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Xia Q, Zhou C, Pan D, Cao J. Food off-odor generation, characterization and recent advances in novel mitigation strategies. Adv Food Nutr Res 2024; 108:113-134. [PMID: 38460997 DOI: 10.1016/bs.afnr.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2024]
Abstract
The pronounced perception of off-odors poses a prevalent issue across various categories of food ingredients and processed products, significantly exerting negative effects on the overall quality, processability, and consumer acceptability of both food items and raw materials. Conventional methods such as brining, marinating, and baking, are the main approaches to remove the fishy odor. Although these methods have shown notable efficacy, there are simultaneously inherent drawbacks that ultimately diminish the processability of raw materials, encompassing alterations in the original flavor profiles, the potential generation of harmful substances, restricted application scopes, and the promotion of excessive protein/lipid oxidation. In response to these challenges, recent endeavors have sought to explore innovative deodorization techniques, including emerging physical processing approaches, the development of high-efficiency adsorbent material, biological fermentation methods, and ozone water rinsing. However, the specific mechanisms underpinning the efficacy of these deodorization techniques remain not fully elucidated. This chapter covers the composition of major odor-causing substances in food, the methodologies for their detection, the mechanisms governing their formation, and the ongoing development of deodorization techniques associated with the comparison of their advantages, disadvantages, and application mechanisms. The objective of this chapter is to furnish a theoretical framework for enhancing deodorization efficiency through fostering the development of suitable deodorization technologies in the future.
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Affiliation(s)
- Qiang Xia
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo, P.R. China
| | - Changyu Zhou
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo, P.R. China
| | - Daodong Pan
- College of Food and Pharmaceutical Sciences, Key Laboratory of Animal Protein Food Processing Technology of Zhejiang Province, Ningbo University, Ningbo, P.R. China
| | - Jinxuan Cao
- School of Food and Health, Beijing Technology and Business University, Beijing, P.R. China.
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Wang Y, Huang J, Li S, Xu W, Wang H, Xu W, Li X. A mechanistic and kinetic investigation on the oxidative thermal decomposition of decabromodiphenyl ether. Environ Pollut 2023; 333:121991. [PMID: 37328125 DOI: 10.1016/j.envpol.2023.121991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/30/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
The thermal processes of materials containing decabromodiphenyl ether (BDE-209) normally result in the exposure of BDE-209 to high-temperature environments, generating a series of hazardous compounds. However, the evolution mechanisms of BDE-209 during oxidative thermal processes remain unclear. Thus, this paper presents a detailed investigation on the oxidative thermal decomposition mechanism of BDE-209 by utilizing density functional theory methods at the M06/cc-pVDZ theoretical level. The results show that the barrierless fission of the ether linkage dominates the initial degradation of BDE-209 at all temperatures, with branching ratio over 80%. The decomposition of BDE-209 in oxidative thermal processes is mainly along BDE-209 → pentabromophenyl and pentabromophenoxy radicals → pentabromocyclopentadienyl radicals → brominated aliphatic products. Additionally, the study results on the formation mechanisms of several hazardous pollutants indicate that the ortho-phenyl-type radicals created by ortho-C-Br bond fission (branching ratio reached 15.1% at 1600 K) can easily be converted into octabrominated dibenzo-p-dioxin and furan, which require overcoming the energy barriers of 99.0 and 48.2 kJ/mol, respectively. The O/ortho-C coupling of two pentabromophenoxy radicals also acts as a non-negligible pathway for the formation of octabrominated dibenzo-p-dioxin. The synthesis of octabromonaphthalene involves the self-condensation of pentabromocyclopentadienyl radicals, followed by an intricately intramolecular evolution. Results presented in this study can enhance our understanding of the transformation mechanism of BDE-209 in thermal processes, and offer an insight into controlling the emissions of hazardous pollutants.
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Affiliation(s)
- Yao Wang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Jinbao Huang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China.
| | - Sijia Li
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Weifeng Xu
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Hong Wang
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Weiwei Xu
- School of Physics and Mechatronic Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Xinsheng Li
- School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China
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3
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Ye C, Lu K, Song H, Mu Y, Chen J, Zhang Y. A critical review of sulfate aerosol formation mechanisms during winter polluted periods. J Environ Sci (China) 2023; 123:387-399. [PMID: 36522000 DOI: 10.1016/j.jes.2022.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/07/2022] [Accepted: 07/08/2022] [Indexed: 06/17/2023]
Abstract
Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing, impacting human health and climate change. Atmospheric models tend to substantially underestimate sulfate concentrations during haze episodes, indicating that there are still missing mechanisms not considered by the models. Despite recent good progress in understanding the missing sulfate sources, knowledge on different sulfate formation pathways during polluted periods still involves large uncertainties and the dominant mechanism is under heated debate, calling for more field, laboratory, and modeling work. Here, we review the traditional sulfate formation mechanisms in cloud water and also discuss the potential factors affecting multiphase S(Ⅳ) oxidation. Then recent progress in multiphase S(Ⅳ) oxidation mechanisms is summarized. Sulfate formation rates by different prevailing oxidation pathways under typical winter-haze conditions are also calculated and compared. Based on the literature reviewed, we put forward control of the atmospheric oxidation capacity as a means to abate sulfate aerosol pollution. Finally, we conclude with a concise set of research priorities for improving our understanding of sulfate formation mechanisms during polluted periods.
