AWWA JAW62058

Groundwater contaminated with perchlorate is a health concern because of its ability to disrupt thyroid hormone production when ingested, which may inhibit normal growth and development. Although several abiotic and biotic technologies can efficiently remove perchlorate from drinking water, currently only ion exchange is being applied for perchlorate removal in full-scale plants, because it is the least expensive option among the abiotic processes. Cost estimates for biotic treatment processes indicate their potential to be relatively inexpensive options for treating perchlorate-contaminated drinking water. However, other concerns have limited their consideration for full-scale perchlorate treatment. In this article, the authors discuss the results of a six-month pilot study that was performed at the Castaic Lake Water Agency in Santa Clarita, California, to evaluate the effectiveness of fixed-bed bioreactors to treat perchlorate-contaminated water. The pilot data showed that perchlorate-reducing fixed-bed bioreactors can be acclimated using organisms indigenous to the local aquifer; can achieve sustained perchlorate removal to below the analytical detection limit using reasonable contact times; can produce biologically stable effluent; do not foster the growth of pathogenic bacteria; and are robust in respect to system upsets. Includes 26 references, table, figures.