The Use of Biomass of Apricot Kernels as a Material for the Extraction of Methylene Blue from Aqueous Media

Abstract

The possibility of using a sorption material based on apricot kernels for the extraction of methylene blue (MG) dye from aqueous media is considered. The maximum sorption capacity of the material was established – 0.58 mmol/g (185.6 mg/g). The obtained isotherm was processed within the framework of monomolecular and polymolecular adsorption models. The equations that most accurately describe the isotherm are determined, and the correlation coefficients are calculated. It has been shown that the sorption isotherm of the MG dye by the crushed apricot kernel (CCA) is best described by the Langmuir (R² = 0.9724) and Dubinin-Radushkevich (R² = 0.9818) models. However, when comparing the plots of the function A = f(C_e) of the sorption processes of the dye by the CCA sorbent according to the models under study with the experimental dependence, it was found that the sorption process is most accurately described by the sorption models of Dubinin-Radushkevich and Temkin. Using the equations of the Langmuir and Dubinin-Radushkevich models, the thermodynamic parameters of the process were calculated: the sorption energy (E = 8.066 kJ/ mol) and the Gibbs energy (∆G^o = -8.597 kJ/mol).