A Review on Advanced Oxidation Processes (AOPs) for Wastewater Remediation

In 21st century, organic and domestic wastes and discharges from varied chemical and manufacturing industries to water bodies become a critical issue and challenge for the researchers, engineers and policy makers. Advanced oxidation processes (AOPs) are efficient, sustainable, economically viable and green techniques to elimination on-degradable organic pollutants by biological and traditional processes. A number of research articles have been published from the past two decades on the wastewater treatment using various advanced oxidation processes. The main objective of this review paper is to provide the quick view for researchers, academicians and scientists in the area of wastewater treatment using various types of AOPs, which incorporate green principles involves in the processes for removal of different pollutants and contaminants including dyes, phenols, pesticides, herbicides etc. from wastewaters, with emphasis on the degradation efficiency of various photocatalysts. The formation reactions of •OH radical and the mechanisms of degradation of various organic pollutants in the wastewater is also discussed. This review covers various types of advanced oxidation processes, viz., ozone-based processes, photocatalysis and Fenton-based reactions.