Desenvolvimento de membranas vítreas porosas impregnadas com TiO2 visando obter propriedades catalíticas para tratamento de efluentes

Abstract

Nowadays, the obligation of companies to treat their effluents is getting more and more demanded. Therefore, various forms of decontamination are studied, for example, porous materials that have selective toxicant removal properties, as well. In this work, the objective was to develop porous glassy membranes impregnated with titanium dioxide to obtain a material with both retention properties and catalytic activity. A prototype reactor was developed to evaluate these properties. Then, a fluent from a used lubricating oil recycling industry located in the interior of the state of São Paulo was used to evaluate the performance of these porous membranes. The conditions of the tests performed in the reactor were as follows: circulation of 1.5 L of the effluent for 80 minutes, use of 4 membranes of approximately 8 g each and coupled to the reactor, with and without the presence of light and all tests were performed at room temperature. The concentration of organic compounds present in the effluent was analyzed by the technique called chemical oxygen demand (COD). The results showed a 23.5% reduction compounds for the TiO2-impregnated porous glass membrane test in the reactor with light on. 20.2% for the same material in the reactor with light off and 16 9% for the porous vitreous membrane no impregnated with the light on. The difference between the results of the tests of the membranes employed with TiO2 with and without light can be seen as possibility of photocatalysis due to TiO2. The several developed materials both before and after reactor testing were characterized by optical microscopy (OM). Optical micrographs showed that the glassy membranes have adsorptive property. Finally, scanning electron imaging (SEM) and dispersive energy spectroscopy (EDS) results confirmed the presence of titanium on the membrane surface and porous structure.