A Semi-Continuos Biotreatment Protocol for Chlorinated Ethanes: Application To The Aerospace Industry

A biological treatment process employing immobilized microbial populations was field tested on contaminated ground water having elevated concentrations of volatile organics, primarily ethylene dichloride (EDC), 1, 1 dichloroethane and 1,1,2 trichoroethane. The process, consisting of a 75 L packed bed reactor containing specific adapted microbial strains immobilized on a porous diatomaceous earth support, was operated in a plug flow configuration over a 14 day period in a semi-continuous mode, i.e., draw and fill. General process measurements included temperature, pH, and titrated chlorides. Microbial adenosine triphoshate (ATP) measurements provided estimates on immobilized biomass performance. Specific chemical analyses of ground water contaminants consisting of gas chromatography/mass spectroscopy determinations of feed and treated streams provided information biotransformation kinetics and control of stripping action…Feed concentrations of 160 mg/L and 230 mg/L of EDC were effectively mineralized to <1.0 mg/L within a 12-18 h retention time. Data will be presented on minimal stripping rates,<1.0 %, and mechanisms for control.* corresponding author