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Affiliation(s)
- Can Ye
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Keding Lu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Huan Song
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Yujing Mu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Yuanhang Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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4
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Liang J, Wang R, Liu H, Xie D, Tao X, Zhou J, Yin H, Dang Z, Lu G. Unintentional formation of mixed chloro-bromo diphenyl ethers (PBCDEs), dibenzo-p-dioxins and dibenzofurans (PBCDD/Fs) from pyrolysis of polybrominated diphenyl ethers (PBDEs). Chemosphere 2022; 308:136246. [PMID: 36044966 DOI: 10.1016/j.chemosphere.2022.136246] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
This study presents the comprehensive investigation for formation pathways of chloro-bromo-mixed products from the pyrolysis of polybrominated diphenyl ethers (PBDEs). In the study, a total of 23 PBDEs with bromination levels from mono-to deca-were selected. Each PBDE standard was sealed in the glass vial and then heated under 450 °C in the muffle furnace to simulate the pyrolysis process. The results demonstrated that PBDEs in the glass vials can unintentionally transform into chloro-bromo diphenyl ethers (PBCDEs) and dibenzo-p-dioxin and dibenzofurans (PBCDD/Fs) during the pyrolysis process. Atmosphere pressure gas chromatography (APGC) coupled with high-resolution mass spectrometry (HRMS) was used to identify these pyrolysis products, which demonstrated that all investigated nPBDEs (n represents the number of bromine substituents) can unintentionally transform into Cl1-(n-1)BDEs, Cl2-(n-2)BDEs, Cl1-(n-1)BDFs, and Cl1-(n-3)BDDs, while some nPBDEs can transform into Cl1-(n-2)PBDD/Fs during pyrolysis. Experimental phenomena assisted with density functional theory (DFT) calculations reveal that Cl atom can substitute at C-Br rather than C-H, and Cl1-(n-1)BDEs can be easily generated by Cl atom attacking at C-Br sites with low energy barriers (3.66-11.9 kcal/mol). In addition, nPBDEs with lower bromination levels are more favorable to generate Cl1-(n-1)BDEs than those with higher bromination levels. Further DFT calculations suggest that PBDEs are preferentially first transformed into Cl1-(n-1)BDEs, then subsequentially transform into PBCDD/Fs. We believe the results of this study can greatly improve our understanding of the transformation mechanism from PBDEs to cholo-bromo-mixed products in thermal treatment processes and provide new insight into controlling the emission of toxic cholo-bromo-mixed products.
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Affiliation(s)
- Jiahao Liang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Rui Wang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
| | - He Liu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Danping Xie
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Xueqin Tao
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jiangmin Zhou
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325035, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China; Guangdong Provincial Key Lab of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
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Hu X, Zhang L, Yan L, Tang L. Recent Advances in Polysaccharide-Based Physical Hydrogels and Their Potential Applications for Biomedical and Wastewater Treatment. Macromol Biosci 2022; 22:e2200153. [PMID: 35584011 DOI: 10.1002/mabi.202200153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/10/2022] [Indexed: 11/06/2022]
Abstract
Polysaccharides have been widely employed to fabricate hydrogels owing to their intrinsic properties including biocompatibility, biodegradability, sustainability, and easy modification. However, a considerable amount of polysaccharide-based hydrogels are prepared by chemical crosslinking method using organic solvents or toxic crosslinkers. The presence of reaction by-products and residual toxic substances in the obtained materials cause a potential secondary pollution risk and thus severely limited their practical applications. In contrast, polysaccharide-based physical hydrogels are preferred over chemically derived hydrogels and can be used to address existing drawbacks of chemical hydrogels. The polysaccharide chains of such hydrogel are typically crosslinked by dynamic non-covalent bonds, and the co-existence of multiple physical interactions stabilize the hydrogel network. This review focuses on providing a detailed outlook for the design strategies and formation mechanisms of polysaccharide-based physical hydrogels as well as their specific applications in tissue engineering, drug delivery, wound healing, and wastewater treatment. The main preparation principles, future challenges, and potential improvements are also outlined. The authors hope that this review could provide valuable information for the rational fabrication of polysaccharide-based physical hydrogel. The specific research works listed in the review will provide a systematic and solid research basis for the reliable development of polysaccharide-based physical hydrogel. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Xinyu Hu
- Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing, 210042, China.,Research Institute of Forestry New Technology, CAF, Beijing, 100091, China
| | - Liangliang Zhang
- Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing, 210042, China
| | - Linlin Yan
- Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing, 210042, China.,Research Institute of Forestry New Technology, CAF, Beijing, 100091, China
| | - Lihua Tang
- Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing, 210042, China
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6
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Lin D, Tong S, Zhang W, Li W, Li F, Jia C, Zhang G, Chen M, Zhang X, Wang Z, Ge M, He X. Formation mechanisms of nitrous acid (HONO) during the haze and non-haze periods in Beijing, China. J Environ Sci (China) 2022; 114:343-353. [PMID: 35459497 DOI: 10.1016/j.jes.2021.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 06/14/2023]
Abstract
As an important precursor of hydroxyl radical (OH), nitrous acid (HONO) plays a significant role in atmospheric chemistry. Here, an observation of HONO and relevant air pollutants in an urban site of Beijing from 14 to 28 April, 2017 was performed. Two distinct peaks of HONO concentrations occurred during the observation. In contrast, the concentration of particulate matter in the first period (period Ⅰ) was significantly higher than that in the second period (period Ⅱ). Comparing to HONO sources in the two periods, we found that the direct vehicle emission was an essential source of the ambient HONO during both periods at night, especially in period Ⅱ. The heterogeneous reaction of NO2 was the dominant source in period Ⅰ, while the homogeneous reaction of NO with OH was more critical source at night in period Ⅱ. In the daytime, the heterogeneous reaction of NO2 was a significant source and was confirmed by the good correlation coefficients (R2) between the unknown sources (Punknown) with NO2, PM2.5, NO2 × PM2.5 in period Ⅰ. Moreover, when solar radiation and OH radicals were considered to explore unknown sources in the daytime, the enhanced correlation of Punknown with photolysis rate of NO2 and OH ( [Formula: see text] × OH) were 0.93 in period Ⅰ, 0.95 in period Ⅱ. These excellent correlation coefficients suggested that the unknown sources released HONO highly related to the solar radiation and the variation of OH radicals.
