Comparing RBF WITH BENCH-SCALE CONVENTIONAL TREATMENT for precursor reduction

• Published in: Journal - American Water Works Association Vol. 95; no. 12; pp. 67 - 80
• Main Authors: WEISS, W. JOSHUA, BOUWER, EDWARD J., BALL, WILLIAM P., O'MELIA, CHARLES R., ARORA, HARISH, SPETH, THOMAS F.
• Format: Journal Article
• Language: English
• Published: Denver, CO American Water Works Association 01.12.2003
• Subjects: Acids; Activated carbon; Adsorption; Applied sciences; Biodegradation; Biofiltration; Bromides; By products; Carbon; Chlorination; Chlorine; Coagulation; Disinfection & disinfectants; Drinking water; Drinking water and swimming-pool water. Desalination; Exact sciences and technology; filteration; Filtration; Flocculation; Groundwater; Laboratories; Microorganisms; Natural Organic Matter; Ozone; Pollution; Potable water; Pretreatment; Reduction; River water; Rivers; Sedimentation; Sedimentation & deposition; Surface Water; Water filtration; Water treatment; Water treatment and pollution
• ISSN: 0003-150X; 1551-8833
• DOI: 10.1002/j.1551-8833.2003.tb10512.x

Reduction of disinfection by‐product (DBP) precursors upon riverbank filtration (RBF) at three drinking water utilities in the midwestern United States was compared with reductions obtained using a bench‐scale conventional treatment train on the corresponding river waters. The river waters were subjected to a treatment train consisting of coagulation, flocculation, sedimentation, filtration, and ozonation. RBF performed as well as or better than the bench‐scale conventional treatment with respect to DBP precursor removal. Total and dissolved organic carbon concentrations were reduced by 20 to 50% after bench‐scale treatment, compared with reductions between 30 and 70% after subsurface travel to the closer wells at the three sites. Reductions in precursor material for a variety of DBPs (trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin) after bench‐scale treatment were generally in the range of 40 to 80%, whereas reductions after RBF ranged from 50 to 100%. After RBF and bench‐scale treatment, a shift was observed from the chlorinated to the more‐brominated DBP species, with the shift more pronounced for the bank‐filtered waters. This shift was likely attributable to the increase in the ratio of bromide to dissolved organic carbon.