Physicochemical, Bacteriological And Hydrogeochemical Assessment Of Ground Water Within Uyo And Itu Areas Of Akwa Ibom State, Southeastern Nigeria

Abstract

Ten (10) groundwater samples collected from boreholes in Itu and Uyo localities of Akwa Ibom State were evaluated for physicochemical, bacteriological and hydrogeochemical assessment using standard analytical techniques. Results showed average pH of 4.49, temperature of 29.14 ^oC, EC of 45.30 μs/cm; TDS of 21.60 mg/l, Hardness of 4.30 mg/l, K of 2.49 mg/l. Mg was found to be 0.74 mg/l, Ca is 13.14 mg/l, SO4 has values of 3.9 mg/l, HCO3 concentration was also found to be 1.35 mg/l, Cl  observed to be  4.07 mg/l. furthermore, NO₃ concentration was also observed to be 17.71 mg/l, Mn²⁺ had 0.049 mg/l concentration, BOD5 is 5.82 mg/l, P2O5 was found to be 12.00 mg/l, Cr is 0.025 mg/l, NH3 is 0.142 mg/l, Zn is 0.138 mg/l, Cy is 0.006 mg/l, Fe is 0.159 mg/l, Pb is 0.002 mg/l, Ni is 0.19 mg/l, Cu²⁺ is 0.034 mg/l, Turbidity is 0.40 mg/l, Salinity is 0.002 ppt, and Alkalinity is 2.40 mg/l.. Comparing these values with WHO (2011a) standards, it was discovered that some parameters, including Ni, Cr, Fe, Mn and NO₃-, had concentrations that were above the permissible limits in some locations while a few other locations showed concentrations which were within the permissible limits. Bacteriological investigations of faecal coliform count (FCC), total coliform count (TCC) and total heterotrophic count (THC) revealed an excessive presence of coliform.  Hydrogeochemical assessment revealed no evidence of saline intrusion and the groundwater is of terrestrial origin. Based on different ionic concentrations, the Piper trilinear diagram revealed two fundamental types of water; the calcium sulphate and calcium bicarbonate waters. The groundwater was classified as acceptable for agricultural purposes based on the magnesium ratio and sodium adsorption ratio, which also indicate that the groundwater is excellent, soft and suitable.