Synergistic adsorption and photocatalytic process for COD removal from petroleum refinery wastewater using AC/TiO2/CeO2composite

Abstract

This work focused on synthesis and application of AC/TiO2/CeO2 composite for chemical oxygen demand (COD) removal from petroleum refinery wastewater (PRW) using a synergetic adsorption and photocatalytic process. AC/TiO2/CeO2 composite was successfully synthesized to investigate the adsorption and photocatalytic performance. The physical and chemical properties of synthesized composite were characterized by scanning electron microscopy (SEM), energy dispersive x-ray (EDX), x-ray diffraction (XRD), and diffuse reflectance spectrometry (DRS). The characterization results strongly suggested that the AC/TiO2/CeO2 composite was successfully attributed the adsorption and photocatalytic properties. Based on the results of adsorption isotherms, adsorption kinetics, adsorption thermodynamics, and photocatalytic activity and kinetics suggested that the adsorption characteristics of AC/TiO2/CeO2 composite has a synergetic effect with the photocatalytic property to effectively remove COD from PRW. It can also be observed that the photocatalytic property is slightly stronger than the adsorption property due to the combination of two prominent photocatalysts i.e., TiO2 and CeO2. Finally, these findings can be useful for current PRW treatment and further for developing the project on other pollutants removals from PRW to continuously enhance the effectiveness of PRW treatment.