Pollution effect of food and beverages effluents on the Alaro river in Ibadan City, Nigeria

Abstract

The main course of water pollution in the Alaro river is the direct discharge of food and beverages processing effluents. The impact of such effluents on the water quality was studied in detail by monitoring selected physicochemical parameters monthly between January 2003 and December 2007. The combined effluent was equally monitored. This study provided a detailed data on the quality of the effluent at the designated discharge point, upstream and downstream locations. The background levels of 250±4 mg/L (TS), 178±3 mg/L (TDS), 6.5±0.2 FTU (turbidity), 132±5 mg/L (total hardness), 157±4 mg/L (Cl^-), 157±0.3 mg/L (NO₃^-), 9.65±0.39 mg/L (SO₄^2-), 2.12±0.01 mg/L (BOD), 103±5 mg/L (COD), 0.54±0.02 mg/L (Ni), 0.59±0.02 mg/L (Zn), 0.25±0.02 mg/L (Cr) and 0.17±0.02 mg/L (Pb). The overall levels of these water quality indicators went up after the effluent discharge point. Overall, the effluent contained contaminants whose levels exceeded the effluent guideline for discharge into surface water and drinking water criteria. Hence, water pollution of the Alaro river is very evident.

KEY WORDS: Water quality, River Alaro, Pollution, Industrial effluent

Bull. Chem. Soc. Ethiop. 2011, 25(3), 347-360.