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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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Yang X, Wu J, Li M, Qi M, Wang R, Hu J, Jin J. Particle size distributions and health risks of polychlorinated dibenzo-p-dioxin/furans, polychlorinated biphenyls, and polychlorinated naphthalenes in atmospheric particles around two secondary copper smelters in Shandong Province, China. CHEMOSPHERE 2021; 269:128742. [PMID: 33127115 DOI: 10.1016/j.chemosphere.2020.128742] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 06/11/2023]
Abstract
Sixteen samples of atmospheric particles in four size fractions (diameter: > 10 μm, 5-10 μm, 2.5-5 μm, and <2.5 μm) were collected around two secondary copper smelters in Shandong Province, China. The levels, particle size distributions, and potential health risks of polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs) in these samples were analyzed. The concentration ranges for the PCDD/Fs, dl-PCBs, and PCNs were 3.13-5.77 pg m-3, 0.43-0.56 pg m-3, and 4.76-9.89 pg m-3, respectively. All of the compounds accumulated strongly in the particles with diameters of <2.5 μm. The congener profiles of PCDD/Fs in particles of various sizes were similar, and were consistent with those in stack gases from local secondary copper smelters. However, the congener profiles of dl-PCBs and PCNs in the particles with diameters of <2.5 μm differed from those for the other particle size fractions. The proportion of highly chlorinated homologs in particles with diameters of <2.5 μm was much higher than that of particles with diameters of >2.5 μm. The results of a risk assessment indicated that the contribution of PCDD/Fs to the total carcinogenic risk (PCDD/Fs + dl-PCBs + PCNs) was >95%. For the PCDD/Fs, dl-PCBs, and PCNs, 78%, 71%, and 86% of the carcinogenic risk was associated with the <2.5 μm fraction, respectively. This study improves our understanding of the particle size distributions and human health risks of exposure to PCDD/Fs, dl-PCBs, and PCNs in the atmosphere around secondary copper smelters.
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Affiliation(s)
- Xinrui Yang
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China
| | - Jing Wu
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China
| | - Meihong Li
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China
| | - Min Qi
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China
| | - Ran Wang
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China
| | - Jicheng Hu
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China; Beijing Engineering Research Center of Food Environment and Public Health, Minzu University of China, Beijing, 100081, China.
| | - Jun Jin
- College of Life and Environmental Science, Minzu University of China, Beijing, 100081, China; Beijing Engineering Research Center of Food Environment and Public Health, Minzu University of China, Beijing, 100081, China
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Ji Z, Fan X, Gan M, Chen X, Lv W, Li Q, Zhou Y, Tian Y, Jiang T. Influence of sulfur dioxide-related interactions on PM 2.5 formation in iron ore sintering. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:488-497. [PMID: 27870602 DOI: 10.1080/10962247.2016.1259692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/04/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED The formation of PM2.5 (aerosol particulate matter less than 2.5 µm in aerodynamic diameter) in association with SO2 emission during sintering process has been studied by dividing the whole sintering process into six typical sampling stages. A low-pressure cascade impactor was used to collect PM2.5 by automatically segregating particulates into six sizes. It was found that strong correlation existed between the emission properties of PM2.5 and SO2. Wet mixture layer (overwetted layer and raw mixture layer) had the function to simultaneously capture SO2 and PM2.5 during the early sintering stages, and released them back into flue gas mainly in the flue gas temperature-rising period. CaSO4 crystals constituted the main SO2-related PM2.5 during the disappearing process of overwetted layer, which was able to form perfect individual crystals or to form particles with complex chemical compositions. Besides the existence of individual CaSO4 crystals, mixed crystals of K2SO4-CaSO4 in PM2.5 were also found during the first half of the temperature-rising period of flue gas. The interaction between fine-grained Ca-based fluxes, potassium vapors, and SO2 was the potential source of SO2-related PM2.5. IMPLICATIONS The emission property of PM2.5 and SO2 throughout the sintering process exhibited well similarity. This phenomenon tightened the relationship between the formation of PM2.5 and the emission of SO2. Through revealing the properties of SO2-related PM2.5 during sintering process, the potential interaction between fine-grained Ca-based fluxes, potassium vapors, and SO2 was found to be the source of SO2-related PM2.5. This information can serve as the guidance to develop efficient techniques to control the formation and emission of PM2.5 in practical sintering plants.
