Enhancing Attenuation of Petroleum Pollutants by Modifying Natural Soil with Surfactants

Abstract

Large oil fields are distributed within the loess plateau of northwest China, where severe soil contamination by petroleum hydrocarbons has been found in several locations. A prevention measure is to modify the topsoils with surfactants to enhance the attenuation capacity in the vadose zone. In this paper, both cationic surfactant hexadecyltrim–ethylammonium bromide (HDTMA-Br) and anionic surfactant—sodium dodethylbenzene sulfonate were used to modify the natural loess soils. The sorption of organic contaminants in the modified soils can be characterized by linear isotherms. By using toluene as an indicator of petroleum hydrocarbons, partition and adsorption contributions to the sorption amount were determined quantitatively. The approach displayed enhanced soil sorption capabilities by 2–10 times. Column tests showed that the retardation capacity of the HDTMA-modified soil for