NUTRIENT POLLUTANT LOADS AND THEIR EFFECTS ON WATER QUALITY OF PERKERRA RIVER, BARINGO COUNTY, KENYA
Keywords:
nitrates, phosphates, chemical oxygen demand, biochemical oxygen demand, dissolved oxygenAbstract
In order to sustain productivity in crop yield, soil nutrients should be replenished using inorganic fertilizers. Appropriate use of fertilizers based on recommendation is generally expected to cause little adverse impact on the environment and health. However, trace amounts of nitrates and phosphates have been detected in soil and water. This has led to increased concerns regarding the potential effects of these inputs on non-target organisms. The objective of this paper was to investigate and quantify nutrient residues in water, sediments and soil in river Perkerra, Baringo county. The samples were collected from five sampling sites. Phosphate and nitrate content were determined using Olsen and calorimetric methods respectively. The highest nitrate in water, sediments and soil recorded were 4.98, 8.24 and 8.13ppm respectively. The highest phosphate concentration was 0.016ppm in water and 33.34ppm in soil compared to WHO value of 10ppm. The dissolved oxygen ranges between 2.15 and 4.42 ppm. The chemical oxygen demand ranges between 13.20 and 53.75ppm. The highest value of 53.75ppm in this study was above the Kenya Bureau of Standards (KEBS) value of 50ppm. The river water studied is therefore polluted with nutrient residues and is not recommended for direct domestic use since some parameters studied are far above the KEBS standards.
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