摘要
      畜牧废水是抗生素抗性基因（ARGs）和抗生素残留的重要来源。膜污染是制约膜生物反应器（MBR）运行和应用的最具挑战性的问题之一。在这项工作中，建立了一种新型的铁碳微电解（ICME）/电生物载体MBR系统，以探索其对实际牲畜废水的污染物去除和防污性能。使用轻质多孔陶粒（体积密度0.98g/cm3）作为MBR生物载体。ICME槽中铁腐蚀产生的电子通过外部电线到达MBR的不锈钢膜组件，质子通过盐桥从MBR槽转移到ICME槽，从而产生自发电场。在优化的条件下，该系统的化学需氧量去除率为76.0%，总悬浮物去除率为100%，抗生素去除率为86.4%，NH4+-N去除率为91.1%，ARGs减少6-8个数量级。最终出水水质可达到国家一级甲等排放标准。添加陶粒不仅可以有效提高生物降解性能，而且可以通过微生物菌群向陶粒的迁移和富集来缓解膜污染。自生电场对污染物的去除没有显著的改善作用，但表现出良好的抗膜污染行为，这可归因于（i）电化学产物（如H2O2和•OH自由基）对膜污染物的氧化，以及（ii）带负电荷的污染物和细菌细胞的静电排斥。利用高通量焦磷酸测序对细菌群落结构和多样性进行了研究，结果证明了电场和生物载体在富集防污群落和排斥产生生物污垢的群落中的作用。
Abstract
Livestock wastewater is an important reservoir of antibiotic resistance genes (ARGs) and antibiotic residues. Membrane fouling is one of the most challenging problems confining the operation and application of membrane bioreactor (MBR). In this work, a novel iron-carbon micro-electrolysis (ICME)/electro-biocarriers-MBR system was established to explore the performance of pollutant removal and anti-fouling for an actual livestock wastewater. A light-weight porous ceramsite (bulk density 0.98 g/cm3) was used as the MBR biocarriers. The electrons generated from iron corrosion in the ICME tank traveled through external wires to the stainless steel membrane modules of MBR and the protons were transferred from the MBR tank to the ICME tank through a salt bridge, thus producing a spontaneous electric field. Under the optimized conditions, the system exhibited chemical oxygen demand removal of 76.0%, total suspended solids removal of 100%, antibiotic removal of 86.4%, NH4+-N removal of 91.1%, and ARGs reduction of 6–8 orders of magnitude. The quality of the final effluent can reach the national Class I-A discharge criteria. Adding ceramsite could not only effectively improve biodegradation performance but also alleviate membrane fouling through the migration and enrichment of microbial flora to the ceramsite. The self-generated electric field had no significant improvement effect on pollutant removal, but exhibited good anti-membrane fouling behavior which could be ascribed to (i) oxidization of membrane foulants by the electrochemical products (such as H2O2 and •OH radicals), and (ii) electrostatic repulsion of negatively charged foulants and bacterial cells. The bacterial community structure and diversity were studied using high-throughput pyrosequencing, and the results demonstrated the roles of electric field and biocarriers in enrichment of anti-fouling communities and repulsion of biofouling-creating communities.

https://www.sciencedirect.com/science/article/abs/pii/S0304389421030338