Fabrication and optimization of activated carbon using sisal fiber biomass through Box–Behnken experimental design

In this research work, sisal fiber (agave sisalana) was converted into activated carbon through chemical activation technique (H₃PO4 activation agent). Three different process parameters such as impregnation % on H₃PO4, the temperature of the treatment, and treatment time have been modified through Box–Behnken design. Three process parameters with three different levels have been considered for investigation, such as impregnation % was kept as 25%, 50%, 75%; treatment temperature was kept as 300 °C, 400 °C, and 500 °C; and treatment time was kept as 30 min, 60 min, and 90 min. The adsorption of Reactive Red 120 (RR 120) dye from an aqueous solution onto sisal fiber activated carbon (SFAC) was examined. Three were 17 experiments conducted according to the pattern of Box–Behnken design. Batch adsorption efficiency was measured through the methylene blue (MB) number and the iodine number. The Design-Expert software tool was used to predict the optimal conditions of the process parameters. The optimal impregnation % was 25%, time was 76 min, and temperature was 434.5 °C for MB analysis. Similar results were reported for the optimal iodine number, where impregnation % was 25%, time was 64 min, and temperature was 441.5 °C. Two different polynomial models were derived, and it was validated through correlation analysis between the actual experimental results.