Interaction of Rutba-Dhabaa Groundwater with the Mulussa Aquifer Host Rocks, Western Iraq

Abstract

Mulussa aquifer extended the area of Rutba-Dhabaa, Western Iraq, has been studied in order to determine the most important chemical functions and interaction between rocks and groundwater (Groundwater–rocks interaction). The results of wet and dry periods indicated that Ca2+ and SO4 2- in the groundwater are the dominant ions. Average of Hydrogen Number (pH), Total Dissolved Solids (TDS), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chlorine (Cl-), sulfate (SO4 2-), bicarbonate (HCO3 -) and nitrate (NO3 -) are 7.43, 718.25 mg/l, 120.8 mg/l, 40.875 mg/l, 32.865 mg/l, 2.93 mg/l, 103.527 mg/l, 195.9 mg/l, 214.85 mg/l and 4.275 mg/l respectively in the dry period, while its averages 7.33, 664.2375 mg/l, 114.25 mg/l, 35.8 mg/l, 29.28 mg/l, 2.33 mg/l, 90.3 mg/l, 181.1 mg/l, 203.85 mg/l, and 3.6 mg/l respectively in the wet period. The groundwater is characterized by low alkalinity hard to very hard water, between moderately and excessively mineralized water, and fresh to slightly water in both periods. Rock–water interaction processes are indicating that there is a possible contribution of the seawater in Mulussa aquifer, the dominant process is limestone–dolomite weathering, where the source of calcium is rather than gypsum or silicates rocks, and contribution of calcite more than dolomite in the Mulussa aquifer.