Synthesis Of Aluminum-doped Strontium Titanate Photocatalyst And Study On Simulated Radioactive Wastewater Treatment

Water is the source of life,and wastewater treatment has always been the most concerned issue of the state,government,enterprises,and ordinary people.The development of nuclear energy has also introduced radioactive pollution into the environment,which has a great impact on human health.At present,people pay more and more attention to the treatment of water pollution.The photocatalytic technology is considered to be an ideal technology for waste disposal due to its advantages of environmental protection,non-toxic and cheap,stable performance,and no secondary pollution.It also complies with the IAEA’s design principles for the minimization of nuclear waste treatment and disposal.Therefore,butyl titanate is the source of titanium,strontium nitrate is the source of strontium,ethylene glycol is the stabilizer,glacial acetic acid is the hydrolysis inhibitor,the strontium titanate（Sr Ti O₃）was synthesized by sol-gel method at 500℃for 3 hours,and aluminum nitrate was used as the aluminum source to dope it with different contents.The crystal structure,surface morphology and energy gap of the synthesized materials were analyzed by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and ultraviolet-visible diffuse reflection（UV-VIS-DRS）.At the same time,photocatalytic performance evaluation and recycling experiments were carried out by reducing the toxic metal chromium Cr（Ⅵ）,oxidizing macromolecular organic compounds rhodamine B（RhB）,and methylene blue（MB）.Finally,a verification experiment of tributyl phosphate（TBP）,which is common in the nuclear industry,was conducted,and the mechanism of photocatalytic degradation of TBP was discussed.The research shows that we successfully synthesized nano-scale aluminum-doped strontium titanate and loaded it on the fiber cloth with a recovery rate of over 85%and recycling it for more than 10 times without inactivation.In terms of photocatalytic reduction of Cr（Ⅵ）,We know that the experiment is affected by the initial concentration of the solution,p H,the amount of catalyst,and the concentration of additives.Under optimal conditions,the 10 mg/L Cr（Ⅵ）solution can be reduced by more than 80%.In terms of photocatalytic treatment of organic matter,the synthesized strontium titanate can degrade 92.47%of the 10 mg/L RhB solution in 30minutes,and the solution changes from purple to colorless in 120 minutes,and the COD removal rate reaches 80%;The MB solution can be degraded by more than 75%within 20 minutes.The solution changes from blue to colorless within 120 minutes,and the COD removal rate reaches 75%.When photocatalytically degrading tributyl phosphate（TBP）,the content of TBP was determined by the meteorological chromatographic hydrogen flame detector with ethanol as the internal standard.The retention times of ethanol and tributyl phosphate were 1.5 and 13 min,respectively.After irradiation with ultraviolet light,the solution was activated,generating a large amount of·OH radical ions,attacking the P=O bond of tributyl phosphate,breaking it,generating new radical ions,and a chain reaction.