Hydrophobic and Robust Sugarcane Bagasse-Based Biosorbents for Oil Spill Cleanup: Synergy of Hydrothermal Treatment and Cellulose Nanofibril Reinforcement

Abstract

Lignocellulosic fibers, particularly those derived from agro-industrial residues, offer a promising alternative for sustainable oil sorbents. However, their practical application in oil spill remediation is often limited by insufficient mechanical resistance, poor hydrophobicity, and challenges in cost-effective processing. To address these limitations, this study proposes a novel approach aligned with Green Chemistry principles, developing an oil sorbent entirely from sugarcane bagasse (SCB) through a sustainable two-step process. First, the biomass was deconstructed via physical milling and hydrothermal treatment with water at 200 °C. Then, the fiber network was reconstructed by incorporating 0.1 wt % cellulose nanofibrils (CNFs) derived from SCB, followed by oven-drying. This is the first report to explore the synergistic effect of redeposited lignin nanoparticles (LNPs) and CNF reinforcement to produce a robust and hydrophobic sorbent from SCB. The resulting sorbent exhibited enhanced mechanical resistance, supporting loads greater than its own weight without structural failure. It also showed inherent hydrophobicity and high oleophilicity with absorption capacities of 4.1 g/g for corn oil, 3.5 g/g for light crude oil, and 5.1 g/g for medium crude oil. Microscopy analyses confirmed the presence of LNPs on the fiber surfaces after hydrothermal treatment, contributing to hydrophobicity alongside micro- and nanoscale surface roughness from fiber packing and LNPs. This work demonstrates how hydrothermal treatment combined with CNF reinforcement can effectively convert sugarcane bagasse into a high-performance, cost-effective, and eco-friendly sorbent for oil spill remediation.