School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou, 510006, PR China.
Chemosphere. 2022 Mar;291(Pt 2):132881. doi: 10.1016/j.chemosphere.2021.132881. Epub 2021 Nov 11.
A sequential reduction-oxidation for DCF degradation was proposed by alternating anaerobic/aerobic conditions at Ru/Fe-biocathode in a dual-chamber bioelectrochemical system (BES). Results showed that Ru/Fe-electrode was successfully fabricated by in-situ electro-deposition, which was rough and uniformly distributed with Ru and Fe particles. The morphologic changing and biocompatibility were favorable to increase the surface area and enhance microbial adhesion on Ru/Fe-electrode. At an applied voltage of 0.6 V, the potential and impedance of Ru/Fe-biocathode were -0.80 V and 26 Ω, respectively, lower than that of carbon-felt-biocathode. It led to a higher DCF degradation efficiency of 93.2% under anaerobic conditions, which was superior to that of 88.0% under aerobic conditions. Using NaHCO as carbon source, DCF removal efficiency increased with increasing applied voltage, but decreased with increasing initial DCF concentration. Thirteen intermediates were measured, and two degradation pathways were proposed, among which sequential reduction-oxidation of DCF was the main pathway, dechlorination intermediates were first generated by [H] attacked under anaerobic conditions, further oxidized by microbes and OH attacked under aerobic conditions, achieving 69.6% of mineralization. After 4 d of reaction, microcystis aeruginosa growth inhibition rate decreased from 22.9 to 8.0%, signifying a significant reduction in biotoxicity. Bacteria (e.g. Nitrobacter, Nitrosomonas, Pseudofulvimonas, Aquamicrobium, Sulfurvermis, Lentimicrobiaceae, Anaerobineaceae, Bacteroidales, Hydrogenedensaceae, Dethiosulfatibacter and Azoarcus) for DCF degradation were enriched in Ru/Fe-biocathode. Microbes in Ru/Fe-biocathode had established defense mechanisms to acclimate to the unfriendly environment, while Ru/Fe-biocathode possessed higher nitrification and denitrification activities than carbon-felt-biocathode, and Ru/Fe-biocathode might be of aerobic and anaerobic biodegradation activities. DCF could be mineralized by the synergistic reaction between Ru/Fe and bacteria under sequential anaerobic/aerobic conditions.
交替厌氧/好氧条件下 Ru/Fe 生物阴极在双室生物电化学系统（BES）中提出了 DCF 降解的顺序还原-氧化。结果表明，Ru/Fe 电极通过原位电沉积成功制备，其表面粗糙且均匀分布着 Ru 和 Fe 颗粒。形态变化和生物相容性有利于增加电极表面面积并增强微生物在 Ru/Fe 电极上的附着力。在 0.6 V 的外加电压下，Ru/Fe 生物阴极的电位和阻抗分别为-0.80 V 和 26 Ω，低于碳纤维毡生物阴极。这导致在厌氧条件下 DCF 降解效率达到 93.2%，优于好氧条件下的 88.0%。使用 NaHCO3 作为碳源时，随着外加电压的增加，DCF 去除效率增加，但随着初始 DCF 浓度的增加而降低。共检测到 13 种中间产物，提出了两条降解途径，其中 DCF 的顺序还原-氧化是主要途径，在厌氧条件下，[H]的攻击首先产生脱氯中间产物，然后在好氧条件下被微生物和 OH 进一步氧化，实现了 69.6%的矿化。反应 4 d 后，铜绿微囊藻生长抑制率从 22.9%降低到 8.0%，生物毒性显著降低。用于 DCF 降解的细菌（如 Nitrobacter、Nitrosomonas、Pseudofulvimonas、Aquamicrobium、Sulfurvermis、Lentimicrobiaceae、Anaerobineaceae、Bacteroidales、Hydrogenedensaceae、Dethiosulfatibacter 和 Azoarcus）在 Ru/Fe 生物阴极中得到了富集。Ru/Fe 生物阴极中的微生物已经建立了防御机制以适应恶劣的环境，而 Ru/Fe 生物阴极的硝化和反硝化活性均高于碳纤维毡生物阴极，并且 Ru/Fe 生物阴极可能具有好氧和厌氧生物降解活性。在顺序厌氧/好氧条件下，Ru/Fe 与细菌的协同反应可将 DCF 矿化。
