Preparation Of New Catalysts For Hydrogen Peroxide And Their Application In Catalytic Degradation Of Bisphenol A

Endocrine disrupting chemicals （EDCs） are exogenous chemicals that interfere withendocrine in human and animals, disrupt the natural hormone functions and even destroythe metabolic, secretion and reproduction functions. As a kind of EDCs that has obviousreproductive hormone effects, Bisphenol A （BPA） becomes an significant research topicrecently because of its characteristics such as large productivity, wide application and hightoxicity. Advanced oxidation processes （AOPs） are green and efficient in disposingrefractory organics; therefore AOPs application to treatment of all kinds of industrialorganic wastewater has been reported in the domestic and overseas literatures.In this thesis, based on the Fenton theory, the preparation processes and catalyticproperties of the two kinds of Hydrogen peroxide new catalytic materials including solidsuper acid and iron oxide coated activated carbon（Fe/AC） are studied. During this study,catalytic activity and stability are used as the evaluation criterion. Furthermore, thethermostability, superficial area and surface chemical nature of the Fe/AC material withbetter performance were analyzed by DTA, XRD and FT-IR. After that, using the Fe/ACmaterial with superior performance, the catalytic reaction kinetics and process of H₂O₂degradation BPA are investigated. The main contributions in this thesis are as follows:1. Solid super acid materials including SO₄^2-/TiO₂（ST）, Gd³⁺-SO₄^2-/TiO₂（GST）,SO₄^2-/TiO₂-Al₂O₃（STA）, Gd³⁺-SO₄^2-/TiO₂-Al₂O₃（GSTA） are prepared using precipitation-impregnation-calcination method. During the preparation, it is found that the catalyticactivity and stability of solid super acid materials is intimately related to the calcining heat,Gd³⁺doping molar percentage and Ti⁴⁺/Al³⁺molar ratio. The comparisons of theexperiment results demonstrate that GST has better performance in the preparationconditions with450℃calcination temperature and1%Gd³⁺doping molar percentage(Gd³⁺and Ti⁴⁺molar ratio). Moreover, it is shown that the performance of solid super acidmaterials is affected by doping Gd³⁺and Al³⁺. Lastly, the desorption experiment indicatesthat not the adsorption but the like-Fenton’s process is a significant cause to reduce theconcentrations of methyl orange solution in the reaction of solid acid catalyzed hydrogenperoxide degradation of methyl orange.2. Fe/AC materials containing Fe³⁺are prepared using acidization, impregnation, adsorption, and calcination method. The preparation process is studied, and the effect ofthe source of Fe³⁺, and the capacity of Fe³⁺, and the calcination temperature on the catalyticactivity and stability are investigated. From the experiment results, the optimumpreparation conditions are obtained as follows: Fe³⁺from Fe（NO₃）₃, Fe³⁺capacity of AC as44.05mg/g, and the calcining temperature as200℃.3. The removal rate of BPA by using Fe/AC to catalyze H₂O₂is higher than that byutilizing only Fe/AC or AC. The removal rate of BPA by using Fe/AC8times to catalyzeH₂O₂maintains about30%in60minutes, which shows the outstanding stability of theFe/AC materials.4. Fe/AC catalyst materials are characterized by the DTA test results show that ACmaterial of Fe³⁺on the thermal stability has no significant effect; XRD characterizationshow that the AC and Fe/AC in the calcination temperature is105⁴00°C present veryweak peaks at24.1°and35.6°.The results indicate that not a crystalline form of Fe2O3abound on the AC surface, but possible with AC surface oxygen-containing groups to theformation of other combined form;FT-IR spectra of AC and Fe/AC show that modifyingAC with HNO3could effectively increase the number of oxygen groups and AC formed onthe surface of the acidic environment, Fe³⁺capacity of AC had no obvious influence to thenumber of oxygen groups.5. Degradation of BPA by hydrogen peroxide catalyze by the Fe/AC materialstechnology research,obtained optimal parameters: The reaction time60min, the reactiontemperature of20℃, the pH range of4.0≦pH≦8.0, Fe/AC material consumption of3g/L,the amount of hydrogen peroxide to2mL/L and Fe³⁺/H₂O₂molar ratio≥0.012.Under theconditions, the Fe/AC materials catalyze degradation of50mg/L BPA, degradation rate ofclose to100%.Fe/AC+H₂O₂compare with the single Fe/AC or AC system, has betterremoval rate to BPA. Fitting the experimental data show that Fe/AC catalyze the reactionof H₂O₂degradation reaction of BPA can better meet the second order reaction kineticsequation:1/Ct1/C0=kttheR2value of0.9926.