The Experts below are selected from a list of 426 Experts worldwide ranked by ideXlab platform
Minghui Zheng - One of the best experts on this subject based on the ideXlab platform.
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concentrations and profiles of persistent organic pollutants unintentionally produced by secondary nonferrous metal smelters updated emission factors and diagnostic ratios for identifying sources
Chemosphere, 2020Co-Authors: Yuanping Yang, Lili Yang, Guorui Liu, Minxiang Wang, Qiuting Yang, Xiaoyun Liu, Jia Shen, Minghui ZhengAbstract:Abstract Secondary nonferrous metal smelters are important sources of unintentionally produced persistent organic pollutants (UPOPs) including Polychlorinated biphenyls (PCBs), Polychlorinated Naphthalenes, pentachlorobenzene, and hexachlorobenzene. Quantifying UPOP emissions by the main sources is an important step when evaluating UPOP emissions and establishing an inventory. In this study, field investigations were performed to allow UPOP emissions and distributions in stack gases emitted by secondary nonferrous metal smelters to be compared. A total of 25 stack gas samples were collected from secondary copper smelters (SCus), secondary zinc smelters, and secondary lead smelters in China. The mean toxic equivalent concentrations (TEQs) and mass concentrations of most of the UPOPs were highest in the secondary zinc smelter stack gas samples, next highest in the SCu stack gas samples, and lowest in the secondary lead smelter stack gas samples. The mean dioxin-like PCB and Polychlorinated Naphthalene TEQs were ∼8.9 and ∼6.6 times higher in stack gases from a SCu equipped with an oxygen-enriched smelting furnace than in stack gases from a SCu with a converter furnace. The mean PCB-118 to PCB-123 ratios and CN-10 to CN-35 ratios varied strongly and could be used as diagnostic ratios for apportioning the sources of UPOPs in the environment. Emission factors for dioxin-like PCBs, Polychlorinated Naphthalenes, pentachlorobenzene, and hexachlorobenzene in stack gases from secondary nonferrous metal smelters were derived and updated. The results improve our understanding of UPOP emission and provide data for establishing UPOP emission inventories for secondary nonferrous metal smelters.
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Polychlorinated Naphthalene congener profiles in common vegetation on the tibetan plateau as biomonitors of their sources and transportation
Environmental Science & Technology, 2020Co-Authors: Rong Jin, Lili Yang, Minghui Zheng, Ahsan Habib, Guorui LiuAbstract:Polychlorinated Naphthalenes (PCNs) are globally transported, carcinogenic, persistent organic pollutants (POPs) that were recently added to the Stockholm Convention with 184 parties. The Tibetan Plateau plays an important role in the global transportation and distribution of POPs. Knowledge of PCN sources and transportation on the Tibetan Plateau is important for their control globally. In this study, we quantified the congener-specific concentrations of PCNs in lichen, moss, soil, and air samples collected on the Tibetan plateau and found that common lichens were effective biomonitors for predicting atmospheric PCNs in this area. The physiochemical properties of the PCNs, the temperatures, and the lichen lipid contents were identified as important factors influencing PCN partitioning between lichens and air. Lichen-air partitioning equations were established and used to predict PCN concentrations in air in Southeast Tibet. The lichens could be used as PCN biomonitors to clarify their spatial variations, sources, and transportation in the southeast of the plateau. PCN concentrations in lichens increased with altitude, suggesting that high-mountain cold-trapping influenced the PCN transportation behavior. Principal component analysis and linear discriminant analysis showed that the major source of PCNs in this region was long-range atmospheric transportation via the Indian monsoon in summer and wind from Southwest Asia in winter. This study provides a novel method using PCN congener profiles as fingerprints and statistical models for studying the geochemical effects of conditions in high-mountain regions on the contamination behaviors of 75 congeners of the notorious PCNs.
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inventory of Polychlorinated Naphthalene emissions from waste incineration and metallurgical sources in china
Environmental Science & Technology, 2020Co-Authors: Lili Yang, Minghui Zheng, Yuanping Yang, Qingqing Zhu, Guorui LiuAbstract:Polychlorinated Naphthalenes (PCNs) are highly toxic persistent organic pollutants (POPs) that are a relatively new addition to the Stockholm Convention as of 2015. The levels of unintentional emissions of PCNs from important industrial thermal sources on national scales are unclear but are important for understanding potential human exposure. In this study, an inventory was compiled of PCN emissions from priority industrial sources of unintentional POPs in China. Estimated emissions from four typical POP sources in the reference year (2014) in China were 511.6 kg by mass and 7650.8 mg of toxic equivalent. Waste incineration, secondary nonferrous smelting, electric arc furnace steelmaking, and iron ore sintering plants contributed 38.8, 15.4, 29.2, and 16.6%, respectively, to the total emissions. The Eastern Seaboard of China and the Hebei region in North China, which have intensive industrial activity and high population densities, were dominant contributors of PCNs. Only 18.6% of the counties where waste incineration plants were located emitted PCNs at a level higher than 1.00 × 10-1 mg of toxic equivalent, whereas 80% of the counties where metallurgical plants were located emitted PCNs at this level. These results indicate effective implementation of POP control in the waste incineration industry in China. This study clarifies the unintentionally emission levels of PCNs in China and provides important information for strategy development to control source emissions.
