Mesoporous high-surface-area activated carbon from biomass waste via microwave-assisted-H3PO4 activation for methylene blue dye adsorption: An optimized process

Abstract

In this study, rubber seed pericarp (RSP) biomass wastes (specific surface area = 0.79 m2/g) were converted into mesoporous high-surface-area activated carbon (RSP-AC) (specific surface area = 1245.7 m2/g) via microwave heating process using H3PO4 as an activating agent. The optimum activation conditions were determined by using response surface methodology with Box-Behnken design (RSM-BBD). The best activation conditions for RSP-AC preparation were found to be impregnation ratio 1:2 (RSP:H3PO4), radiation power 800 W and radiation time 15 min. The effectiveness of RSP-AC material towards removal of methylene blue (MB) dye from aqueous environment was evaluated and optimized by RSM-BBD. The RSP-AC shows effective and fast removal of MB (100 mg/L) of 92 % within 10 min, and at optimum working conditions of RSP-AC dose 0.05 g, and solution pH 7.8 as confirmed by RSM-BBD. The maximum adsorption capacity of RSP-AC towards MB was found to be 347.8 mg/g at 25 ± 2 °C. This result indicates that RSP-AC is a promising activated carbon material with potential application in wastewater treatment.