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Lai J, Wang P, Qi H, Ma Y, Han Z, Heidelore F, Li X, Lin X. Calcium oxide adsorption of gas phase PCDD/Fs and its impact on the adsorption properties of activated carbon. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 361:124750. [PMID: 39151785 DOI: 10.1016/j.envpol.2024.124750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/27/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024]
Abstract
Calcium oxide (CaO), utilized in semi-dry/dry desulfurization systems at municipal solid waste incineration (MSWI) plants, demonstrates some capability to remove polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study assessed the gas-phase PCDD/F removal performance of CaO, activated carbon (AC) and CaO-AC mixtures. Alone, CaO achieved removal efficiencies of only 31.9% for mass and 50.8% for I-TEQ concentration. However, CaO-AC mixtures exhibited significantly higher efficiencies, reaching 96.0% and 92.5% for mass and I-TEQ concentrations, respectively, surpassing those of AC alone, which were 74.7% and 58.5%. BET analysis indicated that CaO's limited surface area and pore structure are major constraints on its adsorption performance. Density functional theory (DFT) calculations revealed that the π-π electron donor-acceptor (EDA) interaction enhances the adsorption between AC and PCDD/F, with adsorption energies ranging from -1.02 to -1.24 eV. Additionally, the induced dipole interactions between CaO and PCDD/F contribute to adsorption energies ranging from -1.13 to -1.43 eV. Moreover, with increasing chlorination levels, PCDD/F molecules are more predisposed to accept electron transfers from the surfaces of AC or CaO, thereby facilitating adsorption. The calculation for mixed AC and CaO showed that CaO modifies AC's properties, enhancing its ability to adsorb gas phase PCDD/Fs, with the higher adsorption energy and more electrons transfer, aligning with gas phase PCDD/Fs adsorption experiments. This study provides a comprehensive understanding of how CaO influences the PCDD/F adsorption performance of AC.
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Affiliation(s)
- Jianwen Lai
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Peiyue Wang
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Hongbo Qi
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yunfeng Ma
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China
| | - Zhongkang Han
- School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, China
| | - Fiedler Heidelore
- Örebro University, School of Science and Technology, 701 82, Örebro, Sweden
| | - Xiaodong Li
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaoqing Lin
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
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Cui C, Liu M, Li L, Yan D, Chen C, Wang M, Wang J, Huang Q. Effects of increasing chlorine concentration in feedstock on the emission and distribution characteristic of dioxins in circular fluidized bed boiler. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:10202-10212. [PMID: 36071356 DOI: 10.1007/s11356-022-22867-3] [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: 05/21/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Field studies were conducted to study the emission and distribution characteristics of dioxins by elevating the chlorine concentration in feedstock in a circular fluidized bed boiler. The concentration and total equivalent quantity of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in all flue gas, electrostatic ash, bag filter ash, and bottom ash samples under blank condition (i.e., feedstock was normal coal) and chlorine labeling condition (i.e., feedstock mixed with coal and chlorine-containing labeling agent) were analyzed. Results illustrated that the concentration of PCDD/Fs in all gaseous and ash samples increased with the addition of chlorine in feedstock, with the largest and least increment in dioxin concentration observed in electrostatic ash and flue gas. PCDDs were the predominate congeners in flue gas, accounted for 50.1-60.4% of the total PCDD/F concentration under chlorine labeling and blank conditions, while PCDD/F distribution changed from PCDD- to PCDF-predominate by increasing chlorine content in feedstock under all field test conditions: 46.6-92.9%, 34.0-76.1%, and 47.0-53.1% of PCDFs were distributed in electrostatic ash, bag filter ash, and bottom ash, respectively. Highly chlorinated PCDD/F congeners such as O8CDD/F and 1,2,3,4,6,7,8-H7CDD/F were the primary contributors to dioxin concentration in flue gas and bottom ash samples, whereas low-chlorinated 2,3,7,8-T4CDF and 1,2,3,7,8-P5CDF congeners became critically dominating in electrostatic and bag filter ash.
