微氧环境氯代烃生物降解的研究现状与展望

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (1303 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要总结了微氧环境的生物氧化特性,系统调研了微氧环境中氯代烃(CAHs)的污染情况,发现地下水,土壤包气带,河床沉积物和垃圾填埋场等微氧环境场地存在广泛的CAHs污染.此外,研究归纳了氧调控下的CAHs降解途径,系统分析了微氧环境CAHs的转化特性、微生物活性及功能基因表达特征.总结发现微氧条件下氧对CAHs降解有5方面影响,CAHs降解速率甚至比好/厌氧条件下更高;微氧环境中好氧和厌氧降解菌能同时存在,多种微氧环境污染场地能同时检测到好氧功能基因(etnC和etnE)和厌氧功能基因(vcrA和bvcA),进一步表明好氧转化和厌氧脱氯能在同一时空发生.最后从监测装置开发、适应机制、转化机制和微生态演变规律4方面展望了未来的发展方向,结果为微氧环境的污染物转化研究及污染控制策略的制定提供了方向.

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	邢志林
	石云椿
	苏夏
	苟芳
	赵天涛

关键词 ：微氧环境, 氯代有机物, 生物降解, 机理调控, 发展方向

Abstract：The biodegradation characteristics of chlorinated hydrocarbons (CAHs) in micro-aerobic environments were summarized in this study. A systematic investigation of CAHs contamination in micro-aerobic environments was conducted, revealing extensive CAHs pollution in locations such as groundwater, soil vadose zones, riverbed sediments, and landfill sites with micro-aerobic conditions. Additionally, the study compiled the pathways of CAHs degradation under oxygen regulation and analyzed the transformation characteristics, microbial activity, and functional gene expression of CAHs in micro-aerobic environments. It was concluded that oxygen had five distinct effects on CAHs degradation under micro-aerobic conditions, with degradation rates often surpassing those observed under strictly aerobic or anaerobic conditions. Moreover, both aerobic and anaerobic degraders coexisted in micro-aerobic environments, as evidenced by the detection of aerobic functional genes (etnC and etnE) and anaerobic functional genes (vcrA and bvcA) in various micro-aerobic pollution sites, indicating that aerobic transformations and anaerobic dechlorination could occur simultaneously in the same spatial and temporal settings. Finally, future development directions were projected in four aspects, including monitoring device development, adaptation mechanisms, transformation mechanisms, and microecological evolution patterns. These results offer valuable insights for the study of pollutant transformation in micro-aerobic environments and the formulation of pollution control strategies.

Key words： micro-aerobic environment chlorinated organic substances biodegradation mechanistic regulation development direction

收稿日期: 2023-02-07

PACS:

X172

基金资助:国家自然科学基金资助项目(51978117,52200145)；重庆市自然科学基金资助项目(CSTB2022NSCQ-MSX0540)

通讯作者: 邢志林,讲师,xingzhilin@cqut.edu.cn E-mail: xingzhilin@cqut.edu.cn

作者简介: 邢志林(1988-),男,河北承德人,讲师,博士,主要从事卤代有机物生物降解研究.发表论文40余篇.xingzhilin@cqut.edu.cn

引用本文:

邢志林, 石云椿, 苏夏, 苟芳, 赵天涛. 微氧环境氯代烃生物降解的研究现状与展望[J]. 中国环境科学, 2023, 43(9): 4837-4848. XING Zhi-lin, SHI Yun-chun, SU Xia, GOU Fang, ZHAO Tian-tao. The current status and prospects of biodegradation of chlorinated hydrocarbons under micro-aerobic conditions. CHINA ENVIRONMENTAL SCIENCECE, 2023, 43(9): 4837-4848.

