Valorization of calcium phosphate glasses: A sustainable and eco-friendly approach to methylene blue dye adsorption from wastewater

This study explores the valorization of calcium phosphate glasses as efficient materials for removing textile dyes from aqueous solutions. Specifically, it examines their potential to adsorb methylene blue (MB), contributing to the reduction of the environmental impact caused by cationic dyes. After detailed characterization, the used phosphate glasses are amorphous, porous and rich in active adsorption sites. The influence of adsorbent dose, time and initial dye concentration on adsorption onto calcium phosphate glasses were studied. The Freundlich isotherm model and the pseudo-second-order kinetic model best describe the adsorption of MB onto the developed calcium phosphate glass material, with a maximum adsorption capacity of approximately 66.43 mg/g at pH 9. Finally, calcium phosphates glasses material shows a good potential as an adsorbent for cationic dyes removal from wastewater.