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Affiliation(s)
- Deng Lin
- Key Laboratory of Oasis Ecology, College of Resource and Environment Sciences, Xinjiang University, Urumqi 830046, China; State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
| | - Shengrui Tong
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China.
| | - Wenqian Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
| | - Weiran Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fangjie Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; College of Chemistry, Liaoning University, Shenyang 110036, Liaoning, China
| | - Chenhui Jia
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
| | - Gen Zhang
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Meifang Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; College of Chemistry and Material Science, Anhui Normal University, Wuhu 241000, China
| | - Xinran Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Chinese Academy of Sciences Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang He
- Key Laboratory of Oasis Ecology, College of Resource and Environment Sciences, Xinjiang University, Urumqi 830046, China.
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Zhao X, Wang J, Xu B, Zhao R, Zhao G, Wang J, Ma Y, Liang H, Li X, Yang W. Causes of PM 2.5 pollution in an air pollution transport channel city of northern China. Environ Sci Pollut Res Int 2022; 29:23994-24009. [PMID: 34820758 DOI: 10.1007/s11356-021-17431-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
To develop effective mitigation policies, a comprehensive understanding of the evolution of the chemical composition, formation mechanisms, and the contribution of sources at different pollution levels is required. PM2.5 samples were collected for 1 year from August 2016 to August 2017 at an urban site in Zibo, then chemical compositions were analyzed. Secondary inorganic aerosols (SNA), anthropogenic minerals (MIN), and organic matter (OM) were the most abundant components of PM2.5, but only the mass fraction of SNA increased as the pollution evolved, implying that PM2.5 pollution was caused by the formation of secondary aerosols, especially nitrate. A more intense secondary transformation was found in the heating season (from November 15, 2016, to March 14, 2017), and a faster secondary conversion of nitrate than sulfate was discovered as the pollution level increased. The formation of sulfate was dominated by heterogeneous reactions. High relative humidity (RH) in polluted periods accelerated the formation of sulfate, and high temperature in the non-heating season also promoted the formation of sulfate. Zibo city was under ammonium-rich conditions during polluted periods in both seasons; therefore, nitrate was mainly formed through homogeneous reactions. The liquid water content increased significantly as the pollution levels increased when the RH was above 80%, indicating that the hygroscopic growth of aerosol aggravated the PM2.5 pollution. Source apportionment showed that PM2.5 was mainly from secondary aerosol formation, road dust, coal combustion, and vehicle emissions, contributing 36.6%, 16.5%, 14.7%, and 13.1% of PM2.5 mass, respectively. The contribution of secondary aerosol formation increased remarkably with the deterioration of air quality, especially in the heating season.
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Affiliation(s)
- Xueyan Zhao
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Jing Wang
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Bo Xu
- Zibo Eco-Environmental Monitoring Center of Shandong Province, Zibo, 255000, China
| | - Ruojie Zhao
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Guangjie Zhao
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Jian Wang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yinhong Ma
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Handong Liang
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Xianqing Li
- State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
| | - Wen Yang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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Zhu X, Song X, Schwarzbauer J. First insights into the formation and long-term dynamic behaviors of nonextractable perfluorooctanesulfonate and its alternative 6:2 chlorinated polyfluorinated ether sulfonate residues in a silty clay soil. Sci Total Environ 2021; 761:143230. [PMID: 33158517 DOI: 10.1016/j.scitotenv.2020.143230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/15/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent and toxic contaminants that are ubiquitous in the environment. They can incorporate into soil as nonextractable residues (NER) which are not detectable with conventional analytical protocols but are still possible to remobilize with changes of surrounding conditions, and thus will be bioavailable again. Therefore, there is a need to investigate thoroughly the long-term fate of NER-PFAS. In this study, a 240-day incubation of perfluorooctanesulfonate (PFOS) and its alternative 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) in a silty clay topsoil was carried out. Solvent extraction, alkaline hydrolysis and sequential chemical degradation were applied on periodically sampled soil to obtain extractable, moderately bound and deeply bound PFAS, respectively. The results confirmed the formation of NER of both compounds but with different preferences of incorporating mechanisms. NER-PFOS was formed predominantly by covalent binding (via head group) and strong adsorption (via tail group). The formation of NER-F-53B was mainly driven by physical entrapment. Both bound compounds within the incubation period showed three-stage behaviors including an initial period with slight release followed by a (re) incorporating stage and a subsequent remobilizing stage. This work provides some first insights on the long-term dynamic behaviors of nonextractable PFAS and will be conducive to their risk assessment and remediation (e.g. estimating potential NER-PFAS level based on their free extractable level, and selecting remediation methods according to their prevailing binding mechanisms).
