The slurry biodegradation process involves excavating the contaminated soil and mixing it in an aerobic reactor with water and nutrients. This process maximizes the contact between the contaminants and the microorganisms capable of degrading those contaminants. The temperature in the reactor is usually maintained at an appropriate level, and neutralizing agents are often added to adjust the pH to an acceptable range (U.S. EPA 1990b). After the treatment is complete, the slurry is dewatered, and the soil can be redeposited on site. This technology is effective for soils contaminated with fuel hydrocarbons (U.S. EPA 1993a). In addition, the contaminants can be completely destroyed and the soil reused.
The technology, however, is less effective for contaminants with low biodegradability. In addition, the presence of chlorides or heavy metals as well as some pesticides and herbicides in the soil can reduce the effectiveness of the process by inhibiting the microbial action.
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