Preparation of chalcone modified polyHIPE for removal of aluminium ions from water

Abstract Aluminium contamination in aquatic environments is an increasing concern because elevated Al³⁺ levels in water resources may pose environmental and human health risks. Therefore, this study addresses the need for cost-effective, chemically tunable and efficient adsorbents for removing aluminium ions from aqueous media as part of sustainable water treatment strategies. In this study, a chalcone-functionalized polymeric adsorbent (Ch-polyHIPE) was developed via the high internal phase emulsion method for the efficient removal of Al³⁺ ions from aqueous solutions. The material, obtained through a multi-step functionalization process involving chlorosulphonation, sulphonamidation and Claisen–Schmidt condensation, was comprehensively characterized using scanning electron microscopy-EDX, FTIR, X-ray Photoelectron Spectrometer and Brunauer–Emmett–Teller analyses. The adsorption performance was systematically evaluated with respect to key parameters, including adsorbent dosage, pH and initial Al³⁺ concentration. The maximum adsorption capacity was achieved at pH 4.0, reaching 56.8 mg g⁻¹. The equilibrium data were best described by the Langmuir isotherm model, indicating monolayer adsorption on a relatively homogeneous surface. Kinetic studies further demonstrated that the adsorption process follows a pseudo-second-order model, suggesting that chemisorption plays a dominant role. Additionally, theoretical calculations supported the strong affinity of chalcone functional groups toward Al³⁺ ions through complex formation, in good agreement with experimental observations. The findings indicate that Ch-polyHIPE materials have the potential to serve as an effective platform for aluminium removal in water treatment applications.