The integration of PbO2-based EAOPs with other advanced oxidation processes for improved treatment of water and wastewater

EAOPs are widely used for the degradation of toxic and non-biodegradable organic pollutants. The non-active PbO2 anode can be used simultaneously with other AOPs due to its significant synergy in the production of HO• radicals. PbO2 composite photoanodes, which have photocatalyst and electrocatalyst hybrid properties, significantly increase the removal efficiency of organic pollutants. In addition, the use of PbO2 anode in three-dimensional electrochemical reactors (3DERs) equipped with granular activated carbon (GAC) particle electrodes and the integration of PbO2 anode with sonoelectrochemical, electro-Fenton, and electro-persulfate processes have also been recently studied for improved degradation of organic pollutants. However, although integrated processes improve removal efficiency, they add more equipment and more complexity to system operation and maintenance. Therefore, nowadays researchers pay attention to modified PbO2 anodes because compared to virgin PbO2, they are more efficient for water and wastewater treatment. Considering the latest research in this field, this review introduces state-of-the-art hybrid electrochemical systems. Then, focusing on the integration of PbO2-based EAOPs with other oxidation processes, their most important results are presented. In the end, a summary of the application of modified PbO2 anodes for the treatment of organic pollutants is provided.