The presence of antibiotics in wastewater poses significant threat to our ecosystems and health. Traditional biological wastewater treatment technologies have several limitations in treating antibiotic-contaminated wastewaters, such as low removal efficiency and poor process resilience. Here, a novel electrochemical-coupled sulfur-mediated biological system was developed for treating wastewater co-contaminated with several antibiotics (e.g., ciprofloxacin (CIP), sulfamethoxazole (SMX), chloramphenicol (CAP)). Superior removal of CIP, SMX, and CAP with efficiencies ranging from 40.6 ± 2.6 % to 98.4 ± 1.6 % was achieved at high concentrations of 1000 μg/L in the electrochemical-coupled sulfur-mediated biological system, whereas the efficiencies ranged from 30.4 ± 2.3 % to 98.2 ± 1.4 % in the control system (without electrochemical stimulation). The biodegradation rates of CIP, SMX, and CAP increased by 1.5∼1.9-folds under electrochemical stimulation compared to the control. The insights into the role of electrochemical stimulation for multiple antibiotics biodegradation enhancement was elucidated through a combination of metagenomic and electrochemical analyses. Results showed that sustained electrochemical stimulation significantly enriched the sulfate-reducing and electroactive bacteria (e.g., Desulfobulbus, Longilinea, and Lentimicrobiumin on biocathode and Geobactor on bioanode), and boosted the secretion of electron transport mediators (e.g., cytochrome c and extracellular polymeric substances), which facilitated the microbial extracellular electron transfer processes and subsequent antibiotics removal in the sulfur-mediated biological system. Furthermore, under electrochemical stimulation, functional genes associated with sulfur and carbon metabolism and electron transfer were more abundant, and the microbial metabolic processes were enhanced, contributing to antibiotics biodegradation. Our study for the first time demonstrated that the synergistic effects of electrochemical-coupled sulfur-mediated biological system was capable of overcoming the limitations of conventional biological treatment processes. This study shed light on the mechanism of enhanced antibiotics biodegradation via electrochemical stimulation, which could be employed in sulfur-mediated bioprocess for treating antibiotic-contaminated wastewaters.

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深入了解电化学刺激对废水处理中硫驱动抗生素生物降解的作用


废水中存在抗生素对我们的生态系统和健康构成重大威胁。传统的生物废水处理技术在处理抗生素污染的废水方面存在一些局限性，例如去除效率低和工艺弹性差。在这里，开发了一种新型电化学耦合硫介导的生物系统，用于处理与多种抗生素（例如环丙沙星 （CIP）、磺胺甲噁唑 （SMX）、氯霉素 （CAP））共污染的废水。在电化学耦合硫介导的生物系统中，在 1000 μg/L 的高浓度下实现了对 CIP、SMX 和 CAP 的出色去除，效率范围为 40.6 ± 2.6 % 至 98.4 ± 1.6 %，而在控制系统中，效率范围为 30.4 ± 2.3 % 至 98.2 ± 1.4 %）（无电化学刺激）。与对照相比，在电化学刺激下 CIP、SMX 和 CAP 的生物降解速率增加了 1.5∼1.9 倍。通过宏基因组学和电化学分析的结合，阐明了电化学刺激对多种抗生素生物降解增强作用的见解。结果表明，持续的电化学刺激显著富集了硫酸盐还原和电活性细菌（例如，生物阴极上的 Desulfobulbus、Longilinea 和 Lentimicrobiumin 以及生物阳极上的 Geobactor），并促进了电子传递介质（例如细胞色素 c 和细胞外聚合物物质）的分泌，这促进了微生物细胞外电子转移过程和随后在硫介导的生物系统中去除抗生素。 此外，在电化学刺激下，与硫和碳代谢以及电子转移相关的功能基因更加丰富，微生物代谢过程增强，有助于抗生素的生物降解。我们的研究首次证明，电化学耦合硫介导的生物系统的协同作用能够克服传统生物处理过程的局限性。本研究阐明了通过电化学刺激增强抗生素生物降解的机制，可用于硫介导的生物过程，以处理抗生素污染的废水。