Degradação de bisfenol A por fotocatálise heterogênea utilizando dióxido de titânio imobilizado em alginato

Abstract

The presence of emerging contaminants such as bisphenol A (BPA), in water bodies designated for public supply, may be harmful for human health. This fact has encouraged the search for alternative removal processes of these contaminants during the water treatment, since the conventional methods currently used are not effective in the removal of this class of substances. In this work, the BPA degradation by heterogeneous photocatalysis using the titanium dioxide (TiO2) catalyst immobilized in alginate was evaluated. The characterization of the immobilized catalyst was performed by Fourier Transform Infrared Spectrometry (FTIR). The immobilized titanium dioxide (TiO2) concentration and parameters such as pH and BPA concentration, were optimized for a higher percentage of degradation of BPA in solution. In addition, the catalyst reuse and also the influence of different matrices, other than ultrapure water, were evaluated. The BPA determination was carried out by high performance liquid chromatography (HPLC), and the results indicate that under the optimal conditions, with 1 g L-1 of TiO2 immobilized in alginate beads at pH 7 and a BPA concentration of 20 mg L-1, the removal of BPA by photocatalysis was equal to 97.14% with exposure time of 120 minutes. With the photolysis method it was possible to remove approximately 99,5% of BPA, but with total reaction time of 180 minutes. Therefore, heterogeneous photocatalysis with the use of catalyst immobilized in sodium alginate, showed to be efficient in the degradation of BPA in aqueous solutions under the conditions evaluated