EFFECTS OF GOLD PROCESSING ACTIVITIES IN CHANCHAGA AREA OF NIGER STATE ON THE CHARACTERISTICS OF RECEIVING WATER BODIES

Abstract

Legal gold processing activities involving the crushing of rocks or sediments invariably leads to generation of tailings that may release some contaminants into the environment. Thus, the aim of this work was to determine the effect of legal gold processing activities in Chanchaga Area, Minna, Niger State on the receiving water bodies. To achieve this, four water samples were collected from the surrounding river called River Chanchaga (upper and lower), a borehole and a well in addition to the tailing effluent from the processing area. The samples were analysed for the presence of the following chemical parameters: Copper, Chromium, Lead, Zinc, Biological Oxygen Demand, Chemical Oxygen Demand, Potassium, Sodium and Calcium. The results obtained show that concentration of the heavy metals in the water samples analysed ranged from 0.00-0.03 mg/l for Cu, 0.40-0.59 mg/l for Cr and 0.63- 1.65 mg/l for Zn while Pb was only detected in one sample (LR) at a concentration of 0.01 mg/l. Also, BOD and COD of the water samples studied ranged from 4.0-8.2 mg/l and 5.0-10.6 mg/l respectively while K, Na and Ca concentrations were found to be in the range of 0.1-0.28 mg/l, 0.021.04 mg/l and 1.3-14.3 mg/l respectively. Thus, comparison of these results with that obtained for the tailing effluent and controlled to the conclusion that the heavy metals considered are released into the environment which subsequently get into the water bodies as a result of the gold processing activities, while K, Na and Ca were also noted to be released into the environment but are significantly retained or absorbed by the soil; hence their relative presence in the surrounding water as a result of mobility through the soil was not noticed. It could also be concluded that the legal gold processing activities have little or no effect on the BOD and COD of the receiving water bodies as compared to the standard.