Water purification in a solar reactor incorporating TiO2 coated mesh structures

The rate of photocatalytic oxidation of contaminants in drinking water using an immobilized catalyst can be increased by properly designing the catalyst structure. By creating a solar reactor in which meshes coated with TiO2 were stacked, we demonstrated that degradation of humic acids with four superimposed stainless steel meshes was up to 3.4 times faster than in a single plate flat-bed reactor. Incorporation of TiO2 coated mesh structures resulted in a high specific photocatalytically active surface area with sufficient light penetration in the reactor, while the coated area for one mesh was 0.77 m2 per m2 projected area. This brought the photocatalytic efficiency of such reactors closer to that of dispersed-phase reactors, but without the complex separation of the very fine TiO2 particles from the treated water.