Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Sciences and Technology, Guangzhou 510650, China.
Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
J Hazard Mater. 2020 Jun 5;391:122213. doi: 10.1016/j.jhazmat.2020.122213. Epub 2020 Jan 31.
The soil bioelectrochemical system (SBES) is a promising biotechnology for the remediation of contaminated soils. However, the effective distance of pollutant removal in the SBES was usually limited in a few centimeters near the electrode surface. In this study, we used biochar as the model conductor to construct a conductive network with microbes in the soil matrix to extend the effective distance of pollutant removal in the SBES. Pentachlorophenol (PCP) was used as the representative contaminant to probe long-distance electron transfer facilitated by the networks. The removal of PCP and microbial community analyses at different distances toward the electrode were monitored. The results showed that PCP transformation in the SBES without biochar amendment mainly occurred within 4 cm around the electrode. However, the effective distance of ∼ 16 cm toward the electrode could be achieved for efficient PCP degradation in the SBES amended with highly conductive biochar. Microbial community analysis confirmed the establishment of bacteria-biochar networks, where Desulfitobacterium and Geobacter were enriched and spatially distributed in the biochar-amended SBES. The results demonstrate that long-distance electron transfer can be achieved in the biochar-amended soil matrix, and shed light on the development of bioelectrochemical strategy for efficient organic pollutant degradation in soils.
土壤生物电化学系统（SBES）是一种很有前途的生物技术，可用于修复受污染的土壤。然而，SBES 中污染物去除的有效距离通常局限在电极表面附近的几厘米内。在本研究中，我们使用生物炭作为模型导体，在土壤基质中构建一个带有微生物的导电网络，以扩展 SBES 中污染物去除的有效距离。五氯酚（PCP）被用作探针来探测网络促进的长距离电子转移。监测了不同距离处电极的 PCP 去除和微生物群落分析。结果表明，没有生物炭修饰的 SBES 中 PCP 的转化主要发生在电极周围 4 厘米内。然而，在添加高导电性生物炭的 SBES 中，可实现对 PCP 的有效降解，其有效距离可达到电极方向约 16 厘米。微生物群落分析证实了细菌-生物炭网络的建立，其中脱硫杆菌属和地杆菌属在生物炭修饰的 SBES 中得到了富集和空间分布。结果表明，长距离电子转移可以在生物炭修饰的土壤基质中实现，这为生物电化学策略在土壤中有效降解有机污染物的发展提供了启示。