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Polychlorinated Naphthalene pcn emissions and characteristics during different secondary copper smelting stages
Ecotoxicology and Environmental Safety, 2019Co-Authors: Xiaoxu Jiang, Lili Yang, Yuanping Yang, Minghui ZhengAbstract:Abstract The amounts and characteristics of Polychlorinated Naphthalenes (PCNs) emitted by a secondary copper smelter were investigated. Differences in the amounts and characteristics of PCNs emitted during different smelting stages were investigated, and the main stage during which PCNs were emitted was identified. PCN concentrations in stack gases emitted during secondary copper smelting were 477.0–762.5 ng/m3 (4.4–8.3 pg toxic equivalents/m3). The contributions of the different stages to total PCN emissions decreased in the order feeding–fusion stage (65% of total PCN emissions) > oxidation stage (27%) > deoxidation stage (8%). The main contributor to PCN emissions during secondary copper smelting was the feeding–fusion stage. PCN concentrations and profiles in stack gas, fly ash, and deposit ash collected during different smelting stages were determined. PCNs in stack gases were mainly less-chlorinated homologs, and fly ash and deposit ash were dominated by highly-chlorinated homologs. These results will help improve strategies for decreasing and eliminating PCN emissions during secondary copper production.
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small scale waste incinerators in rural china potential risks of dioxin and Polychlorinated Naphthalene emissions
Emerging Contaminants, 2019Co-Authors: Lili Yang, Guorui Liu, Qingqing Zhu, Minghui ZhengAbstract:Abstract Rapid development has led to a tremendous increase in the volume of solid waste produced in rural China. The annual amount of solid waste produced from Chinese rural areas is approximately 110 million tons. Many small-scale solid waste incinerators have been built in Chinese rural areas. It was speculated that the emissions and potential risks of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, commonly known as dioxins) and Polychlorinated Naphthalenes (PCNs) from these incinerators could be serious. A preliminary case investigation on PCDD/F and PCN emissions from a small-scale waste incinerator was performed. The stack gas samples were collected using auto isokinetic sampling techniques and PCDD/F and PCN congeners were identified and quantified by high resolution gas chromatography combined with high resolution mass spectrometry. Concentrations and toxic equivalents of PCDD/Fs emitted from the small-scale waste incinerator were 153 ng m−3 and 5.6 ng TEQ m−3, respectively, which was much higher than the regulatory level for municipal solid waste incinerators permitted in China and the European Union Directive. PCNs have similar toxicological effects with PCDD/Fs, and the relative potency factors (RPFs) of some PCN congeners (dioxin-like PCNs) to 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) were previously proposed to evaluate the dioxin-like toxicity of PCNs. The mass concentrations of PCNs and dioxin-like PCNs from the small-scale solid incinerator were 2927 ng m−3 and 1137 ng m−3, much higher than that of dioxins. However, much less attention has been paid to the small-scale incinerators compared with municipal solid waste incinerators. Here, we proposed that there should be a growing need to focus on the emissions and potential risks of dioxins and dioxin-like pollutants from these small-scale waste incinerators in rural China.
Guorui Liu - One of the best experts on this subject based on the ideXlab platform.
