College of Urban Construction, Nanjing Tech University, 211816, China; School of Civil Engineering, Southeast University, Nanjing, 211189, China.
School of Civil Engineering, Southeast University, Nanjing, 211189, China.
J Environ Manage. 2024 Aug;366:121876. doi: 10.1016/j.jenvman.2024.121876. Epub 2024 Jul 16.
Integrated MFC-MBR systems effectively remove antibiotics and control the release of antibiotic resistance genes (ARGs). However, the fouling layers on membranes can potentially act as reservoirs for ARGs. This study aims to elucidate the roles of membrane fouling layers and levels in influencing sulfamethoxazole (SMX) removal and ARGs control within an MFC-MBR system. Our findings demonstrate that low-intensity bioelectricity (400-500 mV) mitigates membrane fouling rates. The membrane fouling layer significantly contributes (39%-47%) to SMX removal compared to the cathode/anode zones. Higher extracellular polymeric substance (EPS) content and a lower protein/polysaccharide (PN/PS) ratio favor SMX removal by the membrane fouling layer. Across different levels of membrane fouling, the PN/PS ratio rather than EPS concentration plays a crucial role in SMX removal efficiency. The MFC-MBR with low fouling achieved superior SMX removal (69.1%) compared to medium (54.3%) and high fouling conditions (46.8%). The presence of ARGs in the membrane fouling layer increases with fouling formation, with intrinsic ARGs prevailing. Dense membrane fouling layers effectively retain ARGs, thereby reducing the risk of extracellular ARGs (eARGs) diffusion in effluents. These results provide insights into controlling ARGs in MFC-MBR systems and underscore the significant role of membrane fouling layers in antibiotics and ARGs removal.
集成 MFC-MBR 系统可有效去除抗生素并控制抗生素抗性基因（ARGs）的释放。然而，膜上的污垢层可能成为 ARGs 的储存库。本研究旨在阐明膜污垢层的作用及其水平对影响 MFC-MBR 系统中磺胺甲恶唑（SMX）去除和 ARGs 控制的影响。我们的研究结果表明，低强度生物电能（400-500 mV）可减轻膜污染速率。与阴极/阳极区相比，膜污垢层对 SMX 的去除有较大贡献（39%-47%）。较高的胞外聚合物（EPS）含量和较低的蛋白质/多糖（PN/PS）比值有利于膜污垢层对 SMX 的去除。在不同程度的膜污染下，PN/PS 比值而非 EPS 浓度在 SMX 去除效率中起着关键作用。低污染的 MFC-MBR 与中污染（54.3%）和高污染条件（46.8%）相比，实现了优越的 SMX 去除（69.1%）。膜污垢层中 ARGs 的存在随污垢形成而增加，其中内在 ARGs 占主导地位。致密的膜污垢层可有效保留 ARGs，从而降低了细胞外 ARGs（eARGs）在废水中扩散的风险。这些结果为控制 MFC-MBR 系统中的 ARGs 提供了深入了解，并强调了膜污垢层在抗生素和 ARGs 去除中的重要作用。
