AWWA ACE60027

The main purpose of this project is to evaluate the use of strong base anion (SBA) exchange resin for the removal of dissolved organic carbon (DOC) from North Bay Aqueduct (NBA) water. The use of SBA technology has shown considerable promise for significant removal of DOC from raw water, resulting in reduction of coagulant and disinfectant demands while reducing disinfection byproduct (DBP) formation. The NBA, part of the State Water Project, is a 27-mile underground pipeline serving municipal and industrial water users in Napa and Solano counties. Rapidly changing water quality conditions have historically been a tremendous operator challenge for utilities treating water from the NBA, particularly in the maintenance of stable coagulation conditions in the treatment process. The use of SBA exchange technology potentially offers a cost-effective way of producing safer water while lowering the overall operating costs of water treatment. A two-phased approach has been taken to evaluate the effectiveness of using ion exchange technology to treat NBA water. During the first phase, bench-scale adsorption studies were undertaken using a series of ion-exchange resins. The purpose of bench-scale testing was to determine an appropriate SBA resin to test at the pilot-scale. The resins were evaluated on their ability to remove natural organic material (NOM) from NBA water prior to simulated conventional treatment. Following the bench-scale tests, pilot-scale tests were undertaken using the resin recommended by bench-scale testing. Pilot scale tests were performed to characterize the benefits of ion exchange pretreatment on the downstream processes of coagulation, sedimentation, and filtration. Optimization of the ion exchange process was followed by observation of the performance of the downstream processes during baseline conditions and events of elevated TOC and turbidity. Comparisons were made by using two trains, one with SBA exchange pretreatment and one without. Includes tables, figures.