Quality and hydrogeochemistry appraisal for groundwater in Tenth of Ramadan Area, Egypt

Abstract

Groundwater at Tenth of Ramadan area, Egypt, is the main source of water supply and it is ranked as high pollution risk area due to the high infiltration rate of the existing unlined oxidation ponds and the wastewater based-irrigation in the reclaimed desert. This investigation aims to evaluate groundwater quality and the spatial distribution of their ions, determine the chemical species (forms) of contaminated ions, and examine the process of water-rock interactions represented by the hydrogeochemical processes (ion exchange, dissolution, and precipitation) at Tenth of Ramadan area, Egypt. Eighteen water quality parameters were determined in triplicate samples collected from twelve wells in July 2017. Visual MINTEQ model was applied for geochemical speciation of cations, anions, trace and heavy elements in groundwater samples. The hydrogeochemical indices were used for investigating the quantity of changes in the chemical composition of groundwater. Outcomes revealed that the trend of spatial pollution for eleven water quality parameters is Site 3> Site 1> Site 2. The geochemical speciation indicated that Ca2+, K+, Mg2+, Na+, Cl−, SO42-, NO3−, F−, HCO3−, and Fe2+ are distributed as free ions. Hydroxides of Al3+, Fe3+ and carbonate of Pb2+ are predominant. The free ions of cadmium are accessible within the absence of dissolved organic carbon (DOC). The results suggest that evaporation, dissolution, and precipitation play an essential control on the groundwater composition within the aquifer. The reverse ion exchange process is more effective than the ion exchange process in controlling the water composition for 58% of samples. Hence, groundwater requires more advanced treatment.