Sunday, May 3, 2009
2-22
Production of biodemulsifier by one strain of Dietzia sp. S-JS-1 in the use of waste frying oils
Jia Liu, Xiang-feng Huang, and Li-jun Lu. College of Environmental Science & Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Room 115#, Mingjing Building,Tongji University,Siping Road 1239#,Shanghai,China,200092, Shanghai, China
As a new demulsifier, bio-demulsifier is explored recently to break the oil-water emulsion. In this study, one demulsifiying strain isolated from oil contaminated soil was identified as Dietzia sp. by 16S rDNA. When it was cultured in MMSW substrate, adding mixed waste frying oil(MWFO) and soybean waste frying oil(SWFO) as the carbon source, it could produce crude bio-demulsifier biomass of 4g/L and 3.5g/L respectively. The bio-demulsifiers produced by S-JS-1 showed high surface activity to lower the surface tension of water from 72mN/m to 32mN/m. Compared with biodemulsifier produced by paraffine as the carbon source, both of them could achieve higher demulsification ratio in breaking W/O and O/W model emulsion. From the dynamic change of kerosene breaking ratio, emulsion breaking ratio and water breaking ratio during demulsification process , it was found that this bio-demulsifier reacted with the continuous phase of the emulsion prior to its reaction with the dispersed phase. Additionally, bio-demulsifer produced by SWFO as the carbon source had the ability to demulsify two model emulsion effectively. By analyzing the carbon utilization, it could be concluded C16 and C18 fatty acid of the two waste frying oils were preferable for Dietzia sp.to use. The three bio-demulsifers cultured on three carbon sources were identified as lipopeptide by TLC and FTIR.