title: Continuous dechlorination of tetrachloroethene in an upflow anaerobic sludge blanket reactor.
abstract: Influences of hydraulic retention time (HRT) on dechlorination of tetrachloroethene (PCE) were investigated in an upflow anaerobic sludge blanket (UASB) reactor inoculated with anaerobic granular sludge non-pre-exposed to chlorinated compounds. PCE was introduced into the reactor at a loading rate of 3 mg/l d. PCE removal increased from 51+/-5% to 87+/-3% when HRT increased from 1 to 4 d, corresponding to an increase in the PCE biotransformation rate from 10.5+/-2.3 to 21.3+/-3.7 micromol/d. A higher ethene production rate, 0.9+/-0.2 micromol/d, was attained without accumulation of dichloroethenes at the HRT of 4 d. Dehalococcoides-like species were detected in sludge granules by fluorescence in situ hybridization, with signal strength in proportion to the extent of PCE dechlorination.
authors.affiliation: Department of Environmental Engineering, Hungkuang University, Taichung County 43302, Taiwan. cshwu@sunrise.hk.edu.tw
authors.forename: Ching-Shyung
authors.initials: CS
authors.lastname: Hwu
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Lu
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002713:Chlorine / Q000302:isolation & purification*; D005740:Gases; D017404:In Situ Hybridization, Fluorescence; D012722:Sewage / Q000382:microbiology; D013750:Tetrachloroethylene / Q000737:chemistry*
chemical_list: D005740:Gases; D012722:Sewage; D002713:Chlorine; D013750:Tetrachloroethylene