Effluent discharge and stream pollution by a rubber factory: a case study of field 20 stream in Odukpani, Cross River State

Abstract

Increases in socio-economic activities worldwide have been accompanied by a faster growth in pollution stress on especially the aquatic environment. In Nigeria, there are many cases of aquatic pollution that have not been documented. Water quality investigation of Field 20 Stream in Pamol (Nigeria) Limited Estate, Odukpani, Cross River State, was conducted weekly between April and June 2004 spanning a period of 10 weeks. The study revealed that the stream has been heavily polluted by effluents discharge into it. The investigation revealed marked changes between the control point and the downstream station with respect to parameters such as turbidity (from 4+0.7 to 19+ 0.9 F.T.U.) and colour (from 42 + 1.4 to 148 + 1.16 Pt-Co Units), which were above the WHO (1984) permissible limits for inland waters (5.0 F.T.U. and 15.0 Pt-Co Units respectively). Also the variation in dissolved oxygen between the upstream station (5.3+ 0.18 mgl-1) and downstream station (4.4 + 0.08 mgl-1) was below the WHO (1984) limit of>5.0 mgl-1 of dissolved oxygen in water for domestic purposes. Hence the water was considered to have been polluted by the effluents discharged into it. Variations in some other measured parameters between the upstream and the downstream stations though still within the WHO (1984) permissible limits were noticed. The rubber effluents were also analysed and were found to be high in turbidity (68+0.9 F.T.U), low in dissolved oxygen (1.7 + 0.7mgl-1), high again in total hardness (512 +3.2mgl-1), moderate in acidity (6.41+0.6) and very high in colour (510+7.8 Pt-Co Units). Mitigation procedures on the control of the pollution resulting from the rubber factory, for example the decolourization of the highly coloured effluents before the discharge were recommended. African Journal of Educational Studies in Mathematics and Sciences Vol. 2(2) 2004: 79-90