AWWA JAW63308

Adsorption isotherm and field tests were conducted to investigate removal of haloacetic acids (HAAs) in the initial stage of granular activated carbon (GAC) filtration. Results from laboratory and field tests indicated that GAC adsorption plays only a minor role in overall HAA removal in GAC filters. In addition, HAAs (except trichloroacetic acid) had a much lower adsorption capacity than did trihalomethanes. Adsorption capacity for HAAs increased with increasing halogen number. Chlorinated HAA species had a lower adsorption capacity than did their brominated analogues. HAA removal in aged GAC filters may be attributable to biodegradation. Includes 19 references, tables, figures.