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Affiliation(s)
- Xiaojing Zhu
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr, 4-20, 52064 Aachen, Germany.
| | - Xin Song
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, 210008 Nanjing, China.
| | - Jan Schwarzbauer
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr, 4-20, 52064 Aachen, Germany.
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9
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Meng J, Li Z, Zhou R, Chen M, Li Y, Yi Y, Ding Z, Li H, Yan L, Hou Z, Wang G. Enhanced photochemical formation of secondary organic aerosols during the COVID-19 lockdown in Northern China. Sci Total Environ 2021; 758:143709. [PMID: 33223177 PMCID: PMC7666554 DOI: 10.1016/j.scitotenv.2020.143709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 05/09/2023]
Abstract
To eliminate the spread of a novel coronavirus breaking out in the end of 2019 (COVID-19), the Chinese government has implemented a nationwide lockdown policy after the Chinese lunar New Year of 2020, resulting in a sharp reduction in air pollutant emissions. To investigate the impact of the lockdown on aerosol chemistry, the number fraction, size distribution and formation process of oxalic acid (C2) containing particles and its precursors were studied using a single particle aerosol mass spectrometer (SPAMS) at the urban site of Liaocheng in the North China Plain (NCP). Our results showed that five air pollutants (i.e., PM2.5, PM10, SO2, NO2, and CO) decreased by 30.0-59.8% during the lockdown compared to those before the lockdown, while O3 increased by 63.9% during the lockdown mainly due to the inefficient titration effect of O3 via NO reduction. The increased O3 concentration can boost the atmospheric oxidizing capacity and further enhance the formation of secondary organic aerosols, thereby significantly enhancing the C2 particles and its precursors as observed during the lockdown. Before the lockdown, C2 particles were significantly originated from biomass burning emissions and their subsequent aqueous-phase oxidation. The hourly variation patterns and correlation analysis before the lockdown suggested that relative humidity (RH) and aerosol liquid water content (ALWC) played a key role in the formation of C2 particles and the increased aerosol acidity can promote the conversion of precursors such as glyoxal (Gly) and methyglyoxal (mGly) into C2 particles in the aqueous phase. RH and ALWC decreased sharply but O3 concentration and solar radiation increased remarkably during the lockdown, the O3-dominated photochemical pathways played an important role in the formation of C2 particles in which aerosol acidity was ineffective. Our study indicated that air pollution treatment sponges on a joint-control and balanced strategy for controlling numerous pollutants.
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Affiliation(s)
- Jingjing Meng
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Zheng Li
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Ruiwen Zhou
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Min Chen
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Yuanyuan Li
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Yanan Yi
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Zhijian Ding
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200062, China
| | - Hongji Li
- College of Environmental Science and Engineering, Jilin Normal University, Siping 136000, China
| | - Li Yan
- Chinese Academy for Environmental Planning, Beijing 100012, China
| | - Zhanfang Hou
- School of Environment and Planning, Liaocheng University, Liaocheng 252000, China
| | - Gehui Wang
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200062, China.
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10
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Zhang X, Wei D, Sun X, Bai C, Du Y. Free available chlorine initiated Baeyer-Villiger oxidation: A key mechanism for chloroform formation during aqueous chlorination of benzophenone UV filters. Environ Pollut 2021; 268:115737. [PMID: 33011608 DOI: 10.1016/j.envpol.2020.115737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
Chloroform, a regulated disinfection by-product in water, is often generated during chlorination disinfection treatment. However, the formation of chloroform is heavily dependent on the molecular structures of precursors. Moreover, compounds containing ketone moiety are ubiquitous in water environments. However, it is unclear if they can generate chloroform during chlorination. In this study, 14 benzophenones (BPs), efficient and widely used UV filters, with different substituents were selected to explore chloroform formation during chlorination. All 14 BPs generated chloroform, with yields dependent on their molecular structures and operational conditions. Compounds 2,2',4,4'-tetrahydroxy-BP and benzophenone produced the highest and lowest chloroform of 0.313 and 0.013 g/g, respectively, corresponding to the fastest and slowest formation rate constants of 1.41 × 10-1 and 2.71 × 10-2 min-1. Alkaline conditions and high chlorine dosages were favorable to chloroform formation. Three reactions played key roles in chloroform formation from BPs: (1) chlorine initiated Baeyer-Villiger oxidation converted ketone moieties of BP molecules into esters; (2) the esters further underwent hydrolysis and formed phenolic and benzoic products; and (3) benzoic acids underwent decarboxylation and hydrolysis to form phenolic products. Subsequently, these phenolic products could further generate chloroform in the chlorination system. More importantly, BPs could generate chloroform in the ambient water matrices during practical chlorination treatment. This work emphasized the critical role of Baeyer-Villiger oxidation for chloroform formation, implying that pollutants containing aromatic ketone moieties generate chloroform during chlorination disinfection, and their potential risk should therefore be reviewed.
