Eco‐Sustainable Alginate‐Embedded Saraca asoca ‐SnO 2 Nanosorbents for Continuous‐Flow Remediation of Fluoride and Toxic Dyes
Shikha Jyoti Borah, Roopal Pal, Tripuresh Shanker Dwiwedi, Ravi Kant, Manoj Khanna, Amod Kumar, Kashyap Kumar Dubey, Ravi Verma, Vinod KumarABSTRACT
Harnessing the potential of natural precursors for sustainable nanomaterials, a Saraca asoca ‐SnO 2 nanocomposite (SA:SnO 2 ) was synthesized and immobilized within an alginate biopolymer to create a versatile, eco‐friendly adsorbent for water purification. The hybrid material effectively demonstrated defluoridation and adsorption of toxic triphenylmethane cationic and azo anionic dyes. Detailed physicochemical characterization using PXRD, SEM, TEM, and FTIR techniques, confirmed the integration of spherical SnO 2 nanoparticles within irregularly‐shaped Saraca asoca , while SEM was used to confirm the immobilization of SA:SnO 2 within a stable, porous alginate matrix. Through systematic batch adsorption studies, the optimized SA:SnO 2 composition (1:0.08) revealed dual‐contaminant removal efficiencies for dyes and fluoride ions, under moderate operational conditions. To determine process dynamics, RSM‐CCD was applied to provide predictive insights into the influence of operational variables on adsorption performance. The adsorbent exhibited recyclability, retaining efficiency across multiple regeneration cycles for both defluoridation and organic dyes removal. Transitioning beyond batch‐scale validation, the composite was implemented in a continuous‐flow column configuration, achieving 90% fluoride removal, along with 84% (CR) and 95% (MG) dye removal. This work establishes Saraca‐asoca as a promising, green‐engineered adsorbent, bridging nanoscale materials innovation and scalable wastewater treatment.