Solar photo-oxidation of recalcitrant industrial wastewater: a review
Ahmed Tawfik, Mohamed Gar Alalm, Hanem M. Awad, Muhammad Islam, Muhammad Abdul Qyyum, Ala’a H. Al‐Muhtaseb, Ahmed I. Osman, Moonyong Lee
Abstract
Abstract Conventional methods to clean wastewater actually lead to incomplete treatments, calling for advanced technologies to degrade recalcitrant pollutants. Herein we review solar photo-oxidation to degrade the recalcitrant contaminants in industrial wastewater, with focus on photocatalysts, reactor design and the photo-Fenton process. We discuss limitations due to low visible-light absorption, catalyst collection and reusability, and production of toxic by-products. Photodegradation of refractory organics by solar light is controlled by pH, photocatalyst composition and bandgap, pollutant properties and concentration, irradiation type and intensity, catalyst loading, and the water matrix.