TREATMENT OF MALACHITE GREEN IN AQUEOUS SOLUTION USING CHITOSAN/PECTIN/SiO2 COMPOSITE

Abstract

The synthesis process of chitosan/pectin/SiO₂ composite (CPS) was performed under the following conditions: mass ratio of chitosan/pectin (CP):SiO₂=1:1.5 (g/g), mixing time of 0.5 h at room temperature. In this work, pectin was extracted from pomelo peel while rice husk ash was used for silica recovery. The obtained CPS were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Field emission scanning electron microscopy (FE-SEM). The typical functional groups of CP and SiO₂ are fully appeared in CPS. Malachite green (MG) was used in this work to evaluate the dye removal possibility of CPS at pH 7, a MG concentration of 60 mg/L, a MG dosage of 1 g/L, and an adsorption time of 30 min. The MG adsorption capacity and adsorption efficiency are 61.3 mg/g and 75.93%, respectively. The MG adsorption process is consistent with the Langmuir and Sips isotherm adsorption models, meaning the adsorption takes place homogeneously, monolayer, independently and is physical adsorption. Besides, the kinetics of the MG adsorption process follows the pseudo 2^nd order kinetic model. As a result, the CPS is a potential composite for treating MG dye in an aqueous solution.