PHOTOCATALYTIC DEGRADATION OF 4-CHLOROPHENOL - A MECHANISTICALLY-BASED MODEL

The photocatalytic degradation of 4-CP was mathematically modelled usi ng the mechanistic insights and data presented in an earlier study [1] . The solution and surface concentrations of reacting species were cal culated by solving a system of differential equations that account for oxidation reactions of dissolved and adsorbed species, adsorption and desorption, reduction of oxygen, and hole-electron recombination. The differential equations were integrated over discrete time-periods and annular regions of the photoreactor. The resulting model predicts the trends observed in studies in other laboratories using different expe rimental apparati. Using the model it is possible to predict effects o f reactor geometry, TiO2 loading, light intensity, and mixing on the c ourse of TiO2 photocatalytic oxidation. The model verifies the importa nce of surface reactions, and reveals the need to better understand th e fate and role of oxygen in TiO2 photocatalytic systems.