ABSTRACT

The effects of abattoir effluents on the water quality of Aba River was studied. Quantitative and physico-chemical. examinations of the samples revealed that there was an upstream-downstream bacterial variations from the abattoir site (P< 0.05) with upstream 2 showing initial lower counts (1.18 x 106 cfu/ml), while the maximum was observed at the abattoir (2.03 x 108 cfu/ml). The predominant bacterial forms include; Staphylococcus spp., Streptococcus faecalis, Escherichia coIl, Salmonella spp., Bacillus and Clostridium spp. Sulphate, nitrate, phosphate and dissolved solids levels in the samples ranged between 255.5 - 429 mg/I, 272 - 579.5mg/I, 17.21 37.35mg/I and 0.04 - 0.14% respectively. Biochemical oxygen demand (BOD) level ranged between 4.0 - 8.0mg DO/I. The results revealed anthropogenic enrichment and implicated urban, abattoir, industrial wastes and run-off water transporting metals from land-derived wastes. The Levels of dissoLved(O.11), pH(6.4), hardness(21.47), calcium(23.97), magnesium(1 .81) and zinc(4.81) were Lower than expected despite heavy loadings from urban, abattoir and industrial wastes. The implication is that the waste assimilation capacity of the river is high, a phenomenon attributable to dilution, continuous water exchange, sedimentation and depuration processes. The high bacterial counts obtained along the river course is of public health significance and the risk associated with the domestic use of the river water calls for the need to plan an adequate pollution control strategy for Aba river.