Abstract

The ever growing saline lake Beseka is located at the northern end of Main Ethiopia Rift; MER. The levels of some selected heavy metals (Pb, Cr, Cd, Fe, As and Mn) were determined in water sample collected from 5 sites of the ever growing Lake Beseka by systematic random sampling methods and analyzed spectrophotometrically for its suitability for drinking, irrigation and other domestic purpose. The results of the heavy metals concentration revealed the following: Pb (0.434-0.916 mg/L), Cd (0.031-0.103 mg/L), As (0.043-0.067 mg/L), Fe (0.163-0.247 mg/L) Cr (BDL) and Mn (0.061-0.092 mg/L). The result obtained revealed that the heavy metals show variation among sampling points. Pb, Cd, As and Fe recorded concentrations above the WHO guideline limits of 0.02, 0.003, 0.01 and 0.04 mg/L, respectively but they are below the ANZECC and ARMCANZ standard guide line limit for irrigation A and Cr were below their respective detection limits. The main causes of deterioration of water quality are disposal of effluent from municipal of MER, agrochemical runoff and effluent discharged from industries without treatment. The results suggest that the use of such waters for drinking and domestic purposes pose a serious threat to the health of the users and calls for the intervention of government agencies.

Key words: Heavy metal, atomic absorption spectrophotometer (AAS), main Ethiopia rift (MER), determination, analysis.