Remoção de fármacos de águas resíduárias por biocarvão e carvão ativado

Abstract

Emerging contaminants are organic compounds of natural or synthetic origin, detectable in various aquatic matrices. They usually occur in trace concentrations and due to the adverse effects they can cause to living beings, it represents a cause for concern. The main sources of contamination are domestic and industrial effluents in natura or treated. Water and effluent treatment plants are not effective in removing these contaminants. In view of this scenario, in this study, cotton boll biochar (BCA) and babassu coconut pulverized activated charcoal (PAC) were used to remove caffeine and ibuprofen, respectively, through adsorption. This dissertation was structured in two chapters, initially composed of a general bibliographical review of the theme, followed by chapter I that describes the adsorption of caffeine by cotton boll biochar. Chapter II discusses the removal of ibuprofen by pulverized babassu coconut activated charcoal. In both chapters, the influence of the initial pH of the solution, concentration of adsorbent materials, contact time and temperature in the adsorption process were evaluated; the adsorbent materials were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The pH did not influence the adsorption of caffeine and ibuprofen. The pseudo-second order model and the Langmuir isotherm model showed the best fits to the adsorption data tested with biochar and activated carbon. The thermodynamic parameters indicated that the adsorption of caffeine by biochar is exothermic, spontaneous and favorable; on the other hand, the thermodynamic parameters of the adsorption of ibuprofen by activated carbon indicated that this process is endothermic and not spontaneous. These data demonstrate that both adsorbent materials are alternatives in the removal of caffeine and ibuprofen and possible other drugs.