Stabilization and Solidification of Oil-Contaminated Sandy Soil Using Portland Cement and Supplementary Cementitious Materials

Abstract

In this research, an attempt was made to explore the possibility of using a stabilization and solidification (S/S) technique for the treatment of sandy soil contaminated with diesel and crude oil using different stabilizers. For this purpose, soil samples were collected and contaminated by diesel and crude oil at three different percentages (2.5%, 5%, and 10% by weight of dry soil). Effects of oil contamination of soil were evaluated, and then S/S treatment was carried out using ordinary portland cement (OPC), cement kiln dust (CKD), and limestone powder (LSP). The performance of S/S-treated soils was evaluated by measuring the changes in compaction characteristics, unconfined compressive strength (UCS), permeability, and heavy metal and hydrocarbon contents. Toxicity characteristic leaching procedure (TCLP) and total petroleum hydrocarbons (TPH) tests on S/S-treated soil were conducted to observe the effect of the S/S treatment on the reduction of the soil pollution potential. Scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analyses were carried out to examine the changes in the microstructure and mineralogy of the soil after its S/S treatment. Results of this investigation indicate that the S/S treatment of the oil-contaminated soil improved the compaction characteristics, UCS, and resistance against permeability and leachability.