CaTiO3 na fotocatálise do azul de metileno

Abstract

The aim of this work was to study the degradation of methylene blue by applying heterogeneous photocatalysis with the use of the CatiO3 as catalyst. CaTiO3 catalyst was synthesized from commercial titanium dioxide and gallinaceous egg shell and characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and zero point of charge (pHzpc). CaTiO3 was applied to the photodegradation of the methylene blue dye. The optimization of the reactional conditions was performed through central composite design. The influence of catalyst concentration, dye concentration and pH of the solution were evaluated. After optimization of the reaction conditions, the kinetics of photodegradation was studied, which fit the Langmuir Hinshelwood pseudo-first order model. The pseudo first order kinetic constant was 0.0147 min-1. The toxicity of the dye was evaluated by means of bioassays with Lactuca sativa seeds. The toxicity tests showed a percentage of germination of 100%. It can be concluded that heterogeneous photocatalysis is a promising process in the removal of color from textile dyes in water, and that CaTiO3 synthesized from gallinaceous egg shell residue has satisfactory catalytic activity.