Hydrogeochemical Processes and Evaluation of Groundwater Aquifer at Sohag City, Egypt

ABSTRACT The study aims to use PHREEQC model to characterize hydrogeochemical characteristics of groundwater aquifer based on the physico-chemical properties and to understand rock-water interactions. Fifteen samples have been hydrochemically analyzed form groundwater wells located in Sohag City, Egypt. Hydrochemical characteristics were spatially depicted to understand the spatial variations such as (pH, EC, TDS, Na+, K+, Ca2+ and Mg2+, SO42−, CO32−, HCO3−, and Cl−). Groundwater quality evaluation is conducted to know the suitability for uses in various purposes. The concentration values of TDS, EC, HCO3− and Na+ are recorded above the permissible limit revealing a deterioration of water quality. The positive correlation between HCO3− and Ca2+ (r=0.62), Mg2+ and HCO3− (r=0.63), Ca2+ and Mg2+ (r=0.66), and K+ and HCO3− (r=0.66) reflects the precipitation processes, while the correlation is high between Cl− and Na+ (r=0.89) is indicating of dissolution of halite minerals. These are also supported by the results obtained from PHREEQC Model.