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concentrations and profiles of persistent organic pollutants unintentionally produced by secondary nonferrous metal smelters updated emission factors and diagnostic ratios for identifying sources
Chemosphere, 2020Co-Authors: Yuanping Yang, Lili Yang, Guorui Liu, Minxiang Wang, Qiuting Yang, Xiaoyun Liu, Jia Shen, Minghui ZhengAbstract:Abstract Secondary nonferrous metal smelters are important sources of unintentionally produced persistent organic pollutants (UPOPs) including Polychlorinated biphenyls (PCBs), Polychlorinated Naphthalenes, pentachlorobenzene, and hexachlorobenzene. Quantifying UPOP emissions by the main sources is an important step when evaluating UPOP emissions and establishing an inventory. In this study, field investigations were performed to allow UPOP emissions and distributions in stack gases emitted by secondary nonferrous metal smelters to be compared. A total of 25 stack gas samples were collected from secondary copper smelters (SCus), secondary zinc smelters, and secondary lead smelters in China. The mean toxic equivalent concentrations (TEQs) and mass concentrations of most of the UPOPs were highest in the secondary zinc smelter stack gas samples, next highest in the SCu stack gas samples, and lowest in the secondary lead smelter stack gas samples. The mean dioxin-like PCB and Polychlorinated Naphthalene TEQs were ∼8.9 and ∼6.6 times higher in stack gases from a SCu equipped with an oxygen-enriched smelting furnace than in stack gases from a SCu with a converter furnace. The mean PCB-118 to PCB-123 ratios and CN-10 to CN-35 ratios varied strongly and could be used as diagnostic ratios for apportioning the sources of UPOPs in the environment. Emission factors for dioxin-like PCBs, Polychlorinated Naphthalenes, pentachlorobenzene, and hexachlorobenzene in stack gases from secondary nonferrous metal smelters were derived and updated. The results improve our understanding of UPOP emission and provide data for establishing UPOP emission inventories for secondary nonferrous metal smelters.
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Polychlorinated Naphthalene congener profiles in common vegetation on the tibetan plateau as biomonitors of their sources and transportation
Environmental Science & Technology, 2020Co-Authors: Rong Jin, Lili Yang, Minghui Zheng, Ahsan Habib, Guorui LiuAbstract:Polychlorinated Naphthalenes (PCNs) are globally transported, carcinogenic, persistent organic pollutants (POPs) that were recently added to the Stockholm Convention with 184 parties. The Tibetan Plateau plays an important role in the global transportation and distribution of POPs. Knowledge of PCN sources and transportation on the Tibetan Plateau is important for their control globally. In this study, we quantified the congener-specific concentrations of PCNs in lichen, moss, soil, and air samples collected on the Tibetan plateau and found that common lichens were effective biomonitors for predicting atmospheric PCNs in this area. The physiochemical properties of the PCNs, the temperatures, and the lichen lipid contents were identified as important factors influencing PCN partitioning between lichens and air. Lichen-air partitioning equations were established and used to predict PCN concentrations in air in Southeast Tibet. The lichens could be used as PCN biomonitors to clarify their spatial variations, sources, and transportation in the southeast of the plateau. PCN concentrations in lichens increased with altitude, suggesting that high-mountain cold-trapping influenced the PCN transportation behavior. Principal component analysis and linear discriminant analysis showed that the major source of PCNs in this region was long-range atmospheric transportation via the Indian monsoon in summer and wind from Southwest Asia in winter. This study provides a novel method using PCN congener profiles as fingerprints and statistical models for studying the geochemical effects of conditions in high-mountain regions on the contamination behaviors of 75 congeners of the notorious PCNs.
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inventory of Polychlorinated Naphthalene emissions from waste incineration and metallurgical sources in china
Environmental Science & Technology, 2020Co-Authors: Lili Yang, Minghui Zheng, Yuanping Yang, Qingqing Zhu, Guorui LiuAbstract:Polychlorinated Naphthalenes (PCNs) are highly toxic persistent organic pollutants (POPs) that are a relatively new addition to the Stockholm Convention as of 2015. The levels of unintentional emissions of PCNs from important industrial thermal sources on national scales are unclear but are important for understanding potential human exposure. In this study, an inventory was compiled of PCN emissions from priority industrial sources of unintentional POPs in China. Estimated emissions from four typical POP sources in the reference year (2014) in China were 511.6 kg by mass and 7650.8 mg of toxic equivalent. Waste incineration, secondary nonferrous smelting, electric arc furnace steelmaking, and iron ore sintering plants contributed 38.8, 15.4, 29.2, and 16.6%, respectively, to the total emissions. The Eastern Seaboard of China and the Hebei region in North China, which have intensive industrial activity and high population densities, were dominant contributors of PCNs. Only 18.6% of the counties where waste incineration plants were located emitted PCNs at a level higher than 1.00 × 10-1 mg of toxic equivalent, whereas 80% of the counties where metallurgical plants were located emitted PCNs at this level. These results indicate effective implementation of POP control in the waste incineration industry in China. This study clarifies the unintentionally emission levels of PCNs in China and provides important information for strategy development to control source emissions.
