萃取膜生物反应器处理苯酚废水的试验研究

从经过驯化的活性污泥中筛选出苯酚降解菌.制备成菌悬液,对比活性污泥体系和菌悬液体系的萃取膜生物反应器(EMB)对苯酚废水的处理效果,考察了料液苯酚浓度、反应器温度等因素对膜萃取速率及生物降解效果的影响.结果表明,通过以苯酚为唯一碳源,逐渐提高苯酚浓度的方法对活性污泥进行驯化.当进水苯酚浓度为700 mg·L-1时,苯酚去除率达99%以上;适当提高反应器温度和料液初始浓度有利于提高膜萃取速率;当初始料液苯酚浓度为2000 mg·L-1时,膜萃取速率高于生物降解速率,生物相中产生苯酚积累;菌悬液体系EMB的生物膜厚度明显小于活性污泥体系,且水力反冲洗可有效控制生物膜厚度.对苯酚生物降解产物的GC-MS分析结果表明,苯酚的生物降解较彻底,基本无苯酚中间产物的残留.

Treatment of Phenol Wastewater by Extractive Membrane Bioreactor

Phenol-degrading bacteria were isolated from activated sludge which had been acclimated, and then bacterium solution was prepared. The effects of initiating phenol concentration, reactor temperature etc. and the velocity of membrane extraction and biodegradation were investigated in order to make the comparison of activated sludge and bacterium solution systems of extractive membrane bioreactor (EMB). The results showed that, by using phenol as single carbon resource and increasing the phenol concentration gradually, the removal rate of phenol was more than 99% when the concentration of phenol was 700 mg x L(-1). Increasing reactor temperature and initiating phenol concentration is propitious to the membrane extraction. There was some phenol accumulation in microbial system when the initiating concentration was 2000 mg x L(-1). The thickness of the membrane-attached biofilm in the bacterium solution system was thinner than that in activated sludge system, and it could be controlled by hydrodynamic backwashing. The results of GC-MS analysis for the effluent of biodegradation showed that biodegradation of phenol was complete, and there was no residual intermediate product.