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Affiliation(s)
- Zhiyun Ji
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Xiaohui Fan
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Min Gan
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Xuling Chen
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Wei Lv
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Qiang Li
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Yang Zhou
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Ye Tian
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
| | - Tao Jiang
- a Department of Iron and Steel Metallurgy, School of Minerals Processing & Bioengineering , Central South University , Changsha , Hunan , People's Republic of China
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Chuang KY, Lai CH, Peng YP, Yen TY. Characteristics of particle-bound polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in atmosphere used in carbon black feeding process at a tire manufacturing plant. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:19451-19460. [PMID: 26257121 DOI: 10.1007/s11356-015-5135-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 07/29/2015] [Indexed: 06/04/2023]
Abstract
Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were estimated for different particle size distributions in a carbon black feeding process at a tire manufacturing plant on 15 days in March and April of 2014. A total of 75 integrated air samples were collected using a micro-orifice uniform deposition impactor (MOUDI). Particle-bound PCDD/Fs were analyzed using a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Concentrations of thoracic particles and total particles produced in the carbon black feeding process of a tire manufacturing plant were measured in ranges of 0.19-2.61 and 0.28-4.22 mg/m(3), respectively. On all sampling days, the three most abundant species of PCDD/Fs were OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF. The mean concentrations of total PCDD/Fs were 0.74-6.83 pg/m(3) within five particle size ranges. Total I-TEQ in particulate matter (PM)<1.0 was 2.2 and 3.2 times higher than those in PM>18 and PM2.5-10, respectively. However, the total I-TEQ of thoracic PM contributed approximately 74 % of the total I-TEQ of total PM. The assessment of health risk indicates that exposure to fractions of thoracic PM by inhalation poses a significant cancer risk (>10(-6)).
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Affiliation(s)
- Kuen-Yuan Chuang
- Department of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung, Taiwan, Republic of China
| | - Chia-Hsiang Lai
- Department of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung, Taiwan, Republic of China.
| | - Yen-Ping Peng
- Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan, Republic of China
| | - Ting-Yu Yen
- Institute of Safety Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung, Taiwan, Republic of China
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Rada EC, Ragazzi M, Schiavon M. Assessment of the local role of a steel making plant by POPs deposition measurements. CHEMOSPHERE 2014; 110:53-61. [PMID: 24880599 DOI: 10.1016/j.chemosphere.2014.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 03/11/2014] [Accepted: 03/15/2014] [Indexed: 06/03/2023]
Abstract
Atmospheric depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were monitored at three sites in the vicinity of a steel making plant, located in an Italian alpine valley. A high variability in the deposition of PCDD/Fs was observed. The influence of the plant was noticeable at two of the sampling sites. However, as the congener profiles demonstrated, wood burning for domestic heating is an additional source of PCDD/Fs for the area under investigation, and this interferes with the characterization of the emissions from the steel plant. The influence of the plant, in terms of PCDD/F deposition, was not noticeable at the most distant site (2km), where an extremely high peak of PCDD/F deposition was measured during the period from 12 January-22 February 2012. The comparison between the congener distribution of PCDD/Fs observed in this sample and the fingerprints of different sources could justify the attribution of this anomalous peak to a possible episode of domestic waste combustion. In order to find a better correlation between the deposition to soil and emissions from the plant, the congener distribution of PCBs was studied. The PCB profiles observed at the three sites well reproduced the average profile found in samples of ash retained by the bag filter of the plant. Thus the monitoring of PCB deposition is an interesting starting point to calibrate dispersion models to assess the impact of steel making activities.
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Affiliation(s)
- E C Rada
- DICAM - Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, I-38123 Trento, Italy.
| | - M Ragazzi
- DICAM - Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, I-38123 Trento, Italy.
| | - M Schiavon
- Fondazione Trentina per la Ricerca sui Tumori c/o DICAM - Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, I-38123 Trento, Italy.
