An application of the mass balance technique to study the impacts of the mining operations on the hydrogeochemistry of the Kafue River as it crosses the Copperbelt of Zambia
MetadataShow full item record
A mass balance technique was used to investigate the hydrogeochemistry of the Kafixe river as it crosses the Copperbelt mining area between Raglans farm and Machiya feiTy. Tlie study is done by examining the mass flow-rates often chemical parameters, namely: total dissolved solids, total suspended soUds, elemental cadmium, cobalt, copper, hon, manganese, lead, barium and sulphur. In this study, the aqueous concentrations in the rivers where obtained from samples collected at four sampling stations along the Kafiie river and one station on the Mwambashi river. The volume discharge rates were obtained from the Department of Water aflfaks. Further data was obtained from Zambia ConsoHdated Copper Mines Limited.The mass flows for the parameters are computed on a monthly basis as the average of the product of the concentrations of the parameters and discharge rates for the particular month.Results obtained indicate that the mass flows of these chemical constituents increase after the river enters the mining areas and decrease after exiting the areas. W\IQ relative impact of the mining operations on the river basin varies fiom place to place and chemical to chemical. In the Mwambashi river on one hand, practically all the total dissolved sohds flowing in the river during the dry season seem to emanate from mining operations. On the other hand, dissolved uon flow rates at certain times of the year actually drop as the river enters the area of the mining operations.Redox conditions also seem to have an effect on the speciation of metals hke iron, lead and manganese. Photosynthesis by aquatic plants has been found to determine the level of dissolved oxygen and the redox potential level.Copper flow^s from Fishers farm to Machiya appear to be affected by iron speciation as a result of the ability of iron oxyhydroxides in adsorbing various heavy metals. Hie same seems to apply to lead. For cadmium, mining activities may not be major factor m the mobihsation of the metal since the biggest input of the metal appears to come between Fishers farm and Machiya ferry samphng point. Most of the mining activities discharge their effluent into the Kafiie at points upstream of Fishers farm. This study has thrown some hght on the hydrogeochemical processes taking place in the Kafiie river. It has shown how mine effluent is effecting the water quality in the Kafue river and how the river itself effects the effluent.
- Mines