Water cleanup through innovative photocatalytic media optimized using solar irradiations «treatment of pyrimethanil» [Dépollution par des média photocatalytiques innovants optimisés par voie solaire «traitement du pyriméthanil«]

Advanced oxidation processes,which include heterogeneous photocatalysis appears to be an alternative for the decontamination of water containing organic pollutants (pesticides,dyes....). the process is energy-efficient and non-selective and leads to total mineralization of the pollutant. photodegradation of pyrimethanil pesticide was chosen as a model pollutant,and it was carried out at room temperature in the presence of a photocatalyst tio2 deposited on a suitable support (media pohotocatalytiques) using sunlight as a source of uv radiation. our present work focuses on the development of innovative materials by deposition of tio2 on alveolar macroporous media (aluminum foam,the metal swarf),in order to avoid filtration phases in post processing. these media are inexpensive and from a scrap metal recyclers. a study was conducted to determine the relationships between the structure and the ability to use radiation,also to define the processing capabilities of these media and compare their performance to that of conventional and industrial media (2d cellulosic fabric impregnated catalyst (grad ahlstrom 1048) and to the suspension of catalyst (degussa p-25 powder). the photocatalytic degradation kinetics was modeled by following the langmuir-hinshelwood equation,in which the rate constant k and the adsorption equilibrium constant klh were evaluated. the effect of the addition of certain ions (cl-,so42,hco3,and ch3coo- no3) hydrogen peroxide and the rate of photodegradation has also been studied. these results show that the photocatalysis is a very suitable technique for the purification of polluted water.