Title: | Adaptation of a constructed wetland to simultaneous treatment of monochlorobenzene and perchloroethene |
Author(s): | Braeckevelt M; Seeger EM; Paschke H; Kuschk P; Kaestner M; |
Address: | "Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany. mareike.braeckevelt@ufz.de" |
DOI: | 10.1080/15226514.2010.549860 |
ISSN/ISBN: | 1522-6514 (Print) 1522-6514 (Linking) |
Abstract: | "Mixed groundwater contaminations by chlorinated volatile organic compounds (VOC) cause environmental hazards if contaminated groundwater discharges into surface waters and river floodplains. Constructed wetlands (CW) or engineered natural wetlands provide a promising technology for the protection of sensitive water bodies. We adapted a constructed wetland able to treat monochlorobenzene (MCB) contaminated groundwater to a mixture of MCB and tetrachloroethene (PCE), representing low and high chlorinated model VOC. Simultaneous treatment of both compounds was efficient after an adaptation time of 2 1/2 years. Removal of MCB was temporarily impaired by PCE addition, but after adaptation a MCB concentration decrease of up to 64% (55.3 micromol L(-1)) was observed. Oxygen availability in the rhizosphere was relatively low, leading to sub-optimal MCB elimination but providing also appropriate conditions for PCE dechlorination. PCE and metabolites concentration patterns indicated a very slow system adaptation. However, under steady state conditions complete removal of PCE inflow concentrations of 10-15 micromol L(-1) was achieved with negligible concentrations of chlorinated metabolites in the outflow. Recovery of total dechlorination metabolite loads corresponding to 100%, and ethene loads corresponding to 30% of the PCE inflow load provided evidence for complete reductive dechlorination, corroborated by the detection of Dehalococcoides sp" |
Keywords: | "Biodegradation, Environmental Chlorobenzenes/*metabolism Chloroflexi/genetics/isolation & purification Cluster Analysis Oxidation-Reduction Oxygen/analysis Rhizosphere Soil/analysis Tetrachloroethylene/*metabolism Time Factors Water/analysis Water Polluta;" |
Notes: | "MedlineBraeckevelt, M Seeger, E M Paschke, H Kuschk, P Kaestner, M eng Research Support, Non-U.S. Gov't 2011/10/07 Int J Phytoremediation. 2011 Nov-Dec; 13(10):998-1013. doi: 10.1080/15226514.2010.549860" |