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small scale waste incinerators in rural china potential risks of dioxin and Polychlorinated Naphthalene emissions
Emerging Contaminants, 2019Co-Authors: Lili Yang, Guorui Liu, Qingqing Zhu, Minghui ZhengAbstract:Abstract Rapid development has led to a tremendous increase in the volume of solid waste produced in rural China. The annual amount of solid waste produced from Chinese rural areas is approximately 110 million tons. Many small-scale solid waste incinerators have been built in Chinese rural areas. It was speculated that the emissions and potential risks of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, commonly known as dioxins) and Polychlorinated Naphthalenes (PCNs) from these incinerators could be serious. A preliminary case investigation on PCDD/F and PCN emissions from a small-scale waste incinerator was performed. The stack gas samples were collected using auto isokinetic sampling techniques and PCDD/F and PCN congeners were identified and quantified by high resolution gas chromatography combined with high resolution mass spectrometry. Concentrations and toxic equivalents of PCDD/Fs emitted from the small-scale waste incinerator were 153 ng m−3 and 5.6 ng TEQ m−3, respectively, which was much higher than the regulatory level for municipal solid waste incinerators permitted in China and the European Union Directive. PCNs have similar toxicological effects with PCDD/Fs, and the relative potency factors (RPFs) of some PCN congeners (dioxin-like PCNs) to 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) were previously proposed to evaluate the dioxin-like toxicity of PCNs. The mass concentrations of PCNs and dioxin-like PCNs from the small-scale solid incinerator were 2927 ng m−3 and 1137 ng m−3, much higher than that of dioxins. However, much less attention has been paid to the small-scale incinerators compared with municipal solid waste incinerators. Here, we proposed that there should be a growing need to focus on the emissions and potential risks of dioxins and dioxin-like pollutants from these small-scale waste incinerators in rural China.
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concentrations and patterns of Polychlorinated biphenyls at different process stages of cement kilns co processing waste incinerator fly ash
Waste Management, 2016Co-Authors: Guorui Liu, Rong Jin, Lili Yang, Minghui Zheng, Jiayu Zhan, Yuyang Zhao, Mei WangAbstract:Cement kilns can be used to co-process fly ash from municipal solid waste incinerators. However, this might increase emission of organic pollutants like Polychlorinated biphenyls (PCBs). Knowledge of PCB concentrations and homolog and congener patterns at different stages in this process could be used to assess the possibility of simultaneously controlling emissions of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and “dioxin-like” compounds. To date, emissions from cement kilns co-processing fly ash from municipal solid waste incinerators have not been analyzed for PCBs. In this study, stack gas and particulate samples from two cement kilns co-processing waste incinerator fly ash were analyzed for PCBs. The average total tri- to deca-chlorinated biphenyl (∑3–10PCB) concentration in the stack gas samples was 10.15 ng m−3. The ∑3–10PCB concentration ranges in particulate samples from different stages were 0.83–41.79 ng g−1 for cement kiln 1 and 0.13–1.69 ng g−1 for cement kiln 2. The ∑3–10PCB concentrations were much higher in particulate samples from the suspension pre-heater boiler, humidifier tower, and kiln back-end bag filters than in particulate samples from other stages. For these three stages, PCBs contributed to 15–18% of the total PCB, PCDD/F, and Polychlorinated Naphthalene toxic equivalents in stack gases and particulate matter. The PCB distributions were similar to those found in other studies for PCDD/Fs and Polychlorinated Naphthalenes, which suggest that it may be possible to simultaneously control emissions of multiple organic pollutants from cement kilns. Homolog patterns in the particulate samples were dominated by the pentachlorobiphenyls. CB-105, CB-118, and CB-123 were the dominant dioxin-like PCB congeners that formed at the back-end of the cement kiln. A mass balance of PCBs in the cement kilns indicated that the total mass of PCBs in the stack gases and clinker was about half the mass of PCBs in the raw materials.
Mei Wang - One of the best experts on this subject based on the ideXlab platform.
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concentrations and patterns of Polychlorinated biphenyls at different process stages of cement kilns co processing waste incinerator fly ash
Waste Management, 2016Co-Authors: Guorui Liu, Rong Jin, Lili Yang, Minghui Zheng, Jiayu Zhan, Yuyang Zhao, Mei WangAbstract:Cement kilns can be used to co-process fly ash from municipal solid waste incinerators. However, this might increase emission of organic pollutants like Polychlorinated biphenyls (PCBs). Knowledge of PCB concentrations and homolog and congener patterns at different stages in this process could be used to assess the possibility of simultaneously controlling emissions of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and “dioxin-like” compounds. To date, emissions from cement kilns co-processing fly ash from municipal solid waste incinerators have not been analyzed for PCBs. In this study, stack gas and particulate samples from two cement kilns co-processing waste incinerator fly ash were analyzed for PCBs. The average total tri- to deca-chlorinated biphenyl (∑3–10PCB) concentration in the stack gas samples was 10.15 ng m−3. The ∑3–10PCB concentration ranges in particulate samples from different stages were 0.83–41.79 ng g−1 for cement kiln 1 and 0.13–1.69 ng g−1 for cement kiln 2. The ∑3–10PCB concentrations were much higher in particulate samples from the suspension pre-heater boiler, humidifier tower, and kiln back-end bag filters than in particulate samples from other stages. For these three stages, PCBs contributed to 15–18% of the total PCB, PCDD/F, and Polychlorinated Naphthalene toxic equivalents in stack gases and particulate matter. The PCB distributions were similar to those found in other studies for PCDD/Fs and Polychlorinated Naphthalenes, which suggest that it may be possible to simultaneously control emissions of multiple organic pollutants from cement kilns. Homolog patterns in the particulate samples were dominated by the pentachlorobiphenyls. CB-105, CB-118, and CB-123 were the dominant dioxin-like PCB congeners that formed at the back-end of the cement kiln. A mass balance of PCBs in the cement kilns indicated that the total mass of PCBs in the stack gases and clinker was about half the mass of PCBs in the raw materials.
