Impact of the disused Kilembe mine pyrites on the domestic water quality of Kasese town, western Uganda

Abstract

This study investigates the impact of the disused Kilembe mine pyrites on the domestic water quality of Kasese town in western Uganda. Surface water samples were collected from 8 sampling stations around Kasese town and were analysed using an atomic absorption spectrophotometer for 6 heavy metals: cadmium, nickel, copper, cobalt, lead and zinc. The results showed that the mean concentrations of the measured heavy metals did not conform to the maximum permissible limits of the WHO standards for drinking water quality. Lead, nickel and cadmium had mean concentrations well above the maximum permissible limits : 0.016 µg mL-1 for lead, 0.024 µg mL-1 for nickel and 0.61 µg mL-1 for cadmium. In general, the total mean concentration, in μg mL−1 , of the metals in all the samples decreased in the order: Co > Cu > Zn > Ni > Pb >> Cd. The results indicated that the total heavy metal content in the water was greater in the Kilembe mine valley followed by the area before the mine (near river sources) and east in the water after the Kilembe mine valley. Nevertheless, the heavy metal concentration in the domestic water remained high for human domestic usage at a number of the sampling stations. It is therefore recommended that working bioremediation projects need to be put in place to resolve the problems of heavy metal contamination and other potential pollutants in the environment in the area.