Physicochemical and heavy metal analysis of well water obtained from selected settlements around Dangote cement factory in Gboko, Nigeria

Abstract

Drinking water in developing countries especially Nigeria is susceptible to toxins as a result of effluents and pollutants. This study investigated the physicochemical characteristics and heavy metal contents of water samples collected from six different hand-dug wells from some settlements around Dangote Cement Plant Gboko. The concentration of all the physicochemical parameter studied were generally below maximum limits prescribed by WHO except for turbidity which was found in two of the samples opposite the factory (OF) and Tarhembe (T) to be 51.8 NTU and 17.5 NTU respectively which were higher than the maximum limit of (5.0 NTU) set by WHO. Total metal digestion of water samples was carried out using concentrated nitric acid (HNO₃). The digests were analyzed for heavy metals (Cd, Cr, Cu, Fe, Mn, Pb, and Zn.) using AAS. Results showed that Cd, Cr and Pb in all the water samples were not detected, the concentrations of Cu and Zn ranged from 0.01-0.05 mgL^-1 and 0.08-0.13 mgL^-1 respectively and were below the permissible limit set by WHO. The concentration of Fe and Mn ranged from 0.25-1.16 mgL^-1 and 0.33-0.92 mgL^-1 respectively and were found to be above the permissible limits recommended by WHO for drinking water. In this study, contaminants level were generally below the WHO maximum recommended limits except Fe and Mn contents which showed elevated values above the recommended levels, hence the need to put mechanisms in place to control the levels of these heavy metals in the well water sources around the area under study.

Keywords: Atomic Absorption Spectrophotometer, Heavy metals, Ground water, WHO