| In recent years, soil contamination with polycyclic aromatic hydrocarbons (PAHs) becomes more and more serious global wide. For it was difficult to repair, many studies about that was paided more attention. There are a lot of means about eluting soil which was contaminated with PAHs, but there have been too many shortcomings for that. So, taking advantage of the Fatty Acid Methyl Ester(FAME):low-carbon, mobility, solubility of insoluble organic pollutants, the synthesis of fatty acid methyl esters was optimized and the ability of dissolving PAHs by FAME was studied; the effect of eluting contaminated soil by Cyclodextrin and Surfactant was compared; the results above provide a new alternative method for PAH contaminated soil remediation. The results of the experiments as follows:1. Results show that the best conditions for FAME synthesis were:20% of immobilized enzyme, mol ratio of methanol to oil was 3:1, added for three times, shaking speed was 160 rmin-1, system reaction temperature was 38℃, and reaction time was 48 h. Under above conditions, transform rate was higher than 93% for methyl ester. There are high purities for the synthesized FAME, it can be competent to the study of dissolving PAHs.2. An analytical method for determination of polycyclic aromatic hydrocarbons (PAHs) in FAMEs was established. Use of the selectivity of dimethyl sulfoxide-cyclohexane to the polycyclic aromatic hydrocarbons, by "liquid-liquid extraction" method of fatty acid methyl esters extracted from polycyclic aromatic hydrocarbons, it can achieved the separation of fatty acid methyl ester; by the anti-sodium sulfate solution and cyclohexane extraction of polycyclic aromatic hydrocarbons and other impurities can be achieved separation of purification; this method allows the recovery of polycyclic aromatic hydrocarbons 96.3～101.1% accuracy.3.The synthesized FAMEs can dissolve>250 mg.L-1 representative PAHs, and can solubilize soil PAHs directly. Fatty acid methyl esters have a high solubility of polycyclic aromatic hydrocarbons. Including phenanthrene, pyrene and benzo (a) pyrene in fatty acid methyl esters in the solubility were 420.6mg.L-1,541mg.L-1 and 436.3mg.L-1. They are the hydroxypropyl-β-cyclodextrin in 5.27,73.40, and 94.64 times that ofβ-cyclodextrin in 66.77,2576.19 and 3356.41 times the Tween 20 in 5.66,10.56 and 11.66 times the Tween 80 in 4.90,3.78 and 9.54 times the Triton 100 in 3.67,4.15 and 12.05 times.4.Most of PAHs reached the equilibrium of eluting between FAME/soil rate 1:1 and 2:1.Taking into account of the economic aspect and the environmental protection, the 1:1 FAME/soil rate was chose for eluting contaminated soil. When the FAME/soil rate was greater than 2:1, the equilibrium line was to go down.5.After quick extraction there will be a satisfied eluting result. After the fourth stage, there was a eluting rate above 95%.It was not adopted because of the complex process. The spiked soil reached the equilibrium in 0.5～1 hours later, and the MGP soil reached the equilibrium in 1～1.5 hours later. 6.FAME was provided with high solution for PAH. The result of extracting the PAHs by FAME was better than other elutes, the FAME was the best elute. According to the result of the PAH contaminated MGP soil remediation experiment, the advantages of FAME washing for the remediation of soil contaminated with high concentrations of PAHs were introduced.7.The soil water had a bad liquidity in MGP soil, it was the root cause of eluting badly. Moisturizing the soil can be blocked the remediation of soil contaminated with high concentrations of PAHs by FAME.8.FAME was provided with higher solution for PAH and more powerful remediation of soil contaminated with high concentrations of PAHs than Methyl oleate. The principal methyl ester which playing a key role were the Linoleic acid methyl ester and the Methyl linen.
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