REDUCTION OF AMMONIACAL NITROGEN AND CHEMICAL OXYGEN DEMAND VIA PILOT-SCALE PHOTOCATALYTIC REACTOR INCORPORATED WITH ZNO-KAOLIN

Photocatalytic is an advanced technology for water remediation which potentially to be applied for river pollution treatment. The key to the highest photocatalytic efficiency is the type of photocatalyst used and the process variables including light sources, light intensity, and time operations. However, the study on the interaction of process variables on photocatalytic efficiency for polluted river water treatment has not been well studied. Thus, the present study focused on the performance of pilot-scale photocatalytic reactor incorporated with ZnO-Kaolin under various light intensities such as 100, 125, and 225 Watts with varied time operation at 20, 40, 60 and 80 minutes for reduction of ammoniacal nitrogen (AN) and chemical oxygen demand (COD). Followed by the elucidation of kinetic study through pseudo-first and pseudo-second-order models. It was found that 225 Watts of UV-light contributed to the highest reduction of AN (59.34%) and COD (90.91%) for 60 minutes of treatment. Furthermore, the kinetic study revealed that the photocatalytic process follows pseudo-first-order model with a rate constant of 0.0184 min-1. Hence, the highest photocatalytic efficiency of ZnO-Kaolin is mainly attributed to the intensive light intensity, leading to the higher generation of reactive species for rapid photocatalytic degradation, consequently improving the performance of pilot-scale photocatalytic reactor.