PAC activity vs by-product precursors in water disinfection

Disinfection by-products (DBP) are among the most significant negative side effects of drinking water treatments. Chlorinated disinfectants and organic precursors found in source waters are involved in their formation. Purpose of this study is to investigate the applicability of powdered activation carbon (PAC) to the adsorptive removal of precursors. Three different PACs provided by manufacturers have been applied to water samples collected from the Po River (Turin, Italy) and a specific analytical approach based on precursors concentration and DBP formation potential was used for comparison and definition of selectivity. The influence of some operating variables on PAC efficiency has been evaluated for only one of the PACs previously examined: PAC dosage and contact time, ozonation, chlorine dioxide addition, sedimentation. From the results obtained it is possible to suggest the most convenient PAC application scheme.