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Affiliation(s)
- Xinyi Zhang
- 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
| | - Dongbin Wei
- 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.
| | - Xuefeng Sun
- 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
| | - Chenzhong Bai
- 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
| | - Yuguo Du
- 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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11
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Li L. Toxicity evaluation and by-products identification of triclosan ozonation and chlorination. Chemosphere 2021; 263:128223. [PMID: 33297179 DOI: 10.1016/j.chemosphere.2020.128223] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 05/05/2023]
Abstract
Triclosan (TCS) has attracted increasing concern due to its ubiquitous occurrence in aquatic environments as well as its potential adverse effects on human health. This study investigated the toxicity and transformation characteristics of triclosan ozonation and chlorination. The results showed that two hydroxylated by-products were formed via nucleophilic substitution during ozonation, while three chlorinated compounds were generated via electrophilic substitution during chlorination. The toxicity results demonstrated that the parent compound, triclosan, exhibited mild genotoxicity and anti-estrogenic activity. The chlorination of triclosan resulted in a 30-fold increase in anti-estrogenic activity owing to the generation of toxic polychlorinated transformation by-products. In addition, the chlorination by-products were found to be genotoxic like the parent compound. Fortunately, in contrast to chlorination, ozonation could mitigate the genotoxicity and anti-estrogenic activity of triclosan-containing water.
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Affiliation(s)
- Liping Li
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China; Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, PR China.
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12
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Zhang M, Fujimori T, Shiota K, Buekens A, Mukai K, Niwa Y, Li X, Takaoka M. Thermochemical formation of dioxins promoted by chromium chloride: In situ Cr- and Cl-XAFS analysis. J Hazard Mater 2020; 388:122064. [PMID: 31954297 DOI: 10.1016/j.jhazmat.2020.122064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 12/23/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
Chromium is commonly found in the flue gases and ashes of Municipal Solid Waste Incineration. It has been reported as an active catalyst for the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) during de novo tests, yet its specific mode of action has remained unclear. This study aims to identify the effects of chromium chloride on the formation of PCDD/F and other chloro-aromatics and to elucidate the underlying reaction mechanisms. A series of de novo tests, conducted over a wide range of temperature (from 250 to 550 °C) and for four different oxygen contents (0, 5, 10, 20 %), confirmed the promoting effect of CrCl3 on the PCDD/F formation. In situ X-ray Absorption Fine Structure (XAFS) spectroscopy was applied to investigate the behavior of CrCl3 during heating, describing the entire picture of CrCl3-promoted formation pathways of dioxins. The effect of oxygen was studied by measuring XAFS spectra on samples heated at different oxygen concentrations. According to these spectra, chromium compounds play two key roles during dioxins formation: (a) chlorinating carbon, using chlorine derived from conversion of CrCl3 into Cr2O3, and further oxidation to Cr(VI), and (b) facilitating oxidative destruction of the carbon matrix, while reducing Cr(VI) to Cr2O3.
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Affiliation(s)
- Mengmei Zhang
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 6158510, Japan; State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Takashi Fujimori
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 6158510, Japan.
| | - Kenji Shiota
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 6158510, Japan
| | - Alfons Buekens
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Kota Mukai
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 6158510, Japan
| | - Yasuhiro Niwa
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, 3050801, Japan
| | - Xiaodong Li
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
| | - Masaki Takaoka
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto, 6158510, Japan
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13
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Wu X, Li M, Chen J, Wang H, Xu L, Hong Y, Zhao G, Hu B, Zhang Y, Dan Y, Yu S. The characteristics of air pollution induced by the quasi-stationary front: Formation processes and influencing factors. Sci Total Environ 2020; 707:136194. [PMID: 31972916 DOI: 10.1016/j.scitotenv.2019.136194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
The quasi-stationary front is a significant weather system which influences East Asia in spring. The air quality deteriorated along with the moist circumstance when the quasi stationary front dominated the area. Surface meteorological parameters, air pollutants and PM2.5 chemical species were observed during the air pollution episode. Liquid water content and aerosol acidity were calculated by thermodynamic model in order to investigate heterogeneous/aqueous reactions for secondary aerosol formation. The episode was divided into four stages based on quasi-stationary front influences. Hourly PM2.5 concentrations were up to 150.2 μg·m-3 while O3 concentrations reached the minimum value of 1.27 μg·m-3, indicating that the precursor gas NOx participated in the different reactions during the episode. Nitrate proportion of water-soluble inorganic ions was 42.2%. High concentrations of secondary inorganic aerosol ions and the high sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) indicated the increasing conversions from SO2 and NOx to their corresponding particulate phases. Ratios of [NO3-]/[SO42-] and [NH4+]/[SO42-] in the four stages declared that nitrate formation preferred heterogeneous conversions. A series of liquid water content (LWC) fitting equations between relative humidity and inorganic ions were conducted to verify heterogeneous aqueous reactions of NO2 and secondary nitrate formation. The results of this study highlighted the significance of LWC and chemical reactions associated with acidity during the specific synoptic situation in South China.
