Hydrodynamic modelling, molecular interactions, and life cycle assessment of corncob‐derived cellulose–chitosan beads for Coomassie Brilliant Blue removal

In this work, cellulose extraction from corncob was performed combining alkaline and deep eutectic solvent pretreatment, which was subsequently combined with chitosan through ionic gelation to produce cellulose–chitosan composite beads. Biopolymer beads were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM), which confirmed suitable morphology, porosity, and adsorption properties. To remove persistent dyes such as Coomassie Brilliant Blue (CBB), a batch adsorption study followed pseudo‐second‐order kinetics, with Langmuir isotherm fitting, yielding a maximum adsorption capacity of 0.749 mg/g, indicating favourable monolayer adsorption. Fixed‐bed column studies demonstrated maximum adsorption capacity of 0.408 mg/g. The analysis of computational fluid dynamics (CFD) showed that the combination of 3 cm column diameter and 8 cm bed height creates optimal hydrodynamic conditions, mainly considering the lowering in superficial velocity and the high turbulent mixing. Molecular docking also confirmed CBB's sturdy bindings to the cellulose–chitosan surface via electrostatic attraction, hydrogen bonding, and van der Waals forces. A gate‐to‐use life cycle assessment for treatment of 1 m 3 dye‐contaminated wastewater with cellulose–chitosan beads revealed 84.18 kg CO 2 equivalent emissions, with electricity and chemical consumption continuing to be the predominant sources. However, the sun‐drying of corncobs decreased emissions by 43%, relative to hot‐air drying for the production of cellulose.