
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Suoqi Zheng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Hao Wu
- School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, China
| | - Linjun Yang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
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Wang H, Zou C, Hu H, Gu G, Dong L, Huang Y, Deng S, Li S. Migration and emission characteristics of trace elements in coal-fired power plant under deep peak load regulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161626. [PMID: 36649769 DOI: 10.1016/j.scitotenv.2023.161626] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
The trace elements (TEs) have caused great harm to the environment due to the large consumption of coal, and their emission from the coal-fired power plant (CFPP) has become a hot issue. The deep peak load regulation (DPLR) become a trend in the CFPP, which will affect the migration and emission of TEs. To explore the effect of the DLPR on the migration and emission characteristics of typical TEs in a 330 MW CFPP, the TEs field tests were carried out during the regulation period. Results showed that a higher load enhanced the migration of Pb, Mn, and Cr from bottom ash to fly ash, while it had little effect on the other TEs. More importantly, >99 % of TEs (93 % of Se) could be captured by air pollution control devices (APCDs), and the emission risk of Se and Mn increased with the load. Compared with the other TEs, it is particularly noteworthy that Se has a higher gaseous proportion in the flue gas, and the emission factor sharply increased from 165 MW to 297 MW. In addition, part of the particulate selenium transformed into a gaseous state across the ESP. This work contributes to understanding the migration characteristic of TEs during the DPLR process of CFPP and provides guidance for TEs control in the CFPP.
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Affiliation(s)
- Huasheng Wang
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chan Zou
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hongyun Hu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Guojian Gu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Lu Dong
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yongda Huang
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shuang Deng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Songgeng Li
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
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5
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Huang Y, Hu H, Fu B, Zou C, Liu H, Liu X, Wang L, Luo G, Yao H. Fine particulate-bound arsenic and selenium from coal-fired power plants: Formation, removal and bioaccessibility. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 823:153723. [PMID: 35150677 DOI: 10.1016/j.scitotenv.2022.153723] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 01/23/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
The arsenic (As) and selenium (Se) in fine particulate matter (PM10) have attracted increasing attentions due to their health effects. However, the emission control of fine particulate-bound arsenic and selenium (fine particulate-bound As/Se) from coal-fired power plants still faces various challenges. Understanding the formation and characteristics of fine particulate-bound As/Se is crucial for developing specific control technologies. This study clarifies the formation mechanism, removal characteristics, and inhalation bioaccessibility of fine particulate-bound As/Se from industrial coal-fired power plants through methods including aerosol generation, As/Se speciation determination, and in vitro bioaccessibility testing. The findings demonstrated that PM1 from pulverized coal-fired (PC) boilers was enriched with As/Se in terms of concentration and mass distribution. Instead, As/Se was mainly distributed in PM2.5-10 from circulating fluidized bed (CFB) boilers. Limestone injection in CFB boilers promoted As/Se enrichment in coarse PM. Fine particulate-bound As was mainly formed by chemical adsorption of As vapors by Ca-minerals, while the formation of fine particulate-bound Se was closely related to active Ca-minerals and Fe-minerals. Furthermore, Ca-bound As was easy to remove by electrostatic precipitator (ESP) and the removal of physically adsorbed SeO2(s) was difficult, which was caused by the specific resistivity of different mineral components. Importantly, finer particulate-bound As/Se posed higher inhalation bioaccessibility, following the order of PM1 ≥ PM1-2.5 > PM2.5-10. In particular, Ca-bound Se in fine PM owned high bioaccessibility. Based on these findings, measures were proposed to suppress the formation of fine particulate-bound As/Se in the furnace and/or strengthen its removal in the post-combustion stage.
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Affiliation(s)
- Yongda Huang
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hongyun Hu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Biao Fu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Chan Zou
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Huimin Liu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaowei Liu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Linling Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Guangqian Luo
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hong Yao
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China
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Ostovar M, Saberi N, Ghiassi R. Selenium contamination in water; analytical and removal methods: a comprehensive review. SEP SCI TECHNOL 2022. [DOI: 10.1080/01496395.2022.2074861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Mojtaba Ostovar
- Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Nima Saberi
- Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, ON, Canada
| | - Reza Ghiassi
- Water and Environmental Measurement and Monitoring Labour, School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran
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Chen YC, Shie RH, Zhu JJ, Hsu CY. A hybrid methodology to quantitatively identify inorganic aerosol of PM 2.5 source contribution. JOURNAL OF HAZARDOUS MATERIALS 2022; 428:128173. [PMID: 35038665 DOI: 10.1016/j.jhazmat.2021.128173] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/10/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
It is difficult to identify inorganic aerosol (IA) (primary and secondary), the main component of PM2.5, without the significant tracers for sources. We are not aware of any studies specifically related to the IA's local contribution to PM2.5. To effectively reduce the IA load, however, the contribution of local IA sources needs to be identified. In this work, we developed a hybrid methodology and applied online measurement of PM2.5 and the associated compounds to (1) classify local and long-range transport PM2.5, (2) identify sources of local PM2.5 using PMF model, and (3) quantify local source contribution to IA in PM2.5 using regression analysis. Coal combustion and iron ore and steel industry contributed the most amount of IA (~42.7%) in the study area (City of Taichung), followed by 32.9% contribution from oil combustion, 8.9% from traffic-related emission, 4.6% from the interactions between agrochemical applications and combustion sources (traffic-related emissions and biomass burning), and 2.3% from biomass burning. The methodology developed in this study is an important preliminary step for setting up future control policies and regulations, which can also be applied to any other places with serious local air pollution.
