PHYSICO-CHEMICAL PROPERTIES OF WATER FROM KAHA RIVER, IN GONDAR TOWN, ETHIOPIA
Keywords:fresh water, in situ measurement, urban river, water quality
Background: Surface waters are habitats for aquatic plants and animals and source of nations’ development. Particularly, rivers are important source of drinking water supply and they have a remarkable role to nations’ development. However, currently, rivers face pollution due to rapid agricultural expansion, urbanization, industrialization and land use change.
Objective: the current study was carried out during February to August 2014 to assess the status of physico-chemical parameters of Kaha River water. Some of the main physico-chemical parameters: pH, temperature, electrical conductivity, total dissolved solid (TDS), salinity and dissolved oxygen (DO) measured on site while others like NO3 and PO4were determined in lab.
Methods: Water samples were collected monthly during dry (February to May, 2014) and wet (July to August, 2014) seasons from four representative sites. At the same frequency, duration and sites in situphysico-chemical parameters measurements were deployed.
Results: The pH of Kaha River water varied from 4.86 to 8.06 with mean value 7.15; the surface water temperature from 19oC to 29oC with mean 24oC; conductivity from 2.50mS/cm to 6.10mS/cm and mean value 3.74; total dissolved solid from 148.88mg/l to 360mg/l and mean value 203.71mg/l. The minimum salinity recorded was 0.99mg/l and the maximum 3.10mg/l with value 1.70mg/l and dissolved oxygen between 4.98mg/l to 8.15mg/l with mean value 6.77mg/l. In addition, nitrate was varied from 0.06mg/l to 2.60mg/l with mean value 0.74mg/l and phosphate from 0.04mg/l to 7.13mg/l with mean value2.28mg/l.
Conclusion: in this study, the mean value of pH was within the permissible limit of EEPA and World Bank standard values. The values of DO are within the permissible limit of Canadian water quality guidelines for the protection of aquatic life. Moreover, temperature, TDS and nitrate are below the limit of WHO and EC and phosphate are beyond the limit.