Assessment of the Physicochemical Quality of Challawa Gorge Dam Kano, Nigeria

Abstract

Water and sediment samples were collected from Challawa Gorge dam during the wet and dry seasons and analyzed for some physicochemical parameters, heavy metals (Cd, Cr, Mn, Pb, Zn) and minerals (Na and K) using Atomic Absorption Spectrophotometric and Flame Photometric techniques. The results showed the following ranges of the physicochemical parameters; pH (7.78±1.1 to 7.82±0.2), Conductivity (45.0±3.2 μs/cm to 65.8±0.2 μs/cm), Nitrates (1.59±0.18 mg/l to 2.03±1.5mg/l), Dissolved oxygen (6.3± 0.5 mg/l to 15.3± 1.45mg/l), Total dissolved solids (34.1±2.4 mg/l to 36.0±3.7 mg/l) and chlorides (3.47±0.36 mg/l to 10.72±0.57mg/l). Variations in concentrations of the heavy metals ranged from 0.01± 0.001 mg/l to 1.41± 0.13 mg/l in water and 1.64 mg/kg to 51.0mg/kg in sediment, while sodium and potassium ranged from 7.65±0.28 mg/l to 11.32±8.62mg/l in water and 50.16±17.92 mg/kg to 144.19±12.09mg/kg in sediment. The levels of all the tested parameters in water were within the WHO and SON standards for drinking water and fishing activities and may not pose immediate health effects on human. However, the high levels of heavy metals in the sediment samples can lead to bioaccumulation and long term adverse effects on the aquatic lives and humans. Therefore continuous monitoring of the heavy metal contents in the Dam and sediment is recommended to safeguard aquatic and human lives.