title: Removal of organic pollutants from oak leachate in pilot scale wetland systems: How efficient are aeration and vegetation treatments?
abstract: This study investigated the effects of aeration and/or vegetation in experimental constructed wetlands (CWs) as mesocosms on the removal of pollutants in oak wood leachate. Twelve outdoor wetland mesocosms, with randomized replicated treatment combinations of vegetation (Phragmites australis) and aeration was monitored during the second and third year after construction. The investigation included control tanks with no aeration and no vegetation. The parameters monitored were polyphenols (PPs), chemical oxygen demand (COD) and water colour. The reduction of COD after 28 days was approx. 50% and more than 50% of PPs, whereas only 40% of the water colour was removed. Aeration increased the effect of both COD and PP removal. The vegetation treatment had a small but significant effect on removal of COD. The vegetation + aeration treatment, as well as aeration alone, increased the removal efficiency of COD from 9.5 g m(-3) d(-1) in the control to 11 g m(-3) d(-1). The results suggest that CWs can be used to treat stormwater contaminated by oak wood leachate. Further, it is suggested that the main processes for removal of pollutants in the leachate occur in the open-water habitat and that the hydraulic retention time is more important for removal than aeration and vegetation related processes.
authors.affiliation: Department of Biology and Environmental Science, Linnaeus University, SE-392 31 Kalmar, Sweden. Electronic address: henric_sven@hotmail.com.
authors.forename: Henric
authors.initials: H
authors.lastname: Svensson
authors.affiliation: Department of Biology and Environmental Science, Linnaeus University, SE-392 31 Kalmar, Sweden. Electronic address: borje.ekstam@lnu.se.
authors.forename: Börje
authors.initials: B
authors.lastname: Ekstam
authors.affiliation: Department of Sanitary and Environmental Engineering, Rio de Janeiro State University UERJ, R. São Francisco Xavier, 524, CEP 20551-013 Rio de Janeiro, Brazil. Electronic address: marcia.marques@lnu.se.
authors.forename: Marcia
authors.initials: M
authors.lastname: Marques
authors.affiliation: Department of Biology and Environmental Science, Linnaeus University, SE-391 82 Kalmar, Sweden. Electronic address: william.hogland@lnu.se.
authors.forename: William
authors.initials: W
authors.lastname: Hogland
mesh_terms: D057919:Biological Oxygen Demand Analysis; D006109:Poaceae / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000378:metabolism; D018508:Water Purification / Q000379:methods; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical
keywords: Aeration; COD; Constructed wetland; Wood leachate