Physico-chemical analysis and determination of the level of some selected heavy metals in protected spring water of jimma town

Abstract

The study investigated the physico-chemical parameters and the level of some heavy metals in different protected spring water samples of Jimma town, Oromia regional state, Southwestern Ethiopia. For this purpose, eight different spring water samples were randomly collected to serve as the subject of the study. Physico-chemical parameters and heavy metals were determined using standard analytical procedures. The result of the physicochemical analysis were obtained in the following range; pH (6.48-8.30), temperature (21.60-23.60 0 C), conductivity (57.80-638.00 μS/cm), dissolved oxygen (1.09-6.70 mg/L), turbidity (1.14-27.70 NTU), total suspended solids (0.385-2.80 mg/L). The turbidity of three of spring water samples (SWS 05, SWS 06 and SWS 08(37.5 %) were found to be above the permissible limit set by WHO drinking water standards, which is 27.7±0.2, 23.6±0.2 and 7.86±0.01 respectively. The electrical conductivities of three of spring water samples (SWS 01, SWS 02 and SWS 04(37.5 %) were found to be above the permissible limit set by WHO drinking water standards, which is 638±1, 410±12 and 394±7 respectively. The range of concentration of nitrate and phosphate were found to be 13.28 to 281.11 and 0.01to 0.10 mg/L respectively. The concentrations of heavy metals (mg/L) in the samples were found within the following ranges; Pb (0.002-0.0615), Cd (0.0015-0.0235), and Cr (VI) (Not detected - 0.052). The level of lead of four of spring water samples (SWS 01, SWS 04, SWS 05 and SWS 08(50 %) were found to be above the permissible limit set by WHO drinking water standards. The level of Cr (VI) of one spring water sample (SWS 04) was found above the permissible limit set by WHO drinking water standards. Therefore, although, all of the sampled spring waters were protected; they need continuous monitoring and needs solutions for the parameters which are above permissible limit set by EU, USEPA and WHO.