title: Evaluation of solid polymeric organic materials for use in bioreactive sediment capping to stimulate the degradation of chlorinated aliphatic hydrocarbons.
abstract: In situ bioreactive capping is a promising technology for mitigation of surface water contamination by discharging polluted groundwater. Organohalide respiration (OHR) of chlorinated ethenes in bioreactive caps can be stimulated through incorporation of solid polymeric organic materials (SPOMs) that provide a sustainable electron source for organohalide respiring bacteria. In this study, wood chips, hay, straw, tree bark and shrimp waste, were assessed for their long term applicability as an electron donor for OHR of cis-dichloroethene (cDCE) and vinyl chloride (VC) in sediment microcosms. The initial release of fermentation products, such as acetate, propionate and butyrate led to the onset of extensive methane production especially in microcosms amended with shrimp waste, straw and hay, while no considerable stimulation of VC dechlorination was obtained in any of the SPOM amended microcosms. However, in the longer term, short chain fatty acids accumulation decreased as well as methanogenesis, whereas high dechlorination rates of VC and cDCE were established with concomitant increase of Dehalococcoides mccartyi and vcrA and bvcA gene numbers both in the sediment and on the SPOMs. A numeric simulation indicated that a capping layer of 40 cm with hay, straw, tree bark or shrimp waste is suffice to reduce the groundwater VC concentration below the threshold level of 5 μg/l before discharging into the Zenne River, Belgium. Of all SPOMs, the persistent colonization of tree bark by D. mccartyi combined with the lowest stimulation of methanogenesis singled out tree bark as a long-term electron donor for OHR of cDCE/VC in bioreactive caps.
authors: Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400, Mol, Belgium.
authors: Siavash
authors: S
authors: Atashgahi
authors: Farai
authors: F
authors: Maphosa
authors: Jo
authors: J
authors: De Vrieze
authors: Pieter Jan
authors: PJ
authors: Haest
authors: Nico
authors: N
authors: Boon
authors: Hauke
authors: H
authors: Smidt
authors: Dirk
authors: D
authors: Springael
authors: Winnie
authors: W
authors: Dejonghe
mesh_terms: D000085:Acetates / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001530:Belgium; D002087:Butyrates / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D005227:Fatty Acids / Q000378:metabolism; D005285:Fermentation; D019015:Geologic Sediments / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D011422:Propionates / Q000378:metabolism; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
chemical_list: D000085:Acetates; D002087:Butyrates; D003470:Culture Media; D005227:Fatty Acids; D006843:Hydrocarbons, Chlorinated; D011422:Propionates; D014874:Water Pollutants, Chemical; D008697:Methane