Synthesis and photocatalytic studies of TiO2-clinoptilolite on spent caustic wastewater treatment

Mixed spent caustic is an industrial wastewater that is generated from oil refineries and olefin units. In this investigation, the TiO₂ film was loaded with Clinoptilolite for preparing TiO₂-clinoptilolite photocatalyst. In order to characterize the surface of composite and its microstructure, scanning electron microscopy (SEM) and powder x-ray diffraction (XRD) have been used. Subsequently, this photocatalyst is utilized for the degradation of spent caustic wastewater to determine the photocatalytic efficiency of TiO₂-clinophotocatalyst. Then the photocatalytic degradation of chemical oxygen demand (COD) in spent caustic wastewater has been modeled using the design of experiment method. This procedure was performed in two ways: in the presence of an oxidant agent (H₂O₂) and by minimizing the amount of oxidant. The results show that the maximum degradation efficiency of TiO₂-clinophotocatalyst is 74.3% and 77.3% under the condition of applying limitation and without concerning limitation for the presence of oxidant, respectively.