The environmentally friendly anionic surfactant fatty acid methyl ester sulfonate (MES) was prepared by esterification of waste cooking oil (WCO), a low-cost raw material, followed by sulfonation with chlorosulfonic acid. MES production from WCO (W-MES) gave yields up to 78 %. Such a value is only slightly lower than the one obtained from soybean oil (S-MES), 82 %, and almost the same as that from reused cooking oil (R-MES), 76 %. According to the two-phase titration results, the content of the active component, a-MES, in S-MES, R-MES and W-MES was equal to 76.82, 69.19 and 66.60 %, respectively. The disalt, RCH(CO 2 Na)SO 3 Na, contents were instead 3.2, 3.8 and 4.7 %, respectively. As proved by the results of the FTIR and NMR characterizations, the chemical structure of W-MES is almost the same as that of S-MES and R-MES. The critical micelle concentration of W-MES is 5.38 mmol/L and the corresponding surface tension is 32.3 mN/m. The hydrophile-lipophile balance value of W-MES is 12.33, which indicates that it can form oil/water emulsions. The three MES demonstrated the same adsorption efficiency, yielding a pC20 value of 3.22, and similar foam stability. Their detergency can be up to 75 % at a concentration of 400 mg/kg and the tolerance to Ca 2? is higher than the one exhibited by linear alkylbenzene sulphonic acid and alpha olefin sulfonate. Additionally, W-MES shows a considerable solubilization capacity towards polycyclic aromatic hydrocarbon as the molar solubilization ratios to pyrene, phenanthrene and acenaphthene in a 30 mmol/L solution are 1.22 9 10 -3 , 2.67 9 10 -3 and 3.81 9 10 -3 , respectively.

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Reduplicate utilization of surfactants is a key factor for Surfactant-Enhanced Remediation (SER) technology to reduce its high operation costs. In order to achieve the reuse of surfactants, this study attempted to construct a novel reversible solubilization system for SER. Three typical polycyclic aromatic hydrocarbons (PAHs) pyrene, phenanthrene, and acenaphthene were controllably solubilized and released by the mixed micelles composed of redox-active cationic surfactant (11-Ferrocenylundecyl) trimethylammoniunm bromide (FTMA) and conventional nonionic surfactant Tween80. Solubilization of PAHs is assumed to be controlled by changing the redox states of FTMA. Cyclic voltammograms tests of FTMA showed the oxidation and reduction potential were 0.4570 and 0.4068 V, respectively, and the peak currents ratio of FTMA and FTMA + was 1.26, verified that FTMA possesses electrochemically reversible property. In FTMA-Tween80 mixed solutions, CMC values demonstrated the nonideal interaction between the two surfactants and the interaction parameters (β) was -5.5296 when the mass ratio was FTMA:Tween80 = 2:8. Due to the synergistic solubilization effect, the apparent water solubilities of PAHs were significantly enhanced by the mixed surfactant, and they were much higher than those in single surfactant. After oxidation, more than 50% of the PAHs in mixed micelles could be released, the cumulative release efficiency of selected PAHs followed the order of pyrene > pherantherene > acenaphthene. Briefly, such results in this article provide a facile method to meliorate the SER technology.