Stabilization of oil-contaminated soils using cement and cement by-pass dust

Purpose - To investigate the effect of cement and cement by-pass dust (CBPD) as a stabilizer on the geotechnical properties of oil-contaminated soils resulting from leaking underground storage tanks, or soils surrounding petroleum refineries and crude oil wells. Design/methodology/approach - Oil-contaminated soil (untreated soil) and a soil treated by bio-remediation (treated soil) as well as a natural soil were obtained from Northern Oman. These soils were stabilized with cement and cement by-pass dust at 0, 5, 10, 15 and 20 percent, by dry weight of the soil, and cured for seven, 14 and 28 days. Compaction, compressive strength, direct shear, permeability and leaching tests were carried out on the stabilized soils. Findings - The results indicate that cement and cement by-pass dust improve the properties of oil-contaminated soils. Traces of arsenic, barium, cadmium, chromium and lead were found in the oil soils, but none of them exceeded the EPA limits. Practical implications - Reuse in construction applications provides a safe and useful solution for the problem of the disposal of oil-contaminated soils. Originality/value - The paper addresses an environmental problem facing many oil companies in disposing of or treating contaminated soil. The approach presented in the paper offers a beneficial, safe and economical solution to this problem.