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Affiliation(s)
- Changhao Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
| | - Meijia Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
| | - Li Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
| | - Dahai Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China.
| | - Chao Chen
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
| | - Mingwei Wang
- School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing, 102206, China
| | - Jianyuan Wang
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
| | - Qifei Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
- State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control, Beijing, 100012, China
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Influence of iron ore properties on dioxin emissions during iron ore sintering. Sci Rep 2022; 12:21080. [PMID: 36473951 PMCID: PMC9726927 DOI: 10.1038/s41598-022-25752-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
Iron ores are principal input materials for iron and steel-making industries. Quality of iron ores is one of the critical parameters for formation of environmental pollutants related to the steel-making process. Dioxins are identified as one of the most toxic pollutants emitted during ironmaking, specifically during the sintering process. This study applied four types of iron ores and analyzed their moisture, density, particle size distribution and element concentrations to investigate their effect on the dioxin formation during sintering. Each type of iron ore was processed in a sinter pot grate. During each processing route, exhausted dust and generated sinter products were collected and subjected to PCDD/F and PCB analysis. Statistical analysis was applied to assess correlations between properties of iron ores and exhausted dioxin emissions, identifying key contributors to dioxin formation during sintering process. Results showed that Fe in iron ores was positively and significantly related to PCB 114 formation in dust and confirmed its co-catalytic effect on dioxin formation. Concentrations of Al, Ti and Cl in iron ores greatly increased PCDD/F and PCB emissions in the sintered products compared to dioxins in dust samples. The S levels and density of iron ores were highly related to the increasing PCDD/F and PCB emissions in both sinter and dust samples. By contrast, concentrations of Si in iron ores played a significant role in decreasing PCDD/F and PCB emissions in both sinter and dust samples. This study also confirmed the optimum size (< 1 mm-2.59 mm) for iron ores, which helps reduce dioxin emissions without affecting the quality of iron and steel-making products.
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Shen J, Yang L, Liu G, Zhao X, Zheng M. Occurrence, profiles, and control of unintentional POPs in the steelmaking industry: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145692. [PMID: 33940761 DOI: 10.1016/j.scitotenv.2021.145692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
The steelmaking industry is an important source of unintentionally produced persistent organic pollutants (UP-POPs). This review summarizes the emission levels, characteristics, and formation mechanisms of UP-POPs, including halogenated dioxins, polychlorinated biphenyls, polychlorinated naphthalenes, and penta- and hexa- chlorobenzenes in the steelmaking industry to improve our understanding of the emissions of UP-POPs from the steelmaking industry. The factors influencing UP-POP formation during the iron ore sintering (IOS) process are also reviewed. The raw materials and temperature during the steelmaking process are important factors influencing UP-POP generation. Raw materials containing plastics, paints, cutting oil, rubber, and iron from electronic waste recycling can contribute to high emissions of UP-POPs during steelmaking processes. Electrostatic precipitator dust contains chlorine, carbon, and metals, which are usually recycled as a component of the raw material, and could also promote dioxin formation and emissions from IOS. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are easily formed in high concentrations at temperatures in the range of 200 °C-650 °C. This review also provides a comprehensive summary of the UP-POP emission limits in the steel industry worldwide and the best available techniques and environmental practices for UP-POP emission reduction. The information in this review will be useful for the reduction of UP-POPs in the steelmaking process.
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Affiliation(s)
- Jia Shen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoguang Zhao
- College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
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Zhan M, Ma Y, Chen T, Lin X, Zhang S, Xu S, Li X, Yan J. PCDD/Fs characteristics in flue gas and surrounding environment of iron and steel smelting industry. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:14092-14104. [PMID: 33205268 DOI: 10.1007/s11356-020-11650-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/12/2020] [Indexed: 06/11/2023]
Abstract
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations and distributions, emission factors and amounts, and ambient air and soil potential sources were investigated by collecting flue gas, ambient air, and soil samples from ten sintering furnaces and two electric arc furnaces of eight iron and steel smelting industries (ISSI) in China. In flue gas, the concentrations of PCDD/Fs ranged from 0.05 to 2.93 ng I-TEQ Nm-3 (mass, from 0.38 to 30.67 ng Nm-3), with an average of 0.42 ng I-TEQ Nm-3 (mass, 4.99 ng Nm-3), respectively. In ambient air, the concentrations ranged from 0.05 to 0.35 pg I-TEQ m-3 (mass, from 0.66 to 5.66 pg m-3), with an average of 0.20 pg I-TEQ m-3 (mass, 2.96 pg m-3), respectively. In surface soil, the concentrations ranged from 1.80 to 21.02 ng I-TEQ kg-1 (mass, from 34.29 to 836.00 ng kg-1), with an average of 5.82 ng I-TEQ kg-1 (mass, 252.10 ng kg-1), respectively. In deep soil, the concentrations ranged from 1.17 to 12.00 ng I-TEQ kg-1 (mass, from 56.83 to 1488.00 ng kg-1), with an average of 7.76 ng I-TEQ kg-1 (mass, 433.20 ng kg-1), respectively. Compared with emission limits for PCDD/Fs, the compliance was 78.9% in flue gas, 100% in ambient air, and 77.3% in soil. In congener profiles, the contributions of PCDFs were much higher than those of PCDDs in flue gas and ambient air, but the opposite was observed in soil. In ten sintering furnaces, the emission factors ranged from 22.11 to 901.22 ng I-TEQ t-1, with an average of 373.80 ng I-TEQ t-1, respectively. In two electric arc furnaces, the emission factors were 1667.52 and 894.96 ng I-TEQ t-1, with an average of 1281.24 ng I-TEQ t-1. According to both principal component analysis and hierarchical cluster analysis, all ambient air samples were affected by the emissions of PCDD/Fs from ISSIs, but to different degrees. However, the concentrations of PCDD/Fs in most soil samples were not influenced by the ISSI emissions.
