Visible light Assisted Photocatalytic Degradation of DIPA Using Fe-Zn/TiO2 Photocatalyst

Diisopropanolamine (DIPA) is washed out into water as a result of the process of carbon absorption, contributing to a high chemical oxygen demand (COD). Water with high COD content is not suitable to be treated by biological method and hence, Advanced Oxidation Processes (AOPs) are gaining more and more interests. The efficiency of photocatalytic degradation of DIPA with the presence of visible light is tested with Fe-Zn/TiO2. There are currently no studies found using this particular combination of dopant metals. There are two parts to this study; synthesis optimization and parametric optimization. Fe-Zn/TiO2 photocatalysts were prepared using both co-precipitation (CP) and wet impregnation (WI) methods and also using different titania to determine the ones which give the highest photocatalytic activity. Parameters tested for the optimization includes metal composition (0-0.5), photocatalyst calcination temperature (200˚C, 300˚C, 400˚C), photocatalyst loading (0.05mg/mL, 0.1mg/mL, 0.5mg/mL), initial DIPA concentration (100ppm, 300ppm, 500ppm) and irradiation duration (1h). Fe-Zn/TiO2 photocatalyst prepared by WI using anatase titania, with metal composition of 0.1Fe-0.4Zn and calcined at 300˚C was found to give the highest percentage of COD removal (66.5%). It was also concluded that the photocatalytic activity decreases with increasing initial DIPA concentration and increases with respect to time. The photocatalysts were characterized using TGA, SEM, FESEM, FTIR, XRD and BET.