IN SITU/EX SITU ACCELERATED ANAEROBIC REDUCTION OF PERCHLORATE

摘要

The anaerobic reduction of perchlorate via indigenous subsurface bacteria is fast becoming a widely accepted tool for the remediation of perchlorate-impacted soil and groundwater. Pilot tests were initiated in 2001 to determine the applicability and effectiveness of stimulating the anaerobic biological treatment of soils and groundwater. Anaerobic composting was demonstrated as an effective ex situ method for treating heavily perchlorate-impacted soils, reducing perchlorate concentrations in site soils from approximately 40 mg/kg to non-detectable levels (I.e., less than 0.01 mg/kg) within 9 to 12 months. The use of an infiltration gallery in conjunction with a soluble substrate (I.e., calcium magnesium acetate) feed system was demonstrated as an effective technique to flush perchlorate from vadose zone soils and create an in situ anaerobic treatment zone in shallow groundwater. The use of a series of injection points to create a subsurface biobarrier composed of insoluble substrate (I.e., recycled vegetable oil) was also proven to be an effective method of creating an in situ anaerobic treatment zone for perchlorateimpacted groundwater. Reductions in perchlorate concentrations in groundwater of 89% and 44% were observed for the infiltration gallery and biobarrier areas, respectively.