Physicochemical Properties and Total Coliform Distribution of Selected Rivers in Osun State, Southwestern Nigeria

Rivers are important freshwater resources for domestic and industrial activities, and the availability of good-quality freshwater is indispensable for preventing water-borne diseases and improving quality of life, especially in communities that lack a water supply system. The physicochemical parameters and coliform distribution of some selected rivers in Osun State, soutwestern Nigeria were evaluated using standard analytical procedures. The physicochemical qualities ranged as follows: pH (6.9-7.6), temperature (26-29 degrees C), turbidity (2.28 = 9.46 NTU), electrical conductivity (229-581 mu S/cm), nitrate (0.03-0.05 mg/L), nitrite (0.00-0.01 mg/L), sulphate (3.33-20.33 mg/L), chloride ions (7.83-27.33 mg/L), dissolved oxygen (4.23-5.57 mg/L), total dissolved solids (56-184 mg/L), total hardness (78-519 mg/L) and alkalinity (50.67-146.67 mg/L). Total coliforms were detected in counts ranging from 59 to 176 CFU/100 ml of water sample. One-way ANOVA showed that pH, temperature, electrical conductivities, nitrates, nitrites, chloride, dissolved oxygen, total dissolved solid, total hardness and alkalinity were significantly different (P<0.05), whereas turbidity and sulphate were not significantly different (P>0.05) from each parameter with respect to sampling sites. Generally, results from this study suggest that the river waters are not suitable for consumption, domestic or recreational use, and confirm the importance of protecting the freshwater resources of southwestern Nigeria.