Seasonal Dynamics of the Microbial and Physicochemical Characteristics of Streams and Boreholes in Uzuakoli, Eastern Nigeria

Abstract

Water samples from twenty water sources (fifteen boreholes and five streams) in Uzuakoli, Nigeria were collected for the period of 6 months covering the dry and rainy seasons to assess the level of contamination. The Microbiological characteristics including heterotrophic counts, coliform counts and physicochemical parameters includes pH, turbidity, dissolved oxygen, calcium, potassium, nitrate, magnesium and phosphate were evaluated using standard methods. The total Heterotrophic counts for the borehole during the dry and rainy season were 8.3 x 10³ cfu/ ml and 10.8 x 10⁴ cfu/ ml. The Heterotrophic counts for the stream were 12.7 x 10⁴ cfu/ ml and 17.8x 10⁶ cfu/ ml. The frequency of occurrence of the isolates are Staphylococcus aureus 63% in borehole and 85% in streams, Pseudomonas aeruginosa 49% in boreholes and 95% in streams, Proteus sp 52% in boreholes and 97% in streams, Streptococcus sp 46% in boreholes and 53% in streams, Enterobacter aerogenes 33% in boreholes and 63% in streams, Escherichia coli 16% in boreholes and 53% in streams and Salmonella sp no percentage in boreholes and 40% in streams. The result shows a significant difference at (P≤0.05) for the bacterial isolates. The physicochemical parameters of the borehole and stream water samples during the dry and rainy seasons were determined. The temperature ranged from 25^oC 32^oC; pH ranged from 5.3 8.1; turbidity ranged 0.03 3.23; dissolved oxygen ranged from 3.45–7.40mg/l; biochemical oxygen demand ranged from 1.20–4.32mg/l; chemical oxygen demand ranged from 2.50–5.21mg/l; Calcium ranged from 0.81–5.64mg/l; potassium ranged from 1.01–4.22mg/l; Nitrate ranged from 1.49–4.02mg/l; magnesium ranged from 0.13–2.20mg/l; phosphate ranged from 0.51–2.01mg/l. The water samples were all within the WHO limits apart from sample from Iyi Agbozu that had temperature of 32^oC.