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Affiliation(s)
- Xin Wu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Mengren Li
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Jinsheng Chen
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China.
| | - Hong Wang
- Fujian Institute of Meteorological Sciences, Fuzhou 350001, PR China
| | - Lingling Xu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Youwei Hong
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Guoqing Zhao
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Baoye Hu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yanru Zhang
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yangbin Dan
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
| | - Shaocai Yu
- Research Center for Air Pollution and Health, Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, College of Environment and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China.
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14
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Zhu X, Dsikowitzky L, Ricking M, Schwarzbauer J. Molecular insights into the formation and remobilization potential of nonextractable anthropogenic organohalogens in heterogeneous environmental matrices. J Hazard Mater 2020; 381:120959. [PMID: 31401459 DOI: 10.1016/j.jhazmat.2019.120959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 06/10/2023]
Abstract
Anthropogenic organohalogens (AOHs) are toxic and persistent pollutants that occur ubiquitously in the environment. An unneglectable portion of them can convert into nonextractable residues (NER) in the natural solid substances. NER-AOHs are not detectable by conventional solvent-extraction, and will get remobilized through changes of surrounding environment. Consequently, the formation and fate of NER-AOHs should be investigated comprehensively. In this study, solvent extraction, sequential chemical degradation and thermochemolysis were applied on different sample matrices (sediments, soils and groundwater sludge, collected from industrial areas) to release extractable and nonextractable AOHs. Covalent linkages were observed most favorable for the hydrophilic-group-containing monocyclic aromatic AOHs (HiMcAr-AOHs) (e.g. halogenated phenols, benzoic acids and anilines) incorporating into the natural organic matter (NOM) as NER. Physical entrapment mainly contributed to the NER formation of hydrophobic monocyclic aromatic AOHs (HoMcAr-AOHs) and polycyclic aromatic AOHs (PcAr-AOHs). The hypothesized remobilization potential of these NER-AOHs follow the order HiMcAr-AOHs > HoMcAr-AOHs/ aliphatic AOHs > PcAr-AOHs. In addition, the NOM macromolecular structures of the studied samples were analyzed. Based on the derived results, a conceptual model of the formation mechanisms of NER-AOHs is proposed. This model provides basic molecular insights that are of high value for risk assessment and remediation of AOHs.
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Affiliation(s)
- Xiaojing Zhu
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, 52064 Aachen, Germany
| | - Larissa Dsikowitzky
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, 52064 Aachen, Germany
| | - Mathias Ricking
- Dpt Wastewater Technology Research, German Environment Agency, Corrensplatz 1, 14195 Berlin, Germany
| | - Jan Schwarzbauer
- Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstr. 4-20, 52064 Aachen, Germany.
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15
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Ding S, Ng BF, Shang X, Liu H, Lu X, Wan MP. The characteristics and formation mechanisms of emissions from thermal decomposition of 3D printer polymer filaments. Sci Total Environ 2019; 692:984-994. [PMID: 31540002 DOI: 10.1016/j.scitotenv.2019.07.257] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/29/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Ultrafine particles (UFP) and volatile organic compounds (VOC) emitted from fused deposition modelling (FDM) 3D printing have received widespread attention. Here, we characterize the formation mechanisms of emissions from polymer filaments commonly used in FDM 3D printing. The temporal relationship between the amount and species of total VOC (TVOC) at any desired operating thermal condition is obtained through a combination of evolved gas analysis (EGA) and thermogravimetric analysis (TGA) to capture physicochemical reactions, in which the furnace of EGA or TGA closely resembles the heating process of the nozzle in the FDM 3D printer. It is generally observed that emissions initiate at the start of the glass transition process and peak during liquefaction for filaments. Initial increment in emissions during liquefaction and the relatively constant decomposition of products in the liquid phase are two main TVOC formation mechanisms. More importantly, low heating rate has the potential to restrain the formation of carcinogenic monomer, styrene, from ABS. A TVOC measurement method based on weight loss is further proposed and found that TVOC mass yield was 0.03%, 0.21% and 2.14% for PLA, ABS, and PVA, respectively, at 220 °C. Among TVOC, UFP mass accounts for 1% to 5% of TVOC mass depending on the type of filaments used. Also, for the first time, emission of UFP from the nozzle is directly observed through laser imaging.
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Affiliation(s)
- Shirun Ding
- Singapore Centre for 3D Printing, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Bing Feng Ng
- Singapore Centre for 3D Printing, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| | - Xiaopeng Shang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Hu Liu
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Xuehong Lu
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Man Pun Wan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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16
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Sun X, Chen M, Wei D, Du Y. Research progress of disinfection and disinfection by-products in China. J Environ Sci (China) 2019; 81:52-67. [PMID: 30975330 DOI: 10.1016/j.jes.2019.02.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/25/2019] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Disinfection is an indispensable water treatment process for killing harmful pathogens and protecting human health. However, the disinfection has caused significant public concern due to the formation of toxic disinfection by-products (DBPs). Lots of studies on disinfection and DBPs have been performed in the world since 1974. Although related studies in China started in 1980s, a great progress has been achieved during the last three decades. Therefore, this review summarized the main achievements on disinfection and DPBs studies in China, which included: (1) the occurrence of DBPs in water of China, (2) the identification and detection methods of DBPs, (3) the formation mechanisms of DBPs during disinfection process, (4) the toxicological effects and epidemiological surveys of DBPs, (5) the control and management countermeasures of DBPs in water disinfection, and (6) the challenges and chances of DBPs studies in future. It is expected that this review would provide useful information and reference for optimizing disinfection process, reducing DBPs formation and protecting human health.
