Periodate-based advanced oxidation processes for wastewater treatment: A review

The current review presents the analysis of the methods of periodate activation and its implementation as an advanced oxidation process for water and wastewater treatment focusing on the bio-resistant organic pollutants. Periodate activation methods were classified into homogeneous activation methods (activation by ultraviolet radiation, ultrasound, microwaves, thermal energy and hydrogen peroxide) and heterogeneous activation methods (photocatalytic activation, activation by granular activated carbon, transition metals, and their compounds, as well as metal nanoparticles). The mechanisms of generating the main reactive species in the periodate-based advanced oxidation processes were discussed. The influence of experimental conditions such as pH, temperature, concentrations of the pollutant, periodate ions, catalyst, the wavelength of UV radiation, and the presence of coexisting inorganic anions on the efficiency of oxidative degradation of organic compounds using periodate-based advanced oxidation processes was analyzed. It was found that the efficiency of periodate activation increases with operation in a near-acidic or neutral medium, using a lower initial concentration of pollutant and optimum catalyst loading as well as optimal IO4- concentration. Overall, the presented analysis of the disadvantages and advantages of periodate-based advanced oxidation processes indicated the promise in industrial wastewater treatment with synergism based on using combination approaches. The most optimum approach for industrial-scale implementation appears to be the activated periodate using an ultrasonic field combined with solid particles such as the granular activated carbon or transition metals and their compounds.