Effect of Seasonal Variation in the Composition of Major and Trace Elements of Lake Chamo, Ethiopia

Water samples was collected from five sampling sites namely; inlet-1, inlet-2, center, outlet-1 and outlet-2 of Lake Chamo. The concentration of certain major and trace metals Na, K, Mg, Ca, Cr, Co, Ni, Mn and Cu were determined in the water within the two consecutive season winter (dry) and spring (wet) season using atomic absorption spectrometer (AAS) and flame photometer (FP). The results revealed that the dissolved metal concentration in water were, Na ranged from 18 - 22, Mg 0.34-0.97, K 10-19, Ca 1.6 -5.5, Cr 0.61- 4.0, Co 1.50-3.8, Ni 0.78-1.10, Mn 1.01– 1.98 and Cu 0.53 -1.20 mg/L in the winter season and in the spring season Na ranged from 12- 17.5, Mg 0.51- 0.62, K 10- 13, Ca 1.5- 3.9, Cr 0.60- 1.20, Co 1.50- 3.80, Ni 0.78-1.10, Mn 1.01–1.9 and Cu 0.50- 0.78 mg/L. the physicochemical values in the winter season were, P H ranged from 9.39 - 9.45, TDS 815 - 910 mg/L, conductivity 1746 -1965 µS/cm, temperature 25.5 – 27.6°C, salinity 0.87 - 0.93ppt, turbidity 21.59 - 28.21 NTU and DO 6.37 mg/L - 8.24 mg/L and in the next season (spring), P H ranged from 9.30 - 9.40, TDS 865 – 920mg/L, conductivity 1739 - 1960µS/cm, temperature 25.8 – 29°C, salinity 0.81- 0.87ppt, turbidity 22.59 - 37.21 NTU and DO 6.27 mg/L - 8.24 mg/L.