STATISTICAL ANALYSIS OF PHYSIOCHEMICAL PROPERTIES OF AJALI RIVER STRETCH IN ENUGU, ENUGU STATE NIGERIA

Abstract

This work studied the physiochemical properties of Ajali River polluted with Industrial effluent at different sampling points from -250m upstream before the pollution to 2250m downstream. Statistical package for Social Science (SPSS) was used for the statistical analysis. Post ANOVA test was used to determine if there is any significant difference between the means and at which distance the difference occurred. A measuring wheel and Global Positioning System (GPS) were used for the exact locations studied. The azide-Winkler method was used for DO determination, while the five-day incubation method was used for BOD. It was observed that there was a significant difference (p˂0.005) between the means of the properties across the sampling points. Dissolve Oxygen was found to be higher in the rainy season with a range of 3.82±0.47 to 7.70±0.40. Biochemical Oxygen demand was equally higher in the rainy season with a range of 2.05±0.02 to 5.02±0.41. Chemical Oxygen demand was higher in the rainy season with a range of 6.20±0.12 to 15.04±0.03. It was observed that the effect of the pollution decreased along the sampling points away from the point of discharge to the stream suggesting that the river has a natural tendency to purify itself.