Fawzia Al-Ruwaih

Higher sulfate concentration in Kuwait’s irrigation water poses serious risks to plant health, as many crops have limited tolerance for such high levels. The study is the first attempt in Kuwait to address the elevated sulfate concentrations in the clastic aquifer of northern Kuwait through numerical modeling and geochemical techniques. The geochemical analytical results reveal that groundwater in northern Kuwait is alkaline, with ion abundances in the order of Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and Cl⁻ > SO₄²⁻ > NO₃⁻ > HCO₃⁻. Sulfate concentrations range from 1200 to 3865 mg/L, with the highest levels found in areas near agricultural zones, raising concerns about the viability of this groundwater for consumption and irrigation without treatment. A likely impact of anthropogenic influence due to the application of fertilizers is observed due to the good correlation between NO₃⁻ and SO₄²⁻. Sulfide oxidation and sulfate mineral weathering also increase the concentration of SO₄²⁻ ions in groundwater. Apart from oxidation, the inferences from geochmical modeling indicate dissolution as due to the undersaturation states of major sulfate minerals (gypsum/anhydrite). Numerical simulations further confirmed that the groundwater chemistry is driven by mineral dissolution, ion exchange, and anthropogenic influences, with key calibrated parameters including a longitudinal dispersivity of 10 m, an adsorption coefficient of 1 × 10⁻⁶ [1/(mg/L)], and a chemical reaction rate of 5 × 10⁻⁵ [1/day]. These findings underscore the critical need to manage sulfate levels in the aquifer to prevent adverse effects on water quality and usability, offering essential guidance for developing sustainable water management practices in northern Kuwait.

Al-Atraf field, is located southwest of Kuwait City, the groundwater is produced from the Kuwait Group aquifer. The objectives are to identify aquifer type and its characteristics. The major geochemical processes operating in the aquifer have to be revealed. In addition, to evaluate the groundwater quality and its suitability of drinking and agriculture usage, an investigation was carried out by estimating physiochemical parameters like pH, EC, TDS, TH, Na+, K+ Ca2+, Mg2+, Cl−, HCO3−, SO42−, total alkalinity, and SiO2. Irrigation parameters like SAR, %Na, RSC, potential salinity, magnesium ratio, Kelly?s ratio, permeability index, and chloro-alkaline index have been determined. The aquifer is confined and occupied by brackish groundwater mainly of NaCl type. Gibb?s plot suggests that the chemical weathering of rock primarily controls the chemistry of the study area. WATEVAL program revealed that the main geochemical processes are silicate weathering, dissolution, precipitation, and reverse ion exchange. WATEQ4F indicates that the groundwater is oversaturated with respect to calcite and dolomite and undersaturated with respect to gypsum and anhydrite. The high total hardness and TDS identify the unsuitability of groundwater for drinking, while irrigation parameters indicate that this water cannot be used on soil without special management for salinity control and salt tolerance plants.