Effect of chemical modification on physicochemical properties of activated carbon derived from empty fruit bunches

Abstract The production of activated carbon (AC) from agricultural waste has garnered significant interest due to its sustainability and cost-effectiveness. This study examines the adsorption capabilities of AC derived from empty fruit bunches (EFB) waste for the removal of methyl orange (MO) dye from aqueous solutions. To enhance adsorption efficiency, the EFB-derived activated carbon was chemically modified using nitric acid (HNO 3 ) and sodium hydroxide (NaOH) to represent acidic and alkaline treatments, respectively. The effects of these chemical modifications on the adsorption performance were thoroughly explored. The results demonstrated that both modifications markedly improved the adsorption capacity of AC compared to the unmodified sample. Specifically, the 15%-NaOH-AC removed 99.3% of MO within 180 minutes, while the 15%-HNO 3 -AC achieved a 97.6% removal in the same time frame. The superior performance of the 15%-NaOH-AC is attributed to its significantly larger BET surface area of 543.35 m 2 /g, in contrast to just 2.24 m 2 /g for pure AC. Additionally, the 15%-NaOH-AC exhibited a well-defined pore structure, as observed in FESEM images, which further enhanced its MO adsorption capacity.