학술논문
Natural core-shell structure activated carbon beads derived from Litsea glutinosa seeds for removal of methylene blue: Facile preparation, characterization, and adsorption properties.
Document Type
Article
Author
Source
Subject
*METHYLENE blue
*ACTIVATED carbon
*ADSORPTION capacity
*ADSORPTION (Chemistry)
*LANGMUIR isotherms
*HYDROGEN bonding
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Language
ISSN
0013-9351
Abstract
In this study, natural core-shell structure activated carbon beads (ACBs) from Litsea glutinosa seeds were successfully produced, characterized, and applied for adsorption of methylene blue (MB). The ACBs were prepared using single-step carbonization-activation with NaHCO 3 at the optimized activation temperature, time, and activating agent concentration of 450 °C, 60 min, and 5%, respectively. Batch experiments were performed to determine the optimum adsorption conditions, suitable kinetic and isotherm models, and thermodynamic parameters for the adsorption of MB onto ACBs. The results showed that the ACBs were displayed as highly porous natural core-shell spheres with a diameter of about 5 mm. The adsorption of MB dye on ACBs was a spontaneous endothermic process, followed the Langmuir isotherm and the pseudo-second-order kinetic models with the rate-controlling step of both external diffusion and intra-particle diffusion. At the optimum conditions (pH of 9, the contact time of 10 h, the temperature of 40 °C, and an adsorbent dosage of 6 g/L), the maximum adsorption capacity reached 29.03 mg/g. The thermal method turned out to be more suitable for regenerating ACBs compared to the chemical method. The ACBs exhibited high reusability and stability, its adsorption efficiency could maintain more than 90% after five consecutive cycles of use. The electrostatic attraction, π–π interaction, hydrogen bonding, and pore-filling were identified as primary contributions to the adsorption mechanism. The overall results revealed that the ACBs could be used as a potential adsorbent for removing MB from water media. [Display omitted] • The Litsea glutinosa seeds were utilized to prepare activated carbon beads (ACBs). • The ACBs were presented as highly porous spheres with the core-shell structure. • The adsorption properties of the ACBs toward methylene blue were investigated. • The possible adsorption mechanism and reusability of the ACBs were clarified. • The ACBs exhibited high adsorption ability and excellent reusability. [ABSTRACT FROM AUTHOR]