Continuous biological ferrous iron oxidation in a submerged membrane bioreactor.
Microbial oxidation of ferrous iron may be available alternative method of producing ferric iron, which is a reagent used for removal of H2S from biogas. In this study, a submerged membrane bioreactor (MBR) system was employed to oxidize ferrous iron to ferric iron. In the submerged MBR system, we could keep high concentration of iron-oxidizing bacteria and high oxidation rate of ferrous iron. There was membrane fouling caused by chemical precipitates such as K-jarosite and ferric phosphate. However, a strong acidity (pH 1.75) of solution and low ferrous iron concentration (below 3000 mg/I) significantly reduced the fouling of membrane module during the bioreactor operation. A fouled membrane module could be easily regenerated with a 1 M of sulfuric acid solution. In conclusion, the submerged MBR could be used for high-density culture of iron-oxidizing bacteria and for continuous ferrous iron oxidation. As far as our knowledge concerns, this is the first study on the application of a submerged MBR to high acidic conditions (below pH 2).
Park
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D
Department of Chemical Engineering, School of Environmental Science and Engineering, Advanced Environmental Biotechnology Research Center, POSTECH, San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk 790-784, Republic of Korea. rapper@postech.ac.kr
Lee
D S
DS
Park
J M
JM
D018441:Biofilms; D019149:Bioreactors; D011232:Chemical Precipitation; D004868:Equipment Failure; D005290:Ferric Compounds / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism*; D006862:Hydrogen Sulfide / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D008566:Membranes; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D013997:Time Factors
D005290:Ferric Compounds; D005296:Ferrous Compounds; C035885:ferric phosphate; D006862:Hydrogen Sulfide