Strategies for in situ bioremediation of chlorinated solvent contaminated groundwater

Chlorinated solvents such as TCE and TCA can be biologically degraded aerobically through cometabolism. PCE and TCE can be degraded anaerobically while being used as electron acceptors in energy metabolism. In situ bioremediation strategies may be directed either towards containing a plume or cleaning it up completely. The DNAPL source for PCE and TCE can also be biodegraded, resulting in enhanced dissolution due to higher reaction rates and toxicity to competing methanogens. All in situ biodegradation processes require the addition of electron donors, and perhaps bioaugmentation. Added materials, the contaminants, and the degrading organisms must be brought together so that the transformation can be effected. This may be accomplished using liquid injection/extraction systems, gas injection, and bioreactive barrier walls.