Desenvolvimento de um reator fotocatalítico solar para a degradação de corantes em efluentes

Abstract

The present work describe the sizing and construction of a photochemical reactor prototype, in a spiral shape, applied for textile wastewater treatment, using the titanium dioxide (TiO2) P25 as photocatalyst, of the heterogeneous photocatalysis reactions. In addition, the solar radiation was used as a renewable energy, since it shows a high efficiency in the process because of it intensity and because it has abundance in all the regions of Brazil. A remazol red RR dye solution was used, which was evaluated by adsorption and photocatalysis in bench tests and in the reactor. The adsorption experiments, in the dark, identified that the pH and loading of catalyst showed the greatest influence in the reactions. In contrast, the photocatalysis tests evaluated the dye initial concentration and the loading catalyst, using as fixed parameters the time of 160 min and the pH of 3,45 (initial of the dye). After performing a statistics analysis of the data obtained by the adsorption in the dark and the photocatalysis experiments, the best conditions were estimated to be applied in the photochemical reactor, being it 0,9 g.L-1 of catalyst concentration and 50 mg/L of dye initial concentration. Thus, the test accomplished in the proposed reactor pattern used 7,65 L of dye solution, that after 6 h of solar irradiation, resulted in 46,37% removal of the color and 51,35% reduction of the chemical oxygen demand (COD), by spectrophotometry analysis.