Enhancement and monitoring of pollutant removal in a constructed wetland by microbial electrochemical technology.
A bench-scale constructed wetland combined with microbial electrochemical technology (MET-CW) was run for 400days with groundwater contaminated with benzene, methyl-tert-butyl ether (MTBE), and ammonium (NH4(+)). Four vertically stacked anode modules were embedded into a sand bed and connected with a stainless steel cathode placed in an open water pond. In the zone of presence of anode modules, significantly more benzene and MTBE were removed in the MET-CW compared to the control CW without MET in the first 150 operation days. Benzene was identified as primary electron donor at the anode. Benzene removal and current densities were linearly correlated, implying the potential of the system for electrochemically monitoring benzene biodegradation. Compound-specific isotope analysis (CSIA) indicated that benzene was initially activated by monohydroxylation forming intermediates which were subsequently oxidized accompanied by extracellular electron transfer, leading to current production. NH4(+) removal was not stimulated by MET.
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318 Leipzig, Germany; Faculty of Natural Sciences, Hohenheim University, 70593 Stuttgart, Germany.
Manman
M
Wei
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318 Leipzig, Germany.
Jana
J
Rakoczy
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318 Leipzig, Germany. Electronic address: carsten.vogt@ufz.de.
Carsten
C
Vogt
Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany.
Falk
F
Harnisch
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318 Leipzig, Germany.
Reinhard
R
Schumann
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318 Leipzig, Germany.
Hans H
HH
Richnow
D001554:Benzene / Q000032:analysis / Q000737:chemistry; D001673:Biodegradation, Environmental; D004784:Environmental Monitoring / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008738:Methyl Ethers / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D053833:Wetlands
D008738:Methyl Ethers; D014874:Water Pollutants, Chemical; C043243:methyl tert-butyl ether; D001554:Benzene
Ammonium; Benzene; Bioremediation; MET; Methyl-tert-butyl ether