Delignified and surface-engineered wood for microplastic removal in water treatment

Microplastics (MPs) pose a growing environmental threat due to their persistence, ubiquity, and capacity to adsorb toxic co-contaminants. Conventional water treatment systems are often ineffective in removing these particles, highlighting the need for sustainable and efficient adsorbent materials. This study investigates delignified wood as a bio-based adsorbent for MP removal. Selective lignin extraction generated a highly porous cellulose scaffold while preserving the natural microchannel structure. To enhance adsorption performance, the cellulose was coated with the cationic surfactant cetyltrimethylammonium bromide (CTAB) in a NaOH/urea solvent system and subsequently, strengthening electrostatic and hydrophobic interactions with MPs. SEM imaging revealed a porous, intact morphology with accessible channels, while ATR-FTIR and XPS analysis confirmed lignin removal and CTAB incorporation. Zeta potential measurements indicated a charge shift from −14 mV to +22 mV, confirming successful cationization. The modified wood eventually, achieved removal efficiencies of 99% for polystyrene (PS) and polyvinyl chloride (PVC) that maintained more than 90% efficiency over multiple cycles, and 92% for poly(butylene adipate- co -terephthalate) (PBAT) that maintained above 80% efficiency over multiple cycles. Microscopy provided visual evidence of MP capture on the adsorbent surface. Overall, the results demonstrate that delignified and chemically modified wood represents a sustainable, scalable, and high-performance platform for microplastic filtration in water treatment applications.