The Application of Surfactants on Treatment of Petroleum-contaminated in Unsaturated Zone
Zhu Mei and Xu Jialin(Institute of Environ.Set.,Beijing Normal University,Beijing 100875),Tian Honghai(Center of Environ.Set.,Peking University,Beijing 100871)
The paper focused on the application of aqueous surfactant washing for cleaning up petroleum contamination in unsaturated zone.Regional geographical features and contamination characteristics have been investigated. Nine commercial nonionic surfactants were analyzed and tested.Their critical micelle concentrations were measured and their effects on emulsification and solubilization of oil and benzene as well as on soil dispersion were compared.The results showed that the best surfactants are AEO-9 and SA-20,i.e.,alcohol polyethoxylated ethers.Their optimum concentrations were also determimed.In batch-washing tests the highest removal efficiency can be as high as 94%. Results of leaching tests for soil columns and lime stone columns were satisfactory as well.From this study,it is clear that the application of surfactants can be included in field experimental research for the treatment of contaminated unsaturated zone of groundwater.