Cost‐Effective Chitosan‐Cellulose Acetate Floatable Beads Embedded With Bentonite for Oil Spills Clean‐Up

ABSTRACT A novel chitosan/cellulose acetate‐bentonite composites (CS/CA@BTX) was successfully developed as an efficient and environmentally friendly adsorbent for oil spill removal from aqueous environments. The composites were synthesized with BT contents of 7.69 and 14.29 w/w% and thoroughly characterized using FTIR, TGA, DSC, XRD, SEM, and BET to evaluate their structural, thermal, and surface properties. Notably, the CS/CA@BT2 composite (~14.29 w/w% BT) exhibited the highest oil adsorption capacity of 434.8 mg/g, demonstrating superior performance compared to unmodified CS/CA and lower‐BT composite (CS/CA@BT1) under optimal conditions. The incorporation of BT into the CS/CA matrix enhanced surface area, porosity, and hydrophobicity, resulting in improved oil sorption performance. The effects of key operational parameters, including adsorption contact time, oil concentration, adsorbent dosage, solution pH, salinity, and agitation speed, were systematically investigated, with optimal adsorption achieved at pH 8. Adsorption kinetics followed the pseudo‐second‐order model, indicating a dominant chemisorption mechanism, while equilibrium data were well described by both Langmuir and Freundlich isotherms, confirming the coexistence of monolayer and heterogeneous multilayer adsorption. Thermodynamic studies revealed that the adsorption process was spontaneous, favorable, and exothermic, with decreased randomness at the solid–solution interface. This study highlights the synergistic integration of natural polymers and BT to produce a low‐cost, biodegradable, and high‐performance oil adsorbent suitable for real‐world environmental remediation applications.