氧化锰基材料催化臭氧氧化酚类混合污染物的活性物种及反应路径研究

发布时间：2020-12-24 07:33

　　催化臭氧氧化是一种有效去除水和废水中有机污染物的处理方法,文献报道氧化锰材料催化分解臭氧活性较高,但在催化臭氧氧化中还缺乏系统研究。本文合成了一系列不同形貌、相态、价态和组成的氧化锰材料,应用于催化臭氧氧化降解酚类污染物。发现了不同条件下酚类污染物降解的活性自由基差异,及不同取代基对酚类污染物的降解速率及主要活性物种的影响关系,揭示了处理酚类混合溶时各组分的相互影响关系。并通过中间产物定性分析,提出了酚类污染物矿化时可能的反应路径。首先合成α,p,γ,6,ε和λ六种相态的MnO2,发现α-MnO2催化4-硝基苯酚降解活性最高。催化剂表面羟基及化学吸附的水分子是催化臭氧分解产自由基的活性位,采用叔丁醇（t-BA）、对苯醌（p-BQ）和叠氮化钠（NaN3）进行自由基抑制实验,发现臭氧氧化和催化臭氧氧化过程中,主要是超氧自由基对4-硝基苯酚降解起作用,而不是羟基自由基。采用两种表面活性剂十六烷基三甲基溴化铵（CTAB）和十二烷基硫酸钠（SDBS）合成了两种α-MnO2。采用0.2 M浓度CTAB溶液制备得介孔α-MnO2比表面积为387.7 m2/g,并在4-硝基苯酚降解和TOC去除中显示很... 

【文章来源】：中国科学院大学(中国科学院过程工程研究所)北京市

【文章页数】：151 页

【学位级别】：博士

【文章目录】：
摘要
Abstract
1. Introduction
    1.1 Water pollution and phenolic compounds contained wastewater
    1.2 Phenolic compounds as pollutants
    1.3 Treating method for phenols contained wastewater
        1.3.1 Biological Treatments
        1.3.2 Physical Treatments
        1.3.3 Chemical Treatments
    1.4 Ozonation
    1.5 Catalytic ozonation
        1.5.1 Homogeneous catalytic ozonation
        1.5.2 Heterogeneous catalytic ozonation
        1.5.3 Manganese based polymorphs and composites materials
    1.6 Goal
    1.7 Thesis Stracture
2. Materials synthesis and characterization
    2.1 Matrials and catalyst preparation methods
        2.1.1 Materials
        2.1.2 Catalyst preparation methods
    2.2 Catayst structure characterization
        2.2.1 X-ray diffraction（XRD）
        2.2.2 Scanning electron microscopy（SEM）
        2.2.3 Transmission electron microscopy（TEM）
        2.2.4 Energy dispersed x-ray spectroscopy（EDS）
        2.2.5 Inductively coupled plasma optical emission spectrometry（ICP）
2 physical adsorption">        2.2.6 N₂ physical adsorption
        2.2.7 Attenuated total reflectance Fourier transforms infrared spectroscopy （ATR-FTIR）
        2.2.8 Electron paramagnetic resonance（EPR）
        2.2.9 Cyclic Voltammetry（CV）
pzc)">        2.2.10 Point of zero charge(pH_pzc)
        2.2.11 Average oxidation state （AOS）
    2.3 Catalytic ozonation
2 and their activities for 4-NP ozonation">3. Synthesis of different phases of MnO₂ and their activities for 4-NP ozonation
    3.1 Synthesis and characterization
2">        3.1.1 Synthesis of α-,β-,δ-,γ-, λ-and ε-MnO2

        3.1.2 Characterization of α-, β-,δ-,γ-,λ- and ε-MnO₂

        3.1.3 Catalytic activity test
    3.2 Results and discussion
2">        3.2.1 p-nitrophenol degradation with MnO₂

        3.2.2 Reactive species and reaction mechanism
    3.3 Summary
2 for catalytic ozonation of 4-NP">4. Preparation of high surface area mesoporous α-MnO₂ for catalytic ozonation of 4-NP
    4.1. Catalyst synthesis
        4.1.1 Catalyst Characterization
        4.1.2 p-nitrophenol degradation
    4.2 Results and discussion
        4.2.1 Materials Characterization
        4.2.2 Catalytic degradation of 4-NP
        4.2.3 Impact of ozone dosage
        4.2.4 Catalytic stability
        4.2.5 Reaction mechanism
    4.3 Summary
x and catalytic ozoantion of phenolic mixture">5. Synthesis of different valences of MnO_x and catalytic ozoantion of phenolic mixture
    5.1. Materials and methods
2, Mn₂O₃ and Mn₃O₄">        5.1.1 Synthesis of MnO₂, Mn₂O₃ and Mn₃O₄

        5.1.2 Characterization of MnO₂, Mn₂O₃ and Mn₃O₄

        5.1.3 Catalytic activity experiment
    5.2 Results and discussion
        5.2.1 Materials characterization
        5.2.2 Mixture of phenolic compounds degradation
        5.2.3 Phenol degradation
        5.2.4 p-chlorophenol degradation
        5.2.5 p-cresol degradation
        5.2.6 TOC removal phenolic mixture
        5.2.7 Reaction kinetics in ozonation and catalytic ozonation
        5.2.8 The interaction of phenols in the mixed solution
        5.2.9 Reactive species and attacking patterns
    5.3 Summary
3O₄/MnO₂ composite and degradation mechanism">6. Phenolic mixture degradation with Fe₃O₄/MnO₂ composite and degradation mechanism
    6.1 Materials and methods
2,Fe₃O₄ and Fe₃O₄/MnO₂">        6.1.1 Synthesis of MnO₂,Fe₃O₄ and Fe₃O₄/MnO₂

        6.1.2 Characterization of MnO₂, Fe₃O₄ and Fe₃O₄/MnO₂

        6.1.3 Catalytic activity experiment
    6.2 Results and discussion
        6.2.1 Structural characterization of catalysts
        6.2.2 Catalytic ozonation of phenolic mixture
        6.2.3 Effective pH for stability of catalyst
        6.2.4 Catalyst activity for phenolic mixture
3O₄/MnO₂ catalytic ozonation">    6.3 Reaction mechanism of Fe₃O₄/MnO₂ catalytic ozonation
        6.3.1 ATR-FTIR
        6.3.2 CV
        6.3.3 Quenching Experiments
        6.3.4 Reaction pathway of phenolic mixture
    6.4 Summary
7. Conclusions and prospects
    7.1 General conclusions
    7.2 Prospects
List of abbreviations
REFERENCES
CURRICULAM VITA
ACKNOWLEDGEMENTS



本文编号：2935251

boshi