Abstract：
Microbial electrochemical technologies represent innovative approaches to contaminated soil and groundwater remediation and provide a flexible framework for removing organic and inorganic contaminants by integrating electrochemical and biological techniques. To simulate in situ microbial electrochemical treatment of groundwater plumes, this study investigates Cr(VI) reduction within a bioelectrochemical continuous flow (BECF) system equipped with soil-buried electrodes, comparing it to abiotic and open-circuit controls. Continuous-flow systems were tested with two chromium-contaminated solutions (20-50 mg Cr(VI)/L). Additional nutrients, buffers, or organic substrates were introduced during the tests in the systems. With an initial Cr(VI) concentration of 20 mg/L, 1.00 mg Cr(VI)/(L day) bioelectrochemical removal rate in the BECF system was observed, corresponding to 99.5% removal within nine days. At the end of the test with 50 mg Cr(VI)/L (156 days), the residual Cr(VI) dissolved concentration was two orders of magnitude lower than that in the open circuit control, achieving 99.9% bioelectrochemical removal in the BECF. Bacteria belonging to the orders Solirubrobacteriales, Gaiellales, Bacillales, Gemmatimonadales, and Propionibacteriales characterized the bacterial communities identified in soil samples; differently, Burkholderiales, Mycobacteriales, Cytophagales, Rhizobiales, and Caulobacterales characterized the planktonic bacterial communities. The complexity of the microbial community structure suggests the involvement of different microorganisms and strategies in the bioelectrochemical removal of chromium. In the absence of organic carbon, microbial electrochemical removal of hexavalent chromium was found to be the most efficient way to remove Cr(VI), and it may represent an innovative and sustainable approach for soil and groundwater remediation. Integr Environ Assess Manag 2024;00:1-17. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
摘要：
微生物电化学技术代表了污染土壤和地下水修复的创新方法，并通过整合电化学和生物技术为去除有机和无机污染物提供了灵活的框架。为了模拟原位微生物电化学处理地下水羽流，这项研究调查了配备土壤掩埋电极的生物电化学连续流（BECF）系统中的Cr（VI）还原，将其与非生物和开路控制进行比较。用两种铬污染的溶液（20-50mgCr（VI）/L）测试了连续流系统。额外的营养，缓冲区,或在系统测试过程中引入了有机底物。初始Cr(VI)浓度为20mg/L,观察到BECF系统中1.00mgCr（VI）/（L天）的生物电化学去除率，对应于九天内去除99.5%。在50mgCr（VI）/L（156天）的测试结束时，残余Cr(VI)溶解浓度比开路控制低两个数量级,在BECF中实现99.9%的生物电化学去除。属于杆菌属的细菌，盖勒莱斯,芽孢杆菌,双子座,和丙酸杆菌表征了土壤样品中鉴定的细菌群落；不同的是，Burkholderiales,分枝杆菌,细胞器，根瘤菌,浮游细菌群落为特征。微生物群落结构的复杂性表明不同的微生物和策略参与了铬的生物电化学去除。在没有有机碳的情况下，微生物电化学去除六价铬是去除Cr(VI)的最有效方法,它可能代表了土壤和地下水修复的创新和可持续方法。国际环境评估管理2024；00：1-17。©2024作者（S）。由WileyPeriodicalsLLC代表环境毒理学和化学学会（SETAC）出版的综合环境评估和管理。
