title: Development of an optimal medium for continuous ferrous iron oxidation by immobilized Acidothiobacillus ferrooxidans cells.
abstract: This study was aimed at developing an immobilized bioreactor system in which long-term continuous ferrous iron oxidation can be realized with no formation of jarosite, which causes clogging of support pores and reactor lines. For this purpose, a medium with no jarosite formation was developed first by selecting optimal nitrogen and phosphate sources and their concentrations. Then with the developed medium containing ammonium phosphate instead of ammonium sulfate and potassium phosphate, repeated batch and continuous operations of ferrous iron oxidation by Acidothiobacillus ferrooxidans cells immobilized in a depth filter were successfully performed for an extended period of time. For about 510 h of operation including 450 h of continuous operation at dilution rates of 0.1, 0.2, and 0.3 h(-)(1), no formation of jarosite and thus no clogging of the reactor system were observed. The maximum ferrous iron oxidation rate was as high as 2.6 g/(L.h) at a dilution rate of 0.3 h(-)(1).
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusung-dong, Yusung-gu, Taejon 305-701, Korea.
authors.forename: Tae Wan
authors.initials: TW
authors.lastname: Kim
authors.forename: Chang Joon
authors.initials: CJ
authors.lastname: Kim
authors.forename: Yong Keun
authors.initials: YK
authors.lastname: Chang
authors.forename: Hee Wook
authors.initials: HW
authors.lastname: Ryu
authors.forename: Kyung-Suk
authors.initials: KS
authors.lastname: Cho
mesh_terms: D000393:Air Pollutants / Q000378:metabolism; D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation / Q000379:methods; D018914:Cells, Immobilized / Q000378:metabolism*; D011232:Chemical Precipitation; D003470:Culture Media / Q000737:chemistry* / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism*; D005374:Filtration; D006862:Hydrogen Sulfide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction; D010710:Phosphates / Q000378:metabolism; D020560:Proteobacteria / Q000378:metabolism*; D012492:Salts / Q000378:metabolism
chemical_list: D000393:Air Pollutants; D003470:Culture Media; D005296:Ferrous Compounds; D010710:Phosphates; D012492:Salts; D009584:Nitrogen; D006862:Hydrogen Sulfide