Physico-chemical profile study of a portion of the Ulasi River from Ezinifite to Ogwu-Aniocha, in Anambra State of Nigeria

Abstract

The physico-chemical profile study carried out on Ulasi river course from Ezinifite to Ogwu-Aniocha in Anambra State of Nigeria shows that the water body has a fairly constant temperature that is in the 2627°C range. The mean pH values of the top level of the river is always higher than that of the bottom, and is outside the 6.58.5 range allowed by WHO for potable water. Apart from the river course from Ezinifite to Lilu statistical analysis has shown, however, that there is no significant difference between the mean pH values of the top and bottom level of the river. Results show that Fe content of the bottom level of the river is higher than that of the top level of the river. Apart from the river course at Ogwu Aniocha statistical analysis has shown, however, that there is no significant difference between the mean Fe values of the top and bottom level of the river. Hydrolysis of the high Fe content found in the sediment have been used to explain the slightly higher Fe content of the river bottom and also the slightly higher acidity of the bottom level of the river. The mean Fe concentration along the course of the river falls in the 0.62.5 mg/L for the top and 0.84.9 mg/L for the bottom levels of the river and are above the 0.2 mg/L guiding limit set by WHO for potable water. Low levels of inorganic PO₄^3- and NO₃- nutrients were reported for the river. Sulphate, sulphite and nitrite ions were not detected and the metals: Cr, Pb, Cd, Mn, Ni, Cu, Co, Al, Ba, V, As, Hg and Mo were also not detected. The mean biochemical oxygen demand (BOD) recorded values lower than 1 mg/L O₂. Unacceptable levels of surfactants (0.50 mg/L) that are above the 0.2 mg/L EEC guiding limit set for potable water bodies were recorded. Unacceptable levels of hydrocarbon in the course of the river, falling within the 0.3-3.9 mg/L range were observed. Hydrocarbon pollution is more serious at Ulasi Ukpor/Okija to Ulasi Okija Junction water fronts and has been attributed to used engine oil waste disposed along the banks of the river. The physicochemical studies on the sediments and soil showed that they can be characterized as ferrous with pH values that are close to 6.2-6.9 and <5 respectively. Unacceptable levels of hydrocarbon were also detected in both sediment and soil samples and have been attributed to unguided disposal of used engine oil.


Keywords: physicochemical studies, Ulasi River, Anambra State

Global Journal of Pure and Applied Sciences Vol. 11(4) 2005: 517-521