MICROBIOLOGICAL AND PHYSICOCHEMICAL QUALITIES OF IKPOBA RIVER IMPACTED BY PIPED TREATED BREWERY EFFLUENT STREAM

Abstract

The impact of discharged treated brewery effluent stream on the microbial andphysicochemical qualities of Ikpoba River which is serving as a receptacle for the treatedwastewater was investigated. Serial dilution, pour plate and multiple tube technique wereemployed in evaluating the culturable microbial diversity of the water samples and thetreated brewery wastewater. The physicochemical attributes of the freshwater and effluentsamples were ascertained using titrimetric and spectrophotometric procedures. The meanheterotrophic bacterial counts for the upstream freshwater samples ranged from 3.7 ×102cfu/ml ± 2.1 to 0. 6 × 102 cfu/ml ± 2. The mean heterotrophic fungal counts for watersamples obtained at the point of discharge ranged from 0.7×103 cfu/ml ± 6.6 to 9.7 × 103cfu/ml ± 6.1. The total coliform counts recorded for water samples obtained at thedownstream sampling point ranged from 2 MPN/105 ml to 5 MPN/105 ml. The E. colicounts for the treated brewery wastewater varied from 2 MPN/105 ml to 4 MPN/105 ml. Theobserved differences in the mean heterotrophic bacterial and fungal counts was statisticallysignificant (P<0.05). Seven bacterial and four fungal isolates were characterized andtentatively identified; Proteus vulgaris, Bacillus cereus, Klebsiella pneumoniae, Escherichiacoli, Streptococcus sp., Pseudomonas sp., Enterobacter aerogenes, Saccharomycescerevisiae, Candida tropicalis, Penicillium sp. and Aspergillus niger. The mean pH, turbidityand conductivity of the respective samples ranged from 5.63±0.05 to 6.78±0.05, 4.1 NTU±0.21 to 6.81 NTU ±0.55 and 3.3 ?s/cm ±0.25 to 73.3 ?s/cm ±6.56 respectively. Thedischarged brewery effluent stream impacted negatively on the as aesthetic quality of theIkpoba River at the point of discharge. The microbiological quality of both the watersamples and the treated effluent is very poor when compared with Federal Ministry ofEnvironment limits for potable water, hence discouraging the direct consumption of thewater sourced from the Ikpoba River at these sampling points by individuals living along thecatchment area of the river