ASSESSSMENT OF DOWNRIVER POLLUTION PROFILE OF GONDAR CITY WASTEWATER AND ITS INFLUENCE ON KEHA RIVER

Abstract

Population growth, disposal of liquid and solid waste to the river  affect the pollution of the river. Keha river is exposed to waste discharge from the city. The main purpose of this study was to assess downriver pollution profile of Gondar city wastewater and its influence on keha river. A total of six sampling sites were chosen. A total of 15 grab samples were collected for analysis. pH and temperature value ranged from 7.10 - 8.55 and 17.2 - 25 (^OC), respectively. Turbidity and TDS were ranged from 17– 205 (NTU) and 404– 631 (mg/l), respectively. Electrical conductivity and TSS were ranged from 712– 1550 (µS/cm) and 36.15  – 224.32 (mg/l), respectively. BOD₅ and COD were ranged from 6.22 – 20.66  (mg/l) and 17.7 – 44.5 (mg/l), respectively. Total kjeldahl nitrogen (TKN), NH₃-N, NO₃-N and No₂-N were ranged from 20 – 29.5 (mg/l), 0.78 – 2.00 (mg/l), 0.41 – 2.2 (mg/l) and 0.06 – 0.58 (mg/l), respectively. Sulphate and Total Phosphate were also ranged from 0.33 - 0.89 (mg/l) and 4.05 – 9.26 (mg/l), respectively. Total Hardness level were ranged from 85 – 250 (mg/l as CaCO₃). There are environmental and health risk associated with the use of these water resources therefore, it is recommended that proper management of solid and liquid waste before disposal to the Keha river was mandatory.