Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China.
Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong 999077, China.
Environ Sci Technol. 2023 Sep 19;57(37):14036-14045. doi: 10.1021/acs.est.3c04262. Epub 2023 Sep 4.
Chloroethenes (CEs) as common organic pollutants in soil could be attenuated via abiotic and biotic dechlorination. Nonetheless, information on the key catalyzing matter and their reciprocal interactions remains scarce. In this study, FeS was identified as a major catalyzing matter in soil for the abiotic dechlorination of CEs, and acetylene could be employed as an indicator of the FeS-mediated abiotic CE-dechlorination. Organohalide-respiring bacteria (OHRB)-mediated dechlorination enhanced abiotic CEs-to-acetylene potential by providing dichloroethenes (DCEs) and trichloroethene (TCE) since chlorination extent determined CEs-to-acetylene potential with an order of -DCE > -DCE > TCE > tetrachloroethene/PCE. In contrast, FeS was shown to inhibit OHRB-mediated dechlorination, inhibition of which could be alleviated by the addition of soil humic substances. Moreover, sulfate-reducing bacteria and fermenting microorganisms affected FeS-mediated abiotic dechlorination by re-generation of FeS and providing short chain fatty acids, respectively. A new scenario was proposed to elucidate major abiotic and biotic processes and their reciprocal interactions in determining the fate of CEs in soil. Our results may guide the sustainable management of CE-contaminated sites by providing insights into interactions of the abiotic and biotic dechlorination in soil.
氯代烃（CEs）作为土壤中常见的有机污染物，可以通过非生物和生物脱氯作用得到衰减。然而，关于关键催化物质及其相互作用的信息仍然很少。在本研究中，FeS 被确定为土壤中非生物脱氯 CE 的主要催化物质，乙炔可用作 FeS 介导的非生物 CE 脱氯的指示剂。由于氯化程度决定了 CEs 向乙炔的潜力，其顺序为-DCE > -DCE > TCE > 四氯乙烷/氯乙烯，因此，卤代烃呼吸细菌（OHRB）介导的脱氯作用通过提供二氯代乙烯（DCEs）和三氯乙烯（TCE），增强了非生物 CE 向乙炔的潜力。相比之下，FeS 被证明会抑制 OHRB 介导的脱氯作用，而添加土壤腐殖质可以缓解这种抑制作用。此外，硫酸盐还原菌和发酵微生物通过再生 FeS 和提供短链脂肪酸，分别影响 FeS 介导的非生物脱氯作用。提出了一个新的方案来阐明主要的非生物和生物过程及其相互作用，以确定土壤中 CE 的命运。我们的研究结果可能通过深入了解土壤中非生物和生物脱氯作用的相互作用，为 CE 污染场地的可持续管理提供指导。