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Onofrio M, Spataro R, Botta S. Deposition fluxes of PCDD/Fs in the area surrounding a steel plant in northwest Italy. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:3917-3929. [PMID: 24585258 DOI: 10.1007/s10661-014-3668-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 01/28/2014] [Indexed: 06/03/2023]
Abstract
The paper aims at investigating the contribution of a steel plant located in a rural area in northwestern Italy (700,000 tons of steel/year) to the deposition fluxes of Polychorinated Dibenzo-p-dioxins and Polychorinated dibenzofurans (PCDD/PCDFs) at local level through the analysis of sampling data, literature data, and air dispersion model (AERMOD)output data. Total measured deposition fluxes of PCDD/PCDFs in three monitoring stations were consistent with other studies carried out in Italy in urban and suburban areas and in rural European areas; while these were lower than those measured in other European urban/suburban areas or in sites influenced by industrial sources. Furthermore, the measured fluxes were also compared with the pattern of PCDD/Fs in ambient air sampled at the same sites in a previous study. This comparison showed a similarity between air concentration and deposition patterns of the samples collected at the three monitoring stations and a clear distinction of these from the source. The study was completed with AERMOD simulations, conducted with a mass mean particle diameter of 0.5 μm, according to the particle size distribution of the samples collected at the source. AERMOD calculated deposition fluxes of two to three orders of magnitude lower than those measured in two monitoring points; while in the most distant monitoring station, the deposition fluxes were too low to be calculated by the model. The simulations confirmed that the most distant monitoring station was not subject to emissions from the steel plant. The analysis highlighted the limited influence of the source in the local PCDD/F deposition fluxes.
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Affiliation(s)
- Maurizio Onofrio
- Department of Engineering of Environment, Land and Infrastructures, Politecnico di Torino, C.so Duca degli Abruzzi, 24, 10129, Turin, Italy
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Combination of a fast cleanup procedure and a DR-CALUX® bioassay for dioxin surveillance in Taiwanese soils. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:4886-904. [PMID: 24806195 PMCID: PMC4053921 DOI: 10.3390/ijerph110504886] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 11/17/2022]
Abstract
Our goal was to determine dioxin levels in 800 soil samples collected from Taiwan. An in vitro DR-CALUX® assay was carried out with the help of an automated Soxhlet system and fast cleanup column. The mean dioxin level of 800 soil samples was 36.0 pg-bioanalytical equivalents (BEQs)/g dry weight (d.w.). Soil dioxin-BEQs were higher in northern Taiwan (61.8 pg-BEQ/g d.w.) than in central, southern, and eastern Taiwan (22.2, 24.9, and 7.80 pg-BEQ/g d.w., respectively). Analysis of multiple linear regression models identified four major predictors of dioxin-BEQs including soil sampling location (β = 0.097, p < 0.001), land use (β = 0.065, p < 0.001), soil brightness (β = 0.170, p < 0.001), and soil moisture (β = 0.051, p = 0.020), with adjusted R2 = 0.947 (p < 0.001) (n = 662). An univariate logistic regression analysis with the cut-off point of 33.4 pg-BEQ/g d.w. showed significant odds ratios (ORs) for soil sampling location (OR = 2.43, p < 0.001), land use (OR = 1.47, p < 0.001), and soil brightness (OR = 2.83, p = 0.009). In conclusion, four variables, including soil sampling location, land use, soil brightness, and soil moisture, may be related to soil-dioxin contamination. Soil samples collected in northern Taiwan, and especially in Bade City, soils near industrial areas, and soils with darker color may contain higher dioxin-BEQ levels.
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Hu X, Xu Z, Peng X, Ren M, Zhang S, Liu X, Wang J. Pollution characteristics and potential health risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil/sediment from Baiyin City, North West, China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2013; 35:593-604. [PMID: 23793509 DOI: 10.1007/s10653-013-9542-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 04/29/2013] [Indexed: 06/02/2023]
Abstract
In order to better understand the environmental behaviors of persistent organic pollutants, the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were investigated in twenty-three soil/sediment samples from Baiying City, Northwest China, in 2008. The possible sources and potential health risk of PCDD/Fs were also discussed. The concentrations of PCDD/Fs in nineteen soil samples varied between 20.13 and 496.26 pg/g dry weight (dw.), with an average value of 125.59 pg/g dw. The highest International Toxic Equivalent (I-TEQ) of PCDD/Fs (8.34 pg/g dw.) in soil was found at sample S1 collected from proximity to a copper metallurgy plant. The concentrations of PCDD/Fs in four sediment samples ranged from 37.69 to 491.49 pg/g dw., with an average value of 169.95 pg/g dw. The highest I-TEQ of PCDD/Fs (8.56 pg/g dw.) in sediment was found at sample S12 collected from the East big ditch with waste water discharged into the Yellow River. The results indicated that PCDD/Fs contamination of soil/sediment is originated from three sources: chlorine-containing chemicals, non-ferrous metal industrial PCDD/Fs emission and coal burning. The health risk exposure to PCDD/Fs through soil, dust ingestion and dermal absorption ranged from 0.0006 to 0.0134 pg/kg/day Word Health Organization's toxic equivalent in 1998 (WHO1998-TEQ) with mean values 0.0032 pg WHO1998-TEQ for adults and varied between 0.0012 and 0.0256 pg/kg/day WHO1998-TEQ with mean values 0.006 pg/kg/day WHO1998-TEQ for children, respectively. These results indicated that health risk of PCDD/Fs for children should be paid more attention.
