Assessment of the Physicochemical Parameters and Determination of the Levels of Some Selected Heavy Metals in Drinking Water in Assella Town, Oromia Regional State of Ethiopia

Abstract

The aim of this study was to determine physicochemical parameters and some selected heavy metals in drinking water in Assela Town, Oromia Regional State, Ethiopia. A total number of three water samples were collected from different sources both raw water and tap water. A total of thirteen (13) physico-chemical parameters and five (5) heavy metals such as:- Temperature, pH, dissolved oxygen, total hardness ,conductivity, turbidity, Alkalinity ,TDS for the analysis of major cations (calcium, sodium, potassium, magnesium) and anions (sulphates) and the concentration of heavy metals ( Nickel , Zinc, Manganese, Cadmium and Lead ) had been analyzed. The physico-chemical parameter results were ranged in the following trend: Temperature (21.60-23.20 ) oC , pH (6.95-7.40), dissolved oxygen (3.52-4.64 mg/L) ,conductivity (51.40-62.17µS/cm), total hardness (33.03-40.40 mg/L) , turbidity (1.56-1.75 NTU), calcium ( 4.75-8.27 mg/L), magnesium( 2.45-5.35 mg/L) , sodium( 10.60-14.00 mg/L) , potassium (4.27- 5.00 mg/L ) , Sulphate(74.21-96.83),Alkalinity (28.27 -39.43 mg/L ),TDS (33.03-40.4 mg/L) and the concentration of heavy metals such as Nickel (0.012-0.067 mg/L), Lead (0.005-0.007 mg/L), Zinc (0.054-0.088mg/L), Cadmium (0.012-0.025 mg/L) and Manganese (0.012-0.027 mg/L) and the ranges of Relative standard deviation of heavy metal analysis (3.33-8.30 %) ,accuracy (84.1- 109.08 %), LOD( 0.001-0.007 mg/L) and LOQ (0.001-0.024 mg/L) . Therefore, the findings of this study had been indicated that physico-chemical properties and the levels of concentrations of heavy metals in the raw and tap water did not cause any serious pollution threat presently .This is because most parameters were within the permissible limits of WHO and still acceptable and conducive to both human and aquatic bodies except the Cadmium metal , due to the application of agricultural inputs such as fertilizers, pesticides and the disposal of waste in the sampling sites. Therefore , it needs intervention .