Avaliação da capacidade de adsorção de sulfametoxazol em argila Pirangi do estado de Sergipe

Abstract

Sulfamethoxazole (SMX) is an antibiotic widely used in human and veterinary medicine to treat diseases and infections and it is often detected in the surface water ecosystem. Thus, the objective of this work was to evaluate the adsorption capacity of this antibiotic from aqueous systems using Pirangi clay (PIR) from the reservoir located in the city of Itabaianinha, State of Sergipe, Brazil. Pirangi clay samples were heat treated at 100, 400 and 600°C and subsequently modified with the hexadecyltrimethylammonium bromide (HDTMA) quaternary ammonium salt. The characterization of clays was performed by X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), N2 adsorption/desorption (BET) and Scanning Electron Microscopy (SEM), confirming that the surfactant molecules were incorporated in the surface of the clay and that they are constituted by kaolinite, illite and quartz. Pirangi clay treated at 100°C (org-PIR-100) had a higher adsorption capacity of 27.3 mg g-1 with 90% removal of SMX in 100 minutes and at pH 6, following the pseudo-second order model and Langmuir isotherm. The results showed that Pirangi organoclay showed efficiency for the decontamination of SMX in aqueous solutions and potential for use as alternative material in water treatment plant filters.