From waste to sorbent: recycling polymers and natural materials for sample preparation and water remediation

The increasing demand for sustainable analytical practices and environmental remediation strategies has intensified research into alternative sorbent materials derived from recycled or low-cost sources. This review summarizes recent advances (2016-2025) in the reuse of polymeric waste and natural materials for sample preparation and water purification. Recycled synthetic polymers, namely polystyrene, polyethylene, polypropylene, polyvinyl chloride, and polymethyl methacrylate, are examined as sorbents, following physical, chemical, or thermal treatments aimed at enhancing their surface activity and selectivity. In parallel, single-use commercial items (e.g., adhesive tape, paper supports, wooden sticks) and natural materials (e.g., cotton, kapok fibre, cellulose, sporopollenin) are evaluated for their potential integration into circular workflows, transforming disposable products into reusable components. Modification strategies including sulfonation, solvent-based restructuring, functionalization with chelating agents, and composite formation are discussed in relation to dispersive-SPE, magnetic SPE, and membrane-based techniques, with emphasis on greenness and scalability. By integrating waste reuse, natural matrices, and functional design, this review highlights pathways for developing next-generation sorbents that align with circular-economy principles and green analytical methodologies.