Wang Hui, Long Xizi, Cao Xian, Li Lei, Zhang Jingran, Zhao Yaqian, Wang Dongqi, Wang Zhe, Meng Haiyu, Dong Wen, Jiang Chunbo, Li Jiake, Li Xianning
State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an 710048, PR China; Department of Municipal and Environmental Engineering, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an 710048, PR China.
Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China; International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Chemosphere. 2023 Apr;320:138087. doi: 10.1016/j.chemosphere.2023.138087. Epub 2023 Feb 6.
Soil microbial fuel cells (MFCs) have been increasingly studied in recent years and have attracted significant attention as an environmentally sustainable bioelectrochemical technology. However, the poor conductivity of the soil matrix and the neglect of the cathodic function have limited its application. In this study, quartz sand and activated carbon were subjected to investigation on their influence on atrazine degradation. Atrazine was introduced in different layers (cathode, upper layer) to explore the cathodic effect on atrazine removal. The results revealed that activated carbon could reduce the internal resistance (693 Ω) and generate the highest power density (25.51 mW/m) of the soil MFCs, and thus increase the removal efficiency (97.92%) of atrazine. The dynamic degradation profiles of atrazine were different for different adding layers. The cathode electrode acted as an electron donor could increase the distance of the effective influence of the soil MFCs' cathode from the middle to the cathode layer. The cathode (region) and the region close to the cathode could degrade atrazine with the atrazine removal efficiencies ranging from 60.67% to 92.79%, and the degradation ability of the cathode was stronger than that of other layers. The degradation effect followed the order: cathode > upper > lower > middle). Geobacter, Desulfobulbus, and Desulfuromonas belonging to the δ-Proteobacteria class were identified as the dominant electroactive microorganisms in the anode layer, while their relative abundances are quite low in the upper and cathode layers. Pseudomonas is an atrazine-degrading bacterium, but its relative abundance was only 0.13-0.51%. Thus, bioelectrochemistry rather than microbial degradation was the primary driving force.
近年来，土壤微生物燃料电池（MFCs）受到了越来越多的研究，并作为一种环境可持续的生物电化学技术引起了广泛关注。然而，土壤基质的低导电性以及对阴极功能的忽视限制了其应用。在本研究中，对石英砂和活性炭对阿特拉津降解的影响进行了研究。将阿特拉津引入不同层（阴极层、上层）以探讨阴极对阿特拉津去除的影响。结果表明，活性炭可以降低内阻（693Ω），并产生土壤微生物燃料电池的最高功率密度（25.51mW/m），从而提高阿特拉津的去除效率（97.92%）。不同添加层的阿特拉津动态降解曲线不同。作为电子供体的阴极电极可以增加土壤微生物燃料电池阴极有效影响范围从中间层到阴极层的距离。阴极（区域）和靠近阴极的区域可以降解阿特拉津，阿特拉津去除效率在60.67%至92.79%之间，且阴极的降解能力强于其他层。降解效果顺序为：阴极＞上层＞下层＞中层。属于δ-变形菌纲的地杆菌属、脱硫球菌属和脱硫单胞菌属被确定为阳极层中的主要电活性微生物，而它们在上层和阴极层中的相对丰度相当低。假单胞菌是一种阿特拉津降解菌，但其相对丰度仅为0.13-0.51%。因此，生物电化学而非微生物降解是主要驱动力。
