ABSTRACT
Photocatalytic oxidation has been used to remove organic pollutants from drinking water and this eld has attracted considerable interest (Malato et al. 2009). TiO2 is commonly used as a photocatalyst for purication of water because it is stable, harmless, inexpensive, and can be potentially activated by solar insolation. TiO2 in suspension is quite effective in utilizing sunlight, because suspended TiO2 particles have a high specic surface area in the range from 50 to 300 m2/g (Balasubramanian et al. 2004; Gumy et al. 2006) and therefore, mass transfer limitations are avoided and high photocatalytic activity is obtained (Mehrotra et al. 2003). However, a small transport limitation appeared on high catalyst loading. One of the major disadvantages is that it is difcult to separate small TiO2 particles from water after treatment (Feitz et al. 2000; McCullagh et al. 2011; Thiruvenkatachari et al. 2008). The TiO2 particles can be immobilized on a suitable support to overcome this problem. A number of attempts have been made to immobilize TiO2 photocatalyst over different supports and at the same time increase the surface/volume ratio, resulting in an enhancement in photocatalytic oxidation efciency.
