A Methodology for Modelling Slurry Photocatalytic Reactors for Degradation of an Organic Pollutant in Water

ALFANO, O.M.; CASSANO, A.E.; BRANDI, R.J.; SATUF, M.L.

Photocatalysis and water purification. From fundamentals to recent applications

WILEY

Año: 2013; p. 335 - 359

Photocatalysis is a reaction that it is said to be known since 1929 [1], when it was discovered the flaking of paints and the degradation of fabrics containing titanium dioxide under solar UV radiation. However, it was not until 1970 when Fujishima and Honda published, first in a Japanese journal and later, with much more diffusion, in Nature [2] and in spite of some limitations and bias, the possibility of water splitting employing TiO2 and UV light. This publication coincided with the petroleum crisis and, up to the year 1980, produced a vertiginous growth of the scientific literature on the topic until its absence of economic feasibility was demonstrated. The gas-phase 2 photocatalytic oxidation of alkanes [3,4] and the formation of superoxide [4] over TiO2 were independently reported at that time. A new thrust of similar extraordinary development occurred in 1977 when Frank and Bard [5], as consequence of previous studies in hydrogen production, found the possibility of using the oxidative properties of the catalyst to destroy organic compounds. This fact guided its application to environmental pollution abatement. These studies, initially aimed at the treatment of contaminated water, were later also directed to the treatment of air pollution. Despite the intensity and diffusion of the work [6], there were no major practical advances and by the end of the 1990s the subject began to decline again. But almost at the same time two new lines of work emerged, particularly applied to large external surfaces. On the one hand, the oxidative properties of titanium dioxide was used to achieve self-cleaning surfaces by means of solar light [7?9] and, on the other hand, it was sought to use the capacity of the aforementioned oxide combined with ultraviolet radiation, to transform surfaces into highly hydrophilic textures, so rains contribute to their cleaning [10]. These uses had a reasonable commercial success. In what seems to be the beginning of a more recent era of photocatalysis, new work oriented towards the use of visible light would extend all its possibilities of application from those conceived from 1970 to the present [11,12]. The goal is to modify the catalyst properties by adding chemical elements so it can be activated by the visible spectrum of the sun.