A bamboo-inspired, biodegradable vanillin-chitosan aerogel for Efficient removal of microplastics and Nanoplastics from water

The pervasive contamination of aquatic systems by microplastics and nanoplastics (MNPs) poses substantial threats to environmental safety and human health, highlighting a pressing demand for eco-efficient and sustainable removal approaches. However, existing chitosan aerogel techniques encounter issues of limited adsorption capacity, and potential environmental toxicity. Drawing inspiration from the rapid fluid transport properties of fiber-reinforced bamboo cell walls, this study developed a green, vertically aligned porous vanillin-chitosan aerogel. This optimized aerogel exhibits outstanding underwater compression performance, achieving a high removal efficiency (>99%) and exceptional adsorption capacity (221.1 ± 2.22 mg·g −1 ) for polystyrene (PS) MPs. Furthermore, the aerogel maintained robust removal efficiencies (>90%) across various MNPs (including PS, polyethylene terephthalate (PET), and polymethyl methacrylate (PMMA)) and within real environmental water matrices. Notably, the material exhibited excellent reusability, retaining over 92% adsorption efficiency after five regeneration cycles. It also demonstrated remarkable mechanical durability, maintaining a 99.99% height retention and an energy loss coefficient of 0.65 after 20 compressive cycles. Under dynamic flow conditions, 1.37 g of chitosan aerogel crosslinked with vanillin (CSV2) removed 99.9% of PS MNPs within 3 h across all tested concentrations. By reconciling an exceptionally high adsorption capacity with a completely green synthesis route, this bamboo-inspired aerogel provides a safe and highly sustainable strategy for practical MNPs remediation.