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Affiliation(s)
- Yu-Cheng Chen
- National Institute of Environmental Health Sciences, National Health Research Institutes, 35 Keyan Road, Zhunan Town, Miaoli 35053, Taiwan; Department of Occupational Safety and Health, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Ruei-Hao Shie
- Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, 321 Guangfu Road, East District, Hsinchu City 30011, Taiwan
| | - Jun-Jie Zhu
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
| | - Chin-Yu Hsu
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan; Center for Environmental Sustainability and Human Health, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist., New Taipei City 24301, Taiwan.
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Ma S, Xu F, Qiu D, Fan S, Wang R, Li Y, Chen X. The occurrence, transformation and control of selenium in coal-fired power plants: Status quo and development. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2022; 72:131-146. [PMID: 34846276 DOI: 10.1080/10962247.2021.2010620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 06/13/2023]
Abstract
As a trace element, selenium can cause serious harm to organisms when the concentration is too high. Coal-fired power plants are the main source of man-made selenium emissions. How to control the selenium pollution of coal-fired power plants to realize the renewable selenium and the sustainability of coal has not attracted enough attention from the whole world. This paper outlines the conversion and occurrence of selenium in coal-fired power plants. A small part of the selenium produced by combustion can be removed by selective catalytic reduction (SCR) and electrostatic precipitator (ESP) after the gas phase undergoes physical condensation and chemical adsorption to combine with the particulate matter in the flue gas.Because the chemical precipitation method has poor selenium removal effect, the remaining part enters the flue gas desulfurization absorption tower and can be enriched in the desulfurization slurry. The occurrence situation and conversion pathway of selenium in desulfurization slurry are introduced subsequently, the research progress of selenium removal from wet desulfurization wastewater is reviewed from three aspects: physics, biology and chemistry. We believe that the coupling application of oxidation-reduction potential (ORP) and pH can optimize selenium removal in the desulfurization system by improving the oxidation control. As a technology for wet desulfurization system to treat selenium pollution, it has a good development prospect in near future.Implications: Selenium is a trace element present in coal. It is not only of great significance to the life activities of organisms, but also a kind of rare resource. As the most important source of man-made emissions, coal-fired power plants will cause waste of selenium resources and selenium pollution in the surrounding environment. In this study, the occurrence, conversion and control of selenium in coal-fired power plants were systematically sorted out and analyzed. It is helpful for scholars to study the selenium transformation process more deeply. It is of great significance for policy formulation of recommended control technologies and emission limits. It is of great value for the formulation of recommended control technology and the in-depth study of the selenium transformation process.
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Affiliation(s)
- Shuangchen Ma
- Hebei Key Laboratory of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, People's Republic of China
- Moe Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, People's Republic of China
| | - Fang Xu
- Hebei Key Laboratory of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, People's Republic of China
- Moe Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, People's Republic of China
| | - Dao Qiu
- Department of Production and Technology, Huadian Xiangyang Electricity Supply Co, Ltd Huadian Xiangyang Electricity Supply Co, Ltd, Xiangyang, People's Republic of China
| | - Shuaijun Fan
- Hebei Key Laboratory of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, People's Republic of China
| | - Ruimin Wang
- Department of Production and Technology, Huadian Xiangyang Electricity Supply Co, Ltd Huadian Xiangyang Electricity Supply Co, Ltd, Xiangyang, People's Republic of China
| | - Yang Li
- Hebei Key Laboratory of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, People's Republic of China
| | - Xiangyang Chen
- Hebei Key Laboratory of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding, People's Republic of China
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9
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Yuan B, Hu H, Huang Y, Fu B, Liu H, Luo G, Zhao Y, Yao H. Condensation and adsorption characteristics of gaseous selenium on coal-fired fly ash at low temperatures. CHEMOSPHERE 2022; 287:132127. [PMID: 34488056 DOI: 10.1016/j.chemosphere.2021.132127] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
Gaseous selenium is of high saturated vapor pressure, making its retention in solid phases quite difficult during coal combustion. The selenium transformation from gaseous form into solid phases at low temperatures can be essential to control selenium emission. To understand the migration of SeO2 (g) on ash particles in the low-temperature zone, this study investigated the speciation of selenium in fly ash and simulated the physical retention of SeO2 (g) on fly ash. The results demonstrated that there was a large proportion of physically-bound Se in the fly ash of pulverized-coal-fired boiler (22.62 %-58.03%), while the content of physically-bound Se in fly ash of circulated fluidized-bed boiler was lower (∼6%). The physically-bound Se was formed through selenium condensation and physical adsorption. The decrease of temperature or the increase of cooling rate could promote the transformation of gaseous selenium to solid phase and the presence of HCl might suppress SeO2 transformation into Se in the condensation process. Meanwhile the compositions of fly ash had a great influence on the selenium adsorption process. Among typical coal-fired ash components, mullite showed the best performance in the selenium capture in the temperature range of 90-200 °C, contributing to the high content of physically-adsorbed selenium in PC fly ash. These findings provided new ideas for improving the removal rate of volatile selenium.
