Heterogeneous Photocatalysis in Wastewater Treatment-A Review

Abstract

Heterogeneous photocatalysis is a low-cost, sustainable and environment friendly advanced oxidation process. It is a process in which highly oxidative OH* free radicals are produced due to the oxidation and reduction reactions on the semiconductor surface in the presence of ultraviolet light and oxygen. It aligns with the “zero” waste scheme in the wastewater industry and has the ability for the removal of persistent organic compounds and microorganism, present in air and water. Semiconductor photocatalyst material and photoreactor design are two important areas involved in this method for remediation of polluted water stream falls. By far, titania is known as the best photocatalyst as compared to others due to its inert nature and photo stability, but the post-recovery of  fine photocatalyst particles after the treatment of contaminated water, still remains the challenge for commercialization of this process at industrial scale. The appropriate design of the photoreactor provides the solution to this problem.

The present review paper seeks to offer a scientific and technical overview of the use of TiO₂ nanoparticles as semiconductor photocatalyst material and photo-reactor design for the remediation and decontamination of wastewater.