Woody lignocellulosic waste conversion into activated carbon via microwave-assisted ZnCl2 activation: multivariable optimization for methylene blue dye removal

• Published in: BIOMASS CONVERSION AND BIOREFINERY
• Main Authors: Hapiz, Ahmad; Jawad, Ali H.; Wilson, Lee D.; Abdulhameed, Ahmed Saud; ALOthman, Zeid A.
• Format: Article; Early Access
• Language: English
• Published: SPRINGER HEIDELBERG 2023
• Subjects: Energy & Fuels; Engineering
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001196255000002

This study involved the conversion of lignocellulosic bamboo waste (BMW) into mesoporous activated carbon (BMWAC) via microwave-assisted ZnCl2 activation, where the BMWAC was evaluated for its removal of methylene blue (MB) dye from aqueous media. Various characterization techniques, including pH(pzc), SEM-EDX, XRD, BET, and FTIR spectral analysis were employed to evaluate the properties of BMWAC. The results revealed that BMWAC is a mesoporous adsorbent with a significant surface area of 928 m(2)/g. To optimize its adsorption capacity, the Box-Behnken design (BBD) was used to modify three operational variables: BMWAC dosage, dye pH, and contact time. The kinetics of MB dye removal by BMWAC followed a pseudo-second-order model, while the equilibrium isotherm conformed to the Langmuir model. The maximal dye adsorption capacity (q(max)) of BMWAC with MB was found to be 285.1 mg/g, where the thermodynamics of the adsorption process was spontaneous and endothermic. The adsorption mechanism of MB dye by BMWAC was attributed to various processes that includes hydrogen bonding, electrostatic forces, pi-pi attraction, and pore filling. Overall, BMWAC was revealed for its effectiveness as an adsorbent for water treatment via efficient removal of cationic dyes from aqueous media.