Impact assessment of effluent discharge on physico-chemical parameters and some heavy metal concentrations in surface water of River Challawa Kano, Nigeria

摘要

In order to understand bioavailability of heavy metals in water, surface water samples were collected from River Challawa, Nigeria, with the view of determining the effect of industrial effluents on the water quality of the river. The fractional concentration of heavy metals (Cd, Cr, Pb and Zn) in water were analysed using Atomic Absorption Spectrophotometer. The water samples were also analysed for physico-chemical parameters. The results show that all physico-chemical parameters determined: Total Solids, Total Dissolved Solids, Total Suspended Solids, pH, Temperature, Chloride, Sulphate, Phosphate with exception of Dissolved Oxygen, Biochemical Oxygen Demand, Chemical Oxygen Demand and Electrical Conductivity are within the recommended standard limits for these contents in drinking water. Also, results obtained from this study indicates the pollution tendencies of the surface waters of river Challawa, attributable to high levels of Pb, Cr and Cd recorded. Generally, elevated levels of Pb and Zn were recorded at control site, which indicates that other sources, than industrial effluents could be responsible. Also, the results showed that with continuous discharge of waste and waste water, pollution event especially with high Cd and Cr within the study area is likely to have severe but localized effects. It is therefore recommended that more strict methods of waste effluent management should be adopted to reduce further inputs into the area.