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Affiliation(s)
- Bing Yuan
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hongyun Hu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Yongda Huang
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Biao Fu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Huimin Liu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Guangqian Luo
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yongchun Zhao
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hong Yao
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China
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10
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Zhang Q, Wu B, Wu J, Qi Y, Chu W, Qiao L, Zhang B, Shen P, Tang T. Study on arsenic, selenium, and lead produced in coal combustion: bibliometric method. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:10.1007/s11356-021-14197-7. [PMID: 33939089 DOI: 10.1007/s11356-021-14197-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
The literature on trace element pollutants (arsenic, selenium, lead) produced during coal burning from 2007 to 2020 was summarized by the bibliometric method, and the characteristics of published articles and research trends were analyzed. Taking 2007 as the starting point for statistics on articles in this research direction, there was a process of rapid growth in the total number of published articles by 2015, and it was increased over time. In the last 5 years of statistics, it is found that the number of articles published in China is the largest, accounting for almost half of the total. Most of the articles are published in the fields of energy, environmental protection, etc. Among them, the research on arsenic, selenium, and lead is mainly related to the use of adsorbents. At the same time, the effects of temperature, catalyst, material, and other conditions on the removal efficiency of arsenic, selenium, and lead in coal were considered. Application of photocatalysis, preparation of new adsorption materials, and mining of the properties of existing materials under different experimental conditions are a good development prospect.
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Affiliation(s)
- Qilin Zhang
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Biao Wu
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Jiang Wu
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China.
| | - Yongfeng Qi
- School of Hydraulic Energy and Power Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Weiqun Chu
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Lingxia Qiao
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Bowen Zhang
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Peng Shen
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
| | - Tianhang Tang
- College of Energy and Mechanical Engineering, Shanghai University of Electric Power, No. 2103 Pingliang Road, Shanghai, 200090, China
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Zhang L, Song Q, Xu Z. Arsenic Removal and Recovery of Germanium and Tungsten in Toxic Coal Fly Ash from Lignite by Vacuum Distillation with a Sulfurizing Reagent. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4027-4036. [PMID: 33663209 DOI: 10.1021/acs.est.0c08784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Every year, billions of tons of lignite are burnt to generate electricity, meanwhile generating large amounts of coal fly ash (CFA) that is regarded as an industrial waste. During lignite combustion, arsenic and scarce metals are simultaneously volatilized in the form of oxide into CFA. This study proposed an effective vacuum distillation method to remove As and recover Ge and W from CFA. The feasibility of separating As and recycling Ge and W from CFA was verified by the theoretical analysis. The experimental result indicated that the removal ratio of As was 96 ± 1% and the contents of Ge and W reached 0.75 ± 0.023 and 0.24 ± 0.016 wt % in the residue, which were enriched 17.2 and 1.2 times, respectively, at a temperature of 550 °C, with 50 wt % sulfurizing agent added under pressure of 1 Pa and 240 min of heating. For the condensed product, chemical species As2S3 and As4S4 were detected by X-ray photoelectron spectroscopy analysis. For Ge and W in the residue, GeOx (x < 2), GeS, WOx (x < 3), and WS2 were the main chemical species. The potential mechanism involved in the release of arsenic from CFA, vacuum sulfurization, evaporation, and condensation was proposed. The kinetic analysis indicated that the apparent activation energy (Eα) was 31.24 kJ mol-1. Those results encourage further exploration of vacuum separation technology to environmentally friendly recycle CFA.
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Affiliation(s)
- Lingen Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Qingming Song
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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