DBP Control in High Bromide Water While Using Free Chlorine During Distribution

The source water for the treatment investigations was California State Project Water (SPW). SPW is characterized by low turbidity, moderate total organic matter concentrations (average of 3.9 mg/L), and high bromide concentrations (up to 0.45 mg/L). This water tends to readily form chlorinated DBPs when free chlorine is used as the secondary disinfectant. From 2001 to 2004, the running annual average (RAA) of TTHMs has approached 80 ug/L at the Palmdale Water District. This study provides operating conditions and costs for four advanced processes to achieve sufficient precursor (bromide and organic matter) removal to comply with the Stage 1 and 2 D/DBP Rules. Processes investigated include the MIEXTM process, fixed-bed ion exchange (using both bromide-specific and organic matter-specific resins), and GAC (for both precursor and THM adsorption). Also, the combination of MIEXTM resin and ceramic membranes showed promise for DBP control and is recommended for further study.