title: Transformation of chloroform in model treatment wetlands: from mass balance to microbial analysis.
abstract: Chloroform is one of the common disinfection byproducts, which is not susceptible to degradation and poses great health concern. In this study, the chloroform removal efficiencies and contributions of sorption, microbial degradation, plant uptake, and volatilization were evaluated in six model constructed wetlands (CWs). The highest chloroform removal efficiency was achieved in litter-added CWs (99%), followed by planted (46-54%) and unplanted CWs (39%). Mass balance study revealed that sorption (73.5-81.2%) and microbial degradation (17.6-26.2%) were the main chloroform removal processes in litter-added CWs, and that sorption (53.6-66.1%) and plant uptake (25.3-36.2%) were the primary contributors to chloroform removal in planted CWs. Around 60% of chloroform got accumulated in the roots after plant uptake, and both transpiration and gas-phase transport were expected to be the drivers for the plant uptake. Sulfate-reducing bacteria and methanogens were found to be the key microorganisms for chloroform biodegradation through cometabolic dechlorination, and positive correlations were observed between functional genes (dsrA, mcrA) and biodegradation rates. Overall, this study suggests that wetland is an efficient ecosystem for sustainable chloroform removal, and that plant and litter can enhance the removal performance through root uptake and microbial degradation stimulation, respectively.
authors.affiliation: †Key Laboratory of Yangtze Water Environment of Ministry of the State Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China.|‡Department of Landscape Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences, Prague 16521, Czech Republic.|§Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research -UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: †Key Laboratory of Yangtze Water Environment of Ministry of the State Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wen
authors.affiliation: †Key Laboratory of Yangtze Water Environment of Ministry of the State Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China.
authors.forename: Junwei
authors.initials: J
authors.lastname: Zhou
authors.affiliation: †Key Laboratory of Yangtze Water Environment of Ministry of the State Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: ‡Department of Landscape Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences, Prague 16521, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Vymazal
authors.affiliation: §Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research -UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Kuschk
mesh_terms: D000327:Adsorption; D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001711:Biotransformation; D002725:Chloroform / Q000737:chemistry*; D005798:Genes, Bacterial; D006207:Half-Life; D007700:Kinetics; D014835:Volatilization; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical; D002725:Chloroform