DETERMINATIONS OF HEAVY METALS IN DUMPSITE SOIL SAMPLE: A CASE STUDY OF UNIVERSITY OF BENIN AND EKOSODIN COMMUNITIES

ABSTRACT

Heavy metal contamination in the soil is a major concern because of their toxicity and threat to human life and the environment. The heavy metals content of soil samples from Ekosodin Community and University of Benin dumpsites were determined. The heavy metals analyzed in this study are Fe, Zn, Pb, and Cu. Soil samples were collected at a depth of 15cm ( top soil ) and 30cm ( subsoil ) and mixed to obtain a composite sample. The soils from the respective sampling points were characterized in terms of Physico-chemical properties, Sequential extraction was also carried out to determine the bioavailability of the respective heavy metals. The heavy metals concentrations were determined using atomic absorption spectrophotometer. The pH from site A to D in Ekosodin Community ranged from 5.20 - 6.50 indicating the acidity of the soil. Also, the pH from sample site A to D in University of Benin ranged from 7.10 - 7.55 indicating that the soil is alkaline. Among the sequential extraction, the metals are mostly associated with Fe - Mn oxides fraction. The low concentration of heavy metals in the exchangeable fraction indicated low bioavailability. A general overview of the study shows that Fe had the highest concentration of all the heavy metals and Pb had the least concentration. The mean concentration of metals and total concentration of metals in the different dumpsites study follows the order; Fe > Zn > Cu > Pb. The results of heavy metals analysis shows that the concentration of heavy metals in the various soil samples were below the WHO permissible limits and thus are of no environmental and health consequence.