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Affiliation(s)
- Mingxiu Zhan
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou, 310018, China.
| | - Yufeng Ma
- Petrochina West Pipeline Company, Urumchi, 830000, China
| | - Tong Chen
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaoqing Lin
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Shiying Zhang
- The Tarim Oilfield Company of Petro China, Korla, 841000, China
| | - Shuaixi Xu
- Zhejiang Electric Power Design Institute Co., Ltd, Hangzhou, 310012, China
| | - Xiaodong Li
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jianhua Yan
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
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Li H, Liu W, Lu A, Li C, Die Q, Lei R, Wu X. PCDD/Fs emissions from secondary copper production synergistically controlled by fabric filters and desulfurization. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 270:116065. [PMID: 33221088 DOI: 10.1016/j.envpol.2020.116065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
The effects of fabric filters and desulfurization systems during secondary copper smelting on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations, emission coefficients, and profiles were studied in an oxygen-rich smelting furnace and an anode furnace. In the anode furnace, the toxic equivalent (TEQ) concentration ranges were 0.106-1.04 ng World Health Organization (WHO)-TEQ/m3 at the fabric filters inlet and 0.027-0.17 ng WHO-TEQ/m3 at the outlet. For the oxygen-rich smelting furnace, the TEQ concentration ranges were 1.21-1.93 and 0.010-0.019 ng WHO-TEQ/m3 at the desulfurization system inlet and outlet, respectively. The TEQs in the outlet stack gases of the desulfurization system from the anode furnace were 0.0041-0.016 ng WHO-TEQ/m3. It is likely that PCDD/Fs that were taken away from the stack gases were adsorbed by the fly ash and gypsum. Solid residues were the dominant release routes for PCDD/Fs. PCDD/Fs congener and homologue profiles of stack gases from different smelting stages were similar. The contributions of more chlorinated homologues from the anode furnace decreased observably after the stack gases passed through the fabric filters. However, the desulfurization process did not greatly change the PCDD/Fs homologue profiles. Overall, both the fabric filters and desulfurization systems showed excellent removal efficiencies for PCDD/Fs in the stack gases, which reduced the TEQ emissions to well below the 0.5 ng WHO-TEQ/m3 to achieve standard discharge.
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Affiliation(s)
- Haifeng Li
- Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing Research Center for Agricultural Standards and Testing, Beijing, 100097, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Wenbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Hangzhou Institute for Advanced Study, UCAS, Hangzhou, 310024, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Anxiang Lu
- Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing Research Center for Agricultural Standards and Testing, Beijing, 100097, China
| | - Cheng Li
- Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing Research Center for Agricultural Standards and Testing, Beijing, 100097, China
| | - Qingqi Die
- Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing Research Center for Agricultural Standards and Testing, Beijing, 100097, China
| | - Rongrong Lei
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaolin Wu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Cui L, Ba K, Li F, Wang Q, Ma Q, Yuan X, Mu R, Hong J, Zuo J. Life cycle assessment of ultra-low treatment for steel industry sintering flue gas emissions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138292. [PMID: 32298887 DOI: 10.1016/j.scitotenv.2020.138292] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 03/09/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
The largest contributor to pollutant emissions is the sintering process in steel industry. Ultra-low emission policy for the Chinese steel industry states that emission concentrations of particulate matter, SO2 and NOx should not exceed 10, 35 and 50 mg/m3 respectively. The emission concentrations of the steel industry are the same as the ultra-low emission policy for the coal-fired power industry, but the pollutant control technologies of the two industries are different. Life cycle assessment method is applied to analyze the latest ultra-low treatment process for sintering flue gas emissions which includes electrostatic precipitation, ozone oxidation, wet desulfurization, wet denitration, condensation dehumidification and wet electrostatic precipitation. Following this novel ultra-low emission treatment, the concentrations of particulate matter, SO2, NOx, and PCDDs in the sintering flue gas decreased very significantly, attaining the new emission standard. With 1 ton of sinter as the functional unit and "cradle to gate" as the system boundary, the environmental impact of the process is 0.1811 and the total economic cost is 172.79 RMB, of which internal cost is 34.64 RMB and external cost is 138.15 RMB. The main environmental impacts result from applying the wet denitration and ozone oxidation processes. Sodium sulfite in the wet denitration process, and electricity and liquid oxygen in the ozone oxidation process are the key inputs that cause environmental impact. These findings are useful for a further optimization of the ultra-low emissions process from both the environmental and economic perspective, which is applicable in other regions of the world.