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Affiliation(s)
- Xuefeng Sun
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Miao Chen
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongbin Wei
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Yuguo Du
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, 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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17
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Liu H, Tian H, Zhang K, Liu S, Cheng K, Yin S, Liu Y, Liu X, Wu Y, Liu W, Bai X, Wang Y, Shao P, Luo L, Lin S, Chen J, Liu X. Seasonal variation, formation mechanisms and potential sources of PM 2.5 in two typical cities in the Central Plains Urban Agglomeration, China. Sci Total Environ 2019; 657:657-670. [PMID: 30677932 DOI: 10.1016/j.scitotenv.2018.12.068] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 05/16/2023]
Abstract
In order to probe the seasonal variation, formation mechanisms as well as geographical origins of fine particles and its chemical components in two cities (Zhengzhou, ZZ and Xinxiang, XX) in Central Plains Urban Agglomeration, daily PM2.5 aerosol samples were collected for four consecutive seasons during 2017-2018. The annual average concentrations of PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) were calculated at 70.5 ± 50.8 and 69.0 ± 46.3 μg m-3 at ZZ and XX, respectively. Daily ambient PM2.5 concentrations ranged from 18.2 to 303.0 μg m-3, among which >81% of the total sampling days exceeded the National Ambient Air Quality Standard of China (NAAQS, 35 μg m-3 as an annual average). Additionally, concentrations of PM2.5 and its major chemical components were seasonally dependent, usually with the highest mass concentration in winter. Compared with previous studies, higher NO3-/SO42- were observed in this study depicted that air pollution caused by motor vehicle exhaust cannot be ignored. OC concentration was higher at ZZ than XX during sampling campaign likely partially caused by larger number of motor vehicles, chemical pesticide and solvent used in ZZ. Both homogeneous and heterogeneous reactions played an important role in the formation of nitrate, while heterogeneous reactions dominated the formation of sulfate. We also found a faster increase in nitrate than in sulfate during the evolution of haze. The characteristics of long-range transportation of PM2.5 and its major chemical components and gaseous precursors were observed at both sites through back trajectories and WPSCF analysis, suggesting the complexity of air pollution and the multi-influence among cities.
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Affiliation(s)
- Huanjia Liu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Hezhong Tian
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China.
| | - Kai Zhang
- Department of Epidemiology, Human Genetics and Environmental Sciences, University of Texas Health Science Center Houston, School of Public Health, Houston, TX 77030, United States
| | - Shuhan Liu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Ke Cheng
- School of Environment, Henan Key Laboratory of Environmental Pollution Control, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang 453007, China
| | - Shasha Yin
- College of Chemistry and Molecular Engineering, Research Institute of Environmental Science, Zhengzhou University, Zhengzhou 450001, China
| | - Yongli Liu
- School of Environment, Henan Key Laboratory of Environmental Pollution Control, Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang 453007, China
| | - Xiangyang Liu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Yiming Wu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Wei Liu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Xiaoxuan Bai
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Yong Wang
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Panyang Shao
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Lining Luo
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Shumin Lin
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Jing Chen
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
| | - Xingang Liu
- State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing 100875, China
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18
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Zhou Y, Liu J. Emissions, environmental levels, sources, formation pathways, and analysis of polybrominated dibenzo-p-dioxins and dibenzofurans: a review. Environ Sci Pollut Res Int 2018; 25:33082-33102. [PMID: 30269281 DOI: 10.1007/s11356-018-3307-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/20/2018] [Indexed: 06/08/2023]
Abstract
Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) were labeled potential persistent organic pollutants by the Stockholm Convention and have structures and toxicities similar to those of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), which has caused considerable concern. This article reviews the current available literature on the status, sources, formation pathways, and analysis of PBDD/Fs. PBDD/Fs are widely generated in industrial thermal processes, such as those for brominated flame retardant (BFR) products, e-waste dismantling, metal smelting processes, and waste incineration. PBDD/Fs can form via the following routes: precursor formation, de novo formation, biosynthesis, and natural formation. The levels of PBDD/Fs in the environment and in organisms and humans have increased due to extensive consumption and the increasing inventory of BFRs; thus, the risk of human exposure to PBDD/Fs is expected to be high.
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Affiliation(s)
- Yanxiao Zhou
- Zhejiang University of Technology, No.18 Chaowang Road, Hangzhou, 310014, Zhejiang, China
| | - Jinsong Liu
- Zhejiang University of Technology, No.18 Chaowang Road, Hangzhou, 310014, Zhejiang, China.
- Zhejiang Environmental Monitoring Center, Hangzhou, 310012, Zhejiang, China.
