Vol. 2, Issue 10 (2015)
Hydrochemical and Bacteriological Evaluation of Awefin Springwater Osin-Ekiti, Southwestern Nigeria
Author(s): A.O. Talabi
Abstract: Awefin Springwater in Osin-Ekiti, Southwestern Nigeria has contributed significantly to domestic and agricultural activities of Osin rural community. The water was consumed without consideration for its potability. This study examined the hydrochemistry and bacterial contents of Awefin springwater with a view to characterize the water and determine its suitability for drinking and irrigation. The methodology entailed collection of 30 samples (3 sets of samples per location) from the spring at interval of 10m downstream into new prewashed polyethylene bottles. Standard method was followed in the collection, preservation and analysis of the springwater samples. Temperature (°C), pH and EC (µS/cm)) were measured in-situ using a Multiparameter portable meter (TestrTm 35 series). Sodium and potassium were estimated using flame photometer (model: synthronic flame photometer 128) while Ca2+ and Mg2+ were determined by titrimetric standard EDTA. Argentometric (AgNO3) titration was employed in the estimation of Cl- concentrations; SO42- was by the turbidimetric method while Ultra Violet–visible spectrophotometer was employed in the determination of NO3- concentrations. Nutrient agar medium was used to obtain plate count of living bacteria while Coliform count was achieved using a lactose medium inoculated with serial dilution of the sample. Results obtained were compared with internationally and locally approved standards for drinking water while data evaluation was carried out employing SPSS. 17.0. The results revealed that the pH ranged from 8.40 – 11.3, EC from 91 – 138 (µS/cm), TDS and TH ranged from 68. 25 – 103.50 (mg/L) and 12.37 – 21.53 (meq/L) respectively. The pH revealed alkaline water while the EC, TDS and TH have values within approved standards of drinking water. All the major ions concentrations were within approved standard values for drinking water (chemically potable) with major cations in mg/L ranged from1.51 (Mg2+) – 12.13 (Na+) while the anions was between 0.00(SO42-) mg/L and 115.21 (Cl-) mg/L. The total bacterial counts and coliform counts ranged from 0.7 x 102 – 1.62 x 105Cfu/100ml and 0.00 – 1.92 x 106 Cfu/100ml respectively. The springwater was characterized as NaCl water (90%) with minor CaCl water type (10%). Estimated irrigation quality parameters (Permeabilitry Index (PI), Sodium Adsorption Ratio (SAR) and soluble sodium product SSP) indicated that Awefin springwater was suitable for irrigation while assessment based on Kelly Ratio (KR) and Magnesium Adsorption Ratio (MAR) revealed 10% compliance. This study revealed that Awefin springwater was low mineralized, chemically potable but polluted bacteriologically. The PI, SAR and SSP signified good quality springwater for irrigation purposes while KR and MAR were indicative of non suitability.