Advanced Oxidation Processes

Advanced oxidation processes (AOPs) received increasing interest in both science and practice of water and wastewater treatment during the last few decades due to their potential of conversion of anthropogenic and biorecalcitrant organic pollutants to biodegradable compounds together with potential of disinfection, decolorization, and deodorization. A prerequisite for safe application of AOPs is the avoidance and minimization of by-product formation and therefore each particular application needs feasibility and validation studies in laboratory and pilot scale before application. Due to the complex character of free radical chemistry which is always involved in AOPs, this chapter aims at summarizing the science and practice of different AOPs from fundamentals via mechanistic aspects of reaction competition, a guide in selecting a suitable AOP, some reactor design criteria, useful process combinations with other non-AOPs, and a compilation of different applications in industrial and domestic wastewater treatment as well as drinking water treatment since the boundaries between drinking water and wastewater treatment have begun to fade. The AOPs treated hereinafter among others are ozone based, photochemical, and homogeneous/heterogeneous catalytic processes.