Characterization of natural organic matter and disinfection byproducts formation potential in pilot-scale coagulation-ultrafiltration membrane combined process in winter

A pilot-scale ultrafiltration membrane plant was set up for treating Luanhe River water with flocculating and precipitation process of waterworks. The aim is to investigate the variation and characteristics of natural organic matter and disinfection byproducts formation potential in the whole process in winter. The results show that dissolved organic matter (DOM), UV254, trihalomethanes formation potential (THMsFP) and haloacetic acids formation potential (HAAsFP) of Luanhe River water were mainly distributed in the range of molecular weight (MW) <1 kDa, so were the membrane feed water and treated water by membrane. Specific UV absorbance, specific THMsFP and specific HAAsFP have the maximal value in the MW fraction of 1-3 kDa, except that specific UV absorbance of membrane feed water is in the range of 3-10 kDa; DOM of membrane backwash water is mainly distributed in the range of MW>30 kDa and MW<1 kDa. It is the DOM in water backwashing in up way that made significant contribution to the higher dissolved organic carbon content in membrane backwash water. However, UV254, THMsFP and HAAsFP were mainly distributed in the range of MW<1 kDa. The highest concentrations of specific THMsFP and specific HAAsFP appeared in the MW fraction of 3-10 kDa. CHCl3 was the major THMs species during MBW chlorination and occupied more than 60% of the total THMsFP. Dichloroacetic acid and trichloroacetic acid were the main components in HAAsFP. The concentration of THMsFP and HAAsFP in MBW was influenced by operation period. © 2010 Tianjin University and Springer-Verlag Berlin Heidelberg.