Adsorção de corante Rodamina B utilizando como adsorventes MCM-41 e SBA-15 modificados por deposição de carbono

Abstract

The dyeing industries generate a large amount of wastewater containing various types of dyes that are harmful to humans and the environment if not treated properly. In the last decades, molecular sieves such as MCM-41 and SBA-15 have been applied in adsorption, proving versatile adsorbents with well-ordered hexagonal structures and large surface areas. This work evaluated the adsorption of basic dye Rhodamine B using MCM-41 and SBA-15. These structures were modified by depositing carbon derived from sucrose, in order to improve the adsorptive capacity of these materials. The adsorbents were synthesized and characterized by X-ray diffraction (XRD), thermogravimetry (TG / DTG), N2 adsorption at 77 K and scanning electron microscopy (SEM). The kinetics of all adsorbent-adsorbate systems follows the model of pseudo-second order and the isotherms studied follow the Langmuir model. MCM-41 in the presence of carbon (MCM-41 CC) showed removal of up to 91,95% dye in solution with concentration of 50 ppm, showing the best adsorbent for this condition. MCM-41 and SBA-15 at concentrations up to 400 ppm, showed maximum adsorption capacity of 63,54 and 69,12 mg/g, respectively.