In Partial Fulfillment Of The Requirements For Master Of Science Degree In Analytical Chemistry

Abstract

The present study was conducted to assess and clarify concerns about quality and safety of drinking spring and deep well water in Jibat-Shenen district of Oromiya state. Water samples were collected from 2 densely populated springs and one deep well of the area, namely: Laga Sose, Abba Moga and Laga Dada, respectively. All the samples were analyzed for six physico- chemical parameters (temperature, pH, total dissolved solids, conductivity, alkalinity, hardness); four Common cations (Ca, Mg, Na ,K) ; four common anions (SO42-, PO43-, NO3-, Cl); and three toxic heavy metals ( Cd, Cr, and Pb) using standard methods. Temperature, pH and Electrical conductivity were measured in situ at the study site; DO was analyzed by titrimetric procedure using the azide modification of Winkler method. Alkalinity, hardness, SO42-, Cl-, Ca and Mg were determined by classical methods. PO43-, NO3-, Na, K and heavy metals were analyzed by instrumental methods i.e. K and Na were analysed using flame photometry; Ca and Mg were determined titrimetrically; SO42- and NO3- concentrations were investigated by using UV-Vis spectrophotometer. Chloride was determined by argentometric titration which is a direct titration of Cl- available in the water sample by standard Ag+(0.1N) using CrO42-as an indicator; Hardness is determined by the EDTA method in alkaline condition and Alkalinity was determined by titration using indicators (phenolphthalein and methyl orange indicators). The metal analysis was done by FAAS to detect cadmium, chromium, and lead. The in-situ measurements showed that mean values of temperature, pH, and conductivity were ranged from 20.85 to 23.27 oC, 6.67 to 8.2 and 27.80 to 47.10µS/cm, respectively. The mean results for TDS, alkalinity, hardness and DO were varied from 18.00 to 32.90 mg/L, 5.76 to 7.20 mg/L, 18.80 to 27.60 mg/L, and 9.140 to 22.043 mg/L, respectively. The major chemical analysis showed that the mean values ranged from 0.009 to 0.015 for PO43-, 1.975 to 9.548 for NO3-, 3.10 to 4.10 for Cl-, 1.45 to 2.23 for Mg , 5.13 to 7.37 for Ca, 0.333 to 7.067 for K, 5.567 to 21.833 for Na. Among the three heavy metals analyzed for waters Cd and Cr were below the method detection limit. However, the concentration of Pb was 0.3 mg/L in laga abba moggaa spring water and 0.5 mg/L in laga Dada deep well. SO42- was undetected in all samples.