AWWA WQTC65958

The City of Glendale, California has been leading a research program to identify effective hexavalent chromium treatment technologies for impacted groundwater wells. The research effort to date has involved a range of funding agencies and organizations, university partners, and local cities. This work has been supported by the U.S. Environmental Protection Agency (USEPA), State of California, AwwaRF, and the Cities of San Fernando, Burbank, and Los Angeles. University partners have included Utah State University, University of California at Los Angeles (UCLA), University of Colorado at Boulder, Wellesley College, and Lehigh University. This extensive university and multi-organizational support has enabled the investigation of the mechanism of hexavalent chromium removal by a new treatment technology application, weak-base anion exchange. In early pilot studies, weak-base anion exchange resin demonstrated a high capacity for hexavalent chromium. Initial technology testing, however, revealed a few hints that the reduction of hexavalent chromium to trivalent chromium occurred on at least one weak-base resin, but not on strong-base resins. Another research group also observed the high capacity of a weak-base resin for chromium and hypothesized that chromium reduction occurred (H?ll et al. 2002), although no evidence of this mechanism was provided. The appearance of this possible chromium reduction process coupled with the high chromium capacity of the weak-base resin led the project team to investigate the mechanism of chromium retention by the resins. Includes 7 references, tables, figures.