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19
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Wang X, Chen J, Ni Y. Polychlorinated dibenzo-p-dioxin and dibenzofuran precursors and formation mechanisms during non-woodpulp chlorine bleaching process. Chemosphere 2018; 211:1-9. [PMID: 30055355 DOI: 10.1016/j.chemosphere.2018.07.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/16/2018] [Accepted: 07/22/2018] [Indexed: 06/08/2023]
Abstract
There is great concern about decreasing the amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) that are formed and emitted during the chlorine bleaching of pulp. The formation of PCDD/Fs during non-woodpulp chlorine bleaching was investigated in the study described here. Wheat straw was separated into three components, cellulose, hemicellulose, and lignin. Chlorination experiments were performed, and lignin and hemicellulose contributed more than cellulose to PCDD/F formation when the pulp was bleached using chlorine. The chemical components of lignin were identified by gas chromatography mass spectrometry, and nine possible PCDD/F precursors were quantified by gas chromatography tandem mass spectrometry. Spiked chlorination experiments were performed to investigate the effects of these compounds on PCDD/F formation. 4-Ethyl-2-methoxyphenol had the strongest effect on PCDD/F formation, followed by p-chlorophenol, and guaiacol. All the test compounds promoted polychlorinated dibenzofuran formation but had limited effects on polychlorinated dibenzo-p-dioxin formation. The results allowed mechanisms for the formation of PCDD/Fs from phenol, chlorophenol, catechol, and guaiacol to be proposed.
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Affiliation(s)
- Xueli Wang
- Key Laboratory of Subsurface Hydrology and Ecological Effects inArid Region, Ministry of Education, Chang' an University, PR China; School of Environmental Science and Engineering, Chang'an University, Xi'an, 710054, China.
| | - Jiping Chen
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Yuwen Ni
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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Li L, Wei D, Wei G, Du Y. Oxidation of cefazolin by potassium permanganate: Transformation products and plausible pathways. Chemosphere 2016; 149:279-285. [PMID: 26872071 DOI: 10.1016/j.chemosphere.2016.01.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 06/05/2023]
Abstract
Cefazolin was demonstrated to exert high reactivity toward permanganate (Mn(VII)), a common oxidant in water pre-oxidation treatment. In this study, five transformation products were found to be classified into three categories according to the contained characteristic functional groups: three (di-)sulfoxide products, one sulfone product and one di-ketone product. Products analyses showed that two kinds of reactions including oxidation of thioether and the cleavage of unsaturated CC double bond occurred during transformation of cefazolin by Mn(VII). Subsequently, the plausible transformation pathways under different pH conditions were proposed based on the identified products and chemical reaction principles. More importantly, the simulation with real surface water matrix indicated that the proposed transformation pathways of cefazolin could be replayed in real water treatment practices.
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Affiliation(s)
- Liping Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Dongbin Wei
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Guohua Wei
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yuguo Du
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
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Tondeur Y, Vining B, Serne J, Hart J. Significance of measuring non-2,3,7,8-substituted PCDD/PCDF congeners and the identification of a new mechanism of formation for a high-temperature industrial process. Chemosphere 2015; 126:47-52. [PMID: 25700184 DOI: 10.1016/j.chemosphere.2015.01.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 01/01/2015] [Accepted: 01/26/2015] [Indexed: 06/04/2023]
Abstract
Many studies involving polychlorinated dibenzo-p-dioxins and dibenzofurans (Cl4-Cl8) are limited to the 17 2,3,7,8-substituted congeners, which are used for the computation of the toxic equivalent concentration (TEQ) and often are the basis for regulatory actions. The values determined for total homolog groups may also be reported in some cases, e.g., Total Tetra-Dioxins, and such results provide some additional information but do not reveal the subtle details that can be derived from the study of individual congeners. There are 136 possible structures for tetra- through octa-chlorinated dibenzo-p-dioxins and dibenzofurans, including the 17 2,3,7,8-substituted congeners. In this work, the valuable role that inclusion of the other 119 congeners plays in understanding emission deviations (upsets) compared to normal operating conditions for a secondary aluminum smelter facility is illustrated. An exponential correlation was observed between the concentrations of specific non-2,3,7,8-substituted tetrachlorinated congeners (e.g., 2,3,6,7/3,4,6,7-TCDFs vs. 1,3,6,8-TCDD and 1,3,7,9-TCDD) and the TEQ-based emissions at the outlet of a baghouse pollution control device. The correlation possibly points to the additional and occasionally essential role played by metal-catalyzed stereoselective chlorination reactions taking place during the melting-purification process, as well as (conceivably) inside the air pollution control device. This chlorination in turn highlights not only the importance of the chlorine addition step and the kinetics involved with regard to regulating emission levels but also the role of measuring all 136 PCDD/F congeners.
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Affiliation(s)
- Yves Tondeur
- SGS Environmental Services, Wilmington, NC 28405, USA.
| | - Bryan Vining
- SGS Environmental Services, Wilmington, NC 28405, USA
| | - Jim Serne
- TRC Environmental Corporation, Raleigh, NC 27606, USA
| | - Jerry Hart
- SGS Environmental Services, Wilmington, NC 28405, USA
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Aidarkhanov AO, Lukashenko SN, Lyakhova ON, Subbotin SB, Yakovenko YY, Genova SV, Aidarkhanova AK. Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site. J Environ Radioact 2013; 124:163-170. [PMID: 23811126 DOI: 10.1016/j.jenvrad.2013.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 05/02/2013] [Accepted: 05/14/2013] [Indexed: 06/02/2023]
Abstract
The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed.
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Affiliation(s)
- A O Aidarkhanov
- Institute of Radiation Safety and Ecology, NNC RK, 071100 Kurchatov, Kazakhstan.
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