title: Experimental investigation on feasible bioreactor using mechanism of hydrogen oxidation of natural soil for detritiation system.
abstract: A passive reactor for tritium oxidation at room temperature has been widely studied in nuclear engineering especially for a detritiation system (DS) of a tritium process facility taking possible extraordinary situation severely into consideration. We have focused on bacterial oxidation of tritium by hydrogen-oxidizing bacteria in natural soil to realize the passive oxidation reactor. The purpose of this study was to examine the feasibility of a bioreactor with hydrogen-oxidizing bacteria in soil from a point of view of engineering. The efficiency of the bioreactor was evaluated by kinetics. The bioreactor packed with natural soil shows a relative high conversion rate of tritium under the saturated moisture condition at room temperature, which is obviously superior to that of a Pt/Al2O3 catalyst generally used for tritium oxidation in the existing tritium handling facilities. The order of reaction for tritium oxidation with soil was the pseudo-first order as assessed with Michaelis-Menten kinetics model. Our engineering suggestion to increase the reaction rate is the intentional addition of hydrogen at a small concentration in the feed gas on condition that the oxidation of tritium with soil is expressed by the Michaelis-Menten kinetics model.
authors.affiliation: Japan Atomic Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan. Electronic address: edao.yuki@jaea.go.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Edao
authors.affiliation: Japan Atomic Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Iwai
authors.affiliation: Japan Atomic Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Japan Atomic Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D057005:Bioengineering; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D007700:Kinetics; D008954:Models, Biological; D009681:Nuclear Fusion; D009688:Nuclear Reactors; D010084:Oxidation-Reduction; D012988:Soil Microbiology; D013696:Temperature; D014316:Tritium / Q000302:isolation & purification* / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D014316:Tritium; C033961:tritium oxide; D006859:Hydrogen
keywords: Bacteria; Bioreactor; Detritiation; Hydrogen oxidation; Hydrogenoxidizing; Soil; Tritium