不同电极间距下自生电场膜生物反应器中的膜污染行为分析

以自制铜纳米线（Cu-NWs）导电微滤膜为膜组件兼阴极，构建自生电场膜生物反应器（SEF-MBR），研究不同电极间距下自生电场强度、跨膜压差（TMP）与膜污染行为的变化规律，可为MBR技术升级及进一步推广应用提供理论依据。结果表明，当电极间距从4cm减小到2cm时，自生电场强度从0.7mV/cm提高到1.2mV/cm，TMP的上升速度从0.15kPa/d降低到0.08kPa/d。缩短电极间距有利于缓解膜污染。随电极间距减小，静电斥力提高了40.5%，阴极产生的H₂O₂和·OH浓度也大大增加。电极间距对SEF-MBRs好氧活性污泥的胞外聚合物含量影响不大，但均低于对照MBR系统。共聚焦激光扫描电镜（CLSM）观察发现，与对照系统相比，导电微滤膜表面的污染层厚度减小了20.2%，膜表面污染物以微生物总细胞和β-D-glucopyranose多糖为主。缩短电极间距可提高系统自生电场强度，进而提高静电斥力及H₂O₂和·OH产生量，减缓膜污染。

Membrane fouling behavior in a spontaneous electric field membrane bioreactor under different electrode distance

A novel spontaneous electric field membrane bioreactor (SEF-MBR) was established in this paper by taking the prepared Cu-nanowires (Cu-NWs) conductive microfiltration membrane as membrane module and cathode. The variations in spontaneous electric field strength, transmembrane pressure (TMP) and membrane fouling behavior under different electrode distances were studied, which will provide theoretical basis for the upgrading and further application of MBR technology. When the electrode distances decreased to 2cm from 4cm, the average electric field strength increased to 1.2mV/cm from 0.7mV/cm, and the rising rate of TMP decreased to 0.08kPa/d from 0.15kPa/d. With the shorten electrode distance, the electrostatic repulsion force increased by about 40.5%, and the concentrations of H₂O₂ and·OH also increased significantly. The influence of electrode distance on the contents of extracellular polymeric substances of aerobic sludge was negligible, but both lower than that of the control MBR system. The observation of confocal laser scanning microscopy (CLSM) revealed that the cake layer thickness of conductive microfiltration membrane was reduced by 20.2% and dominated by the total cells and β-D-glucopyranose polysaccharides compared with the commercial PVDF membrane. The reduction of electrode distance increased the electric field intensity, and further increased the electrostatic repulsion force and concentrations of H₂O₂ and·OH. The membrane fouling was finally mitigated.