UV/Periodate Advanced Oxidation Process: Fundamentals and Applications

UV/periodate (IO - 4 ) process is one of the recent advanced oxidation processes (AOPs) that have been efficiently applied to degrade various persistent organic pollutants and lower chemical oxygen demand in industrial wastewater. The photo-irradiation of periodate (λ < 400 nm) in aqueous solutions can produce several reactive radicals and non-radical species comprising . OH, IO • 3 ,IO • 4 , H 2 O 2 ,O( 3 P),O 3 and IO - 3 , which work together and make the degradation process much faster than that of UV/H 2 O 2 and other similar AOPs. Surprisingly, reports on this process are very limited as compared to other AOPs. Additionally, there are no review articles or book chapters that assemble the existing works and explain the principles of the process. The present review presents first the fundamental aspects of the photochemical decomposition of aqueous solutions of periodate. The recent works on the degradation of organic pollutants by the UV/IO - 4 process are then reviewed. Besides, the specific contribution of each reactive species in the degradation process is discussed. Further, factors influencing the process efficiency are addressed. In the last part, the performance of the process is compared with those of UV/H 2 O 2 and UV/persulfate AOPs. To the best of our knowledge, this is the first review on the UV/IO - 4 process. This contribution gives the reader the main fundamental and practical aspects of this emerging oxidation technology in the field of water and wastewater treatment.