链接本文:

http://www.zghjkx.com.cn/CN/ 或 http://www.zghjkx.com.cn/CN/Y2023/V43/I9/4837

[1]	Xing Z L, Su X, Zhang X P,et al. Direct aerobic oxidation (DAO) of chlorinated aliphatic hydrocarbons:A review of key DAO bacteria, biometabolic pathways and in-situ bioremediation potential[J]. Environment International, 2022,162:107165.
[2]	Chen H M, Wu M T. Residential exposure to chlorinated hydrocarbons from groundwater contamination and the impairment of renal function-An ecological study[J]. Scientific Reports, 2017,7:40283.
[3]	Chen P P, Liu H, Xing Z L, et al. Cometabolic degradation mechanism and microbial network response of methanotrophic consortia to chlorinated hydrocarbon solvents[J]. Ecotoxicology and Environmental Safety, 2022,230:113110.
[4]	Stroo H F, Ward C H. In situ remediation of chlorinated solvent plumes[M]. Springer, 2010:537-571.
[5]	Nijenhuis I, Kuntze K. Anaerobic microbial dehalogenation of organohalides-state of the art and remediation strategies[J]. Current Opinion in Biotechnology, 2016,38:33-38.
[6]	Chen S, Chin Y, Yang H, et al. Cometabolic biodegradation of chlorinated ethenes with methanotrophs in anaerobic/aerobic simulated aquifer[J]. Journal of Environmental Biology, 2021,42(4):1033-1045.
[7]	刘帅,赵天涛,邢志林,等.氯代脂肪烃生物与非生物共促降解机制研究进展[J]. 生物工程学报, 2018,34(4):510-524. Liu S, Zhao T T, Xing Z L, et al. Advances in biotic and abiotic mutual promoting mechanism for chlorinated aliphatic hydrocarbons degradation[J]. Chinese Journal of Biotechnology, 2018,34(4):510-524.
[8]	Cbo A, Plb A, Dh B, et al. Assessment of chlorinated ethenes degradation after field scale injection of activated carbon and bioamendments:application of isotopic and microbial analyses[J]. Journal of Contaminant Hydrology, 2021,240:103794.
[9]	Weatherill, John J, Atashgahi, et al. Natural attenuation of chlorinated ethenes in hyporheic zones:a review of key biogeochemical processes and in-situ transformation potential[J]. Water Research, 2018, 128:362-382.
[10]	Xiao Z, Jiang W, Chen D, et al. Bioremediation of typical chlorinated hydrocarbons by microbial reductive dechlorination and its key players:a review[J]. Ecotoxicology and Environmental Safety, 2020, 202:110925.
[11]	Kesson S, Sparrenbom C J, Paul C J, et al. Characterizing natural degradation of tetrachloroethene (PCE) using a multidisciplinary approach[J]. Ambio:A Journal of the Human Environment, 2021, 50(5):1074-1088.
[12]	Richards P M, Liang Y, Johnson R L, et al. Cryogenic soil coring reveals coexistence of aerobic and anaerobic vinyl chloride degrading bacteria in a chlorinated ethene contaminated aquifer[J]. Water Research, 2019,157:281-291.
[13]	Carpani G, Marchesi M, Pietrini I, et al. 1,2-DCA natural attenuation evaluation in groundwater:insight by dual isotope 13C/37Cl and molecular analysis approach[J]. Water, 2021,13(5):728-728.
[14]	Trueba-Santiso A, Palau J, Soder-Walz J M, et al. Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation[J]. Journal of Environmental Science, 2022,118(8):204-213.
[15]	Armiento G, Caprioli R, Cerbone A, et al. Current status of coastal sediments contamination in the former industrial area of Bagnoli-Coroglio (Naples, Italy)[J]. Chemistry and Ecology, 2020, 36(6):579-597.
[16]	Wanner P, Parker B L, Chapman S W, et al. Identification of degradation pathways of chlorohydrocarbons in saturated low-permeability sediments using compound-specific isotope analysis[J]. Environmental Science & Technology, 2018,52(13):7296-7306.
[17]	Gossett J M. Sustained aerobic oxidation of vinyl chloride at low oxygen concentrations[J]. Environmental Science & Technology, 2010,44(4):1405-1411.
