title: Biological wastewater treatment of 1,4-dioxane using polyethylene glycol gel carriers entrapping Afipia sp. D1.
abstract: A biological treatment system for 1,4-dioxane-containing wastewater was developed using the bacterium Afipia sp. D1, which can utilize 1,4-dioxane as the sole carbon source. Strain D1 was entrapped in a polyethylene glycol gel carrier to stably maintain it in a bioreactor, and continuous feeding tests were performed to treat model industrial wastewater containing 1,4-dioxane. 1,4-Dioxane removal activity rapidly increased soon after the start of feeding of influent with 400 mg/L 1,4-dioxane, and the volumetric removal rate reached 0.67 kg dioxane/m(3)/d on day 36 by a stepwise increase in loading. The start-up period of the 1,4-dioxane treatment reactor was approximately 1 month, and stable removal performance was subsequently achieved for more than 1 month. The average 1,4-dioxane effluent concentration and 1,4-dioxane removal efficiency were 3.6 mg/L and 99%, respectively, during stable operation. Further 1,4-dioxane degradation activity of the of the gel carrier was characterized in batch experiments with respect to temperature. The optimum temperature for 1,4-dioxane treatment was 31.7°C, and significant removal was observed at a temperature as low as 6.9°C. The apparent activation energy for 1,4-dioxane degradation was estimated to be 47.3 kJ/mol. This is the first report of the development of a 1,4-dioxane biological treatment system using gel entrapment technology.
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: Matsudo Research Center, Infrastructure System Company, Hitachi, Ltd., 537 Kami-hongo, Matsudo, Chiba 271-0064, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-1 Yamadaoka, 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, 2-1 Yamadaoka, 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 / Q000737:chemistry* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000378:metabolism; D018914:Cells, Immobilized / Q000737:chemistry / Q000378:metabolism; D004146:Dioxanes / Q000302:isolation & purification* / Q000378:metabolism*; D005782:Gels; D011092:Polyethylene Glycols / Q000737:chemistry*; D013696:Temperature; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D002244:Carbon; D004146:Dioxanes; D005782:Gels; D011092:Polyethylene Glycols; D062065:Wastewater; C025223:1,4-dioxane
keywords: 1,4-Dioxane; Afipia sp.; Biodegradation; Bioreactor; Enzyme activity; Gel; Immobilization; Immobilized cells; Moving bed bioreactors; Wastewater treatment