Shandong Provincial Key Laboratory of Oilfield Produced Water Treatment and Environmental Pollution Control, SINOPEC Petroleum Engineering Corporation, Dongying 257026, China.
State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Sci Total Environ. 2021 Feb 20;756:144142. doi: 10.1016/j.scitotenv.2020.144142. Epub 2020 Nov 27.
Oil leakage, which is inevitable in the process of extraction, processing, transportation and storage, seriously undermines the soil and groundwater environment. Surfactants can facilitate the migration and solution of oil contaminants from nonaqueous phase liquid (NAPL) or solid phase to water by reducing the (air/water) surface tension, (oil/water) interfacial tension and micellar solubilization. They can effectively enhance the hydrodynamic driven remediation technologies by improving the contact efficiency of contaminants and liquid remediation agents or microorganism, and have been widely used to enhance the remediation of oil-contaminated sites. This paper summarizes the characteristics of different types of surfactants such as nonionic, anionic, biological and mixed surfactants, their enhancements to the remediation of oil-contaminated soil and groundwater, and examines the factors influencing surfactant performance. The causes of tailing and rebound effects and the role of surfactants in suppressing them are also discussed. Laboratory researches and actual site remediation practices have shown that various types of surfactants offer diverse options. Biosurfactants and mixed surfactants are superior and worth attention among the surfactants. Using surfactant foams, adding shear-thinning polymers, and combining surfactants with in-situ chemical oxidation are effective ways to resolve tailing and rebound effects. The adsorption of surfactants on soils and aquifer sediments decreases remediation efficiency and may cause secondary pollution, Therefore the adsorption loss should be noticed and minimized.
石油泄漏在开采、加工、运输和储存过程中不可避免，严重破坏了土壤和地下水环境。表面活性剂可以通过降低（空气/水）表面张力、（油/水）界面张力和胶束增溶作用，促进油污染物从非水相液体（NAPL）或固相迁移和解吸到水中。它们可以通过提高污染物和液体修复剂或微生物的接触效率，有效地增强水动力驱动修复技术，并已广泛用于增强受污染场地的修复。本文总结了不同类型的表面活性剂（如非离子型、阴离子型、生物型和混合表面活性剂）的特性，它们对污染土壤和地下水的修复增强作用，并考察了影响表面活性剂性能的因素。还讨论了拖尾和回弹效应的原因以及表面活性剂在抑制这些效应中的作用。实验室研究和实际现场修复实践表明，各种类型的表面活性剂提供了不同的选择。生物表面活性剂和混合表面活性剂是表面活性剂中优越且值得关注的。使用表面活性剂泡沫、添加剪切稀化聚合物以及将表面活性剂与原位化学氧化相结合，是解决拖尾和回弹效应的有效方法。表面活性剂在土壤和含水层沉积物上的吸附降低了修复效率，并可能导致二次污染，因此应注意并尽量减少吸附损失。
