Investigations on Nano and Micro Titania Photocatalyst Activities in Waste-Water Treatment; Taking into Account the Turbidity in the Kinetic Study

Among the reported methods for waste water treatment, the UV/TiO2 process has been shown to be potentially advantageous; as it can lead to qualified treatments with complete mineralization of pollutants to carbon dioxide, water and mineral acids. The aim of this work is to compare the extensive potential of two major type commercial titanium dioxide products, belonging to Degussa (nano particles) and Merck (micro particles) companies in photocatalytic process. For this purpose, as a typical and widely used pollutant substrate, called direct blue 71 (DB71) is used and its concentration is followed during the process. A suspending and circulating conic shape photo-reactor is employed; the influence of different operational parameters and the contribution of different active species are to be studied. For the first time the well known qualified effect of the catalyst particles turbidity on the photolysis branch of UV/TiO2 process is to be considered quantitatively by means of a specific manner and to be taken into account for the kinetic study.