Box–Behnken design with desirability function for methylene blue dye adsorption by microporous activated carbon from pomegranate peel using microwave assisted K₂CO₃ activation

Abstract

This research aims to convert pomegranate peel (PP) into microporous activated carbon (PPAC) using a microwave assisted K₂CO₃ activation method. The optimum activation conditions were carried out with a 1:2 PP/K₂CO₃ impregnation ratio, radiation power 800 W, and 15 min irradiation time. The statistical Box–Behnken design (BBD) was employed as an effective tool for optimizing the factors that influence the adsorption performance and removal of methylene blue (MB) dye. The output data of BBD with a desirability function indicate a 94.8% removal of 100 mg/L MB at the following experimental conditions: PPAC dose of 0.08 g, solution pH of 7.45, process temperature of 32.1 °C, and a time of 30 min. The pseudo-second order (PSO) kinetic model accounted for the contact time for the adsorption of MB. At equilibrium conditions, the Freundlich adsorption isotherm describes the adsorption results, where the maximum adsorption capacity of PPAC for MB dye was 291.5 mg g⁻¹. This study supports the utilization of biomass waste from pomegranate peels and conversion into renewable and sustainable adsorbent materials. As well, this work contributes to the management of waste biomass and water pollutant sequestration.

NOVELTY STATEMENT

The novelty of this research work comes from the conversion of the biomass waste, namely; the conversion of pomegranate peel (PP) into microporous activated carbon (PPAC) via a microwave assisted K₂CO₃ activation process. The applicability of the PPAC toward the removal of methylene blue dye (MB) was statistically optimized using Box Behnken design in the response surface methodology (BBD-RSM).

Keywords:

• Activated carbon
• adsorption
• desirability function
• methylene blue dye
• microwave
• pomegranate peel

Acknowledgments

The authors are thankful to the Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM) Shah Alam, Malaysia for the research facilities.

Additional information

Funding

The author (Zeid A. ALOthman) is grateful to the Researchers Supporting Project No. [RSP2023R1], King Saud University, Riyadh, Saudi Arabia.