Effect of storage on rainwater quality of selected locations within Benue State, Nigeria

Samples of stored rainwater were collected from Ojo and Adoka areas of Benue State and analysed for physicochemical properties, heavy metals and antimicrobial parameters using standard methods in order to determine the quality of stored rainwater. The results of the study indicate physicochemical parameters such as temperature, colour, pH, electrical conductivity, total dissolved solids (TDS) and total hardness to be within the acceptable limit for drinking water, while nitrates, chloride, phosphates and sulphates were observed to be 3.33–14.00 mg/L, 24.83–59.90 mg/L, 0.13–0.19 mg/L and 7.55–8.39 mg/L, respectively. Dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) had values of 1.40–1.70 mg/L, 1.63–1.66 and 163.33–193.33, respectively. Heavy metal ions in the samples were found to be aluminum (0.104 mg/L) and chromium (0.012 mg/L). Zinc was found to range between 0.451 and 1.47 mg/L, while iron ranged from 0.57 to 1.606 mg/L. Cadmium, nickel and lead were in the range of 0.014–0.020 mg/L, 0.54–2.332 mg/L and 0.006–3.143 mg/L, respectively. Coliform count ranged between 130.00 and 402.00 (cfu/100 mL). All the parameters tested except coliform count were found to be within acceptable limits by the World Health Organization (WHO) and the Nigerian Standard for Drinking Water Quality (NSDWQ) guidelines.