Simultaneous bio-reduction of trichloroethene, trichloroethane, and chloroform using a hydrogen-based membrane biofilm reactor.
The contamination of water by chlorinated solvents is recognized as a serious and widespread problem throughout the industrialized world. Here, we focus on three chlorinated solvents that are among those most commonly detected and that have distinct chemical features: trichloroethene (TCE), trichloroethane (TCA), and chloroform (CF). Because many contaminated waters contain mixtures of the chlorinated solvents, a treatment technology that detoxifies all of them simultaneously is highly desirable. The membrane biofilm reactor (MBfR) is a recent technological advance that makes it possible to deliver H(2) gas to bacteria efficiently and safely, despite hydrogen's low water solubility and risk of forming a combustible atmosphere when mixed with air. The objectives of this work are to document whether or not the three chlorinated compounds can be dechlorinated simultaneously in a H(2)-based MBfR and to determine if competitive or inhibitory interactions affect bio-reduction of any of the solvents. The main finding is a demonstration that directly using H(2) as the electron donor makes it possible to bio-reduce combinations of different chlorinated solvents. This finding supports that the H(2)-based MBfR can treat multiple chlorinated solvents in one step, addressing a common groundwater situation. We saw possible evidence of inhibition by CF at a concentration greater than about 1 muM, competition for H(2) from sulfate and nitrate reductions, and possible inhibition of TCE reduction from the accumulation of chloroethane (CA) or chloromethane (CM).
Chung
Jinwook
J
R&D Center, Samsung Engineering Co. Ltd., 39-3 Sungbok-Dong, Yongin-Si, Gyeonggi-Do 449-844, South Korea. jin-wook.chung@samsung.com
Rittmann
Bruce E
BE
D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D002725:Chloroform / Q000378:metabolism*; D006859:Hydrogen / Q000737:chemistry; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D014240:Trichloroethanes / Q000378:metabolism*; D014241:Trichloroethylene / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
D008567:Membranes, Artificial; D014240:Trichloroethanes; D014241:Trichloroethylene; D002725:Chloroform; D006859:Hydrogen