Coagulation Optimization: Pilot-Scale Analysis of UF Fouling and DBP Formation

The most widely applied pre-treatment to UF is coagulation, often to aggregate fractions of organic matter that cause fouling or those fractions that form disinfection by-products (DBPs) upon chlorination. Recent bench-scale studies have indicated that a low dose of coagulant (< 1 mg/L) is effective at reducing membrane fouling when considering several Ontario, Canada surface waters. However, the effect of low coagulant dosages on UF fouling at pilot-scale remain unknown, as does the impact on removal of DBP precursors. The objective of the present study was to investigate optimized coagulant dosages prior to ultrafiltration at pilot-scale for the reduction of membrane fouling as well as removal of DBP precursors. This study indicates that a low dose of coagulant may be suitable prior to UF for fouling reduction and some DBP precursor removal.