Photocatalytic degradation of nitroaromatic derivatives of Redwater in visible light

In this paper degradation of the PNP and TNT were performed by the catalysts of WO3 ،Fe3O44 /WO3 and Bi2WO6 under visible light. The catalysts were synthesized by hydrothermal method and the process was performed in a suspension reactor equipped with a metal halid lamp (400 W). The synthesized catalysts were characterized using X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), and Diffuse reflection spectroscopy (DRS). The effective parameters of pH, reaction temperature, and light intensity have been studied. The results showed that using [Catalyst] =2000 ppm, [PNP] =20 ppm, T=250C, and pH=12 after 240 min, the degradation efficiency for WO3 ،Fe3O4 /WO3 and Bi2WO6 obtained about 40%, 32%, and 22%, respectively.