Dehalogenation of tetrachloroethylene by biological with hydrogen-based membrane biofilm reactor

Tetrachloroethylene (PCE) is used as solvents and cleaning operations in various industries for different purposes, and classified as carcinogens and also causes contamination in surface and underground waters. Therefore, the removal of PCE from the water environment is important. In this study, experimental studies were performed for reduction of PCE to ETH biologically in drinking water by using H2-based membrane biofilm reactor. As a result of experimental studies, it is aimed to dehalogenation of PCE to ETH, to determination of the rate of reduction, to determination of the flux of reduction, to determination of quantity of hydrogen used by the biofilm, and to describe of microbial species during the process of dehalogenation. In order to obtain these aims, one H2-based anaerobic reactor, one completely mixed H2-based membrane biofilm reactor, and four circulation H2-based membrane biofilm reactors have been established. Some of these reactors have been fed both by PCE and TCE and also have been operated both batch feed and continuos feed.At the end of these study, both PCE and TCE have been reduced to ethene (ETH) biologically in both H2-based anaerobic reactor and in H2-based membrane biofilm reactor. Microbial species have been described in biofilm samples which have been taken during these biological process and also dehalococcoides strains are determined and these strains are responsible for converting PCE to ETH. Furthermore, electron-equivalent flux for halogen is determined as range of average 0,0003-0,0058 e-eq/m2.day, electron-equivalent flux for nitrate is determined as range of average 0,00541-0,1391 e-eq/m2.gün, and electron-equivalent flux for sulfate is determined as range of average 0,01112-0,165 e-eq/m2.day depending on the quantity of electron acceptors in H2-based membrane biofilm reactors. The quantity of H2 which is used by biofilm in H2-based membrane biofilm reactors is determined as range of average 0,283-1,513 gH2/m2.day.