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case study of Polychlorinated Naphthalene emissions and factors influencing emission variations in secondary aluminum production
Journal of Hazardous Materials, 2015Co-Authors: Xiaoxu Jiang, Guorui Liu, Mei Wang, Wenbin Liu, Chen Tang, Minghui ZhengAbstract:Secondary aluminum production has been recognized as an important source of Polychlorinated Naphthalenes (PCNs). Large variations in PCN emissions as the smelting process proceeds have not been determined. In this study, solid and gaseous discharges, including fly ash, slag, and stack gas samples collected from four secondary smelting plants during different smelting stages were analyzed for PCNs. The average emission factor of ∑(1-8)PCNs to air was calculated to be 17.4 mg t(-1), with a range of 4.3-29.5 mg t(-1). The average emission factors of ∑(1-8)PCNs from fly ash and slag were 55.5 ng t(-1) and 0.13 ng t(-1), respectively. The derived emission factors may enable a more accurate estimation of annual emissions and a more comprehensive knowledge of the distribution of PCNs emitted from secondary aluminum production. The emission levels and characteristics of PCNs during different smelting stages were compared. Possible factors, including the organic impurities from aluminum scrap, fuel, and chloride additives, which could contribute to variations in PCN emissions and characteristics were discussed. These results may provide useful information for developing better control strategies for reducing PCN emissions in secondary aluminum production.
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fly ash mediated formation of Polychlorinated Naphthalenes during secondary copper smelting and mechanistic aspects
Chemosphere, 2015Co-Authors: Xiaoxu Jiang, Mei Wang, Guorui Liu, Minghui ZhengAbstract:Abstract Thermal experiments (at 250–450 °C for 10–240 min) on fly ash from secondary copper smelting process (SeCu) were performed to study the Polychlorinated Naphthalene (PCN) formation in the post-zone of a secondary copper smelter. Unexpectedly high concentrations of PCNs were formed. Total PCN concentrations and toxic equivalents were 47–104 and 44–80 times higher than the initial concentration and toxic equivalent, respectively. The thermal disposal of SeCu fly ash should therefore be reconsidered. The kinetic of each homolog was determined under different thermal conditions. Less chlorinated homologs favored 350 °C and more chlorinated homologs favored higher temperature. Most of the homologs reached an equilibrium of formation and degradation within 30 min, except octachloroNaphthalene which did not appear to reach such an equilibrium even after 240 min. Chlorine substitution of the formed PCNs was identified and a similar pattern was found in chlorination products starting with Naphthalene and chlorine. Furthermore, inorganic chlorine and unsubstituted Naphthalene were found in the reaction products, confirming that the formation of Naphthalene and the chlorination of that Naphthalene could occur and could be suggested to be an important PCN formation route. A detailed formation pathway from Naphthalene through octachloroNaphthalene is proposed.
Xiaoxu Jiang - One of the best experts on this subject based on the ideXlab platform.
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Polychlorinated Naphthalene pcn emissions and characteristics during different secondary copper smelting stages
Ecotoxicology and Environmental Safety, 2019Co-Authors: Xiaoxu Jiang, Lili Yang, Yuanping Yang, Minghui ZhengAbstract:Abstract The amounts and characteristics of Polychlorinated Naphthalenes (PCNs) emitted by a secondary copper smelter were investigated. Differences in the amounts and characteristics of PCNs emitted during different smelting stages were investigated, and the main stage during which PCNs were emitted was identified. PCN concentrations in stack gases emitted during secondary copper smelting were 477.0–762.5 ng/m3 (4.4–8.3 pg toxic equivalents/m3). The contributions of the different stages to total PCN emissions decreased in the order feeding–fusion stage (65% of total PCN emissions) > oxidation stage (27%) > deoxidation stage (8%). The main contributor to PCN emissions during secondary copper smelting was the feeding–fusion stage. PCN concentrations and profiles in stack gas, fly ash, and deposit ash collected during different smelting stages were determined. PCNs in stack gases were mainly less-chlorinated homologs, and fly ash and deposit ash were dominated by highly-chlorinated homologs. These results will help improve strategies for decreasing and eliminating PCN emissions during secondary copper production.
