Circular Valorization of Sugarcane Bagasse into Functionalized Activated Carbons for Low-Cost and Sustainable Sugar Decolorization

The circular conversion of agricultural residues into functional materials offers a sustainable strategy to reduce waste, lower carbon footprints, and replace resource-intensive adsorbents. In this study, sugarcane bagasse, an abundant agroindustrial byproduct, was valorized into activated carbons (ACs) through phosphoric acid activation and employed for the decolorization of remelted brown sugar solutions. Characterization by N2 sorption, X-ray photoelectron spectroscopy, and temperature-programmed desorption revealed that oxygen-containing surface functional groups, especially hydroxyl moieties, significantly enhanced colorant removal, whereas carboxylic, lactone, and quinone groups hindered adsorption efficiency. The optimized AC (BAC700) achieved >90% decolorization, surpassing commercial activated carbon and ion-exchange resin despite its moderate surface area. By substituting costly synthetic resins with waste-derived carbons, this approach reduces production costs, environmental impact, and dependence on fossil-based adsorbents. These findings highlight the importance of coupling waste valorization with surface chemistry engineering to advance sustainable separation processes in food production and related industries.