title: Enhancement of phase separation by the addition of de-emulsifiers to three-phase (diesel oil/biocatalyst/aqueous phase) emulsion in diesel biodesulfurization.
abstract: Ethanol, added as a de-emulsifier to separate oil and biocatalyst (or bacterial cells) from a three-phase (oil/biocatalyst/aqueous phase) emulsion, formed in diesel biodesulfurization employing Gordonia nitida, improved oil recovery by centrifugation from about 50% in its absence to almost 100% at 3% (v/v). The biocatalyst recovered with ethanol addition showed similar specific growth rates (0.03 h(-1)) and dibenzothiophene desulfurization rates (6-7.2 mol l(-1) h(-1)) to those (0.03 h(-1) and 7.1 mol l(-1), respectively) of the biocatalyst recovered with no ethanol addition. The desulfurization activity significantly increased as the number of the repeated recovery and reuse of the biocatalyst.
authors.affiliation: Department of Environmental Science and Engineering, Ewha Womans University, 11-1 Daehyon-dong, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: Ok Kyoung
authors.initials: OK
authors.lastname: Choi
authors.forename: Kyung Suk
authors.initials: KS
authors.lastname: Choi
authors.forename: Hee Wook
authors.initials: HW
authors.lastname: Ryu
authors.forename: Yong Keun
authors.initials: YK
authors.lastname: Chang
mesh_terms: D000192:Actinomycetales / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D000397:Air Pollution / Q000517:prevention & control; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002384:Catalysis; D018929:Cell Culture Techniques / Q000379:methods*; D002498:Centrifugation / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D004655:Emulsions; D000431:Ethanol / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D005742:Gasoline; D010578:Petroleum / Q000378:metabolism; D011786:Quality Control; D013455:Sulfur / Q000378:metabolism*; D013457:Sulfur Compounds / Q000378:metabolism; D013500:Surface Tension; D014783:Viscosity
chemical_list: D003470:Culture Media; D004655:Emulsions; D005079:Excipients; D005742:Gasoline; D010578:Petroleum; D013457:Sulfur Compounds; D000431:Ethanol; D013455:Sulfur