Valorization of cooked rice waste via activated carbon synthesis and application in removal of methyl orange dye from water

Abstract

This study explores the conversion of cooked rice waste (CRW) into an affordable, activated carbon material with effective adsorption capabilities. Activated carbon (AC) was initially produced through combustion under a nitrogen atmosphere at 550 .  The resulting charcoal was then chemically activated using phosphoric acid (H3PO4). The FT-IR, XRD, SEM, and TGA techniques were used to characterize the produced AC. The characterization analysis showed that the AC has an amorphous surface with varied pore sizes, and that CRW was richer in functional groups than the prepared activated carbon. The obtained AC demonstrates effective adsorption capabilities for removing methyl orange dye (MO), achieving a maximum adsorption capacity of 3.68 mg/g at 298 K over a 30 min contact period. Regression coefficients indicated that the adsorption behavior followed the Freundlich isotherm model and pseudo-second-order kinetics. Response surface methodology (RSM) confirmed that the predicted results were in significant agreement with experimental results. KEY WORDS: Water treatment, Methyl orange, Activated carbon, Cooked rice waste