Performance of different photocatalytic oxidation processes in petroleum wastewater treatment: A Comparative Study

Abstract

The present study was conducted to compare the performance of different solar photocatalytic processes (TiO2 photocatalysis, photo-Fenton, photo-Fenton coupled with TiO2 photocatalysis, and photo-Fenton coupled with TiO2/ZnO photocatalysis) for the treatment of petroleum wastewater. The removal efficiency of chemical oxygen demand (COD) is evaluated. TiO2 dosage and pH are the main factors that improve the COD removal in the TiO2 photocatalysis process while Fe+2 and H2O2 concentration are the main factors in photo-Fenton process. The photo-Fenton coupled with TiO2/ZnO photocatalysis is the most efficient process for treatment of petroleum wastewater at the neutral conditions (pH 7). Therefore, no need to adjust pH during this treatment. In acidic conditions (pH<7), the photo-Fenton process is more efficient than the TiO2 photocatalysis process while it is less efficient than the TiO2 photocatalysis process in alkaline conditions (pH>7). © 2017 Global NEST Printed in Greece. All rights reserved.