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Affiliation(s)
- Lin Cui
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China
| | - Kaiming Ba
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China
| | - Fangqiu Li
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China
| | - Qingsong Wang
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China
| | - Qiao Ma
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China
| | - Xueliang Yuan
- School of Energy and Power Engineering, Shandong University, Jinan 250061, China.
| | - Ruimin Mu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Jinglan Hong
- School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Jian Zuo
- School of Architecture & Built Environment, The University of Adelaide, SA 5005, Australia
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Shi Q, Long HM, Chun TJ, Gao ZF. Catalytic Combustion of Chlorobenzene with VOx/CeO2 Catalysts: Influence of Catalyst Synthesis Method. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2019. [DOI: 10.1515/ijcre-2019-0084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
VOx/CeO2 catalysts with various nanostructure were synthesized by the hydrothermal method and used in catalytic combustion of chlorobenzene (CB) at a low temperature. XRD, BET, TEM, Raman, XPS, and H2-TPR were employed to reveal that catalysts VOx on CeO2 support had considerable activity for CB combustion. VOx/CeO2 catalysts prepared with ammonium to adjust pH value and added P123 as a surfactant, showed the highest CB conversion ratio of 60 % at 250 °C and 100 % at 400 °C. It showed that preparation method could infect the shape evolution and surface species during the synthesis. The new phase CeVO4 formed in VOx/CeO2 catalysts improved the catalysts efficiency by increasing oxygen vacancies.
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Song S, Zhou X, Guo C, Zhang H, Zeng T, Xie Y, Liu J, Zhu C, Sun X. Emission characteristics of polychlorinated, polybrominated and mixed polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs, and PBCDD/Fs) from waste incineration and metallurgical processes in China. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 184:109608. [PMID: 31505407 DOI: 10.1016/j.ecoenv.2019.109608] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/09/2019] [Accepted: 08/22/2019] [Indexed: 06/10/2023]
Abstract
Typical thermal processes are common sources of polychlorinated, polybrominated and mixed polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, PBDD/Fs, and PBCDD/Fs); however, very few reports have investigated their coemission. To clarify the emission characteristics of these DD/Fs, two municipal waste incinerators (MWIs), three hazardous waste incinerators (HWIs), one cement kiln coprocessing municipal waste incinerator (CMWI), one secondary copper smelter (SCu), and one iron and steel sintering smelter (ISS) in China were investigated. In total, 17 congeners of PCDD/Fs, 14 congeners of PBDD/Fs, and 12 congeners of PBCDDs in stack flue gases from these thermal processes were analyzed using a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS) in this study. PCDD/Fs, PBDD/Fs and PBCDD/Fs were detectable in all samples, with total concentrations of 911-5.15 × 103 pg/Nm3 (80.2-414 pg TEQ/Nm3). The concentrations of each DD/F were similar within the same type of facility and varied among different types of facilities. The contributions of PBDD/Fs and PBCDD/Fs to the total concentrations exceeded that of PCDD/Fs in some cases, such as in HWIs and SCu. In general, the ∑Cl4-7 CDFs and ∑Cl7-8 CDDs, 1,2,3,4,6,7,8-HpBDF, and 1-B-2,3,7,8-TeCDD and 2-B-1,3,7,8-TeCDD were the dominant congeners in the PCDD/F, PBDD/F, and PBCDD/F mass concentrations, respectively. Several other congeners present at low mass concentrations, such as 1,2,3,4,7,8-HxBDF, have potential as major contributors to the TEQs due to their high toxic equivalency factors. These results reveal the necessity of synergistically inhibiting the occurrences of PCDD/Fs, PBDD/Fs, and PBCDD/Fs from these sources and provide valuable information for use in the source identification of these pollutants in the environment.
