Application of solar light for degradation of ammonia in petrochemical wastewater by a floating TiO2/LECA photocatalyst

Abstract

In this study, photocatalytic degradation of ammonia in petrochemical wastewater was investigated by solar light/TiO2 photocatalysis. The TiO2 nanoparticles were used as photocatalysts which were immobilized on light expanded clay aggregate (LECA) granules as a new porous and light weight support. Maximum concentration of ammonia (975mg/L) in petrochemical wastewater was selected, and to optimize the photocatalytic reaction, the effect of pH and catalyst dosage was investigated in two aerated and agitated reactor systems. Also, the morphology and chemical structure properties of the prepared catalysts were characterized by SEM and XRF analyses. The experimental results were shown that the performance of two types of aeration reactor systems was almost the same. Also, the ammonia removal efficiency was increased by increasing the pH value, and after solar light irradiation in three days, the solar reactor system lead degradation of ammonia in pH=11–96.5%. The floating of photocatalyst can be reused at least three consecutive times with 14% decreases on the ammonia removal efficiency. The results suggest that the photocatalytic purification followed by solar photocatalytic reactor would be a promising method for the purification of chemical wastewater.