In-situ synthesis of magnetic nanoparticles/wood-structural holocellulose hybrid for metal ions adsorption

Abstract

Effective removal of metal ions from water is crucial for reducing pollution during manufacturing processes. To address this issue, we have developed a block Fe₃O₄/wood-structural holocellulose hybrids (MW) for removing heavy metal ions from industrial wastewater. By employing chemical pretreatment, solvent-induced self-impregnation, and in-situ deposition, Fe₃O₄ nanoparticles were attached into the cell's lumen while also embedded within the cell walls, achieving a loading capacity of 35.89 %. The MW exhibited notable magnetic responsiveness. Adsorption experiments were then conducted to evaluate the performance of MW in adsorbing Pb²⁺, and the adsorption mechanism was elucidated based on density functional theory (DFT) calculations. The results demonstrated that MW exhibited high adsorption efficiency for Pb²⁺ (537.63 mg/g), This is primarily attributed to the porous structure of MW and the interactions among -COOH, -OH, and FeO groups within the structure with Pb²⁺. The adsorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm model. After three consecutive reuse cycles, the adsorption capacity remaining at 77.62 % after three cycles. Furthermore, DFT calculations indicated that the composite of Fe₃O₄ and cellulose could enhance the adsorption energy between Pb²⁺ and MW. This indicates that MW offers high adsorption, recyclability, and magnetic control, making it a promising material for wastewater treatment.