ABSTRACT
Photocatalysis has the capability to destroy pollutants or convert them into less toxic substances, in contrast to current treatment methods such as adsorption where contaminants are merely concentrated by transferring them onto the adsorbent but they do not convert into non toxic wastes [1]. It should be noted that, for photocatalytic reduction process, two methods of catalyst metal oxide application are preferred: (i) suspension in aqueous media [2] and (ii) immobilization on suitable support material [3]. Although suspended photocatalyst systems always give higher reduction rates due to the larger surface area when compared to the immobilized system, there is one obvious problem arising from it. The nanosized particles in the range of 30-200 nm [4] needs to undergo separation process by which the system must be installed with a liquid-solid separator, which is expensive and constitutes a major drawback in the
commercialization of this system. The second disadvantage of the freely suspension system is that nanometer particles from the effluent may cause turbidity in the downstream. Thus, there is a need to develop a practical technology for the separation of the catalyst and effluent.
