Diffusion Control Regimes in a Slurry Photocatalytic Reactor for Water Treatment

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

Gramado, Brasil

Simposio; XX Simposio Ibero-Americano de Catálisis (XX SICat); 2006

The majority of suspended solid photoreactor studies have considered perfect mixing conditions and have not deeply studied the possibility of mass transport limitations. But sometimes mass transfer restrictions appear and the kinetic regime control is not guaranteed. In the present work, a flat plate, slurry photocatalytic reactor employing titanium dioxide is modeled considering the possibility of the existence of a diffusion control regime. The main mass transport limitations are the result of concentration gradients in the bulk that can be avoided only with very strong mixing conditions (or very high flow rates) and rather low reaction rates (resulting from low catalyst concentrations and low irradiation rates).