[18]	Nicholas V, Coleman, Jim C, et al. Epoxyalkane:coenzyme M transferase in the ethene and vinyl chloride biodegradation pathways of Mycobacterium strain JS60[J]. Jouranal of Bacteriology, 2003, 185(18):5536-5545.
[19]	Schmidt K R, Tiehm A. Natural attenuation of chloroethenes:identification of sequential reductive/oxidative biodegradation by microcosm studies[J]. Water Science and Technology, 2008,58(5):1137-1145.
[20]	Atashgahi S, Maphosa F, Doğan E, et al. Small-scale oxygen distribution determines the vinyl chloride biodegradation pathway in surficial sediments of riverbed hyporheic zones[J]. FEMS Microbiology Ecology, 2013,84(1):133-142.
[21]	Tentori E F, Fang S, Richardson R E. RNA biomarker trends across type I and type II aerobic methanotrophs in response to methane oxidation rates and transcriptome response to short-term methane and oxygen limitation in Methylomicrobium album BG8[J]. Microbiology Spectrum, 2022,10(3):1-16.
[22]	Kim J, Lee W B. The development of a prediction model for the kinetic constant of chlorinated aliphatic hydrocarbons[J]. Environmental Modeling & Assessment, 2007,14(1):93-100.
[23]	Liu C G, Xue C, Lin Y H, et al. Redox potential control and applications in microaerobic and anaerobic fermentations[J]. Biotechnology Advances, 2013,31(2):257-265.
[24]	Chen C C, Gong G C, Shiah F K. Hypoxia in the East China Sea:one of the largest coastal low-oxygen areas in the world[J]. Marine Environmental Research, 2007,64(4):399-408.
[25]	顾孝连,徐兆礼.河口及近岸海域低氧环境对水生动物的影响[J]. 海洋渔业, 2009,31(4):426-437. Gu X L, Xu Z L. A review on the effects of hypoxia on aquatic animals in estuaries[J]. Marine Fisheries, 2009,31(4):426-437.
[26]	Li C H, Zhou H W, Wong Y S, et al. Vertical distribution and anaerobic biodegradation of polycyclic aromatic hydrocarbons in mangrove sediments in Hong Kong, South China[J]. Science of the Total Environment, 2009,407(21):5772-5779.
[27]	Nancy N, Rabalai, Turner R. Hypoxia in the northern gulf of Mexico:description, causes and change[M]. Washington:American Geophysical Union, 1997:1-36.
[28]	Li C H, Wong Y S, Tam N F. Anaerobic biodegradation of polycyclic aromatic hydrocarbons with amendment of iron (III) in mangrove sediment slurry[J]. Bioresource Technology, 2010,101(21):8083-8092.
[29]	宋永亭.不同配气条件下微生物驱油生长代谢规律[J]. 应用与环境生物学报, 2017,23(6):974-978. Song Y T. Regulation of microbial growth and metabolism and oil displacement under different gas distribution conditions[J]. Chinese Journal of Applied and Environment Biology, 2017,23(6):974-978.
[30]	Liu J, Qu W, Kadiiska M B. Role of oxidative stress in cadmium toxicity and carcinogenesis[J]. Toxicology and Applied Pharmacology, 2009,238(3):209-214.
[31]	Zehl K, Jürgen E. Influence of atmospheric oxygen on heavy metal mobility in sediment and soil (7pp)[J]. Journal of Soils & Sediments, 2005,5(3):164-170.
[32]	Táncsics A, Farkas M, Horváth B, et al. Genome analysis provides insights into microaerobic toluene-degradation pathway of Zoogloea oleivorans BucT[J]. Archives of Microbiology, 2020,202(2):421-426.
[33]	Bai L, Liu X, Hua K, et al. Microbial processing of autochthonous organic matter controls the biodegradation of 17α-ethinylestradiol in lake sediments under anoxic conditions[J]. Environmental Pollution, 2022,296:118760.
[34]	He R, Su Y, Leewis M C, et al. Low O2level enhances CH4-derived carbon flow into microbial communities in landfill cover soils[J]. Environmental Pollution, 2019,258:113676.
[35]	Elena G, Igor G. Simultaneous nitrification and denitrification with low dissolved oxygen level and C/N ratio[J]. Procedia Engineering, 2016, 153:189-194.
