Physico-Chemical Properties of Soil Sourced from Automobile Mechanic Workshop in Ikoku Mechanic Village, Mile 3 Diobu, Port Harcourt, Rivers State, Nigeria

Abstract

This study investigated the impacts of automobile mechanic workshops on the concentrations of PAHs, T.H.C, T.O.C, pH, EC, Cations, heavy metal and particle size distribution in urban soil sourced from automobile workshops in Ikoku mechanic village, Mile 3 Diobu, Port Harcourt, Rivers state. Six samples were collected at sites of close proximity to the selected automobile workshops (Experimental sites) and sites that are far away from the workshop without the influence of automobile mechanic activities (control sites). The levels of Zinc (Zn), lead (Pb), Chromium (Cr) and cadmium (Cd) were determined using atomic absorption spectrophotometer (AAS), the PAHs were determined using GC-FID and GC-MS. The levels of T.O.C and T.H.C were determined using Titration method and Genesis 10 UV spectrometer, the pH and EC were determined using Pre-calibrated pH and EC meters, the Particle Size Distribution was determined by Sieve analysis method. Data interpretation involved the use of descriptive statistics for test of significant variation in the levels of heavy metals, Physico-chemicals and PAHs between the experimental sites and control site. Findings revealed that concentrations of Heavy metals, PAHs, T.H.C, T.O.C, EC and Cations were generally higher in soils under the influence of automobile mechanic workshop activities than sites with no such influence. The mean values of Pb, Zn, Cr and Cd were 32.94, 74.17, 5.35 and 2.86mg/kg respectively in soils under the influence of automobile mechanic activities and 32.52, 100.69, 10.09 and 3.68mg/kg respectively in soils with no such influence. The mean concentrations of PAHs, T.H.C, T.O.C, EC, pH and Cations as compared to those of the Control sites are 332.35 to 65.28, 2.47 to 1.94, 36.20 to 22.35, 273.2 to 119.7, 7.145 to 7.245 and 30.52 to 42.99 respectively. There were significant variations in the levels of PAHs, Heavy metals and the Physico- chemical parameters between the experimental sites and the control sites. The Particle Size Distribution revealed that the soil is of low permeability thus limiting the degree of seepage and supporting more accumulation of the contaminants at the top soil. It is recommended that mechanic villages should be sited far from residential areas, Quick remediation of polluted soil using various remediation methods should be encouraged and continuous education and training should be provided for the automobile workers, emphasizing on the environmental implications of their poor occupational waste management.