Nutrients input into Ekulu River, Nigeria: Implications on Algal Bloom

This study investigated the potential of nutrients input into Ekulu river to cause unwanted growth of algae that could adversely affect the aquatic ecosystem. The concentrations of nitrogen, silicon and phosphorus in the water column of Ekulu river were determined in addition to determining the pH, electrical conductivity, total dissolved solids, total organic carbon, dissolved oxygen, biochemical oxygen demand and chemical oxygen demand following standard procedure by APHA (1998). The results show that there was increase in concentration of phosphorus, nitrogen and silicon in the rainy season. The N/P ratios varied from 6.2-15.7 indicating the possibility of nitrogen being the limiting nutrient as ratio values are less than the optimum value of 16. The Si/N ratio for both dry and wet seasons varied from 2.7- 9.1 indicating that Si input into the river is adequate and favourable to the growth and development of diatoms rather than  non-diatom phytoplankton species such as dinoflagellates. Consequently, there is no significant risk of eutrophication at the present level of nutrients and silicon in Ekulu river. Keywords: Nutrients; River;  Eutrophication; Diatoms; Phtoplankton. DOI: 10.7176/JEES/9-1-0

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

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/9-1-1