Geochemical processes of groundwater salinization in an arid area, southeastern Tunisia

Abstract

Salinization is an environmental issue that affects different regions worldwide. Geochemical approaches and statistical tools are combined to investigate the origin and process of groundwater salinization in Menzel Habib shallow aquifer. The inland aquifer from Menzel Habib area is in the northwest of Gabès, southeastern Tunisia. A total of twenty-five water samples were selected and collected in the study area. Physicochemical parameters (electrical conductivity, pH, total dissolved solids) were measured in situ, and major ions (Na, Mg, Ca, K, Cl, SO 4 , HCO 3 , F, and Br) were determined. The obtained results show a Na-Cl groundwater dominant facies (60%), Na-SO 4 (36%), and mixed water type (4%). Thus, a correlation between total dissolved solids and major ions shows the contribution of SO 4 , Cl, Na, Ca, and Mg in groundwater salinization. The salinization of groundwater is due to the dissolution of Triassic evaporites, which are related to the tectonic context of the region, and to the cationic exchange. Furthermore, statistical approaches, especially principal component analysis, reveal that the high groundwater mineralization is due to the evaporite dissolution. Multiple linear regression leads to establish a model linking total dissolved solids to the different chemical elements involved in groundwater salinization.Keyword Salinization . Groundwater . Geochemical approaches . Principal component analysis . Multiple linear regression .

Groundwater quality for irrigation in an arid region—application of fuzzy logic techniques

“…6b). That leads to confirm that cationic exchange and inverse cationic exchange with soil and aquifer materials could also be identified as main origins of major ions (Abid et al 2009;Ahmed et al 2013;Kammoun et al 2018;Dhaoui et al 2021Dhaoui et al , 2022.…”

“…As a result, negative saturation indices are registered for halite, anhydrite, and gypsum, while positive ones characterize dolomite and calcite. Thus, the main hydrogeochemistry origin should be associated to the dissolution of evaporites and dissolution/precipitation of carbonates (Farid et al 2012;Patel et al 2016;Argamasilla et al 2017;Bahir et al 2018;Mejri et al 2018;Dhaoui et al 2021Dhaoui et al , 2022Sunkari et al 2021). Some groundwater samples are represented by an adsorption of Na and release of Ca, while others are characterized by adsorption of Ca and release of Na (Fig.…”