ENHANCING NATURAL ORGANIC MATTER REMOVAL IN AN ULTRAFILTRATION MEMBRANE PLANT THROUGH COAGULATION

Abstract

Four polyaluminum chlorides were tested in bench-scale coagulation experiments to determine an optimal pH and dose for each, while also establishing an ideal treatment option for a small water treatment plant in Nova Scotia for removal of natural organic matter. PAC-A, PAC-B, PAC-C, and PAC-D were coagulated using raw water from Pottle Lake Water Treatment Plant at pH 5.5 and 6.5, and it was determined that the optimal pH for all coagulants was pH 6.5. There was no statistically significant difference in overall reduction of natural organic matter between any of the polyaluminum chlorides tested, indicating that each coagulant effectively removed natural organic matter equally. All four coagulants showed promising results in removing precursors of disinfection by-products for Pottle Lake Water Treatment Plant, but the optimal PACl coagulant was determined to be PAC-A-1.8 at pH 6.5 due to its reduction of UV254, turbidity, and specific UV absorbance (SUVA).