Determination Of Some Physico-Chemical Characteristics And Heavy Metals Levels In Ground Drinking Water And Soil Samples Collected From Olonkomi Town, Ejersa Lafo District, West Shoa Zone, Oromia, Ethiopia

Abstract

The objective of the study determined physico-chemical parameters in water, and the concentration levels of metals in soil and water samples collected from Olonkomi town West Shoa Zone, Oromia regional state, Ethiopia were analyzed. The soil and water samples were digested following optimized procedures before Flame Atomic Absorption Spectroscopy (FAAS) analysis for the metals. Appropriate standard sample preparation and pretreatment procedures were also followed for the analysis of physicochemical parameters. The results obtained revealed that the concentration of selected metals (Mg, Na, K, Ca, Cu, Mn, Ni, Cr, Cd, Zn, and Pb) in the study sites the concentration of Mg and Na were higher than all other metals in soil and water, respectively. The mean metals concentration range in the soil and in the water samples were mg/Kg and mg/L Cu (33.2 - 45.88, 0 - 0.12), Mg (4554 - 4593, 4.9-5.8), Ca (771- 847, 16 - 44), Mn (1672 - 2158, 0.12), Pb (15 - 50, 0.3 - 1),Cd (25 - 29,0 - 0.5), Cr (0 - 6.45, 0 - 0.13), Zn (146 - 163, 0 - 0.12), Na (72 - 110, 68 - 69), K (1135 - 1196, 1.89 - 1.9), respectively. The water samples had been analyzed for various physicochemical characteristics like pH, electric conductivity (EC), Turbidity, Total dissolved solid (TDS), Total alkalinity (TA), Total hardness (TH), as well as major chemical parameters like chloride, fluoride, phosphate, and sulfate. The results of the physico-chemical parameters in the water showed range: TA (402.7 - 440.7) mg/L as CaCO3, EC (47 - 536) µs/cm, Turbidity (1.05-38.63) NTU, TDS (316.33 - 362.67) mg/L, pH (8.06 - 8.35), TH (60.67 - 130.67) mg/L as CaCO3, Cl- (49.39 - 57.40) mg/L, F- (1.98 - 3.08) mg/L SO4 -2 (79.90 - 237.40) mg/L, PO4 -3 (0.06 - 0.07) mg/L. The concentration of fluoride was determined in both soil and water samples by using of ion-selective electrode methods and the concentration range of the soil and water samples are (0.34 - 0.55) mg/Kg. All the selective heavy metals and physico-chemical parameters of water analyzed in the sampling sites were within the recommended standard limits except fluoride ion which is slightly higher than the WHO guideline of 1.5 mg/L limit of drinking water.