Virus Removal’ by Low Pressure Membranes in Wastewater Treatment: Effects of Ion Composition and Effluent Organic Matter

Low pressure membranes (LPMs) have been increasingly applied in the disinfection of wastewater effluent. The efficiency of LPM in disinfection is affected by the quality of the effluent, including ion composition and effluent organic matter (EfOM). In order to better understand the two effects, two types of commercial LPMs with similar pore size rating were challenged with MS2 bacteriophage in this study at bench and pilot scales. It was found that ion composition had different effects on the performance of LPMs with loose and tight pore structures, probably as a result of different role of electrostatic repulsions between viruses and the membranes. Meanwhile, the EfOM effect was related to the presence of a colloidal fraction larger than other dissolved organics. Detailed mechanism for the EfOM effect has not been identified.The results indicate that the performance of LPMs in wastewater disinfection may be strongly influenced by the effluent ion composition and EfOM properties and different from that determined in standard bench-scale challenge tests. This should be carefully considered in the evaluation and selection of LPMs for full-scale applications.