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PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF INORGANIC CONTAMINANTS
Citation:
Wilkin*, R T. PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF INORGANIC CONTAMINANTS. Presented at Zinc/Cadmium Symposium, Coeur d'alene, ID, September 09 - 12, 2002.
Impact/Purpose:
To inform the public.
Description:
The permeable reactive barrier (PRB) technology is an in-situ approach for groundwater remediation that couples subsurface flow management with a passive chemical or biochemical treatment zone. The development and application of the PRB technology has progressed over the last decade from laboratory-based proof-of-concept studies to full-scale implementations at hazardous waste sites. A wide variety of inorganic contaminants can be treated with PRBs, including cadmium and zinc.
The National Risk Management Research Laboratory of USEPA-ORD has recently completed a three-year federal tri-agency initiative with the Department of Energy and the Department of Defense to study the long-term performance of PRBs at a dozen installations across the United States. The research initiative focused on the following issues: long-term effects on hydrologic flow patterns in the vicinity of barriers; the rate of precipitate formation in the reaction zone; and microbiological effects within and near the barriers as a result of their placement within the subsurface. These long-term performance studies at PRB sites in operation for over six years provide a basis for predicting rates of porosity loss due to mineral precipitation and biofouling. A principal conclusion is that long-term water treatment is possible with this technology, but that adequate site characterization is essential for meeting longevity and hydraulic performance goals. Topics addressed in the presentation will include: technology overview, status of long-term performance studies, a site characterization strategy, discussion of reactive media for removal of cadmium and zinc from water, and discussion of factors influencing cost and performance. These topics may serve as a launch point for discussions regarding the Coeur d'Alene Basin and will help in identifying potential data gaps and the construction of a research plan to address water treatment.