title: Pilot test of biological removal of 1,4-dioxane from a chemical factory wastewater by gel carrier entrapping Afipia sp. strain D1.
abstract: A pilot-scale (120 L) bioreactor system using a gel carrier-entrapped pure bacterial strain, Afipia sp. strain D1, capable of degrading 1,4-dioxane as a sole carbon and energy source was constructed and applied to treat real industrial wastewater containing 1,4-dioxane from a chemical factory. Although the wastewater not only contained high concentrations of 1,4-dioxane but also considerable amounts of other organic compounds (73 mg-TOCL(-1) on average), the bioreactor could efficiently remove 1,4-dioxane without significant inhibitory effects. The reactor startup could be completed within approximately 1 month by increasing the 1,4-dioxane loading rate (0.09-0.47 kg-dioxanem(-3)d(-1)) in a stepwise manner. Effective 1,4-dioxane removal was stably maintained for 3 months with an influent 1,4-dioxane of 570-730 mg L(-1), giving an average effluent concentration and removal rate of 3.4 mg L(-1) and 0.46 kg-dioxanem(-3)d(-1), respectively. A 1,4-dioxane loading fluctuation between 0.14 and 0.72 kg-dioxanem(-3)d(-1) did not significantly affect its removal, and more than 99% removal efficiency was constantly maintained. The Monod model could well describe the relationship between the effluent 1,4-dioxane concentration and 1,4-dioxane removal rates of the bioreactors, showing that the half-saturation constant (Ks) was 28 mg L(-1).
authors.affiliation: Matsudo Research Center, Infrastructure System Company, Hitachi, Ltd., 537 Kami-hongo, Matsudo, Chiba 271-0064, Japan. Electronic address: kazuichi.isaka.mp@hitachi.com.
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Isaka
authors.affiliation: Matsudo Research Center, Infrastructure System Company, Hitachi, Ltd., 537 Kami-hongo, Matsudo, Chiba 271-0064, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Udagawa
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Osaka University, Yamadaoka, 2-1, Suita, Osaka 565-0871, Japan; Department of Health Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa 252-0373, Japan. Electronic address: ksei@kitasato-u.ac.jp.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Sei
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Osaka University, Yamadaoka, 2-1, Suita, Osaka 565-0871, Japan. Electronic address: ike@see.eng.osaka-u.ac.jp.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Ike
mesh_terms: D020622:Afipia / Q000378:metabolism*; D019149:Bioreactors; D002617:Chemical Industry; D004146:Dioxanes / Q000378:metabolism*; D005782:Gels; D007220:Industrial Waste; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004146:Dioxanes; D005782:Gels; D007220:Industrial Waste; D062065:Wastewater; D014874:Water Pollutants, Chemical; C025223:1,4-dioxane
keywords: 1,4-Dioxane; Afipia sp.; Biodegradation; Gel; Immobilization