• 关键词：填埋场  氯乙烯  好氧/厌氧共代谢  降解贡献度  功能菌属

• 基金项目：国家自然科学基金（No.51978117）；重庆理工大学科研启动项目（No.2019ZD72）；重庆理工大学研究生创新基金（No.clgycx 20203075）

• 曹昆
• 重庆理工大学化学化工学院，重庆 401331

• 苏夏
• 重庆理工大学化学化工学院，重庆 401331

• 邢志林
• 重庆理工大学化学化工学院，重庆 401331

• 王永琼
• 重庆理工大学化学化工学院，重庆 401331

• 陈尚洁
• 重庆理工大学化学化工学院，重庆 401331

• 刘毫
• 重庆理工大学化学化工学院，重庆 401331

• 肖芃颖
• 重庆理工大学化学化工学院，重庆 401331

• 赵天涛
• 重庆理工大学化学化工学院，重庆 401331

• 摘要：填埋场已成为氯乙烯污染的重要来源，明晰覆盖层土壤中氯乙烯的降解特性及功能微生物群落组成对氯乙烯污染控制具有重要意义.基于填埋场覆盖土系统开展了典型氯乙烯的好氧/厌氧共代谢降解研究.结果显示，好氧和厌氧条件下CH₄均可发生降解，二氯乙烯（DCE）只能在好氧条件下被降解，净降解速率为50 μg·h^-1·L^-1；三氯乙烯（TCE）可同时发生好氧共代谢和厌氧共代谢转化，净降解速率分别为38和5 μg·h^-1·L^-1；四氯乙烯（PCE）只能发生厌氧共代谢，降解速率为0.77 μg·h^-1·L^-1，发现好氧共代谢速率远高于厌氧共代谢速率.构建了覆盖层中氯乙烯的分布模型并评估了CH₄及氯乙烯好氧/厌氧共代谢贡献度，CH₄好氧和厌氧降解贡献度分别为59%~70%和30%~41%，TCE好氧和厌氧共代谢降解贡献度分别为73%和27%.对氯乙烯厌氧/好氧共代谢降解过程的微生物群落组成及潜在功能菌属进行了分析，发现好氧共代谢中变形菌门Proteobacteria及厌氧共代谢中绿弯菌门Chloroflexi、放线菌门Actinobacteria和硝化螺旋菌门Nitrospirae微生物起重要作用，关键 甲烷氧化菌为甲基暖菌属Methylocaldum和甲基杆菌Methylobacter.比较填埋气扩散速率、覆盖土吸附速率及氯乙烯生物降解速率，增大覆盖土对氯乙烯的吸附量，同时通过生物刺激和生物强化手段强化覆盖土对氯乙烯的降解，能缓解填埋气对大气的污染.

• Abstract：Landfills have become a major source of chloroethylene pollution； thus， it is important to clarify the degradation characteristics of chloroethylene in landfill cover soil and the composition of related functional microbial communities to control chloroethylene pollution. Here， a study on the aerobic/anaerobic co-metabolic degradation of chloroethylene was performed using landfill cover soil. The results showed that CH₄ was degraded by cover soil under aerobic and anaerobic conditions， and DCE was only degraded under aerobic conditions， with a net degradation rate of 50 μg·h^-1·L^-1. TCE simultaneously underwent aerobic and anaerobic co-metabolism with net degradation rates of 38 μg·h^-1·L^-1 and 5 μg·h^-1·L^-1， respectively. PCE was only degraded by anaerobic co-metabolism with a degradation rate of 0.77 μg·h^-1·L^-1. The biodegradation data indicated that the degradation rate of aerobic co-metabolism was much higher than that of anaerobic co-metabolism. In addition， the distribution model of chloroethylene in landfill cover was constructed， and the contribution of aerobic/anaerobic co-metabolism of CH₄ and chloroethylene was evaluated. The contribution of aerobic and anaerobic degradation of CH₄ was 59%~70% and 30%~41%， respectively. The contribution of aerobic and anaerobic co-metabolic degradation of TCE was 73% and 27%， respectively. Simultaneously， the microbial community structure and potential functional bacteria in landfill cover soil were analyzed， and it was found that Proteobacteria， Chloroflexi， Actinobacteria， and Nitrospirae played important roles in chloroethylene biodegradation. The key methanotrophs were Methylocaldum and Methylobacter. Finally， by comparing the biodegradation rate of chloroethylene with the diffusion rate of landfill gases and the adsorption rate of chloroethylene in landfill cover soil， it was found that increasing the chloroethylene adsorption capacity of the cover soil and strengthening the chloroethylene degradation rate via bioaugmentation mitigated chloroethylene air pollution in landfill gases.

• Key words：landfill  chloroethylene  aerobic/anaerobic co-metabolism  contribution of biodegradation  functional bacteria

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