Fotodegradação do corante azul de metileno utilizando Nb2O5 suportado em óxidos mistos

Abstract

Water is an indispensable commodity for life, but it is also vital to the functioning of many industries. Textile production requires large amounts of water which according to the literature can vary from 25 to 250 m3 of water per ton of product, much of this contaminated water after the production process is released into the environment without treatment. The dyes currently used by the textile industry are predominantly synthetic, designed to withstand exposure to light, water and oxidizing agents and, in this way, are very stable and therefore difficult to degrade, able to remain in the environment for long periods. When treatment does not occur, the release of these colored wastewater into the ecosystem causes aesthetic pollution, eutrophication and disturbances in aquatic life. This work proposes the development of an advanced oxidative process type (POA), which is an alternative for the treatment of effluents contaminated with synthetic dyes. The use of Nb2O5 supported in mixed oxides was studied; and, through a series of experiments, it was verified the great efficiency of this composite, demonstrating that it is able to degrade 100% of the dye studied, converting the pollutant into non-toxic substances, in a period of approximately 3 hours, using solar light as energy source. In addition to using a free energy source, it can also be reused without significant loss of its degradation power. The main characteristics are: no additives are needed for the degradation process to occur; the proposed non-toxic catalyst is inexpensive, easy to produce, simple to use and can be completely removed at the end of the process, in accordance with green chemistry principles.