Abstract:
Freshwater pollution (e.g., rivers) due to various human activities such as industrial effluents, agricultural activities, urban waste management issues, and increase in urbanization is threatening the ecosystem. In this study selected, physicochemical parameters and concentrations of some heavy metals in Teji river waters of Waliso district, Oromia Regional state, Ethiopia were investigated. Totally, 10 water samples and 10 sediment samples were collected for the analysis. The purpose of this research work is to monitor pollution status of Teji River and levels of heavy metals in water and sediment samples. Physico-chemical parameters (Temperature, pH, Total dissolved solids and electrical conductivity) were measured on site. Concentrations of selected heavy metals (Cd, Cr, Co, Fe and Pb) were determined by flame atomic absorption spectroscopy. The results indicated that the mean values of water temperature, pH, TDS, EC in Teji River during dry season were 20.8-25.7 °C, 6.93-7.89, 60-120 mg/L, 168-920 μs/cm, whereas the mean values in wet season were 19.7 – 22.40 °C, 6.66-6.83, 70-100 mg/L, 95.6-811 μs/cm respectively for sites of 1, 2, 3, 4 and 5 as in their order written. The result showed that the average values of Fe, Co, Pb, Cr and Cd in Teji River during dry season in five sampling points were 0.891, 0.019, 0.069, 0.048 and 0.016 mg/l while the mean values in wet season were 0.809, 0.044, 0.067, 0.208 and 0.017 mg/l respectively. The average values of Fe, Pb, Co Cr and Cd in Teji River Sediment during dry season in five sampling points were 30.494, 0.25, 0.315, 1.105 and 0.171 mg/kg whereas the average concentration during wet season were 28.902, 0.16, 0.261, 0.891 and 0.311 mg/kg respectively. The mean water concentration levels of Cr, Pb and Fe in majority of the sampling sites exceeded drinking water quality guideline established by WHO, while others not. This indicates that use of the raw water from the river for drinking water use or domestic purpose may likely pose human health risk. Therefore, it recommended that the government and other responsible authorities have to take appropriate corrective action and should support further study has to be conducted on other physical, chemical and untested biological parameters of significant health concern and identification of potential source of the contaminants of the river.
