Effective decontamination of Ca and Mg hardness from groundwater using innovative muscovite based sodalite in batch and fixed-bed column studies; dynamic and equilibrium studies.

A novel form of sodalite was synthesized from muscovite (M.SD) as low-cost softening material for both Ca and Mg ions from real groundwater in batch and column studies. The sodalite sample showed significant surface area (105 m/g) and ion exchange capacity (87.3 meq/100 g) which qualifies it strong for softening applications. The incorporation of the M.SD as a fixed bed in column system at a fixed thickness of 4 cm and flow rates of 5 mL/min resulted in removal percentages of 90.5% and 92.2% for Ca and Mg, respectively at pH 7.6. Considering the real concentrations of the ions (Ca (233 mg/L) and Mg (114 mg/L)), the M.SD bed has the ability to reduce their concentrations according to the recommended limits (75 mg/L for Ca and 50 mg/L for Mg). These conditions resulted in purification of about 8.1 L and 8.7 L with breakthrough intervals of 1380 min and 1440 min; and saturation interval more than 1620 min for Ca and Mg, respectively. The M.SD columns' performances were described considering the assumption of the Thomas model, Adams-Bohart model, and Yoon-Nelson model. The batch studies demonstrate the uptake of both Ca and Mg ions according to the Pseudo-First order kinetics and Langmuir equilibrium behaviour. Considering the values of Gaussian energies (0.77 KJ/mol (Ca) and 1.36 KJ/mol (Mg)), the uptake of these ions occurred by homogenous reactions of monolayer form and physical nature. The thermodynamic studies declared the spontaneous properties of the reactions and their exothermic properties.