Functionalized b-zeolite with -NH₂ groups as a highly efficient adsorbent for the treatment of water contaminated with cadmium and zinc

This study investigates the adsorption performance of modified synthetic b-zeolite for the removal of heavy metal ions, specifically zinc (Zn²⁺) and cadmium (Cd²⁺), from aqueous solutions. To enhance the surface properties and increase the number of functional sites suitable for metal ion binding, b-zeolite was functionalized with the organosilane agent (3-aminopropyl)triethoxysilane. The obtained results revealed a substantial improvement in adsorption capacity - from 17.5 mg/g to 40.7 mg/g for Zn²⁺, and from 21.2 mg/g to 62.3 mg/g for Cd²⁺ - following the applied modification. Kinetic analysis indicated that the adsorption process follows a pseudo-second-order model with a high correlation coefficient (R² > 0.99), suggesting that chemisorption is the dominant mechanism governing the metal ion uptake on the surface of the modified adsorbent.