Use of modified zeolites CaX and MgX as adsorbents of organic compounds

Abstract

In this work, the adsorption capacity of modified zeolites, CaX and MgX, was evaluated in contact with a by-product solution of the stevioside extraction process, a sweetener extracted from Stevia rebaudiana leaves. The effects of adsorption process in the zeolitic structure were evaluated through several characterization techniques. Thermal analysis showed that the adsorbed compounds suffer small structural changes under heating. From infrared spectroscopy, it was verified that the adsorption process doesn't change the zeolite structure. Superficial area and pore volume indicated that adsorption occurs on the external surface and mesopores of the zeolite. Further acidity indicated that the adsorption of colored organic compounds occurs mainly on the compensation cations.