Removal of organic pollutants from wastewater by advanced oxidation processes and its combination with membrane processes

Wastewater treatment is becoming one of the most important issues facing the world. A large amount of effluents of different sources releases various contaminants in water bodies. Among these pollutants, organic pollutants are gaining great attention because of the related risk to their discharge into the environment. Membrane filtration, advanced oxidation processes (AOPs), and their combination have been widely applied for treating these contaminants. Ozonation, Fenton, sulfate based processes, photocatalysis and sonolysis are the main AOPs investigated in the present work. Photocatalytic ozonation, photoperoxonation and ultrasound associated to peroxonation can present higher efficiencies (> 90%) compared to conventional ozonation, being cost efficient and sustainable techniques. The association of UV and/or ultrasound irradiation to Fenton, sulfate based oxidation and photocatalysis leads to synergic effects on organic pollutants removal efficiency up to their total removal. AOPs/membranes coupled processes, i.e., AOPs as pre or post treatment for membrane systems and the one-pot configuration of AOPs/membranes were considered to showcase their potential for organic pollutant removal from wastewater based on the recent endeavors and recent publications. The enhancement of produced water quality, energy saving, environmental friendliness, and the reduction of plant capital and operating costs are the main advantages of AOPs/membranes hybrid processes.