TRICHLOROETHYLENE CONCENTRATION EFFECTS ON PILOT FIELD-SCALE IN-SITU GROUNDWATER BIOREMEDIATION BY PHENOL-OXIDIZING MICROORGANISMS

A Pilot study of in-situ aerobic cometabolic degradation of trichloroethylene (TCE) through the injection of phenol and oxygen into a confined aquifer was conducted at the Moffett Field test site together with a related laboratory study. With injected phenol and dissolved oxygen concentrations of 12.5 and 35 mg/L, respectively, first-order TCE removal of 88% was obtained over a concentration range of 62-500 mug/L. With 1000 mug/L TCE, removal was lower (77%), but increased to 90% when the phenol concentration was raised to 25 mg/L. The maximum field transformation yield of 0.062 g of TCE/g of phenol compared favorably with the highest measured resting-cell laboratory yield of 0.11 g of TCE/g of phenol. These results demonstrate high promise for in-situ aerobic cometabolic biodegradation of TCE with phenol-induced enzymes.