MFC-MBR耦合系统运行效果

Analysis of performances of microbial fuel cell-membrane bioreactor system

膜生物反应器(MBR)是一种高效的污水处理工艺,而微生物燃料电池(MFC)能有效降解污泥中的胞外生物有机质(EBOM)并回收电能。将MFC与MBR联用,建立了一套能够有效抑制膜污染同时回收电能的新系统———MFC-MBR耦合系统,MBR的剩余污泥经MFC处理后回流。以传统MBR为对照,对耦合系统中污水处理效果、膜污染情况和污泥混合液的性质进行研究。研究表明,耦合系统的污水处理效果没有明显恶化,COD去除率为94%,NH4+-N的去除率为92%。耦合系统能够有效减缓膜污染的发生,清洗周期延长了28%。污泥混合液的MLVSS/MLSS稳定在80%～88%,系统内几乎没有无机颗粒积累。松散结合态胞外聚合物(LB-EPS)降低了48%,使污泥混合液性质得到改善。较低的污泥比阻(2.69×1012m/kg)和标准化毛细吸水时间(1.67 s.L/g MLSS),证明耦合系统污泥混合液脱水性能提高了。

Membrane bioreactor（MBR） is an effective process for wastewater treatment,whereas the process of microbial fuel cell（MFC） can effectively degrade extracellular biological organic matter（EBOM） and recover electricity.A new process for combining MBR with MFCs was established to mitigate membrane fouling and recover electricity.The excess sludge of MBR was treated by MFCs,and then recycled to MBR.The combined system was compared with the conventional MBR with respect to the performances of wastewater treatment,the membrane fouling and the characteristics of mixed liquor.The result showed that the effluent quality of the combined system was not deteriorated significantly,with removal efficiencies of 94% and 92% for COD and NH4＋-N,respectively.Membrane fouling of the combined system was mitigated dramatically and the chemical cleaning cycle was prolonged by 28%.The ratios of mixed liquor volatile suspended solids（MLVSS） to mixed liquor suspended solids（MLSS） for the two systems were almost identical,in the range 80%～88%,indicating that the inorganics from the MFCs did not accumulate as particulates in the MBR.Loosely bound extracellular polymeric substances（LB-EPS） decreased by 48%,resulting that the sludge was modified.Lower specific resistance to filtration（2.69×1012 m/kg） and normalized capillary suction time（1.67 s·L/g MLSS） demonstrated that the dewaterability of mixed liquor in the combined system was improved.