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Affiliation(s)
- Shuang Song
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Xin Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China; Zhejiang Environmental Monitoring Center, Hangzhou, 310012, China
| | - Chenqi Guo
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Haiyan Zhang
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China.
| | - Tao Zeng
- College of Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Yidong Xie
- Zhejiang Environmental Monitoring Center, Hangzhou, 310012, China
| | - Jinsong Liu
- Zhejiang Environmental Monitoring Center, Hangzhou, 310012, China
| | - Chaofei Zhu
- State Environmental Protection Key Laboratory of Dioxin Pollution Control, National Research Center for Environmental Analysis and Measurement, Beijing, 100029, China
| | - Xingrong Sun
- South China Institute of Environmental Sciences, MEE, Guangzhou, 510655, China
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Xu Y, Zhou M, Hu J, Xu Y, Luo G, Li X, Yao H. Particulate matter filtration of the flue gas from iron-ore sintering operations using a magnetically stabilized fluidized bed. POWDER TECHNOL 2019. [DOI: 10.1016/j.powtec.2018.09.095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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11
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Wang M, Li Q, Liu W. Effects of Desulfurization Processes on Polybrominated Dibenzo- p-dioxin and Dibenzofuran Emissions from Iron Ore Sintering. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5764-5770. [PMID: 29687723 DOI: 10.1021/acs.est.8b01028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Installing desulfurization operations and closing outdated facilities can effectively decrease pollutant emissions from iron ore sintering plants (IOSPs). Polybrominated dibenzo- p-dioxin and dibenzofuran (PBDD/F) emissions from different-sized IOSPs with different desulfurization operations were analyzed. The desulfurization operations' PBDD/F removal efficiencies were 53.6%-97.1%, and were higher for wet desulfurization operations than for semidry and dry operations. The removed PBDD/Fs were transferred to the desulfurization products. The removal efficiencies of PBDF homologues increased with the degree of bromination. A PBDD/F emission inventory for Chinese IOSPs was compiled. PBDD/F emissions in stack gases, desulfurization products, and discarded fly ash (previously ignored) from 2003 to 2015 were 1218, 400, and 245 g toxic equivalents, respectively. PBDD/F concentrations in stack gases and fly ash were higher for small IOSPs (<90 m2), indicating the importance of phasing them out. Indeed, in China, such phasing out decreased PBDD/F emissions in stack gases, desulfurization products, and discarded fly ash by 1021, 891, and 3253 g toxic equivalents, respectively, between 2003 and 2015. PBDD/F emissions in stack gases have been controlled in Chinese regions with the highest emissions, but PBDD/F emissions in desulfurization products and fly ash are increasing.
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Affiliation(s)
- Mengjing Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- School of Civil and Environmental Engineering , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639789 , Singapore
| | - Qianqian Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Wenbin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
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Wang M, Li Q, Liu W, Fang M, Han Y. Monochlorinated to Octachlorinated Polychlorinated Dibenzo-p-dioxin and Dibenzofuran Emissions in Sintering Fly Ash from Multiple-Field Electrostatic Precipitators. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1871-1879. [PMID: 29345127 DOI: 10.1021/acs.est.7b04848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emissions in fly ash from multiple-field electrostatic precipitators in different sized sintering plants were studied. The monochlorinated-trichlorinated and tetrachlorinated-octachlorinated PCDD/F concentrations were higher for small plants (90 m2) than for medium (91-180 m2) and large (>180 m2) plants. The PCDD/F concentrations and less-chlorinated PCDD/F contributions to the total PCDD/F concentrations increased as the fly ash particle size decreased moving through the precipitator stages; the abundance of monochlorinated-trichlorinated PCDD/F congeners and homologues also increased. The ash particle size and surface area can be directly used to indicate monochlorinated-trichlorinated PCDD/Fs and toxic equivalents (TEQs). Previously ignored PCDD/F emissions in discarded fly ash were identified. Estimated total monochlorinated-trichlorinated PCDD/F and TEQ emissions in discarded fly ash were 155 and 1.979 kg TEQ, respectively, in 2003-2014, and the ratio between annual PCDD/F emissions in discarded fly ash and flue gases has gradually increased. Reductions in monochlorinated-trichlorinated PCDD/F emitted in flue gas and fly ash in 2003-2014 were 28 and 40 kg, respectively, because of the phasing out of small-scale plants. Reductions in TEQs emitted in flue gas and fly ash in 2003-2014 were 7476 and 180 g TEQ, respectively.
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Affiliation(s)
- Mengjing Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- School of Civil and Environmental Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639789, Singapore
| | - Qianqian Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Wenbin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Mingliang Fang
- School of Civil and Environmental Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639789, Singapore
| | - Ying Han
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
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Liu X, Ye M, Wang X, Liu W, Zhu T. Gas-phase and particle-phase PCDD/F congener distributions in the flue gas from an iron ore sintering plant. J Environ Sci (China) 2017; 54:239-245. [PMID: 28391935 DOI: 10.1016/j.jes.2016.01.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/25/2016] [Accepted: 01/26/2016] [Indexed: 06/07/2023]
Abstract
The activated carbon injection-circulating fluidized bed (ACI-CFB)-bag filter coupling technique was studied in an iron ore sintering plant. For comparison, the removal efficiencies under the conditions without or with ACI technology were both evaluated. It was found that the polychlorinated dibenzo-p-dioxins and dibenzofuran (PCDD/F) removal efficiency for total international toxic equivalence quantity (I-TEQ) concentration was improved from 91.61% to 97.36% when ACI was employed, revealing that ACI was very conducive to further controlling the PCDD/F emissions. Detailed congener distributions of PCDD/Fs in the gas-phase and particle-phase of the Inlet and Outlet samples were determined. Additionally, the PCDD/F distribution for the Fly ash-with ACI sample of was also studied.
