Methylene Blue Adsorption by Chemically Foamed Geopolymer Based on Fly Ash

Abstract

The storage and disposal of fly ash, which is generated as an industrial waste of thermal power plants, is a challenging process, as is the case with all wastes. In this study, it is aimed to obtain a useful product for methylene blue adsorption by using fly ash in the production of foamed geopolymer. Geopolymers, which were obtained by doping Zn and Al metals, were cured in 2 different environments, at room conditions and at room conditions with pre-curing at 80 degrees C. NaOH and Na2SiO3 solutions were used for geopolymerization. X-ray fluorescence spectroscopy (XRF), Fourier transform infrared spectroscopy (FTIR), Brunauer, Emmet, and Teller surface area analysis (BET), and X-ray diffraction (XRD) analysis were applied for the characterization of fly ash and geopolymers. It was observed that optimum geopolymer sample produced has 27.355 m(2)/g surface area. Langmuir isotherm (R-2 = 0.9962) was the most suitable adsorption isotherm in adsorption studies with the optimum geopolymer sample. The highest adsorption efficiency was obtained 97.4% in 50 ppm solution. As a result, it was observed that the geopolymer surface area could be increased by using chemical foaming method and obtained geopolymer could be successfully used for methylene blue adsorption.