Degradação do corante eritrosina b através de fotólise e fotocatálise

Abstract

Approximately 700,000 tons of industrial dyes are released into the environment annually, many of which are toxic and genotoxic, requiring advanced treatments. Advanced Oxidative Processes (AOPs) emerge as an alternative for efficient manipulation by reactive oxygen species; these processes can be optimized by specific oxides such as TiO2. Thus, the main objective of this study was to analyze the efficiency of the manipulation of the dye Erythrosine B, with the application of AOPs, photolysis and photocatalysis with the addition of titanium dioxide, and to verify the effects related to the modification of some parameters, namely pH, type of catalyst (different crystal structures) and concentration of catalyst. The results showed that Erythrosine B presents satisfactory manipulation (maximum absorption at 526.5 nm) during photolysis and photocatalysis, presenting manipulation efficiency of 39.8% after 5h of photolysis and 48.3% after the period of 2h and 15 minutes in photocatalysis. The optimized settings were: TiO2 (P25 – 80%/20% anatase/rutile); TiO2 concentration 1.0 g/L and medium pH equal to 7.0. In the optimized scenario, the kinetic constant was 1.51×10−3 min−1 for photolysis and 4.91×10−3 min−1 in photocatalysis.