Oil Spill Eliminate Agent Influence On Biodegradation Of PAHs In Seawater

With the development of economy, oil spill has been paid more attention,bioremediationhas become a low-carbon environment, simple and effective method of treatment of oil spill.However the PAHs of the oil spill has the characteristics of low solubility,not easy to beutilized and degradation product toxicity which brings great difficulties to the bioremediationof PAHs in the ocean.Dispersant and biodiesel is usually used in oil spill emergency treatment and subsequentbioremediation. The main component of dispersant is surfactant,which contributing to thecrude oil disperses into the water. The main component of biodiesel is lipids, which can helpto enhance the mobility of crud oil.However, dispersant and biodiesel exert influence onbiodegradation of PAHs coming from oil spill has not yet been system studied.In this paper, mainly studying the influence of biodiesel and dispersant onbiodegradation of PAHs in seawater throughing shaking flask experiment. The results are asfollows:（1）Compared with the experimental group of no adding dispersant. When the dispersant andcrude oil ratio is0.2, dispersing agent can improve the dispersion effect of PAHs in seawaterand can promote the growth of microorganisms, which improves the removal rate of PAHs,naphthalene, phenanthrene, anthracene, pyrene total removal rate increased by20.1%、22.3%、22.1%、28.3%.When the dispersant and crude oil ratio is0.6, the promoting effect ofPAHs biodegradation is most significant, compared with the experimental group of thedispersant and crude oil ratio is0.2, the removal rate of PAHs, naphthalene, phenanthrene,anthracene, pyrene total removal rate increased by1.2%、4.6%、5.4%、13.6%。.（2）Compared with the experimental group of no adding biodiesel.When the biodiesel andcrude oil ratio is0.4, adding biodiesel can improve the effect of PAHs dissolved in seawaterand can promote the growth of microorganisms, so as to improve the removal rate of PAHs,naphthalene, phenanthrene, anthracene, pyrene total removal rate increased by21.1%,7.5%,15.6%and17.3%.When the biodiesel and crude oil ratio is1,the promoting effect of PAHsbiodegradation is most significant,Compared with the experimental group of the biodiesel andcrude oil ratio is0.4,the removal rate of PAHs, naphthalene, phenanthrene, anthracene, pyrene total removal rate increased by2.8%、6.5%、4.0%、15.9%.（3）Under the optimal dosage of biodiesel and dispersant, the solubilzation of dispersant toPAHs is more significant. The second day, in the experimental group of the dispersant andcrude oil ratio is0.6, the concentration of naphthalene, phenanthrene，anthracene, pyrenerespectively are higher than3.7738mg/L,3.074mg/L,0.0708mg/L,7.7397mg/L.From the pointof total removal of four PAHs, biodiesel promoting effect on biodegradation of PAHs is moreobvious, naphthalene, phenanthrene, anthracene, pyrene, the total removal rate respectivelyabove11.5%,10.8%,15.6%,10.6%.（4）At the same dosage of dispersant or dosage of biodiesel,the biodegradation ofnaphthalene is best,followed by phenanthrene, anthracene, pyrene.