Effect of industrial effluents on water quality of River Atuwara in Ota, Nigeria. In Adeyemo

The impacts of industrial wastewaters discharged into River Atuwara were estimated from the physical and chemical characteristics of the samples using standard methods. The quality of the effluent before and after dilution in the receiving water and impact on the use of the water for irrigation was studied using QUAL2K software for hydrodynamic analysis of streams and rivers. From the inputted data into the QUAL2K software, the average (and range) of the stream depth, velocity of flow and flow rates of the reaches studied were respectively 0.915m (0.49-2.59 m), 0.336 m/s (0.21-0.4 m/s) and 14.66 m3/s (3.48-59.36 m3/s). Majority of the water quality parameters exceeded the maximum concentration permissible: BOD: ≥ 31 mg/L; COD: ≥ 181 mg/L; Alkalinity: ≥ 138.4 mg/L; TSS: ≥ 826 mg/L; TDS: ≥ 501 mg/L; Chloride: ≥ 9.95 mg/L; Nitrates ≥ 11.3 mg/L and Phosphates ≥ 2.92 mg/L. High concentration of heavy metals such as Cadmium (≥ 0.017 ppm), Pb (≥ 0.29 ppm), Zn (≥ 0.001 ppm), Fe (≥ 7.04 ppm) and Mn (≥ 0.127 ppm) portends environmental hazard to riparian users. Although the water in the river could be used for irrigation to encourage urban agriculture as practiced along the river, the gross pollution of the river underscores the need for pre-treatment of the industrial effluents before discharge into the receiving water body