Comparative Thermodynamic Theoretical Modeling of Brines From Chott Djerid, Southeastern Tunisia and Sebkha Bazer, Northeast Algeria

Abstract

The thermodynamic theoretical modeling of brines from the Chott Djerid, Southeastern Tunisia and Sebkha Bazer, Northeast Algeria between the initial solution and evaporation of 100% shows different geochemical evolutions and variable precipitated mineral species. This is due to different initial geochemical compositions, which are basically related to different geological and climatic contexts. A rigorous thermodynamic model has been presented for determining the crystallization sequence during the different stages of the evaporation process. A geochemical software program (PHREEQC) was used. Based on the analyses, PHREEQC appears the precipitation of a sequence of minerals. These results are confirmed by the mineralogical analyses (XRD results). The gradual evaporation process of brine showed that thenardite, gypsum, halite, and huntite are the feasible salts that could be extracted. Halite is the most abundant mineral along with the evaporation experiment of the two sebkhas.

Geochemical, Mineralogical and Isotopic Fracturing during the Progressive Evaporation of Chott Djerid Brine (Southern Tunisia)

“…This saline system is dominated by a semi-arid climate with an annual average of air temperature of 21.3 • C [24]. It has an area of approximately 5000 km 2 [25][26]. This endorheic area is limited to the north by the Chott El Gharsa depression to the west by the Algerian border, to the east by the Northern Chott range, and by the Saharan platform.…”