title: Synergistic effect using vermiculite as media with a bacterial biofilm of Arthrobacter sp. for biodegradation of di-(2-ethylhexyl) phthalate.
abstract: Vermiculite is one of matrix material used for constructed wetland (CW) for the treatment of municipal wastewater. Arthrobacter sp. strain C21 (CGMCC No. 7671), isolated from a constructed wetland receiving municipal wastewater, forms biofilm on the surface of vermiculite. Di-(2-ethylhexyl) phthalate (DEHP), a typical phthalate pollutant in environment, can be degraded by the biofilm of strain C21 formed on vermiculite. Results of laboratory studies indicated that DEHP was removed from aqueous phase via biodegradation, adsorption by vermiculite, and adsorption by biofilm biomass. Synergistic effect of these three reactions enhanced the overall DEHP removal efficiency. During a batch incubation test with vermiculite and the cell suspension, bacterial adhesion to the media surface occurred within 5h and the phthalate esters (PEs) removal was due to both biodegradation and vermiculite adsorption. As the biofilm developed on surface of vermiculite (5-36 h), biodegradation became the predominance for PEs removal. As mature biofilm was formed (36-54 h), the adsorption of PEs by biofilm biomass became a main driving force for the removal of PEs from aqueous phase. The content of extracellular polymers (EPS) of the biofilm and DEHP removal performance showed a significant positive correlation (rp>0.86).
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
authors.forename: Zhi-Dan
authors.initials: ZD
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Department of Civil and Environmental Engineering, William and Cloy Codiga Resource Recovery Research Center, Centre for Sustainable Development & Global Competitiveness, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Nan-Qi
authors.initials: NQ
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address: dawengao@gmail.com.
authors.forename: Da-Wen
authors.initials: DW
authors.lastname: Gao
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry; D001173:Arthrobacter / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D004051:Diethylhexyl Phthalate / Q000378:metabolism*
chemical_list: D000538:Aluminum Silicates; C003760:vermiculite; D004051:Diethylhexyl Phthalate
keywords: Biodegradation; Biofilm; Constructed wetland; Phthalate esters (PEs); Vermiculite