چكيده به لاتين
Geopolymers (GP) are aluminosilicates considered an alternative to Portland cement. In this study, however, its efficiency in removing Malachite Green (MG), a cationic dye, from an aqueous solution by absorption method has been investigated. Characterization analyses such as, XRF, XRD, FTIR, and BET were carried out on the GP powder and the results indicated that the GP matrix was formed flawlessly from its precursor, meta-kaolin. Absorption tests were performed under different experimental conditions including adsorbent dosage, pH of the dye solution, contact time, initial concentration of the dye solution, and operating temperature. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms were evaluated and the best data fit was done by Langmuir isotherm with a maximum monolayered adsorption capacity of 185.18 mg/g. Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models were studied and the pseudo-second-order model was followed better than other models in terms of kinetics. With the determination of ∆G, ∆H, and ∆S, the adsorption was found to be spontaneous and endothermic. The results showed that the synthesized adsorbent is, in fact, efficient in the treatment of colored water.
