Na-Kenyaite as Efficient Basic Blue-41 Dye Removal: Synthesis and Regeneration Studies

Abstract

Na-kenyaite materials are available in nature and can easily be prepared in the laboratory. These materials exhibit interesting adsorption properties; therefore, they can be invested in the new wastewater treatment technologies. This study investigates the removal of basic blue-41 (BB-41) dye from artificially contaminated water using Na-kenyaite materials in batch mode. Firstly, Na-kenyaites were prepared by the hydrothermal process at a temperature of 150 to 170 °C for a period of 2 to 7 days using different silica sources and ratios of SiO2/NaOH/H2O. The prepared materials were characterized by different techniques such as XRD, FTIR, 29Si MAS NMR, TGA/DTA, SEM, and nitrogen adsorption isotherms. A pure Na-kenyaite phase was successfully obtained using a fumed silica source and 5SiO2/Na2O/122H2O ratio. The removal experiments of basic blue-41 estimated the effectiveness of Na-kenyaites in removing properties, investigating the influence of the solid dosage, initial basic blue-41 concentration, and solution pH or Na-kenyaite solid. Results showed optimal dye removal of around 99% at pH levels above 7. Furthermore, the estimated maximum removal capacity from the Langmuir isotherm was between 124 and 165 mg/g. The results demonstrated efficient removal by Na-kenyaites and its prominence for wastewater treatment. Finally, this study explored the regeneration and reuse of Na-kenyaites through seven cycles and reported a design of a batch adsorber system to reduce the initial concentration of 200 mg/L at different percentages.