纳米零价铁强化微生物电催化-厌氧膜生物组合反应器抗膜污染能力及其调控机制

膜污染是厌氧膜生物反应器（anaerobic membrane bioreactor,AnMBR）产业化应用面临的最大挑战.本研究构建新型微生物电催化（bio-electrochemical systems,BES）-AnMBR组合反应器,以探究纳米零价铁（nano-zero-valent iron,nZVI）投加对BES-AnMBR组合系统膜污染削减和甲烷产生等性能的影响.结果表明,BES-AnMBR组合系统运行稳定,COD去除率一直维持在95%左右.nZVI投加量（以VS计）为0.1 g ·g^-1时,运行性能最佳,跨膜压差（transmembrane pressure,TMP）较对照组降低28.1%,膜通量亦有轻微增加;甲烷产量为81.3 mL ·g^-1（以COD_removed计）,较对照组提高了12.1%.胞外聚合物（extracellular polymeric substance,EPS）变化和膜阻过滤分析表明,nZVI可以加强EPS分解,促进膜表面无机和有机富铁结垢层形成,改善膜污染分布特征,从而显著缓解膜污染.本研究将丰富传统AnMBR的基础理论,为污泥处理与资源化利用提供了新视角.

Enhanced Membrane Anti-fouling Ability of Anaerobic Membrane Bioreactor Equipped with Bio-electrochemical System Using Nano-zero-valent Iron and Its Regulation Mechanism

Membrane fouling is the biggest challenge of membrane bioreactor industrialization. In this study, a bio-electrochemical system (BES)-anaerobic membrane bioreactor (AnMBR) system was constructed, and the effect of nano-zero-valent iron (nZVI) on membrane anti-fouling ability and methane production was investigated. The results showed that the BES-AnMBR system was stable and the chemical oxygen demand (COD) removal rate was maintained at approximately 95%. The optimum condition was observed to be nZVI 0.1 g·g^-1(VS). Under this condition, transmembrane pressure (TMP) was reduced by 28.1%, the membrane flux had a slight improvement, and methane production was up to 81.3 mL·g^-1(COD_removed). This was 12.1% higher than that of the control. In addition, a further analysis of extracellular polymeric substances (EPS) fraction and membrane resistance showed that nZVI enhanced EPS decomposition, promoted the formation of an iron-rich layer of inorganic and organic matters on the membrane surface, and changed the distribution of organics and inorganics, thereby significantly alleviating membrane fouling. This study will enrich basic theory of conventional AnMBR and provide a new solution for efficient sludge treatment and resource utilization.