Studies on homogeneous and heterogeneous photo-catalytic degradation

The photo oxidative treatments are environmental friendly since the contaminants are totally mineralised rather than transferred from one phase to another, thus avoiding the possibility of secondary pollution. This book compares the ability of several AOPs, including UV, UV + H2O2, UV + H2O2 TiO2 and UV + H2O2 +ZnO in terms of energy required to produce .OH radicals. The generation of the very reactive hydroxyl radicals is demonstrated by kinetic modeling. These techniques are studied for the photo catalytic degradation of benzoic acid and its derivatives. The photolytic and photo catalytic oxidation using environmental friendly oxidant H2O2 and non toxic. Photo-catalysts TiO2 and ZnO proves itself to be a feasible and relatively inexpensive process. The oxidant hydrogen peroxide shows a rapid decrease in concentration on exposure to UV radiation and is completely utilized when used in optimum concentration levels in the reacting system. The application cost of this process although on a higher side, compensates itself because of the fact that no secondary pollutant problems remain after treatment.