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case study of Polychlorinated Naphthalene emissions and factors influencing emission variations in secondary aluminum production
Journal of Hazardous Materials, 2015Co-Authors: Xiaoxu Jiang, Guorui Liu, Mei Wang, Wenbin Liu, Chen Tang, Minghui ZhengAbstract:Secondary aluminum production has been recognized as an important source of Polychlorinated Naphthalenes (PCNs). Large variations in PCN emissions as the smelting process proceeds have not been determined. In this study, solid and gaseous discharges, including fly ash, slag, and stack gas samples collected from four secondary smelting plants during different smelting stages were analyzed for PCNs. The average emission factor of ∑(1-8)PCNs to air was calculated to be 17.4 mg t(-1), with a range of 4.3-29.5 mg t(-1). The average emission factors of ∑(1-8)PCNs from fly ash and slag were 55.5 ng t(-1) and 0.13 ng t(-1), respectively. The derived emission factors may enable a more accurate estimation of annual emissions and a more comprehensive knowledge of the distribution of PCNs emitted from secondary aluminum production. The emission levels and characteristics of PCNs during different smelting stages were compared. Possible factors, including the organic impurities from aluminum scrap, fuel, and chloride additives, which could contribute to variations in PCN emissions and characteristics were discussed. These results may provide useful information for developing better control strategies for reducing PCN emissions in secondary aluminum production.
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Polychlorinated Naphthalene concentrations and profiles in cheese and butter and comparisons with Polychlorinated dibenzo p dioxin Polychlorinated dibenzofuran and Polychlorinated biphenyl concentrations
International Journal of Environmental Analytical Chemistry, 2015Co-Authors: Sufang Sun, Shujun Dong, Guorui Liu, Xiaoxu Jiang, Minghui ZhengAbstract:Polychlorinated Naphthalenes (PCNs) are candidates for inclusion in the Stockholm Convention on persistent organic pollutants. PCNs are structurally and toxicologically similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and its analogues. Intake in food is considered to be an important human exposure pathway for PCNs. In this preliminary study, cheese and butter samples were analysed for PCNs, Polychlorinated dibenzo-p-dioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs) and Polychlorinated biphenyls (PCBs) using an isotope dilution gas chromatography high-resolution mass spectrometry method. The aim of this study was to evaluate the PCN concentrations in the cheese and butter samples and to compare them with the PCDD, PCDF and PCB concentrations. The PCN concentrations were 5.6–103 pg g−1 of wet weight in the seven cheese samples tested and 5.0–199 pg g−1 of wet weight in the seven butter samples tested. The mass concentrations of lower chlorinated congeners were greater than those of the hi...
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identification and preliminary evaluation of Polychlorinated Naphthalene emissions from hot dip galvanizing plants
Chemosphere, 2015Co-Authors: Guorui Liu, Wenbin Liu, Zhiqiang Nie, Xiaoxu Jiang, Minghui ZhengAbstract:Hot dip galvanizing (HDG) processes are sources of Polychlorinated-p-dioxins and dibenzofurans (PCDD/Fs). Close correlations have been found between the concentration of PCDD/Fs and Polychlorinated Naphthalenes (PCNs) that are produced and released during industrial thermal processes. We speculated, therefore, that HDG plants are potential PCN sources. In this preliminary study, PCNs were analyzed in solid residues, ash and precipitate from three HDG plants of different sizes. The total PCN concentrations (Sigma(2-8)PCNs) in the residue samples ranged from 60.3 to 226 pg g(-1). The PCN emission factors for the combined ash and precipitate residues from the HDG plants ranged from 75 to 178 ng t(-1) for the dichlorinated and octachlorinated Naphthalenes. The preliminary results suggested that the HDG industry might not currently be a significant source of PCN emissions. The trichloroNaphthalenes were the dominant homologs followed by the dichloroNaphthalenes and the tetrachloroNaphthalenes. The PCN congeners CN37/33/34, CN52/60, CN66/67, and CN73 dominated the tetrachlorinated, pentachlorinated, hexachlorinated, and heptachlorinated Naphthalene homologs, respectively. The PCNs emitted from the HOG plants had similar homolog distributions and congener profiles to the PCNs emitted from combustion plants and other metallurgical processes. The identification and preliminary evaluation of PCN emissions from HOG plants presented here will help in the prioritization of measures for controlling PCN emissions from industrial sources. (c) 2014 Elsevier Ltd. All rights reserved.