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Affiliation(s)
- Xiaolong Liu
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Meng Ye
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Xue Wang
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen Liu
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Tingyu Zhu
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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Wang M, Liu W, Hou M, Li Q, Han Y, Li H, Yan N, Zheng M. Mono- to Octachlorinated Polychlorinated Dibenzo-p-dioxin and Dibenzofuran Emissions from Sintering Plants Synergistically Controlled by the Desulfurization Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:5207-5215. [PMID: 27124088 DOI: 10.1021/acs.est.5b06095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The influence of desulfurization systems in sintering plants on polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations, profiles, and emission factors was studied. Mono- to tri-CDD/Fs and tetra- to octa-CDD/F concentrations were 4.4 ± 2.3 and 10.5 ± 8.3 ng m(-3), respectively, at the inlets and 0.87 ± 0.48 and 0.47 ± 0.22 ng m(-3), respectively, after desulfurization. The toxic equivalents (TEQs) were 0.95 ± 0.093 and 0.51 ± 0.040 ng of I-TEQ m(-3) at the inlets and after desulfurization, respectively. The congener profiles and homologue distributions were dominated by 2-MoCDF and MoCDF, respectively. The PCDD/F removal efficiencies achieved by desulfurization increased as the chlorination level increased. The PCDD/Fs became adsorbed to gypsum. Annual mono- to tri-CDD/Fs PCDD/F and TEQ (tetra- to octa-CDD/F) emission factors for flue gas and gypsum between 2003 and 2012 were determined. The total amounts of mono- to tri-CDD/Fs emitted in flue gas and gypsum between 2003 and 2012 were 10.7 and 10.2 kg, respectively. The total TEQs emitted in flue gas and gypsum between 2003 and 2012 were estimated to be 15486 and 1878 g of I-TEQ, respectively. PCDD/Fs adsorbed to gypsum are not effectively eliminated. The PCDD/F concentrations increased as the fly ash surface area increased moving through the electrostatic precipitator stages.
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Affiliation(s)
- Mengjing Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
- School of Ecological Technology and Engineering, Shanghai Institute of Technology , Shanghai 201418, China
| | - Wenbin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Meifang Hou
- School of Ecological Technology and Engineering, Shanghai Institute of Technology , Shanghai 201418, China
| | - Qianqian Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Ying Han
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Haifeng Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Nan Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
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Mi HH, Wang WJ, Lin SL, Lai YC, Mwangi JK, Wang LC, Chang-Chien GP. Long-term monitoring and modeling of polychlorinated dibenzo-p-dioxins and dibenzofurans from municipal solid waste incinerators and surrounding area in northern Taiwan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:10751-10764. [PMID: 24888609 DOI: 10.1007/s11356-014-3019-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 05/07/2014] [Indexed: 06/03/2023]
Abstract
Municipal solid waste incinerators (MSWIs) have long been the major contributors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to ambient air in Taiwan. After stringent MSWI emission standards were introduced in 2001, the long-term continuous monitoring of flue gas and ambient air quality became necessary to ensure the effectiveness of the related control strategies. Three MSWIs and the surrounding ambient air were investigated in the current study for PCDD/F characteristics during 2006 to 2011. The average concentrations in the flue gas ranged from 0.008 ~ 0.0488 ng I-TEQ/Nm(3), which is much less than the emission standard in Taiwan (0.1 ng I-TEQ/Nm(3)) (I-TEQ is the abbreviation of International Toxic Equivalent). This led to extremely low levels in the ambient air, 0.0255 pg I-TEQ/Nm(3), much less than the levels seen in most urban areas around the world. Additionally, the results obtained using the Industrial Source Complex Short-Term Dispersion Model (ISCST3) indicate that the PCDD/F contributions from the three MSWIs to the ambient air were only in the range from 0.164 ~ 0.723 %. Principal component analysis (PCA) showed that the PCDD/Fs in the air samples had very similar characteristics to those from mobile sources. The results thus show that stringent regulations have been an effective control strategy, especially for urban areas, such as Taipei City.
