title: [Performance of demulsification by Rhodococcus sp. PR-1].
abstract: Rhodococcus sp. PR-1 with high capability of demulsification on a surfactant-stabilized kerosene-water model emulsion was isolated from sewage of Dagang oil field. It could demulsify the model emulsion completely in 8 hours at 55 degrees C and had better demulsifying capability than chemical demulsifier DGF-01. The freezing-thawing and autoclaving had no effect on the process of demulsification, yet ultrasonic disposal and deal with organic solvent could inhibit its activity. A linear relationship, not the first order reaction that was used in some references, was observed between the percentage of demulsification and reaction time. The demulsifying capability of PR-1 was mainly resulted from the hydrophobic surfaces of microbial cells, which were characterized by the mycolic acids with the carbon-chain-length from 27 to 54. These results provide foundation for biological application on demulsifying crude oil emulsions in produced water of oil field.
authors.affiliation: College of Environment Sciences and Engineering, Nankai University, Tianjin, China. tingma@nankai.edu.cn
authors.forename: Ting
authors.initials: T
authors.lastname: Ma
authors.forename: Feng-lai
authors.initials: FL
authors.lastname: Liang
authors.forename: Yan-wei
authors.initials: YW
authors.lastname: Xi
authors.forename: Ru-lin
authors.initials: RL
authors.lastname: Liu
mesh_terms: D001673:Biodegradation, Environmental; D045703:Emulsifying Agents / Q000378:metabolism*; D004655:Emulsions; D010578:Petroleum / Q000378:metabolism* / Q000382:microbiology; D012240:Rhodococcus / Q000302:isolation & purification* / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology
chemical_list: D045703:Emulsifying Agents; D004655:Emulsions; D010578:Petroleum; D012722:Sewage