Removal of styrene from air by photocatalytic process of Zeolite Socony Mobil-5 coated with zinc oxide nanoparticles

Volatile organic compounds (VOC) are considered as major environmental contaminants that have a harmful effect on human and ecosystem health, so much effort has been focused on their removal. The aim of this study was to investigate the removal efficiency of styrene by Zeolite Socony Mobil-5 (ZSM-5) after immobilization of nanoparticles of zinc oxide (ZnO) on it.
In this experimental study and in order to produce styrene, clean dry air with a constant flow rate of 1 l/minute was pumped into an impinger containing styrene solution which resulted in the evaporation of styrene. Produced vapors entered into the mixing chamber to be mixed with clean air. Produced styrene with certain concentrations of 20, 100 and 300 ppm was sent to a reactor containing ZSM-5/ZnO bed to investigate the effectiveness of the bed in the elimination of styrene.
This study focused on removal of styrene using ZnO nanoparticles stabilized on ZSM-5 Zeolite. The highest removal efficiency of styrene was 47.5% in concentrations of 20 ppm. For concentrations of 100 and 300 ppm, the efficiency was 22% and 12.5%, respectively.
Both adsorption and catalytic mechanisms can be effective in removal of pollutants in different conditions. Findings related to adsorption and removal of styrene also showed that coating ZnO nanoparticles on zeolite absorbent in presence of ultraviolet (UV) has increased the removal efficiency.