Government, industry, medicine, and biotechnology facilities have produced hazardous and mixed hazardous wastes that amount to hundreds of thousands of kilograms per year. These compounds are used in products such as solvents and for analytical processes. Non-chlorinated hydrocarbons contribute to both liquid and vapor effluent streams that ultimately must be controlled, treated, or disposed. Bioprocessing offers significant cost-effective methods for the degradation of hazardous and mixed hazardous organic wastes.
An example of this biotechnology is an in-line process developed for the degradation of methylated benzene compounds (xylenes, toluene, pseudocumene). This bioprocess utilizes the capabilities of a unique bacterium that has been adapted for use in a continuous flow bioreactor system.
This system consists of two continuously stirred tank reactors coupled with a counter flow vapor-phase reactor. The bacterium used in this bioprocess is not only able to live in neat concentrations of the above solvents, but will actively metabolize them under these conditions. In addition, it is extremely tolerant to high concentrations of surfactants. Exploiting these capabilities, the patented method uses surfactant to emulsify high concentrations of the organics (in excess of 1.5%) in the aqueous treatment stream feeding the continuously stirred tank reactors. At the end of the process stream, the vapor-phase reactor is used as a polishing step for liquid and gas streams.
The developed bioprocess has been demonstrated on stored drums of mixed waste containing liquid scintillation cocktail (LSC). The demonstrations have taken place at two government facilities. The mixed liquid waste was successfully processed at both facilities. The effluent was disposed as a low-level aqueous liquid rad waste. The process feed rates for the LSC waste was 40 mL/reactor liter/day, 100% of the organic solvent (pseudocumene) was degraded/eliminated and the plutonium was concentrated in the cells during the processing from the remaining low-level wastes.
This process can be applied to industrial wastes containing toluene, xylene, and other aromatic methylated compounds. Hospital diagnostic wastes and laboratory wastes have also been treated with this unique strain of microorganism.
This technology is available for licensing to commercial firms and for cooperative development arrangements.
Jim Wolfram
DOE-Idaho national Engineering & Environmental Laboratory
Director of Technology Transfer
PO Box 1625
Lockheed Martin - MS 3805
Idaho Falls, ID 83415-3805
Phone: (208) 526-0441 Fax: (208) 526-0876
http://www.inel.gov/capabilities/biotech/Hazwaste.html
Bioprocess, Hazardous Waste, Medical Waste, Biological Decontamination