Adsorption of Rhodamine-B (RhB) and Regeneration of MCM-41 Mesoporous Silica

Abstract

Rhodamine (RhB) adsorption was carried out on MCM-41 and MCM-41 calcined. The effect of parameters such as pH was investigated. The reusability potential of MCM-41 was also established and the mechanism of RhB adsorption was discussed. MCM-41 was synthesized and calcined, with all samples characterized by X-Ray Diffractometry, X-ray Fluorescence by Dispersive Energy, Infrared Spectroscopy, Scanning Electron Microscopy, and Thermogravimetric analysis. The results of the characterization techniques performed confirmed the formation of the MCM-41 structure. During the adsorption of the RhB dye, high removal percentages and rapid kinetics occur in an acid medium. The adsorption kinetics was evaluated by two models: pseudo-first order and pseudo-second order. The pseudo-first-order kinetic model represented the interaction mechanism well during RhB adsorption by MCM-41. However, the pseudo-second-order model better represented the interaction mechanism during RhB adsorption by MCM-41 calcined. The regeneration study found that the MCM-41 and MCM-41 calcined were maintained at 80 and 90% of their original condition after three successive regeneration cycles. The overall results show that the process could be used as a strategy for environmentally sustainable wastewater treatment.