Heavy metal pollution and microbial water quality of Tafo and Dadi Rivers in Lega Tafo Lega Dadi Town, Ethiopia

Abstract

Industrial effluents entering a water body represent a heavy source of environmental pollution in rivers and affect the water quality. This study characterized the physicochemical and microbial features of Tafo and Dadi River water and examined pollution its status. Primary methods of data collection, such as in situ measurements, laboratory analysis, and observation have been carried out. Secondary data were collected from different sources to obtain detailed information in addition to data collected through primary methods. Data were analyzed using both quantitative and qualitative methods. Both the upper stream and downstream sampled water from the selected points were analyzed for the color of water, which was dark black color and emitted a noxious smell. The other water parameters also analyzed such as: - temperature (ranged from 21.4 to 23.4^oC), pH (ranged from 7.9 to 8.4), EC (ranged from 221 to 2410 μS/cm), turbidity (ranged from 0.9 to 21 NTU), Dissolved Oxygen (ranged from 4.4 to 5.52 mg/l), Biological Oxygen Demand (ranged from 15.84 to 38.82 mg/l), Mg²⁺ (ranged from 27 to 156 mg/l), Ca²⁺ (ranged from 31 to 1130 mg/l), Na⁺ (ranged from 26 to 637 mg/l), Pb (ranged from 0.30+0.32 to 2.2+1.13 mg/l), different value observed for cations and anions, total Coliforms (ranged from 1600000 to 8900000 CFU/100ml) and fecal coliforms (ranged from 400000 to 5400000 CFU/100ml). The study concluded that the lower stream of the rivers was slightly polluted and it affected the river water quality.