Bacterial Community of leachate from a waste-dump and an adjacent stream

Abstract

A total of 48 water samples collected from raw leachate and an adjacent stream were examined for temperature, pH and for the frequency of occurrence of bacterial isolates. The mean temperature values of the leachate ranged from 24.8oC to 28.3oC while values for the stations of the stream ranged from 23.2oC to 25.5oC. The mean pH values of the leachate ranged from pH 6.3 to 7.2 and pH values for the stream ranged from pH 6.7 to 7.9. The mean total viable aerobic heterotrophic bacterial counts for the leachate and stream ranged from, 2.5 x 106 CFU/ml to 6.5 x 106 CFU/ml and from 1.2 x 106 CFU/ml to 1.20 x 107 CFU/ml respectively. The bacteria with their frequency of isolation from the leachate and stream during the investigation are; Bacillus (26.08%), Citrobacter (4.35%), Enterobacter (4.35%), E. coli (4.35%), Klebsiella (4.35%), Nieseria (4.35%), Pseudomonas (4.35%), Shigella (4.35%), Staphylococcus (13.04%), Streptococcus (26.08%) and Vibrio (4.35%). However, this frequency of isolation is quite different from their frequency of isolation from each station. Only Bacillus sp occurred in the leachate and all the stations of the stream. Staphylococcus and Streptococcus sp occurred in the leachate and some stations of the stream. Klebsiella and Shigella occurred only in the leachate while Citrobacter, Enterobacter, E. coli, Neiseria, Pseudomonas and Vibrio species occurred only in some stations of the stream. Statistical analysis using ANOVA (F-test) showed that there is no significant difference at 5% level among the bacterial counts (population) of the raw leachate and the stations of the stream. (Journal of Applied Sciences & Environmental Management: 2002 6(2): 71-76)