Impact of Hydrochemical Processes on The Groundwater Quality Southwest Sinai Egypt. By Ehab Zaghlool

Abstract The evolutionary mechanisms and potentiality development of the five aquifers in the southwestern Sinai Peninsula were detected using the hydrogeochemical, isotopic, and water quality characteristics. Hydrochemical and isotopic data reveal distinguishing between shallow, evaporation-dominated resources and deep, rock-water interaction regimes. Highly mineralized brackish waters have been produced in the shallow Quaternary Aquifer by kinetic evaporation and agricultural return flows. Mineral dissolution, silicate weathering and structurally mediated fault mixing control the Nubian Sandstone, Carboniferous Sandstone, Cambrian-Ordovician and fractured Basement aquifers. Sustained by unevaporated paleo recharge from ancient humid climates, the Nubian Sandstone represents the freshest, most viable reservoir for domestic supply and agricultural irrigation. While the fresher aquifers demonstrate major-ion suitability for agricultural expansion, active geogenic weathering across all five stratigraphic units causes pervasive exceedance of World Health Organization (WHO, 2022) drinking water thresholds for \(\:\text{Pb}\), \(\:\text{Cd}\), and \(\:\text{Cr}\). Consequently, a stratified management strategy is recommended, prioritizing the Nubian Sandstone for municipal utilization while mandating targeted remediation technologies to mitigate heavy metal toxicity prior to domestic consumption.