Desenvolvimento de material adsorvente a partir do resíduo da colheita do arroz (Oryza sativa) para a remoção de poluentes emergentes em solução aquosa

Abstract

Adsorbents of natural origin are called biosorbents, differentiating themselves from those of synthetic origin. In this work, residues of agricultural origin were used for the biosorption of potentially toxic species from liquid effluents. The main advantages of biosorbents, in relation to synthetic adsorbents, is that these materials are abundant, with indeterminate commercial value, generally discarded in agricultural cultivation areas. In this work, ash from the burning of rice husks, an abundant agricultural residue from the harvest, was used. The new biosorbents were characterized using the analytical techniques of scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms (BET), Raman spectroscopy and X-ray fluorescence. To verify its efficiency as an adsorbent material, three representatives of emerging pollutants were used as test molecules: 2-Nitrophenol, dichlorophenoxyacetic acid (2.4 D), the most widely used pesticide in the region, and ibuprofen, the residue of which is found abundantly in residual waters. Adsorption isotherms of these molecular species were obtained using biosorbents in batch adsorption systems. The Langmuir model was the one that best fit the experimental data for the three pollutants. The work demonstrated that the surface has the capacity to remove the tested pollutants, highlighting the removal of ibuprofen with Qmax 25.2 mg.g-1.