Geochemistry and ionic interaction in the Bizerte Lagoon waters (Northern Tunisia)

Abstract

The Bizerte Lagoon is classified in the category of medium salinity environments. The lagoon geochemistry, with regard to the major ions, is essentially controlled by the continental contributions and interactions with the marine environment. The geochemical analyses of the major ions as well as their behaviour in the lagoon water permitted to describe the eventual ability of a solution chemical composition, to precipitate different minerals. Sampling and geochemical analysis of the principal ions (Ca++, K+, Na+, Mg++, Cl-, SO42- and HCO3-) at the water surface (0 to 2 m) and at the bottom (over 2 m) of the lagoon (9 stations), in the Channel (3 stations) and in the bay of Bizerte (3 stations), was performed monthly during one year. The results for the Bizerte Lagoon waters show that only carbonates and gypsum can precipitate. Key words: Water, Bizerte lagoon, ionic ratio, precipitation.