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Affiliation(s)
- Hsiao-Hsuan Mi
- Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, No. 60, Sec. 1, Erren Rd., Tainan, 71710, Taiwan, Republic of China
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Chen YC, Tsai PJ, Mou JL, Kuo YC, Wang SM, Young LH, Wang YF. A pilot study for determining the optimal operation condition for simultaneously controlling the emissions of PCDD/Fs and PAHs from the iron ore sintering process. CHEMOSPHERE 2012; 88:1324-1331. [PMID: 22704976 DOI: 10.1016/j.chemosphere.2012.05.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/05/2012] [Accepted: 05/19/2012] [Indexed: 06/01/2023]
Abstract
In this study, the cost-benefit analysis technique was developed and incorporated into the Taguchi experimental design to determine the optimal operation combination for the purpose of providing a technique solution for controlling both emissions of PCDD/Fs and PAHs, and increasing both the sinter productivity (SP) and sinter strength (SS) simultaneously. Four operating parameters, including the water content, suction pressure, bed height, and type of hearth layer, were selected and all experimental campaigns were conducted on a pilot-scale sinter pot to simulate various sintering operating conditions of a real-scale sinter plant. The resultant optimal combination could reduce the total carcinogenic emissions arising from both emissions of PCDD/Fs and PAHs by 49.8%, and increase the sinter benefit associated with the increase in both SP and SS by 10.1%, as in comparison with the operation condition currently used in the real plant. The ANOVA results indicate that the suction pressure was the most dominant parameter in determining the optimal operation combination. The above result was theoretically plausible since the higher suction pressure provided more oxygen contents leading to the decrease in both PCDD/F and PAH emissions. But it should be noted that the results obtained from the present study were based on pilot scale experiments, conducting confirmation tests in a real scale plant are still necessary in the future.
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Affiliation(s)
- Yu-Cheng Chen
- Department of Environmental and Occupational Health, Medical College, National Cheng Kung University, 138, Sheng-Li Road, Tainan 70428, Taiwan
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Mosca S, Torelli GN, Tramontana G, Guerriero E, Rotatori M, Bianchini M. Concentration of organic micropollutants in the atmosphere of Trieste, Italy. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2012; 19:1927-1935. [PMID: 22767290 DOI: 10.1007/s11356-011-0696-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 12/13/2011] [Indexed: 06/01/2023]
Abstract
PURPOSE PCDD/Fs, PCBs, and PAHs, ubiquitous environmental pollutants which are part of the POPs, are mainly produced by anthropogenic activities as well as by natural processes. Occurrences of these pollutants in different sites in Trieste are presented. PCDD/Fs distribution and their possible emission sources are discussed. METHODS Air samples were collected in different sites near the industrial area, in the city center, and in a background area, using a high-volume sampler equipped with a quartz fiber filter and a PUF. Each sampling lasted a week. RESULTS The concentrations of the organochlorinated pollutants are consistent with literature data (ΣPCDD/Fs and Σdl-PCBs were 5-38 fg TEQ/Nm(3) and 4-31 fg TEQ/Nm(3), respectively), and an apparent seasonal trend was found with slightly higher concentrations in the winter and lower levels in both summer campaigns. Moreover, the isomer profile of each sampling campaign was compared to the fingerprint of a sintering plant, a cement plant, and an incinerator, the main industrial activities in Trieste. CONCLUSIONS The organic micropollutants were detected in levels consistent with literature data. The results show that the pollutants are uniformally distributed in the atmosphere of Trieste. PCDD/F fingerprints in each site remained almost identical during summer and winter, confirming the yearly prevalence of the emissions from the nearby sintering plant.
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Affiliation(s)
- S Mosca
- Institute for Atmospheric Pollution Research, Italian National Research Council (CNR-IIA), Via Salaria km 29,300, 00015 Monterotondo, Rome, Italy.
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Bandyopadhyay A. Selecting Particulate and Gaseous Pollution Control Device. PARTICULATE SCIENCE AND TECHNOLOGY 2012. [DOI: 10.1080/02726351.2011.567320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Kuo YC, Chen YC, Yang JH, Tsai PJ, Wang LC, Chang-Chien GP. Correcting the gas and particle partitioning of PCDD/F congeners in the flue gas of an iron ore sinter plant. JOURNAL OF HAZARDOUS MATERIALS 2012; 209-210:402-407. [PMID: 22305603 DOI: 10.1016/j.jhazmat.2012.01.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 01/07/2012] [Accepted: 01/14/2012] [Indexed: 05/31/2023]
Abstract
This study was aimed at developing an approach for correcting the gas and particle partitioning of PCDD/F congeners for samples collected from the flue gas of an iron ore sinter plant. An iron ore sinter plant equipped with an electrostatic precipitator (EP) and a selective catalytic reduction (SCR) was selected. Flue gas samples were collected at EP inlet, EP outlet and SCR outlet. Both particle- and gas-phase PCDD/Fs were analyzed for each collected sample. PCDD/F contents in EP ashes (EP(ash)) were also analyzed and used to correct the gas and particle partitioning of PCDD/F congeners of the collected flue gas samples. Results show that PCDD/Fs in the flue gas were dominated by the gas-phase. Before correction, the removal efficiencies for the gas- and particle-phase PCDD/Fs for EP were -58.1% and 64.3%, respectively, and SCR were 39.4% and 83.9%, respectively. The above results were conflict with the expected results for both EP and SCR indicating the need for correcting the gas and particle partitioning of PCDD/F congeners for all collected flue gas samples. After correction, the removal efficiencies become more reasonable for EP (=4.22% and 97.7%, respectively), and SCR (=54.7% and 62.0%, respectively). The above results confirm the effectiveness of the approach developed by this study.
