膜蒸馏生物反应器处理模拟废水膜污染过程解析

摘要

Membrane distillation bioreactor was used to treat synthetic wastewater.Results showed that removal rates of COD and NH4+-N were 98％ and 95％,respectively,and the conductivity was below 15 μS/cm.However,membrane flux decreased from 10.2 L/(m2 · h) to 2.2 L/(m2 · h) after running for 20 d.Through analysis of membrane flux and membrane fouling resistance,it was found that a stable fouling layer was formed on the membrane surface.SEM,FTIR and EEM analysis indicated that membrane foulant was mainly composed of protein and polysaccharide.These substances were mainly derived from the supernatant of activated sludge in the reactor.This study showed that controlling microbial metabolites in the reactor was the primary means of reducing membrane fouling.%采用膜蒸馏生物反应器深度处理模拟废水,结果显示反应器出水COD和NH:-N去除率分别达到98％和95％以上,电导率降至15 μS/cm以下.但是运行20 d后,膜通量从10.2 L/(m2·h)降到2.2L/(mz.h).通过膜通量变化和膜污染阻力分析,发现膜表面形成了稳定的污染层.进行扫描电镜(SEM)、傅里叶红外(FTIR)及三维荧光(EEM)表征,表明污染层主要成分为蛋白质和多糖,而这些物质主要来自反应器内的活性污泥上清液.研究表明控制反应器内的微生物代谢产物是减轻膜污染的主要手段.