Soil analysis of a mined-out area at Afiesa, Ghana

Abstract

This study investigated some physical and chemical properties of composite soil samples obtained from a mined-out area at Afiesa near, Kyebi-Apapam in the Eastern region of Ghana. Soil samples were collected and analysed for total Arsenic (As), Copper (Cu) and Lead (Pb) concentrations using an Agilent 4210 MP AE Spectrophotometer. Physical and chemical properties including porosity, pH, soil organic matter (SOM), total nitrogen, texture and particle size of soil samples were measured. Contamination factor (CF) and degree of contamination (C_degree) were also determined. The mined-out soil sample had a loamy silt texture, was acidic (pH 6.00), with a relatively high porosity (40.50% ± 0.10) and particle size (2.00 mm) compared to the reference soil which had a loamy texture, (pH 6.53), with porosity of (35.3% ±0.10) and smaller particle size (0.42 mm). The SOM and total nitrogen of the mined-out soil were found to be quite low (4.71±0.11g/kg, 0.24±0.20g/kg) compared to the reference soil. The degree of contamination of the mined-out soil was found to be 5.839 showing that the mined-out soil was moderately contaminated. Levels of both As and Cu in the mined soil were below the WHO (2001) recommended values (20 ppm and 100 ppm respectively). However, the level of Pb in the mined-out soil was above the background value (11.33 ppm) but below the WHO (2001) recommended standard (50 ppm) making the mined-out soil less hazardous.