Chitosan and zeolite-based composites: Characterization and removal of methylene blue dye from aqueous solution
摘要
The present work describes the synthesis of a composite based on chitosan and zeolite as an eco-friendly and low-cost alternative material capable of removing methylene blue dye from aqueous solution. The composite was synthesized by an ionic gelation method. Methylene blue removal tests were performed at pH 3, 7, and 9, at 25 °C. The pH of the solution influenced the adsorption of methylene blue. An increase in adsorption capacity was observed as the pH increased, with a minimum value of 8.3 mg g−1 at pH 3 and a maximum of 19.7 mg g−1 at pH 9. Characterization of the composite before and after the methylene blue adsorption process, as well as the precursor materials, was obtained through analytical techniques: scanning electron microscopy, N2 physisorption, infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, charge distribution and point of zero charge. The proposed mechanism for the adsorption of methylene blue involved electrostatic interactions.
Graphical Abstract