Photocatalytic Degradation Of Nitrobenzene Sulfonate By Modified Titanium Dioxide And Hydrogen Peroxide

3-nitro-benzenesulfonic aci sodium (3NBSAS) is a widely used chemical intermediate. Due to its stability,toxicity and severe environmental pollution to the water body, the removal of 3NBSAS has become an increasingly hot topic. Photocatalytic methods using TiO₂ is favovered in the degradation of organic matter for its poisonlessness, harmlessness, excellent photoelectricity properties and high avalability of catalytic mateiral. This paper aims to remove 3NBSAS using the doped and loaded TiO₂ under visible light while ensuring the stability and recyclablity of the catalyst.In this paper, Fe/TiO₂ photocatalyst is prepared with sol-gel method. The influence of ethanol, deionized water, nitric acid, iron doping and calcination temperature on catalyst performance was examined by gorthogonal experiments. It was found that the catalyst had the best performance when the volume ratio of butyl titanate: ethanol: deionized water: nitric acid was 20:120:12:1.0, iron doped ratio was 1.25wt%, and calcination temperature was 500℃. The substrate removal rate was 67.2% under above conditions. The effect of reaction conditions, including solution pH, H₂O₂ volume ,amount of catalyst, substrate concentration, reaction time on catalyst performance was also considered. The results showed that the substrate concentration was the key factor. The catalyst removal efficiency was satisfactory when substrate concentration was less than 100mg/L. The substrate removal rate was 69.3%, when the substrate concentration was 25mg/L, pH was 6, H₂O₂ was 0.8mL/L, and catalyst amount was 1.2mg/L.Fe/TiO₂ was loaded on the activated carbon with sol-gel method. The results showed: the photocatalytic activity had been increased after loading. The removal rate of 3NBSAS is 81.4%, with a 14.2% increacement, when the proportion of TiO₂ and activated carbon is 0.52. After 5 times catalyst recycle, the recyclable rates of catalyst were higher than 97% and the substrate removal rates were all higher than 80%.Then the loaded catalyst was doped with S, Ce, for higher catalytic activity under visible light. The one doped with S responsed to the visible light, but the Ce-doped catalyst did not. The removal rate of 3NBSAS (25mg/L) was about 45.5% with 1.5wt% S.