INVESTIGATION OF THE POLLUTION LEVEL IN RIVER OOKUN DUE TO DISCHARGE OF SOAP EFFLUENTS

Abstract

The pollution effects of effluent discharges from a soap making industries into surface waters were studied over both the wet and dry seasons, using River Ookun and Global Soap industries in Ilorin, Kwara State. Samples are collected at effluent discharge point (Global soap industry), River Ookun (Yidi/Irewolede Area) and at a point, about 50m away from effluent discharge. These were analysed in the water resources laboratory to determine quantity from some physico-chemical parameters, which ranged as follows, for both season: Temp: 29-30^oC, Colour 100-500 TCu, pH: 8.5-11.31, conductivity: 0.35-300(Vmho/mg), TDS: 0.18-150(mg/l), Alkalinity: 150-900(mg/l), Total Hardness: 45-120(mg/l), turbidity: N0₃: 1.2-3.9(mg/l), SO₃: 0.14-0.23(mg/l) cl: 60-500(mg/l), D0₅: 4.1-0.1(mg/l), D0₅: 0.5-0.1(mg/l), BOD₅: 20.4-0.6(mg/l), Fe: 2-3(mg/l), Zn²⁺: 0.1-0.2(mg/l).

The result of analyses as shown in the range listed above and also given in the summary, showed a direct relationship between samples of effluent and those from River Ookun. A comparison of the physico-chemical properties of the effluent (listed above) with limit for discharges to surface waters as presented in the extract from the Federal Environmental Protection Agency (FEPA) Monograph also showed non-compliance to the limit. Especially the pH, colour, chloride, iron and BOD were far beyond the limit. Likewise, a comparison of the physico-chemical properties of River Ookun for both seasons fell short of the limits for Rivers e.g. pH (6 – 9), Alkalinity (50), Iron (0.5), BOD (10 – 20), as presented in the extract from FEPA monograph.

The close relationship between the properties of the samples of effluent and those from RiverOokun and the comparison with the given limit implied that the river is polluted in both seasons (i.e all round the year). The river therefore, can no longer fulfill as many purposes especially domestic uses as it was previously put to before the existence of the soap making industry. The uses of River Ookun are now actually restricted to laundering and washing of vehicles, especially because short of the limit for Potability, Recreation, fish Culture, Industrial and Irrigation.