title: Bioremediation of benzene-, MTBE- and ammonia-contaminated groundwater with pilot-scale constructed wetlands.
abstract: In this pilot-scale constructed wetland (CW) study for treating groundwater contaminated with benzene, MTBE, and ammonia-N, the performance of two types of CWs (a wetland with gravel matrix and a plant root mat) was investigated. Hypothesized stimulative effects of filter material additives (charcoal, iron(III)) on pollutant removal were also tested. Increased contaminant loss was found during summer; the best treatment performance was achieved by the plant root mat. Concentration decrease in the planted gravel filter/plant root mat, respectively, amounted to 81/99% for benzene, 17/82% for MTBE, and 54/41% for ammonia-N at calculated inflow loads of 525/603 mg/m(2)/d, 97/112 mg/m(2)/d, and 1167/1342 mg/m(2)/d for benzene, MTBE, and ammonia-N. Filter additives did not improve contaminant depletion, although sorption processes were observed and elevated iron(II) formation indicated iron reduction. Bacterial and stable isotope analysis provided evidence for microbial benzene degradation in the CW, emphasizing the promising potential of this treatment technique.
authors.affiliation: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Permoserstr 15, 04318 Leipzig, Germany. eva.seeger@ufz.de
authors.forename: Eva M
authors.initials: EM
authors.lastname: Seeger
authors.forename: Peter
authors.initials: P
authors.lastname: Kuschk
authors.forename: Helga
authors.initials: H
authors.lastname: Fazekas
authors.forename: Peter
authors.initials: P
authors.lastname: Grathwohl
authors.forename: Matthias
authors.initials: M
authors.lastname: Kaestner
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D001554:Benzene / Q000378:metabolism*; D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D008738:Methyl Ethers / Q000378:metabolism*; D008954:Models, Biological; D010865:Pilot Projects; D018517:Plant Roots / Q000378:metabolism; D006109:Poaceae / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands
chemical_list: D008738:Methyl Ethers; D014874:Water Pollutants, Chemical; C043243:methyl tert-butyl ether; D000641:Ammonia; D001554:Benzene