Preparation Of Heterogeneous Fenton Catalyst And Its Deradation Of Bisphenola

In industrial wastewater treatment,organic wastewater is the key and difficult point of water treatment because of its complex composition,strong toxicity and refactory.As an important chemical raw material,bisphenol A is widely used in various industrial productions.Therefore,a large amount of industrial wastewater containing bisphenol A is produced.Heterogeneous Fenton-like process in advanced oxidation technology can oxidize and degrade most organic compounds non-selectively,and it has become an effective method to treat this kind of wastewater.In this paper,50 mg/L bisphenol A solution was used to simulate organic wastewater and different heterogeneous Fenton-like catalysts were prepared in order to overcome the shortcomings of the traditional Fenton method.The degradation effects of different catalysts on bisphenol A under different conditions were studied.The aim is to synthesize catalysts by a simple method,which can help to degradate bisphenol A effectively under neutral conditions,with less catalyst and less H₂O₂consumption.Firstly,we prepared Fe₂O₃/Cd O and Fe₂O₃/Cd O/γ-Al₂O₃by the precipitation-ice-water bath ultrasonic method.An ultraviolet lamp with the wavelength of 254 nm was selected as the irradiation light source.The influence of the three factors of the amount of H₂O₂,the temperature and the amount of catalyst on the degradation effect of bisphenol A under neutral conditions was investigated.The results showed that when the dosage of H₂O₂and catalyst were respectively 500 mg/L and 2.5 g/L at temperature of 30℃,the degradation rate of Cd O/Fe₂O₃to bisphenol A could reach 97.98%.Based on the research of Cd O/Fe₂O₃withγ-Al₂O₃as the carrier,nine different ratios of Fe₂O₃/Cd O/γ-Al₂O₃were prepared.The same ultraviolet lamp with the wavelength of 254 nm was selected as the irradiation light source.The effects of Fe₂O₃/Cd O/γ-Al₂O₃with different proportions on the degradation of bisphenol A were studied under the conditions of H₂O₂dosage of 500 mg/L,catalyst dosage of 2.5 g/L at temperature of 30℃in 40 minutes.By comparison,it is found that the degradation effect of Fe₂O₃/Cd O/γ-Al₂O₃on bisphenol A is not as good as that of Fe₂O₃/Cd O.Based onα-MnO₂,which has good catalytic activity and it is pollution-free.Then,a simple method was used to synthesizeα-Mn O₂,α-Mn O₂/AC（w/w 2:1）andα-Mn O₂/AC（w/w 1:1）.These heterogeneous Fenton-like catalysts were characterized by UV-Vis,FTIR,XRD,SEM and TEM,and the UV-Vis analysis confirmed that they have good absorption in the ultraviolet wavelength of 350-380nm.A 365 nm ultraviolet lamp was chosen as the light source during the catalytic degradation.The optimal conditions of every factor for the degradation of bisphenol A,such as the amount of catalyst,temperature,p H,and amount of H₂O₂,were determined through single factor experiments.Through orthogonal experimental design,the optimal experimental conditions forα-Mn O₂to degrade bisphenol A were determined.Under these conditions,the degradation rate of bisphenol A can reach91.02%within 70 minutes.Whenα-Mn O₂/AC（w/w 2:1）degraded bisphenol A under neutral conditions,the degradation rate of bisphenol A was 92.10%within 70 min under the best experimental conditions.Whenα-Mn O₂/AC（w/w 1:1）degraded bisphenol A under neutral conditions,the degradation rate of bisphenol A was 94.17%within 70 min under the best experimental conditions.According to the above results of these three synthesized materials,α-Mn O₂/AC（w/w 1:1）can achieve better degradation effect on bisphenol A under neutral conditions with less amount of catalyst and H₂O₂.