Effect of Mining on Physicochemical Properties of Soil At Ifewara Gold Mining Site, Osun State, South-Western, Nigeria

S. A. Agbalajobi, and R. I. Obaro

Department of Mineral and Petroleum Resources Engineering Technology, Institute of Technology, Kwara State Polytechnic, Ilorin, Nigeria.

Keywords: Concentration, Heavy metal, Mining, Physicochemical, Properties, Soil.

Abstract

This study investigates the effects of mining on the soil quality of Ifewara gold mining site area, Osun State, through the determination of the physicochemical parameters and heavy metals composition of the soil within and outside the mine perimeter. Soil samples were collected and analyzed for the physicochemical parameters such as the soil pH, temperature, Total Dissolved solids using digital pH meter for the values. Soil electrical conductivity was determined using conductivity meter according to the method outlined. The sodium and potassium were determined using Atomic Absorption Spectrometry (AAS) after the samples were digested using aqua regia method, and other parameters determined by titration method (calcium, magnesium, sulphate and chloride etc). Also some heavy metal such as Fe, Co, Zn, Ni, Pb, Cr and Cd were analyzed using standard analytical method. The pH values ranged from 5.1 – 6.8, EC values ranged from 1129 – 1500 μS/cm, TDS values ranged from 179 – 298 ppm, Na2+ ranged from 13.24 – 41.21 + 2+ 2+ mg/kg, K range from 9.07 – 31.08 mg/kg, Mg ranged 10.43 – 22.28 mg/kg, Ca ranged from 18.12 – 49.28 mg/kg, SO 2- ranges from 13.80 – 55.3mg/kg, Cl- ranged from 5.22 – 8.30 mg/kg, TOC 4 range from 1.57 – 2.27%. Heavy metal analysis showed the concentration of Fe, Co, Zn, Ni, Pb, Cr, and Cd ranging from 3.1850 – 3.5725mg/kg, 2.033 – 3.166 mg/kg, 2.033 – 3.166 mg/kg, 0.462 – 0.672 mg/kg, 0.058 – 0.363 mg/kg, 0.0040 – 0.039 mg/kg respectively. The results show higher changes in soil physicochemical properties and high heavy metal concentration in the samples with the mine perimeter, which might have resulted from the mining activities and waste from the mine. The indices for analysisng the contamination level of the heavy metals generated on the samples cannot be ascertained due to the wet season.