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Affiliation(s)
- Yu-Chieh Kuo
- Department of Environmental and Occupational Health, Medical College, National Cheng Kung University. 138, Sheng-Li Road, Tainan 704, Taiwan
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Ooi TC, Lu L. Formation and mitigation of PCDD/Fs in iron ore sintering. CHEMOSPHERE 2011; 85:291-299. [PMID: 21880347 DOI: 10.1016/j.chemosphere.2011.08.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 08/03/2011] [Accepted: 08/04/2011] [Indexed: 05/31/2023]
Abstract
The sintering of iron ore is presently a significant industrial source of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) worldwide owing to the fundamental requirement of the operation of a high temperature process to pre-treat fines and to recycle plant by-products arising from the integrated iron and steelworks. The process is a noteworthy contributor of PCDD/F indirectly due to decreasing PCDD/F releases from municipal solid waste incineration. Commonly PCDD/F formation from the process is associated with the addition of oily mill scales although raw material containing a combination of C, Cl and specific metal catalyst has been shown to drastically increase PCDD/F formation in the process. The degenerate graphitic structure of carbon present in coke fuel and soot formed and the chemistry of catalytic metals and Cl are important factors. A review on PCDD/F emission in this process has been carried out, including examination of its formation mechanism, congener distribution, contributing factors and mitigation strategies, with emphasis on the use of inhibiting compound to achieve suppression. A detailed analysis of the de novo and precursor theories of formation and the contributing factor is given since the subject of PCDD/F formation is still controversial. The de novo formation pathway identified in sinter plants and controlled studies performed in the laboratory as well as at pilot-scale are discussed; where appropriate, a comparison is drawn between sintering and other thermal processes emitting PCDD/Fs. Summary of the latest developments in PCDD/F downstream abatement strategies presently employed in full scale industrial plants is provided. Potential inhibiting compounds are discussed in terms of their mode of action and merits under sintering conditions.
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Affiliation(s)
- Tze Chean Ooi
- Fortescue Metals Group Ltd, 87 Adelaide Terrace, East Perth, WA 6004, Australia.
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Hung PC, Lo WC, Chi KH, Chang SH, Chang MB. Reduction of dioxin emission by a multi-layer reactor with bead-shaped activated carbon in simulated gas stream and real flue gas of a sinter plant. CHEMOSPHERE 2011; 82:72-77. [PMID: 21040943 DOI: 10.1016/j.chemosphere.2010.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 08/18/2010] [Accepted: 10/03/2010] [Indexed: 05/30/2023]
Abstract
A laboratory-scale multi-layer system was developed for the adsorption of PCDD/Fs from gas streams at various operating conditions, including gas flow rate, operating temperature and water vapor content. Excellent PCDD/F removal efficiency (>99.99%) was achieved with the multi-layer design with bead-shaped activated carbons (BACs). The PCDD/F removal efficiency achieved with the first layer adsorption bed decreased as the gas flow rate was increased due to the decrease of the gas retention time. The PCDD/F concentrations measured at the outlet of the third layer adsorption bed were all lower than 0.1 ng I-TEQ Nm⁻³. The PCDD/Fs desorbed from BAC were mainly lowly chlorinated congeners and the PCDD/F outlet concentrations increased as the operating temperature was increased. In addition, the results of pilot-scale experiment (real flue gases of an iron ore sintering plant) indicated that as the gas flow rate was controlled at 15 slpm, the removal efficiencies of PCDD/F congeners achieved with the multi-layer reactor with BAC were better than that in higher gas flow rate condition (20 slpm). Overall, the lab-scale and pilot-scale experiments indicated that PCDD/F removal achieved by multi-layer reactor with BAC strongly depended on the flow rate of the gas stream to be treated.
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Affiliation(s)
- Pao Chen Hung
- Graduate Institute of Environmental Engineering, National Central University, Chungli, Taiwan
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