CL-Out bioremediation of carbon tetrachloride was tested in a bench-scale study in 2001. Carbon tetrachloride is a common ground water contaminant originating from the chemical’s use in fire supression and aerosols. Other research has demonstrate bioremediation by anaerobic reductive dechlorination of carbon tetrachloride. CL-Out orgasmisms are facultative aerobes. A successful treatability study would present opportunities for aerobic bioremediation of carbon tetrachloride.
Bench-Scale Results
The bench study tested the applicability of CL-Out organisms to degrade carbon tetrachloride by cometabolism. The study involved two microcosms of contaminated ground water. One microcosm was untreated and used as a standard for comparison. The other microcosm was treated by adding CL-Out microbes and dextrose, which was added as the cometabolic substrate. The target microbial population in the treated microcosm was one million cells per milliliter. After 48 hours samples of the microcosms were tested by GC mass spectroscopy to determine the carbon tetrachloride concentrations. The laboratory analysis showed carbon tetrachloride at 1,500 ug/l in the control. The CL-Out treated microcosm had 1,100 ug/L of carbon tetrachloride. This difference is a 27% decrease in concentration in less than two days. We look forward to opportunities to bring this technology to pilot study or full-scale field application. CL-Out cometabolism has sucessfully remediated a wide range of recalcitrant chemicals including tetrachloroethylene, 1,1,1-trichloroethane, vinyl chloride, DNT, perchlorate and dieldrin. Click here for more information and case studies.
