Remediation of Used Motor Engine Oil Contaminated Soil: A Soil Washing Treatment Approach

Abstract

The increasing contamination of soil by used motor oil is very common and of great concern to our society because of the possible harm that it can cause the environment. Remediation of contaminated soil is the application of suitable techniques in the removal of contaminants present in soil. Contaminants like heavy metals and aromatic hydrocarbons are found in used motor oil as a result of reactions in motor engines occurring during use of motor oil. The study determined the effect of soil washing using detergent as a remediation technique for soils contaminated with used motor oil. Detergent solution was added to soil contaminated by used motor oil. After twenty four (24) hours, the concentration of heavy metals (Cr, Zn, Cd, Pb, Ar, and Cu) and Polyaromatic Hydrocarbons (PAHs) in the soil residue were determined. A control experiment was carried out for a soil sample with no used motor oil added to it. The control experiment indicated that PAHs were not present in the soil before introduction of used motor oil. The removal rate of contaminants for this technique was 63.8% for Zn, 100% for Ar, 52.9% for Cd, 67.3% for Cr, 89.2% for Pb, 43.4% for Cu and 95.6% for PAHs. Soil washing was found to be effective in remediation of soils contaminated by low concentrations of used motor oil.