Abstract:
Petroleum hydrocarbons, as a priority control pollutant, have attracted widespread global attention to the residual of petroleum-based pollutants in underground aquifers. In this study, highly efficient and environmentally friendly single surfactants were selected using static and dynamic experiments, and the optimal surfactant compounding system was also determined, and indoor simulation tests and performance evaluation were conducted to verify their remediation effects. The solubilization ability of eight surfactants on gasoline was shown as rhamnolipid > TritonX-100 > AEO-9 > APG > AES > Brij 30 > Tween 80 > SDS; the adsorption ability of gasoline in medium sand media was shown as Brij 30 > Tween 80 > APG > TritonX-100 > AEO-9 > rhamnolipid > AES > TritonX-100 was determined to be the most effective single surfactant by combining the results of the selection experiments. By mixing TritonX-100 with Tween 80, the gasoline removal rate of 99.28% was achieved. According to the results of dynamic elution experiments, the highest gasoline removal rate was found to be 64.55% in this mixture, which was 22.26% higher than that of the single surfactant TritonX-100. The indoor simulation tests verified that TritonX-100 and Tween 80 combination system can effectively improve the solubility of gasoline pollutants in aquifers and enhance the remediation effect of petroleum hydrocarbon pollutants in subsurface aquifers. Meanwhile, the results of infrared spectroscopy test showed that Tween 80 has strong elution effect on long-chain and branched hydrocarbons, while TritonX-100 contains benzene ring, which increases the solubility of aromatic hydrocarbons in gasoline in TritonX-100. The above results can provide a theoretical reference as well as technical support for the application of surfactant enhanced aquifer remediation technology (SEAR) in practical sites.