J. Sci. Agri. Technol. (2023) Vol. 4 (2): 5 – 21
DOI: https://doi.org/10.14456/jsat.2023.8
Abstract
In this research, glucose-based carbon, fructose-based carbon, and sugarcane juice-based carbon materials were successfully synthesized by a simple, rapid, and one-step reaction for methylene blue adsorption. The samples were produced by the reaction of sugarcane juice with sulfuric acid. The characterization of the synthesized samples was performed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and nitrogen adsorption-desorption analysis (BET). The adsorption behaviors of all samples were investigated by the determination of the adsorption capacity of methylene blue. The optimum condition for the highest adsorption capacity was at pH 7 and a contact time of 480 min. The kinetic and adsorption isotherms and thermodynamics of methylene blue on all samples were studied. Pseudo–second–order and Langmuir’s isotherm were best fitted for methylene blue removal. This is indicated by chemical and monolayer adsorption. The mechanism of the adsorption process can be illustrated by the intra-particle diffusion model. A study of the thermodynamic parameters showed positive enthalpy (ΔH) and entropy (ΔS) values. This suggested that endothermic adsorption processes increased the randomness of adsorbate and adsorbent. Additionally, the negative value of Gibbs free energy (ΔG) indicated a spontaneity of adsorption. The presence of salts (NaCl and MgCl2) and coexisting ions (Pb2+ and Zn2+) cause a decrease in the adsorption efficiency.
Keywords: adsorption, carbon, sugarcane juice, sulfuric acid, methylene blue
Received: March 27, 2023. Revised: May 29, 2023; July 12, 2023. Accepted: October 20, 2023.
