Effluent organic matter in Beijing´s WWTPs: Characterization and comparison

Dissolved organic matter (DOM) in sewage effluents from Beijing´s wastewater treatment plants (WWTPs) were characterized and compared. Results revealed that the characteristics of DOM in sewage effluents were related to the nitrification degree, sewage property and the adopted technology of WWTPs. Good nitrification contributed to the degradation of effluent organic matter and increase the humification degree of effluent. The physical entrapment effect of membrane biological reactor (MBR) as well as its longer sludge retention time decreased the humification degree of effluent, while a portion of organic matters with high molecular weight were still retained. Aerobic biofilm with a longer sludge retention time might induce the aggregation of protein-like soluble microbial products. Comparing with municipal domestic sewage, the characteristics of DOM from WWTP feeding with domestic and industrial mixed sewage displayed obvious differences.