Effect of spent engine oil contamination on the soil properties in selected automobile mechanic villages in Enugu, Enugu State, Nigeria

Abstract

AbstractThis study was carried out to determine the effect of spent engine oil on the soil properties in selected automobile mechanic villages in Enugu, Enugu State, Nigeria. Spent engine oil (SEO) was collected and characterized according to ASTM test methods. Soil samples were collected at 0–30 and 30–60 cm depths from the mechanic villages and uncontaminated agricultural farmlands 500 m away as control and properties analyzed. The extent of contamination of heavy metals in soils was assessed. The results of the SEO characterization showed the values of 2.87 wt%, 218°C, 13.18 mg/kg, 0.75 mg/kg, 4.06 mg/kg, and 0.94 mg/kg for toluene insoluble, flash point, Pb, As, Cr and Cd. The soil bulk density, pH, TOC, TOM, N, P, Cu, Cd, Pb, and Fe decreased with increasing depth while particle density, TSP, S, Cr, and As increased with increasing depth. The ANOVA results showed that a statistically significant difference existed between values of soil parameters (p < 0.05), indicating that SEO has a significant effect on soil properties (α = 0.05). The study will provide useful insights for developing a precautionary strategy and inform environmental policy implementation for an effective risk management approach in the study area.