The impact of rubber effluent discharges on the water quality of a tropical rain forest river in Nigeria

Abstract

The impact of a rubber effluent on the water quality of Oken River, Nigeria, was assessed. Surface water was analysed for water quality parameters at four sites; one upstream and three downstream. Significantly raised (p ≤ 0.05) levels of electrical conductivity, salinity, colour, turbidity, TSS, TDS, DO, COD, HCO₃ ^-, Ca, Cl, P, Mn, Cu, Pb and THC at the site immediately downstream of the pollution point source were recorded, with levels of colour, turbidity, Cd and Ni in all the stations higher than the WHO permissible limits. Principal component analysis (PCA) yielded 28 variables under six components that accounted for 92.33% of the total variance between sites. The PCA and water quality index (WQI) revealed significant influence by anthropogenic activities on the water quality of the river. Furthermore, the WQI output showed that the river water was not fit for human consumption. The cluster analysis revealed similarity in the physico-chemical conditions at Stations 1 and 4, whereas Stations 1 and 2 were the most dissimilar. This study advocates monitoring and protection of water bodies upstream and downstream of the influx of untreated effluents.