PHYSICO-CHEMICAL CHARACTERSTICS AND HEAVY METALS CONCENTRATIONS OF DEBRE BIRHAN TANNERY WASTE WATER AND BERESSA RIVER WATER IN NORTH SHOA, ETHIOPIA

Abstract

Tannery Industries are one of the most highly polluting sectors in developing countries like Ethiopia. Debre Birhan Tannery Industry releases effluent that pollutes the nearby Beressa River. This study was characterized effluent discharged from Tannery Industry and Beressa River water. The (effluent and river water samples) were analyzed for various physicochemical properties like temperature, pH, Conductivity, Turbidity, Total dissolved solid, Chemical oxygen demand, Biological Oxygen Demand. They were determined by using standard methods. Samples of both tannery effluent and river water have been analyzed for Cadmium, Nickel, Lead, Zinc and Chromium using Atomic Absorption Spectrophotometer (AAS). From this study, the experimented characters recorded mean values indicates that; pH=7.7,temperature=20.5oC, turbidity 127.3NTU,EC=14799μs/cm, TDS =7502mg/l, Cl- =1975.3mg/l, COD =1651.3mg/l, BOD= 751.3mg/l, DO =1.5mg/l, PO4 3-= 58.1mg/l, SO4 2−=33.4mg/l, Fe =0.7mg/l, Ni=0.6mg/l, Cr =3.5mg/l, Cd= 0.007mg/l and Zn=0.7mg/l were from the Tannery effluent sample. Similarly, River water samples also ranges as pH=7.4-7.3, temperature=18.9-19.8oC, turbidity=47-122.7NTU,EC=492.6-1232μs/cm, TDS=338.7-657.7mg/l, Cl-=37.6-60.5mg/l, COD=213.3-310.3mg/l, BOD=23.3-66.7mg/l, DO=1.8-3.0 mg/l, PO4 3−=21.6-45.4mg/l, SO4 2−=19.0-25.4mg/l, Fe=0.13-0.16mg/l, Ni=0.04- 0.69mg/l, Cr= 0.05-1.46 mg/l, Cd=0.003-0.01 mg/l, Zn =0.02-0.04mg/l. Tannery effluent creates challenges to the nearest river and decrease the quality of water bodies into which they are discharged is large scale environmental concern. Some of the analyzed Physico chemical parameters from Debre Birhan Tannery Industry showed that it discharged their effluent beyond the Ethiopian Tannery effluent discharge limit value. Water sources from the studied area have a problem for the people and environment it needs to be subjected to further treatments.