Abstract
Heterogeneous photocatalytic oxidation processes employing semiconducting oxides such as TiO2, ZnO, etc. and appropriate irradiation sources have demonstrated promising results for the degradation of many persistent organic pollutants, producing more biologically degradable and less toxic substances. Recent advances in photocatalysis have focused on improving current photoreactor performance to make the process economically feasible. The immobilization of the photocatalyst in the form of a thin film significantly reduces some of the drawbacks of practical application of heterogeneous photocatalysis with nanoparticles. The photolytic and photocatalytic activity was investigated in the photocatalytic batch annular reactor system with recirculation, using different sources of irradiation. Terbuthylazine (N-tert-buthyl-6-cloro-N’-ethyl-1,3,5-triazine- 2,4-diamine), a substitute for atrazine, was used as model pollutant. The influence of various operating conditions on degradation of terbuthylazine was investigated and obtained results are discussed. The Langmuir-Hinshelwood (l-H) mechanistic model is employed to describe the overall reaction rate. The results obtained in this study have shown that the delicate balance between excellent mechanical properties of the woven roving glass fibers and satisfactory adhesion of the photocatalytic layer, have important role in preparation of the functional modular photocatalyst easily placed inside the photoreactor. Apparently, the modelling of the photoreactor to optimize its performance will be crucial from the perspective of efficient design and the application of the heterogeneous photocatalytic degradation of herbicides in wastewater.