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fly ash mediated formation of Polychlorinated Naphthalenes during secondary copper smelting and mechanistic aspects
Chemosphere, 2015Co-Authors: Xiaoxu Jiang, Mei Wang, Guorui Liu, Minghui ZhengAbstract:Abstract Thermal experiments (at 250–450 °C for 10–240 min) on fly ash from secondary copper smelting process (SeCu) were performed to study the Polychlorinated Naphthalene (PCN) formation in the post-zone of a secondary copper smelter. Unexpectedly high concentrations of PCNs were formed. Total PCN concentrations and toxic equivalents were 47–104 and 44–80 times higher than the initial concentration and toxic equivalent, respectively. The thermal disposal of SeCu fly ash should therefore be reconsidered. The kinetic of each homolog was determined under different thermal conditions. Less chlorinated homologs favored 350 °C and more chlorinated homologs favored higher temperature. Most of the homologs reached an equilibrium of formation and degradation within 30 min, except octachloroNaphthalene which did not appear to reach such an equilibrium even after 240 min. Chlorine substitution of the formed PCNs was identified and a similar pattern was found in chlorination products starting with Naphthalene and chlorine. Furthermore, inorganic chlorine and unsubstituted Naphthalene were found in the reaction products, confirming that the formation of Naphthalene and the chlorination of that Naphthalene could occur and could be suggested to be an important PCN formation route. A detailed formation pathway from Naphthalene through octachloroNaphthalene is proposed.
Wenbin Liu - One of the best experts on this subject based on the ideXlab platform.
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temporal trends in Polychlorinated Naphthalene emissions from sintering plants in china between 2005 and 2015
Environmental Pollution, 2019Co-Authors: Mengjing Wang, Wenbin LiuAbstract:Abstract The Chinese Government has established stringent policies since 2005 to control SO2, particulate matter, and NOx emissions from sintering plants with the aim of tackling severe air pollution in China. Notably, sintering is also important sources of Polychlorinated Naphthalenes (PCNs), but it is not clear whether the air pollution control policies have led to decreased PCN emissions. In this study, the PCN concentrations in 144 stack gas, 87 discarded fly ash, and 24 desulfurization by-product samples from 24 Chinese sintering plants were determined. This study revealed that desulfurization processes decreased PCN emissions by 47.2%–72.2%. However, these PCNs were not completely eliminated, and transformed to desulfurization by-product. PCN emission in such previously ignored solid residues, including of desulfurization by-product and fine particles, produced in the process of cutting down air pollutants emissions from Chinese sintering plants between 2005 and 2015 was found contained 324 kg, and these residues therefore need to be managed better than currently. Furthermore, PCN concentrations were higher from produced in old plants than produced in new plants, so it is necessary to increase the rate at which out-of-date sintering plants are eliminated. Phasing out old sintering processes decreased total PCN emissions in China by 1549 kg between 2005 and 2015.
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case study of Polychlorinated Naphthalene emissions and factors influencing emission variations in secondary aluminum production
Journal of Hazardous Materials, 2015Co-Authors: Xiaoxu Jiang, Guorui Liu, Mei Wang, Wenbin Liu, Chen Tang, Minghui ZhengAbstract:Secondary aluminum production has been recognized as an important source of Polychlorinated Naphthalenes (PCNs). Large variations in PCN emissions as the smelting process proceeds have not been determined. In this study, solid and gaseous discharges, including fly ash, slag, and stack gas samples collected from four secondary smelting plants during different smelting stages were analyzed for PCNs. The average emission factor of ∑(1-8)PCNs to air was calculated to be 17.4 mg t(-1), with a range of 4.3-29.5 mg t(-1). The average emission factors of ∑(1-8)PCNs from fly ash and slag were 55.5 ng t(-1) and 0.13 ng t(-1), respectively. The derived emission factors may enable a more accurate estimation of annual emissions and a more comprehensive knowledge of the distribution of PCNs emitted from secondary aluminum production. The emission levels and characteristics of PCNs during different smelting stages were compared. Possible factors, including the organic impurities from aluminum scrap, fuel, and chloride additives, which could contribute to variations in PCN emissions and characteristics were discussed. These results may provide useful information for developing better control strategies for reducing PCN emissions in secondary aluminum production.
