Abstract：
Triclocarban (TCC), as a widely used antimicrobial agent, is accumulated in waste activated sludge at a high level and inhibits the subsequent anaerobic digestion of sludge. This study, for the first time, investigated the effectiveness of microbial electrolysis cell-assisted anaerobic digestion (MEC-AD) in mitigating the inhibition of TCC to methane production. Experimental results showed that 20 mg/L TCC inhibited sludge disintegration, hydrolysis, acidogenesis, and methanogenesis processes and finally reduced methane production from traditional sludge anaerobic digestion by 19.1%. Molecular docking revealed the potential inactivation of binding of TCC to key enzymes in these processes. However, MEC-AD with 0.6 and 0.8 V external voltages achieved much higher methane production and controlled the TCC inhibition to less than 5.8%. TCC in the MEC-AD systems was adsorbed by humic substances and degraded to dichlorocarbanilide, leading to a certain detoxification effect. Methanogenic activities were increased in MEC-AD systems, accompanied by complete VFA consumption. Moreover, the applied voltage promoted cell apoptosis and sludge disintegration to release biodegradable organics. Metagenomic analysis revealed that the applied voltage increased the resistance of electrode biofilms to TCC by enriching functional microorganisms (syntrophic VFA-oxidizing and electroactive bacteria and hydrogenotrophic methanogens), acidification and methanogenesis pathways, multidrug efflux pumps, and SOS response.
摘要：
三氯卡班(TCC),作为一种广泛使用的抗菌剂，大量积累在废活性污泥中，并抑制了随后的污泥厌氧消化。这项研究,第一次,研究了微生物电解池辅助厌氧消化（MEC-AD）在减轻TCC对甲烷产生的抑制作用方面的有效性。实验结果表明，20mg/L的TCC抑制污泥崩解，水解，酸发生，和产甲烷过程，最终将传统污泥厌氧消化产生的甲烷减少了19.1%。分子对接揭示了这些过程中TCC与关键酶结合的潜在失活。然而,具有0.6和0.8V外部电压的MEC-AD实现了更高的甲烷产量，并将TCC抑制控制在5.8％以下。MEC-AD系统中的TCC被腐殖质吸附并降解为二氯碳酰胺，导致一定的排毒效果。MEC-AD系统中的产甲烷活性增加，伴随着完整的VFA消耗。此外，施加电压促进细胞凋亡和污泥崩解，释放可生物降解的有机物。宏基因组分析显示，施加的电压通过富集功能性微生物（互养VFA氧化和电活性细菌和氢营养产甲烷菌）增加了电极生物膜对TCC的电阻，酸化和产甲烷途径，多药外排泵，和SOS响应。
