Assessment Of Physico-Chemical Characteristics And The Level Of Selected Trace Metals In Spring Waters Of Hericha Kebele, Haru District, West Wollega Zone, Oromia Region, Ethiopia

Abstract

The present study was undertaken to assess the spring water quality in Hericha rural area of Haru district, West Wollega, Oromia, Ethiopia. Spring water samples were collected from 4 spring sites, namely: Abba Fasige, Mumme, Abba Nura, and Chirecha. All the samples were analyzed for seven physico-chemical parameters (temperature, pH, total dissolved solids, chemical oxygen demand, conductivity, alkalinity, hardness, SO42-, PO43-, NO3-, Cl-, Ca, Mg, Na and K), and for six heavy metals ( Mn, Cd, Cu, Cr, Fe and Zn) using standard methods. Temperature, pH and conductivity were measured in-situ. The COD, alkalinity, hardness, -, Cl-, Ca and Mg were determined by classical methods. SO42-, PO43-, NO3-, Na, K and heavy metals were analyzed by instrumental methods .The in-situ measurements showed that mean values of temperature, pH, and conductivity were ranged from 23.333 to 24.233oC, 5.96 to 7.28, and 56.67 to 107.67 µS/cm, respectively. The mean results for TDS, COD, alkalinity, and hardness were varied from 38.67 to 71.33 mg/L, 8.67 to 10.67 mg/L, 22.67 to 38.67 mg/L, and 24.96 to 49.92 mg/L, respectively. The major chemical analysis showed that the mean values ranged from 3.24 to 5.59 mg/L for SO42-, 0.07 to 0.34 mg/L for PO43-, 1.26 to 32.6 mg/L for NO3-, 3.916 to 6.77 mg/L for Cl-, 4.71 to 10.26 mg/L for Ca, 3,16 to 5.82 for Mg, 2.90 to 4.94 mg/L for Na and 0.79 to 2.33 mg/L for K. Among the six heavy metals analyzed for waters Cd and Cr were below the method detection limit. However, the concentration of Mn, Cu, Fe and Zn were ranged from mean values of 0.02 to 0.13 mg/L, 0.039 to 0.07 mg/L, 0.03 to 0.146 mg/L and 0.55 to 0.70 mg/L, respectively. The analyzed parameters in waters were below the currently recommended guidelines for drinking water quality except pH of three spring sites: Abba Fasige, Mumme and Abba Nura which were below in the range of WHO and different national water quality standard.