AWWA JAW10521

Four cationic polymers were tested in this study as sole coagulants for removing trihalomethane precursors from synthetic and natural waters. Polymer dosages of 2.5 to 20 mg/L were used with natural waters, whereas dosages of 2.5 to 30 mg/L were used with humic acid water and dosages up to 60 mg/L were used with fulvic acid water. Waters synthesized from humic acid were more amenable to polymer coagulation than those synthesized from fulvic acid. The presence of kaolinite appeared to improve removal of trihalomethane formation potential (THMFP) from these waters. In general, the performances of the polymers were comparable. For the natural waters, the effectiveness of polymer coagulation in THMFP reduction varied as a function of raw water source. Ambient pH of the water appeared to influence polymer performance. For both types of water, the reductions in THMFP were generally greater than the corresponding decreases in total organic carbon. Includes 16 references, tables, figures.