Kinetic and efficiency of TiO2-coated on foam or tissue and TiO2-suspension in a photocatalytic reactor applied to the degradation of the 2,4-dichlorophenol

摘要

In the field of advanced oxidization processes based on solar radiation, heterogeneous solar catalysis involves exciting a photocatalyst with UV rays and one of the major problems encountered is optimizing the use of the sunlight. The work presented here aimed to use an efficient material able to provide a high active specific surface expressed in square meter per unit volume of the reactor. Recently, macroporous reticulated materials such as foams have been utilized as substrates in heterogeneous catalysis on account of their uniform cellular structure. Thanks to their macroscopic arrangement, they provide a large interface for exchange between the targeted molecules and the solar radiation. The reactor in which the degradation kinetics were observed was a cylindrical borosilicate glass tube operated in a recirculation batch mode. The measurement of the degradation kinetics was carried out on a model target molecule, 2,4 dichlorophenol, at an initial concentration of 20 mg H. The effects of photolysis, output flow and the intensity of the radiation were studied. The results were treated using a first order kinetic law according the TOC concentration. It emerges that the rate of degradation is related exclusively to the quantity of light absorbed. For each material, the efficiency of the material was independent of the intensity of the radiation received. In this context, macroporous reticulated materials such as foams show promise as supports for photocatalysts.