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identification and preliminary evaluation of Polychlorinated Naphthalene emissions from hot dip galvanizing plants
Chemosphere, 2015Co-Authors: Guorui Liu, Wenbin Liu, Zhiqiang Nie, Xiaoxu Jiang, Minghui ZhengAbstract:Hot dip galvanizing (HDG) processes are sources of Polychlorinated-p-dioxins and dibenzofurans (PCDD/Fs). Close correlations have been found between the concentration of PCDD/Fs and Polychlorinated Naphthalenes (PCNs) that are produced and released during industrial thermal processes. We speculated, therefore, that HDG plants are potential PCN sources. In this preliminary study, PCNs were analyzed in solid residues, ash and precipitate from three HDG plants of different sizes. The total PCN concentrations (Sigma(2-8)PCNs) in the residue samples ranged from 60.3 to 226 pg g(-1). The PCN emission factors for the combined ash and precipitate residues from the HDG plants ranged from 75 to 178 ng t(-1) for the dichlorinated and octachlorinated Naphthalenes. The preliminary results suggested that the HDG industry might not currently be a significant source of PCN emissions. The trichloroNaphthalenes were the dominant homologs followed by the dichloroNaphthalenes and the tetrachloroNaphthalenes. The PCN congeners CN37/33/34, CN52/60, CN66/67, and CN73 dominated the tetrachlorinated, pentachlorinated, hexachlorinated, and heptachlorinated Naphthalene homologs, respectively. The PCNs emitted from the HOG plants had similar homolog distributions and congener profiles to the PCNs emitted from combustion plants and other metallurgical processes. The identification and preliminary evaluation of PCN emissions from HOG plants presented here will help in the prioritization of measures for controlling PCN emissions from industrial sources. (c) 2014 Elsevier Ltd. All rights reserved.
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characterization of Polychlorinated Naphthalenes in stack gas emissions from waste incinerators
Environmental Science and Pollution Research, 2013Co-Authors: Minghui Zheng, Ke Xiao, Guorui Liu, Bing Zhang, Wenbin Liu, Zhiqiang Nie, Lirong GaoAbstract:Nine typical waste incinerating plants were investigated for Polychlorinated Naphthalene (PCN) contents in their stack gas. The incinerators investigated include those used to incinerate municipal solid, aviation, medical, and hazardous wastes including those encountered in cement kilns. PCNs were qualified and quantified by isotope dilution high resolution gas chromatography–high resolution mass spectrometry techniques. An unexpectedly high concentration of PCNs (13,000 ng Nm−3) was found in the stack gas emitted from one waste incinerator. The PCN concentrations ranged from 97.6 to 874 ng Nm−3 in the other waste incinerators. The PCN profiles were dominated by lower chlorinated homologues, with mono- to tetra-CNs being the main homologues present. Furthermore, the relationships between PCNs and other unintentional persistent organic pollutants involving Polychlorinated dibenzo-p-dioxins and dibenzofurans, Polychlorinated biphenyls, hexachlorobenzene, and pentachlorobenzene were examined to ascertain the closeness or otherwise of their formation mechanisms. A good correlation was observed between ΣPCN (tetra- to octa-CN) and ΣPCDF (tetra- to octa-CDF) concentrations suggesting that a close relationship may exist between their formation mechanisms. The results would provide an improved understanding of PCN emissions from waste incinerators.
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estimation and characterization of Polychlorinated Naphthalene emission from coking industries
Environmental Science & Technology, 2010Co-Authors: Guorui Liu, Chengzhi Wang, Minghui Zheng, Bing Zhang, Wenbin Liu, Ke XiaoAbstract:Occurrence of polycyclic aromatic hydrocarbons (PAHs) during the coking process has been widely recognized. The formation of Polychlorinated Naphthalenes (PCNs) from PAHs during some thermal related processes has been confirmed in many studies. Thus, the coking process is assumed to be a potential source of PCNs. However, intensive investigations on PCN emissions during the coking process are lacking. In order to evaluate PCN emissions from the coking process, an intensive study comprising 11 typical coke plants was undertaken. PCNs were qualified and quantified by isotope dilution HRGC/HRMS techniques. The concentrations of PCNs in stack gas samples collected from the investigated coke plants were in the range of 1.6-91.8 ng Nm(-3) (0.08-4.23 pg TEQ Nm(-3)). The emission factors of PCNs were found to be in the range of 0.77-1.24 ng TEQ per ton of coke production. The estimated annual toxic emissions of PCNs from the global coking industry vary from 430 to 692 mg TEQs. Characteristics of the PCN profiles were dominated by the lower chlorinated homologues, with mono-CN being the most abundant homologue. According to the PCN distribution and correlations of PCN homologues, it was speculated that chlorination is possibly the dominant pathway of PCN formation during the coking process.