[36]	吴松,肖勇,郑志勇,等.微氧环境中电化学活性微生物的分离与鉴定[J]. 环境科学, 2014,35(10):3933-3939. Wu S, Xiao Y, Zheng Z Y, et al. Isolation and identification of electrochemically active microorganism from micro-aerobic environment[J]. Environment Science, 2014,35(10):3933-3939.
[37]	陈元彩,陈竹,蓝惠霞,等.微氧条件下固定化颗粒污泥的氯酚降解及菌群结构[J]. 华南理工大学学报(自然科学版), 2006,32(9):128-132. Chen Y C, Chen Z, Lan H X,et al. Chlorophen degradation and microorgannism community structure of immobilized granular sludge under micro-aeration condition[J]. Journal of South China University of Technology, 2006,32(9):128-132.
[38]	Xiong S, Zhao J, Lun B, et al. Reconsidering the use of ferrous hydroxide for remediation of chlorinated ethylene contaminated groundwater:ultra-fast trichloroethene dechlorination by ferrous hydroxide and bone char mixture[J]. Chemical engineering journal, 2022,438:135516.
[39]	胡文庆,邢志林,赵天涛.包气带中氯代烃运移特性及原位生物修复研究进展[J]. 应用与环境生物学报, 2022,28(4):1094-1101. Hu W Q, Xing Z L, Zhao T T. Migration behavior and in-situ bioremediation of chlorinated hydrocarbon solvent in vadose zone:a review[J]. Chinese Journal of Applied & Environmental Biology, 2022,28(4):1094-1101.
[40]	Yu M, Luo Z, Wang Y, et al. Chlorobenzenes contamination in soils/sediments at a site of decommissioned plant in central China[J]. Journal of Earth Science, 2018,29(3):639-645.
[41]	杨旭,邢志林,张丽杰.填埋场氯代烃生物降解过程的机制转化与调控研究及展望[J]. 微生物学报, 2017,57(4):468-479. Yang X, Xing Z L, Zhang L J. Advances in transformation and regulation biodegradation of chorinated hydrocarbons in landfill[J]. Acta Microbiology Sinica, 2017,57(4):468-479.
[42]	赵天涛,杨旭,邢志林,等.填埋场覆盖土对典型氯代烃的吸附特性[J]. 中国环境科学, 2018,38(4):1403-1410. Zhao T T, Yang X, Xing Z L, et al. Adsorption of chlorinated hydrocarbons in landfill cover soil[J]. China Environmental Science, 2018,38(4):1403-1410.
[43]	Wright J, Kirchner V, Bernard W, et al. Bacterial community dynamics in dichloromethane-contaminated groundwater undergoing natural attenuation[J]. Frontiers in Microbiology, 2017,8:1-15.
[44]	Imfeld G, Hellal J, Joulian C, et al. Chlorinated ethene biodegradation and associated bacterial taxa in multi-polluted groundwater:Insights from biomolecular markers and stable isotope analysis[J]. Science of The Total Environment, 2020,763:142950.
[45]	Li H, Zhang S Y, Wang X L, et al. Aerobic biodegradation of trichloroethylene and phenol co-contaminants in groundwater by a bacterial community using hydrogen peroxide as the sole oxygen source[J]. Environmental Technology, 2014,36:667-674.
[46]	Nw A, Wen Z B, Ww A, et al. Field study of chlorinated aliphatic hydrocarbon degradation in contaminated groundwater via micron zero-valent iron coupled with biostimulation[J]. Chemical Engineering Journal, 2020,384:123349.
[47]	Trueba-Santiso A, Palau J, Soder-Walz J M, et al. Assessment of aerobic biodegradation of lower-chlorinated benzenes in contaminated groundwater using field-derived microcosms and compound-specific carbon isotope fractionation[J]. Journal of Environmental Sciences, 2022,118:204-213.
[48]	Jiang F, Li Y, Zhou W, et al. Enhanced degradation of monochlorobenzene in groundwater by ferrous iron/persulfate process with cysteine[J]. Chemical Engineering Journal, 2020,387:124048.
[49]	Chen S K, Yang H Y, Huang S R, et al. Complete degradation of chlorinated ethenes and its intermediates through sequential anaerobic/aerobic biodegradation in simulated groundwater columns (complete degradation of chlorinated ethenes)[J]. International Journal of Environmental Science and Technology, 2021,17(11):4517-4530.
