Removal of styrene by the synthesized ZnO nanoparticles coated on the activated carbon adsorbent in the presence of UV irradiation

Abstract

Background: Volatile organic compounds are the major environmental pollutants causing adverse effects on the human health and the environment, therefore, tremendous effort has been put toward eliminating these compounds. Methods: In this study, the effect of synthesized nanoparticles on the removal of styrene from gas phase by photocatalytic process under UV irradiation in the cylindrical photoreactor was studied. The activated carbon-zinc oxide (AC-ZnO) catalysts were prepared at different weight ratios (6%, 12%, and 18%) of ZnO. The prepared catalyst was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller (BET) analyses. The effects of various parameters, such as concentrations of styrene, various weight percentage (wt%) of nanoparticles, and UV irradiation, were investigated. The efficiency of the AC-ZnO catalyst was determined based on its adsorption capacity, breakthrough time, and removal efficiency. Results: It was revealed that the photocatalytic removal efficiency of styrene was high in the presence of both ZnO nanoparticle and AC under UV light. Under optimal conditions, the efficiency of UV/AC-ZnO 18%, UV/AC-ZnO 12%, and UV/AC-ZnO 6% catalysts was 77%, 86%, and 83%, respectively. By increasing the concentration of input styrene, the photocatalytic removal efficiency was reduced, while the adsorption capacity of styrene increased. Conclusion: According to the results, the AC-ZnO 12% exhibited higher activity compared to other photocatalysts. Also, the amount of stabilized ZnO nanoparticles on the activated carbon affects the elimination rate of styrene.