Degradation performance and cost implication of UV-integrated advanced oxidation processes for wastewater treatments

Advanced oxidation processes (AOPs) are commonly used for treating recalcitrant wastewater with varying degree of efficiency, depending on several operating parameters. In this review, a comparative study among selected AOPs integrated with ultraviolet (UV) (UV/Fenton, UV/H2O2, UV/O-3, UV/TiO2, UV/persulfate, UV/H2O2/O-3, and UV/TiO2/H2O2) was conducted. The cost implication, changes in kinetics, changes in reaction rates, and effects of various parameters such as type of contaminants, pH, catalyst loading concentration of oxidants, and type of UV light are explained and concluded in this paper. From this review, it is concluded that UV-integrated AOPs are efficient for wastewater treatment. However, a few aspects must be considered including process scale-up, kinetics of combined processes, reactor configuration, modeling of a system, and optimization of operating parameters to enhance the process efficiency.