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.