Hydrogeochemical processes and water-rock interaction of groundwater in al-Dammam aquifer at Bahr al-Najaf, central Iraq

Abstract EN

The hydrogeochemistry of groundwater in the Dammam aquifer was studied via 22 wells in Bahr Al-Najaf basin in order to identify the main hydrogeochemical processes and rockwater interaction.

Groundwater in the Dammam aquifer is characterized by neutral to slightly alkaline hard water, excessively mineralized, and slightly brackish water type, in which Na+ and SO4 2– are the dominant ions.

The average contribution of cations in the aquifer is Na+ (24%), Ca2+ (14%), Mg2+ (11%) and K+ (1%); whereas the contribution of anions is SO4 2– (23%), Cl– (20%) and HCO3 – (7%).

Rock-water interaction processes are identified to include dissolution (carbonates, sulfates, halite, and some silicates such as clay minerals), leaching, and cation exchanges, while evaporation has only a very little impact.