College of Environmental Science and Engineering, Taiyuan University of Technology (TYUT), Taiyuan, China; Shanxi Construction Investment Group Co., Ltd., Taiyuan, China.
College of Environmental Science and Engineering, Taiyuan University of Technology (TYUT), Taiyuan, China.
Sci Total Environ. 2024 Nov 15;951:175599. doi: 10.1016/j.scitotenv.2024.175599. Epub 2024 Aug 20.
Indole and pyridine, which are highly produced refractory compounds in the industrial wastewater, exhibit poor degradation capabilities in natural environments. In this study, we developed an anaerobic digestion system coupled with weak electric mediation (ED), and investigated the promoting effect of weak electricity on indole and pyridine biodegradation. The degradation characteristics were systematically explored, and the results showed that the degradation rate and mineralization of indole and pyridine were significantly enhanced, the production of CH was increased 1.4-fold, and the optimal voltages were 1.0 V and 0.8 V in the ED, respectively. Moreover, simultaneous removal of carbon and nitrogen was achieved. Gas chromatography-mass spectrometry analysis verified the transformation products, and possible pathways were proposed. Several byproducts of indole and pyridine were identified, with oxindole and glutaric dialdehyde being the main metabolites, respectively. Additionally, density functional theory (DFT) analysis was performed to investigated the radical indices and stabilities of the molecules to further confirm the degradation pathway. Microbial structure analysis demonstrated that the electrically mediated enhanced metabolism and activity of functional microbes, led to the promotion of indole and pyridine mineralization. Moreover, such species as degrading bacteria (Alicycliphilus, Shinella) and electroactive bacteria (Achromobacter), anaerobic ammonia-oxidizing bacteria (SM1A02), and denitrifying bacteria (Thiobacillus) coexisted. This study demonstrates that weak electric mediation is a promising methodology for enhancing the removal of indole and pyridine from wastewater under anaerobic conditions.
吲哚和吡啶是工业废水中高度产生的难降解化合物，在自然环境中降解能力较差。本研究开发了一种厌氧消化系统与弱电场调节（ED）耦合，研究了弱电场对吲哚和吡啶生物降解的促进作用。系统地探讨了降解特性，结果表明，吲哚和吡啶的降解率和矿化率显著提高，CH 产量增加了 1.4 倍，ED 的最佳电压分别为 1.0 V 和 0.8 V。此外，实现了碳氮的同步去除。气相色谱-质谱分析验证了转化产物，并提出了可能的途径。鉴定出吲哚和吡啶的几个副产物，分别以氧化吲哚和戊二醛为主要代谢物。此外，还进行了密度泛函理论（DFT）分析，以研究分子的自由基指数和稳定性，进一步证实了降解途径。微生物结构分析表明，电介导增强了功能微生物的代谢和活性，促进了吲哚和吡啶的矿化。此外，还共存有降解菌（Alicycliphilus、Shinella）和电活性菌（Achromobacter）、厌氧氨氧化菌（SM1A02）和反硝化菌（Thiobacillus）等物种。本研究表明，弱电场调节是一种在厌氧条件下增强废水中吲哚和吡啶去除的有前途的方法。