[50]	Saiyari D M, Chuang H P, Senoro D B, et al. A review in the current developments of genus Dehalococcoides, its consortia and kinetics for bioremediation options of contaminated groundwater[J]. Sustainable Environment Research, 2018,28(4):149-157.
[51]	Höhener P, Ponsin V. In situ vadose zone bioremediation[J]. Current Opinion in Biotechnology, 2014,27:1-7.
[52]	Riha B D, Noonkester J V, Looney B B, et al. Application of biodegradable oils (VOSTM) for treatment of chlorinated ethenes in the vadose zone-12085[R]. United States:W M Symposia, 2012.
[53]	Imir B, Yan J, Im J, et al. Natural attenuation in streambed sediment receiving chlorinated solvents from underlying fracture networks[J]. Environmental Science & Technology, 2017,51(9):4821-4830.
[54]	Duan Z, Kjeldsen P, Scheutz C. Trace gas composition in landfill gas at Danish landfills receiving low-organic waste[J]. Waste Management, 2021,122:113-123.
[55]	Duan Z, Scheutz C, Kjeldsen P. Trace gas emissions from municipal solid waste landfills:A review[J]. Waste Management, 2020,119:39-62.
[56]	Tassi F, Montegrossi G, Vaselli O, et al. Degradation of C2-C15volatile organic compounds in a landfill cover soil[J]. Science of the Total Environment, 2009,407(15):4513-4525.
[57]	Huang B, Chao L, Wei C, et al. Chlorinated volatile organic compounds (Cl-VOCs) in environment-sources, potential human health impacts, and current remediation technologies[J]. Environment International, 2014,71:118-138.
[58]	Yilmaz M, Tinjum J M, Acker C, et al. Transport mechanisms and emission of landfill gas through various cover soil configurations in an MSW landfill using a static flux chamber technique[J]. Journal of Envirounment Management, 2021,280:111677.
[59]	王永琼,邢志林,陈尚洁,等.典型功能层带-填埋场覆盖层中四氯化碳代谢机制及功能微生态响应[J]. 生物工程学报, 2022,38(5):1874-1888. Wang Y Q, Xing Z L, Cheng S J, et al. Study on transformation mechanism of carbon tetrachloride and micro-ecology in in landfill cover-a typical functional layer zone[J]. Chinese Journal of Biotechnology, 2022,38(5):1874-1888.
[60]	Xing Z L, Zhao T T, Gao Y H, et al. Real-time monitoring of methane oxidation in a simulated landfill cover soil and MiSeq pyrosequencing analysis of the related bacterial community structure[J]. Waste Management, 2017,68:369-377.
[61]	马欣程,徐红霞,孙媛媛,等.氯代烃污染场地生物自然衰减修复研究进展[J]. 中国环境科学, 2022,42(11):5285-5298. Ma X C, Xu H X, Sun Y Y, et al. Research progress on biotic natural attenuation for the remediation of chlorinated hydrocarbon-contaminated sites[J]. China Environmental Science, 2022,42(11):5285-5298.
[62]	宋久浩,吴乃瑾,李培中,等.两种修复模式下CAHs污染地下水的原位对照[J]. 中国环境科学, 2022,42(10):4668-4675. Song J H, Wu N J, Li P Z, et al. In-situ comparation of CAHs contaminated groundwater under two remediation strategies[J]. China Environmental Science, 2022,42(10):4668-4675.
[63]	Frascari D, Zanaroli G, Danko A S. In situ aerobic cometabolism of chlorinated solvents:A review[J]. Journal of Hazardous Materials, 2015,283:382-399.
[64]	邢志林,张丽杰,赵天涛.专一营养与兼性甲烷氧化菌降解氯代烃的研究现状、动力学分析及展望[J]. 生物工程学报, 2014,30(4):531-544. Xing Z L, Zhang L J, Zhao T T. Advances in degradation of chlorinated hydrocarbons by obligate and facultative methanotrophs[J]. Chinese Journal of Biotechnology, 2014,30(4):531-544.
[65]	Jugder B E, Ertan H, Lee M, et al. Reductive dehalogenases come of age in biological destruction of organohalides[J]. Trends in Biotechnology, 2015,33(10):595-610.
[66]	Chambon J C, Bjerg P L, Scheutz C,et al. Review of reactive kinetic models describing reductive dechlorination of chlorinated ethenes in soil and groundwater[J]. Biotechnology & Bioengineering, 2012, 110(1):1-23.
[67]	Amos B K, Ritalahti K M, Cruz-Garcia C,et al. Oxygen effect on Dehalococcoides viability and biomarker quantification[J]. Environmental Science & Technology, 2008,42(15):5718-5726.
