Effects of KBr and KI on Photocatalytic Degradation of Dye W-7G with Nano-TiO[sub.2] as Catalyst

To investigate the influence of inorganic salt on the photocatalytic degradation, the effects of KBr and KI at various concentrations and pH values on the photocatalytic degradation of dye W-7G using nanoscaled titanium dioxide as photocatalyst in a bubbling fluidized bed photocatalytic reactor (BFBPR) were studied. The results indicated that the degradation apparent rate constant (K[sub.app]) of the system with KI was clearly higher than that with KBr under acidic or alkaline conditions. And the maximum value of K[sub.app] (0.01127) appeared at the KI concentration of 0.075gL[sup.-1] with a pH value of 9.37, meaning the highest degradation efficiency. Furthermore, the possible mechanism of photocatalytic degradation of W-7G in the presence of KBr and KI was proposed, which could provide a theoretical support for the further study of inorganic salt effects on the photocatalytic degradation of dyes.