Microbial Studies Supporting Implementation of In Situ Bioremediation at TAN

Barnes, Joan Marie ; Matthern, Gretchen Elise ; Rae, Catherine ; Ely, R. L.

Idaho National Laboratory

关键词: In Situ;    Hydraulics;    Dechlorination;    Valence Bioreactor;    Binding Energy;   

DOI  :  10.2172/911020
RP-ID  :  INEEL/EXT-98-00474
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  911020

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Idaho National Engineering and Environmental Laboratory is evaluating in situ bioremediation of contaminated groundwater at its Test Area North Facility. To determine feasibility, microcosm and bioreactor studies were conducted to ascertain the ability of indigenous microbes to convert trichloroethene and dichloroethene to non-hazardous byproducts under aerobic and anaerobic conditions, and to measure the kinetics of microbial reactions associated with the degradation process. Microcosms were established from core samples and groundwater obtained from within the contaminant plume. These microcosms were amended with nutrients, under aerobic and anaerobic conditions, to identify electron donors capable of stimulating the degradation process. Results of the anaerobic microcosm studies showed that lactate, acetate and propionate amendments stimulated indigenous cell growth and functioned as effective substrates for reductive degradation of chloroethenes. Bioreactors inoculated with cultures from these anaerobic microcosms were operated under a batch mode for 42 days then converted to a fed-batch mode and operated at a 53-day hydraulic residence time. It was demonstrated that indigenous microbes capable of complete anaerobic reductive dechlorination are present in the subject well. It was also demonstrated that aerobic microbes capable of oxidizing chlorinated compounds produced by anaerobic reductive dechlorination are present. Kinetic data suggest that controlling the type and concentration of electron donors can increase trichlorethene conversion rates. In the event that complete mineralization of trichlorethene does not occur following stimulation, and anaerobic/aerobic treatment scheme is feasible.