Variation of mechanical and hydraulic properties of oil-contaminated soil due to a surfactant-enhanced washing process

Soil contaminated with a high level of hydrocarbons was obtained from an area near an oil extraction facility located in the Tamiahua region, Veracruz,Mexico, and submitted to a surfactant enhanced washing (SEW) process to remove contaminants. The purpose of this article was to characterize the variations in the mechanical and hydraulic properties of the soil after the application of the SEWprocess, as these characteristics are important in soil mechanics and might affect the behavior of the material for construction purposes. During the experimental assessment, each test was conducted several times for three different soil conditions (contaminated, non-contaminated, and washed soil), applying the same specifications and features to each one to allow accurate comparison of data. Results show that the soil washing process produces a loss of fine particles that affect the mechanical and hydraulic behavior of the tested materials. Data also indicates that the presence of the contaminant modifies soil characteristics generating different soil properties under all the conditions studied.