两种修复模式下CAHs污染地下水的原位对照

为探究氯代脂肪烃（CAHs）污染地下水原位修复的长效性及环境的长期响应，选择华北某废弃化工厂污染区，开展了生物刺激、零价铁（ZVI）-生物刺激耦合中试对照试验，系统对比了2种修复模式下CAHs的降解效率及地下水生物化学参数的动态变化规律.结果表明，修复后长达4~5a内总CAHs含量均降至50 μg/L以下，耦合修复策略提高了CAHs的整体降解效率且未出现浓度反弹，同时可更快速地改善地下环境，为潜在降解菌的生长提供有利条件.两种修复方式对地下水细菌多样性的长期影响基本一致，均有利于向脱硫菌门Desulfobacterota和绿弯菌门Chloroflexi演化.最终生物刺激区总细菌数量高于耦合修复区约1个数量级，但后者地下水中的脱卤球菌属Dehalococcoidia数量（2.1~35）×10³copies/mL反而高于前者（8.3~9.1）×10³copies/mL，这更有利于CAHs的彻底脱氯.

In-situ comparation of CAHs contaminated groundwater under two remediation strategies

To explore the long-term effectiveness and environmental response of in-situ remediation of chlorinated aliphatic hydrocarbon (CAHs) contaminated groundwater, a pilot comparison experiment of biostimulation and zero valent iron (ZVI)-biological stimulation coupling remediation strategies was carried out in a polluted area of an abandoned chemical plant in North China. The degradation efficiency of CAHs and the dynamic variations of biochemical parameters for groundwater under these two remediation modes were systematically compared. Total CAHs decreased to less than 50μg/L within 4~5 years after remediation under the two strategies. The coupling remediation strategies increased the overall degradation efficiency of CAHs without concentration rebound and improved the groundwater environment and provided favorable conditions for the growth of potential degrading bacteria. The long-term effects on the bacterial diversity of groundwater by using these two remediation strategies were basically the same, which were conducive to the evolution to Desulfobacterota and Chloroflexi. Finally, the total number of bacteria in the biostimulation pilot area was about one order of magnitude higher than the coupling remediation pilot area, but the number of dehalococcoidia in the latter groundwater (2.1~35)×10³ copies/mL was higher than the former (8.3~9.1)×10³ copies/mL, which was more conducive to the complete dechlorination of CAHs.