Fe-silicalite for the removal of cationic emerging contaminants

Abstract

The effective and large-scale removal of emerging cationic contaminants requires low-cost materials with an inherent negative surface charge, thus eliminating the need for expensive surface functionalization. To address this, Fe-silicalite zeolite was synthesized via a simple hydrothermal route using an industrial-grade poly(N-silicate) solution (FeS-I) and compared to a counterpart obtained from analytical-grade sodium metasilicate (FeS-A). Structural, morphological, and textural characterizations confirmed the formation of well-defined MFI structures with isomorphic Fe substitution. Adsorption performance was evaluated using metformin as a model cationic pharmaceutical contaminant. FeS-I exhibited superior kinetic behavior, achieving a removal efficiency of 97% in as little as 45 minutes, demonstrating that low-cost industrial precursors can yield highly efficient and sustainable adsorbents for water remediation.