Photocatalytic membrane for removal of organic contaminants during ultra-purification of water

Experiments were performed using a photocatalytic membrane fabricated by embedding titanium dioxide particles within a polymer matrix. Catalyst particles were activated by ultraviolet illumination of the membrane. Experimental results demonstrated the feasibility of the photocatalytic process for elimination from water of trace organic solute concentrations. A mathematical model is proposed that aided in the estimation of kinetic parameters associated with the process. The process simulation is based upon a mechanism whereby the primary organic solvent is mineralized via a series of reactions that involve not less than two organic solute intermediates. The reaction rate parameter associated with 254-nm illumination is estimated to be directly proportional to light intensity. Where 185-nm light and 254-nm light were used together, their catalytic effects were shown to be comparable, but the oxidative effect of 185-nm illumination had the added benefit of noncatalytic oxidation. Catalyst and support system improvements are indicated to increase the photocatalytic effect.