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Affiliation(s)
- Xibang Hu
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China
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Zhao H, Zhong W, Zhou G, Shao Y, Wang T, Liu F, Jin BS. Experimental Research on Utilization of Steel Rolling Sludge in Sintering Process. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2013. [DOI: 10.1515/ijcre-2013-0040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A quantity of steel rolling sludge (SRS) produced in the rolling mill is harm to the environment and difficult to dispose. This article is devoted to study on utilization of SRS in sintering process. A sinter pot system with capacity of 75 kg was established. The sintering time, the flue gas temperature, the sintering temperature and the suction pressure in sintering process were measured. Besides the sinter quality, air pollutants discharged from the sintering process with the mass fraction of SRS ranging from 0 to 3% was investigated. The results showed that the CO2 concentration is corresponding to the sintering process, the SO2 concentration has a self-sustaining characteristic and the NOX concentration maintains stability. Increase in mass fraction of SRS leads to the decrease of sintering temperature, particle size, tumbler index and basicity of the sinter. Besides, the sintering time and the average concentration of NOX decrease first and then increase, while the suction pressure appears an opposite trend with increasing mass fraction of SRS. Moreover, the average concentration of CO2 and SO2 both decrease with increasing mass fraction of SRS, and the fuel consumption per sinter produced is the least when the mass fraction of SRS is 2%. Therefore, when the mass fraction of SRS was 2%, the sintering process had the best performance in consideration of sinter quality, emission of air pollutants and behaviors in sintering process.
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Chang HJ, Wang S, Wang YF, Li HW, Wang LC. Contributions of dry and wet depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans to a contaminated site resulting from a penetachlorophenol manufacturing process. ENVIRONMENTAL MONITORING AND ASSESSMENT 2011; 175:475-485. [PMID: 20559715 DOI: 10.1007/s10661-010-1545-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 05/26/2010] [Indexed: 05/29/2023]
Abstract
The soils at a factory for manufacturing pentachlorophenol were heavily contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In order to verify the contributions of dry and wet deposition of PCDD/Fs from the ambient air, the concentration of PCDD/Fs in ambient air and soil were measured, the partition of particle- and gas-phases of atmospheric PCDD/Fs was calculated, and the annual fluxes of total dry and wet PCDD/F depositions were modeled. Average atmospheric PCDD/F concentration was 1.24 ng Nm(-3) (or 0.0397 ng I-TEQ Nm(-3)). Moreover, over 92.8% of total PCDD/Fs were in the particle phase, and the dominant species were high chlorinated congeners. The total PCDD/F fluxes of dry and wet deposition were 119.5 ng m(-2) year(-1) (1.34 ng I-TEQ m(-2) year(-1)) and 82.0 ng m(-2) year(-1) (1.07 ng I-TEQ m(-2) year(-1)), respectively. By scenario simulation, the total fluxes of dry and wet PCDD/F depositions were 87.1 and 68.6 ng I-TEQ, respectively. However, the estimated PCDD/F contents in the contaminated soil were 839.9 μ g I-TEQ. Hence, the contributions of total depositions of atmospheric PCDD/F were only 0.02%. The results indicated that the major sources of PCDD/F for the contaminated soil could be attributed to the pentachlorophenol manufacturing process.
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Affiliation(s)
- Hwang J Chang
- Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-kuang Road, Taichung, 402, Taiwan
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