诺氟沙星对MBR除污效果的影响及其作用机制

Impact and Mechanisms of Norfloxacin on Pollutants Removal by Membrane Bioreactor

为了考察诺氟沙星对MBR工艺运行的影响,采用聚四氟乙烯(PTFE)和聚偏氟乙烯(PVDF)两种不同膜材质的反应器,对比分析了诺氟沙星对去除有机物和氨氮、活性污泥中微生物、膜污染的影响,并分析其作用途径和机制。结果表明,诺氟沙星导致MBR对有机物和氨氮的去除效果下降,两种膜生物反应器对氨氮的平均去除率均下降了17%左右,而对COD的平均去除率降幅则分别为7. 7%(PTFE-MBR)和2. 4%(PVDF-MBR)。其中,对氨氮的去除影响与膜材质的相关性不大,诺氟沙星对MBR的影响体现在对活性污泥微生物的作用。根据微生物活性、种群及数量分析,发现诺氟沙星仅对少部分微生物菌群产生作用,其中对一种鞘脂杆菌的完全杀灭导致了脱氮效果的下降。诺氟沙星对膜污染的作用主要通过其对活性污泥的作用而间接导致的,两种膜对比条件下,PVDF膜在诺氟沙星污水中具有更好的抗污染能力。

In order to investigate the effect of norfloxacin on the operation of MBR process, two different membrane (PTFE and PVDF) reactors were used to compare the removal of organic matters and ammonia nitrogen, activity, types and quantities of bacteria in activated sludge, and membrane fouling. Mechanisms of norfloxacin influence on MBR were analyzed. The average removal rate of NH4^+- N were declined by about 17% when norfloxacin existed in domestic wastewater, while the average removal rate of COD decreased by only 7. 7%(PTFE - MBR) and 2. 4%(PVDF - MBR), which meant norfloxacin had its effect on MBR by working on activated sludge. According to the analysis on microbial activity, population and quantity, little bacteria was effected by norfloxacin except Sphingobacteriaceae, which was related with nitrogen removal. Norfloxacin could not led to membrane fouling direcdy, it worked on membrane by poisoning activated sludge microorganism. PVDF membrane showed better performance when treating wastewater containing norfloxacin.