Adsorption and kinetic studies of methylene blue from aqueous solution using modified spent tea leaves

Abstract

In this study, methylene blue was removed from an aqueous solution using modified waste tea leaves. Temperature, pH, contact time, methylene blue concentration, and other adsorption mechanisms were studied. The characterization of the samples was performed using the FTIR and SEM analyses. The isotherm models were carrying out to analyzed the adsorption mechanisms and for representing data, the Freundlich isotherm model seemed more appropriate. The findings exhibited the highest adsorption capacity was 3.66 mg/g for the untreated biomass at 298 K, 5.46 mg/g for the 0.1 M HCl group at 318 K, and 5.98 mg/g for the 0.05 M NaOH group at 298 K. The adsorption kinetics were used and the pseudo-second-order model performed well for each group. As a natural substitute biomass for methylene blue adsorption from aqueous solution, used tea leaf residue may be employed.