The Study Of Sulfate-radical Based Advanced Oxidation Processes For Degradation Of BPA

Since the entry of mankind into the era of industrialization,as people's demand for materials has increased,the demand for various synthetic materials in life and production has become more diversified,and the amount of use has also increased year by year.Currently,it is conservatively estimated that at least about 27 million tons of plastics containing bisphenol A are produced each year,and the amount of synthetic polycarbonate and epoxy resin is huge.Bisphenol A is medically known as an endocrine disruptor along with alkylphenols,phthalates,polybrominated diphenyl ethers,tetrabromobisphenol A,and synthetic musk.Studies have shown that bisphenol A can cause endocrine disorders,which is extremely harmful to the fetus and children.Moreover,this substance can accumulate in the environment.Therefore,timely treatment of bisphenol A present in wastewater has attracted the attention of more and more researchers.Since the structure of bisphenol A contains two benzene rings,it is difficult to mineralize it using conventional biological methods,so it is classified as a refractory pollutant.This experiment used an advanced oxidation technology developed in recent years,based on the advanced oxidation technology of sulfate radicals,to study the removal effect of wastewater containing bisphenol A.Firstly,the use of nanometer ferroferric oxide as a catalyst to activate sodium persulfate to produce sulfate radicals to treat bisphenol A wastewater,to obtain the best operating conditions and treatment effects,and then the removal rate is not very thorough for the study,The nanometer ferroferric oxide catalyst is treated by treating the nanometer ferroferric oxide and the transition metal silver to form a bimetallic catalyst for use in combination,and the other is to pass the bimetallic catalyst and the modified activated carbon.The combined treatment materials were used in combination.Finally,the optimal preparation conditions of the two synthesized catalysts and the removal effects and conditions of the two catalysts for the treatment of bisphenol A-containing wastewater by activated sodium persulfate to produce sulfate radicals were studied.Optimization.In the experiment of using sodium ferrotitanate as a catalyst to activate sodium sulfate to generate sulfate radicals to treat wastewater containing bisphenol A,the experimental results show that temperature has little effect on the experimental results,and other factors affect the activation of nanometer ferroferric oxide.The degree of influence of sodium persulfate treatment is from large to small: sodium persulfate dosage ? nanometer ferroferric oxide usage ? reaction time ? stirring speed.The optimum treatment effect obtained in the single factor optimization experiment was as follows: when the concentration of bisphenol A was 60 mg/L,the pH was 6.0,and the dosage of nanometer ferroferric oxide was 15 mmol/L(mass concentration was 3.4800 g)./L),the dosage of sodium persulfate was 1.5 mmol/L,the stirring speed was 90 r/min,the reaction time was 60 min,and the highest removal rate of bisphenol A was 75.23%.In the experiment of using sodium-silver bimetallic catalyst to activate sodium sulfate to generate sulfate radicals to treat bisphenol A wastewater,the experimental results are as follows: the best molar ratio of composite preparation is M(ferric oxide)): M(silver sulfide)= 1:3.The temperature has little effect on the experimental results.The influence of other factors on the effect of the composite activated persulfate treatment from large to small is: sodium persulfate usage ? stirring speed ? bimetallic catalyst usage ? reaction time.The optimum treatment effect obtained in the single factor optimization experiment is as follows: when the concentration of bisphenol A is 60 mh/L,the pH is 7.0,and the dosage of iron-silver bimetallic catalyst is 7.5 g/L.The addition amount is 1.5mmol/L,the reaction time is 60 min,and the removal rate of bisphenol A can reach 86.63%.In the experiment of treating bisphenol A wastewater with modified activated carbon-supported iron-silver bimetallic catalyst composite,the removal rate of bisphenol A can reach 97.41% due to the combination of adsorption of activated carbon and catalysis of composite materials.Basically,the effect of complete removal can be achieved.Moreover,the reaction rate is greatly accelerated,and a high removal effect can be achieved within 30 minutes.When the re-use performance of the material is further examined,after six repeated tests,the removal rate of bisphenol A can still be as high as possible under the optimum conditions.75.34%.It shows that the composite material obtained under reasonable load environment can be reused very well,which greatly reduces the loss of composite materials,and further expands the application range of oxidation technology based on sulfate radicals.