Xanthan gum-based Magnosorbent: A selective, rapid, and high-capacity adsorbent for pH-tolerant methylene blue...

Efficient and sustainable removal of dyes from wastewater remains a critical challenge in environmental remediation. Magnosorbent, a magnetically retrievable, dual-functionalized biopolymer-based nanocomposite, was designed by integrating xanthan gum (XG), a natural and biocompatible polysaccharide, with poly (3-sulfopropyl methacrylate) (PSPMA) which is also recognized for its biocompatibility, to enable efficient, selective, and sustainable removal of methylene blue (MB) from complex pollutant systems. This design enables a synergistic combination of magnetic recoverability, pH-resilient adsorption, and selective dye affinity. Comprehensive characterization confirmed the structural, chemical, and magnetic properties of the nanocomposite. The material exhibited an amorphous nature, with a saturation magnetization of 38.075 emu/g and a BET surface area of 46.68 m²/g, supporting magnetic separability and high surface accessibility. The adsorption process followed the Langmuir isotherm model, achieving a maximum capacity of 235 mg/g, and demonstrated spontaneity and exothermic behavior. Magnosorbent showed remarkable stability and efficiency across a broad pH range (2-12), retaining high adsorption efficiency. The rapid kinetics (≥80 % removal within 5 min) and ease of magnetic recovery underscore its practical applicability. High adsorption performance for MB was maintained even in complex multi-pollutant mixtures, retaining over 72 % removal efficiency despite competition from interfering cations, heavy metal ions, endocrine-disrupting compounds, dye mixtures, and surface-active agents. The nanocomposite maintained robust performance over multiple regeneration cycles and batch-to-batch reproducibility, highlighting its reusability. These results position Magnosorbent as a scalable, eco-friendly solution for industrial wastewater treatment, with potential extensions to other environmental pollutants.