Assessment of the Water Quality of Oji River Using Water Quality Index (WQI)

Abstract

This study measured the physico-chemical parameters and concentration of the heavy metals of Oji river and assessed the water quality of the river by means of water quality index (WQI). The physico-chemical parameters were determined following the APHA (1998) procedure and the heavy metals were analyzed using Atomic Absorption Spectrometry (AAS). The results of this study revealed that the WQI of the river in the various locations studied varied from 241-830 for the rainy season indicating ‘poor’ to ‘unsuitable for drinking’ whereas the WQI varied from 68- 946 for the dry season indicating ‘good’ to ‘unsuitable for drinking’. It was only the location down-steam the Power Station in the dry season that was ranked good. The main contaminants that accounted for the poor quality of the river for drinking purposes were lead, cadmium and hydrocarbons. The Abattoir appears to be mainly responsible for the input of the heavy metals into the river. Keywords : Water quality; water quality index; contaminants, river, heavy metals, physico-chemical parameters. DOI : 10.7176/JEES/9-1-10