Engineering properties of the crude oil–contaminated soils of Niger Delta southern Nigeria
The study investigated engineering properties of crude oil contaminated soils from the Niger Delta of Nigeria in 2008. The percentages of clay, silt and sand of various soil samples and amounts of total hydrocarbon (THC) of the crude oil samples applied were the determinant factors. The comparison between the uncontaminated and the crude oil contaminated soils showed wide variations in their engineering properties. There were pronounced increases in Aterberg limits, plasticity limits, maximum dry density (MDD) with low optimum moisture content (OMC), organic matter and the compressibility of the soil samples, when crude oil of high hydrocarbon content was applied on the soil samples of appreciable clay content. Also observed was a decrease in the permeability of various contaminated soil samples. There was a reverse trend when soil samples with appreciable percentages of sand and crude oil of low THC were used. The knowledge of these will aid geotechnical engineers on their designs and remediation techniques.
Keywords: Engineering properties, soils, crude oil, hydrocarbon, Niger Delta, Nigeria