[68]	Mattes T E, Jin Y O, Livermore J, et al. Abundance and activity of vinyl chloride (VC)-oxidizing bacteria in a dilute groundwater VC plume biostimulated with oxygen and ethene[J]. Applied Microbiology & Biotechnology, 2015,99(21):9267-9276.
[69]	许妍,傅大放.多氯联苯微生物厌氧脱氯研究进展[J]. 环境化学, 2014,33(6):908-914. Xue Y, Fu D F. A review on microbial-catalyzed reductive dechlorination of polychlorinated biphenyls[J]. Environmental Chemistry, 2014,33(6):908-914.
[70]	VanBriesen J M, Blough M S, Brown W E, et al. Critical oxygen concentrations for biodegradation of PCBs[R]. Symposia Papers Presented Before the Division of Environmental Chemistry, 2008.
[71]	DeVaull G E. Indoor vapor intrusion with oxygen-limited biodegradation for a subsurface gasoline source[J]. Environmental Science & Technology, 2007,41(9):3241-3248.
[72]	Atashgahi S, Lu Y, Ramiro-Garcia J, et al. Geochemical parameters and reductive dechlorination determine aerobic cometabolic vs aerobic metabolic vinyl chloride biodegradation at oxic/anoxic interface of hyporheic zones[J]. Environmental Science & Technology, 2017, 51(3):1626-1634.
[73]	Singh H, Lffler F E, Fathepure B Z. Aerobic biodegradation of vinyl chloride by a highly enriched mixed culture[J]. Biodegradation, 2004,15(3):197-204.
[74]	Bradley P M, Chapelle F H. Microbial mineralization of dichloroethene and vinyl chloride under hypoxic conditions[J]. Ground Water Monitoring & Remediation, 2011,31(4):39-49.
[75]	Richards P M, Ewald J M, Zhao W, et al. Natural Biodegradation of vinyl chloride and cis-Dichloroethene in aerobic and suboxic conditions[J]. Environmental Science and Pollution Research, 2022,29(37):56154-56167.
[76]	Kaown D, Jun S C, Kim R H, et al. Characterization of a site contaminated by chlorinated ethenes and ethanes using multi-analysis[J]. Environ Earth Sciences, 2016,75(9):745-757.
[77]	Nestler H, Kiesel B, Kaschabek S R, et al. Biodegradation of chlorobenzene under hypoxic and mixed hypoxic-denitrifying conditions[J]. Biodegradation, 2007,18(6):755-767.
[78]	Urgun-Demirtas M, Pagilla K R, Stark B C, et al. Biodegradation of 2-Chlorobenzoate by recombinant Burkholderia cepacia expressing vitreoscilla hemoglobin under variable levels of oxygen availability[J]. Biodegradation, 2003,14(5):357-365.
[79]	Fullerton H, Rogers R, Freedman D L, et al. Isolation of an aerobic vinyl chloride oxidizer from anaerobic groundwater[J]. Biodegradation, 2014,25(6):893-901.
[80]	Polasko A, Zulli A, Gedalanga P B, et al. A mixed microbial community for the biodegradation of chlorinated ethenes and 1,4-Dioxane[J]. Environmental Science & Technology Letters, 2019,6(1):49-54.
[81]	Němeček J, Dolinová I, Machackova J. et al. Stratification of chlorinated ethenes natural attenuation in an alluvial aquifer assessed by hydrochemical and biomolecular tools[J]. Chemosphere, 2017,184:11557-1167.
[82]	Liang Y, Johnson R L, Mattes T E. Cryogenic soil coring reveals coexistence of aerobic and anaerobic vinyl chloride degrading bacteria in a chlorinated ethene contaminated aquifer[J]. Water Research, 2019,157:281-291.
[83]	Liang Y, Liu X, Singletary M A, et al. Relationships between the abundance and expression of functional genes from vinyl chloride (VC)-degrading bacteria and geochemical parameters at VC-contaminated sites[J]. Environmental Science & Technology, 2017,51(21):12164-12174.
[84]	Němeček J, Marková K, Špánek R, et al. Hydrochemical conditions for aerobic/anaerobic biodegradation of chlorinated ethenes-a multi-site assessment[J]. Water, 2020,12(2):1-18.