Advanced Oxidation Processes

Advanced oxidation processesAdvanced oxidation process (AOPs) are effective at removing persistent organic pollutants (POPs) from water and wastewater. They are also promising and environmentally benign. AOPs mineralise pollutants by powerful oxidising agents such as hydroxyl radicalsHydroxyl radical (HO•) and sulphate radicalsSulphate radical (SO4•−). This chapter presents an overview of various AOPs such as sonochemicalSonochemistry processes, hydrocavitation, ozoneOzone-based processes, sulphate radicalSulphate radical-based processes, and UV-based processes. The strategies to enhance the radical generation via various combinations of the above processes such as sono-FentonFenton, sono-photo-Fenton, sonophotolysis, sonophotocatalysis, and hydrocavitation combined with H2O2/O3/persulphate; ozonolysis combined with UV/activated carbon/H2O2 were also explored. Along with improved pollutant degradationDegradation efficiency, processes such as sonophotocatalysis have an additional advantage as ultrasoundUltrasound cleans the catalyst surface providing additional surface area for the pollutants to degrade. In order to utilise the benefits of the coupling processes to the fullest, the proper study is necessary to diminish the radical scavenging effects and the associated drawbacks.