Biosurfactant Collaborated Phenanthrene Degrading Bacteria Enhanced Elcctrokinetic Dislodged Phenanthrene From Sandy

Phenanthrene is a special PAHs with the structure of K zone and bend zone, it is quitestable in the environment and hard to removal by environmental microbial. The phenanthrenewas sensitive to people’s skin and carcinogenic effects in animals. While just rely on the roleof the electrokinetic remediation the PAHs contaminated soil is very difficult to achieve thedesired effect, for polycyclic aromatic hydrocarbons adsorbed on soil particles hardlydissolved in water. So the biosurfactant and degrading bacteria were added in the electricreactor in order to enhancing the efficiency of electrokinetic remediation.The paper mainly dissused the efficiency of removal phenanthrene in sandy byelectrokinetic, meanwhile the sandy pH and electrical conductivity influenced by electricalpower and phenanthrene degrading bacteria influenced by electric power was discussed. Thecontents of the research mainly included:(1) screening of biosurfactant producing and crudeoil degrading bacteria and optimizing the fermentation condition of aiming bacteria;(2)purification and identification of the fermentation produced by the aiming bacteria and studyits influence on phenanthrene degrading system;(3) applying the biosurfactant and microbialto the reactor to research the removing efficiency of phenanthrene, the characteristic varies ofsandy and the growing number varies of degrading bacteria. The main results have beenobtained in this paper as follows:Firstly, strain MZ01was enriched and screened from the oil contaminated soil of arefinery. It was identified as Pseudomonas aeruginosa by using16S rDNA sequencing. Thestrain was rod-shaped, with1200nm,300nm in length and width, the colonies was roundness,pale green and smooth margin in plate and it identified to be the gram negative bacteria. Alsoit could degrade crude oil by54.7%with9days. Fermentation condition optimized byorthogonal experiment, result shows yeast extract as nitrogen source, corn oil as carbonsource and the initial pH was7, the salinity as5%performed in25℃considered to be thebest condition. And by range analysis, the selection of influence fermentation order as follows:nitrogen source> initial pH> temperature> carbon source> salt content. What`s more theproduction yield of the biosurfactant was2.27g/L.Secondly, the fermentation produced by MZ01was purified and identified and it`s effect to phenanthrene degrading bacteria GY2B were discussed. Result shows that thebiosurfactants identified to be peptide, and the peptide can significantly promote the growthof GY2B. With the concentration of the biosurfactant was50mg/L, the growing of GY2Bincreased five times than that without biosurfactant systems in72h. At the same time, thebiosurfactant did not restrain GY2B degrading phenanthrene, instead with the increase ofbiosurfactant concentration, the phenanthrene degrading efficiency was increased in72h.Finally, this paper discussed the effect of electrokinetic remediation system. Study showsthat peptides biosurfactant, phenanthrene degrading bacteria and peptides with phenanthrenedegrading bacteria added to the electrokinentic remediation system individually, and all ofthem worked5days. In the electrokinetic remediation system with GY2B added, the removalefficiency of phenanthrene compared with cases without bacteria increased by more than5%;The electrokinetic remediation system with peptides added compared to electrical system, theremoval efficiency of phenanthrene increased10%. While both biosurfactant and strain GY2Badded to the electrokinetic remediation system, phenanthrene degradation efficiency was25%than only electrical system. And phenanthrene degradation efficiency was above75%closedto the cathod and aboout90%closed to the anode. Result shows that sphingosine GY2B andbiosurfactant produced by pseudomonas MZ01could efficiently enhance electric powerremoving phenanthrene in the sandy.