中性红介导的Shewanella oneidensis MR-1对金属复合偶氮染料的还原脱色

发布时间：2024-06-02 00:10

　　纺织工业是染料的主要用户,它每年要排放大量的染料废水,严重威胁着环境的安全。染料废水的治理势在必行。微生物修复已被证明是治理纺织染料污染最理想、最经济的方法。一些微生物能对染料进行脱色和降解,可用于修复纺织染料污染的环境。其中,产电菌受到更多的关注,因为它对环境污染物具有非特异性还原能力,即它通过新陈代谢过程中释放的电子来降解污染物。而且这种降解能力还可以通过人工电子递质予以强化,这一点对难生物降解染料(如金属复合偶氮染料)特别有用。因此,本研究以中性红(NR)作为电子递质,利用模式产电细菌Shewanella oneidensis MR-1,探究了难降解金属复合偶氮染料酸性兰193(AB 193)的生物可降解性。首先对AB 193的直接生物降解和电子递质强化下的生物降解情况进行研究,建立起NR强化下的AB 193厌氧生物脱色体系,并对脱色体系的影响因素进行研究,然后用响应面法(RSM)优化该脱色体系,并研究了各脱色参数之间的交互作用,最后对该体系的生物脱色机理和化学脱色机理进行进一步研究,并对脱色产物的植物毒性进行了评估。本研究的开展为难降解金属复合偶氮染料废水处理提供了新的思路,同...

【文章页数】：91 页

【学位级别】：硕士

【文章目录】：
abstract
摘要
Chapter 1 Literature review
    1.1 Introduction
    1.2 Brief introduction to azo dyes
    1.3 Source of azo dye wastewater and its potential threat to the environment
    1.4 Available technologies for the treatment of azo dye containing textile wastewater
        1.4.1 Physical methods
        1.4.2 Chemical methods
        1.4.3 Biological methods
    1.5 Electrogenic bacteria
        1.5.1 Anaerobic respiration mechanism of S.oneidensis MR-1
        1.5.2 Extracellular electron transfer of S.oneidensis MR-1
        1.5.3 Electron mediator
        1.5.4 Recent applications of Shewanella in azo dye degradation and detoxification
    1.6 Goal and contents of this study
        1.6.1 The goal of the study
        1.6.2 Research contents
Chapter 2 Anaerobic decolorization of AB 193 by S.oneidensis MR-1 with NR as a redox mediator
    2.1 Introduction
    2.2 Material and methods
        2.2.1 Laboratory reagents and instrumentation
        2.2.2 Strains and culture conditions
        2.2.3 Biological decolorization experiment of AB 193
        2.2.4 Influencing factors of AB 193 reduction decolorization by S.oneidensis MR-1
        2.2.5 Toxicity evaluation of AB 193 and its decolorized products
    2.3 Results and discussion
        2.3.1 Influences of electron mediators on AB 193 decolorization by S.oneidensis MR-1
        2.3.2 Biodecolorization of AB 193 by S.oneidensis MR-1 using NR as electron mediator
        2.3.3 Effects of operation parameters on AB 193 decolorization by S.oneidensis MR-1 mediated with NR
    2.4 Phytotoxicity evaluation
    2.5 Conclusions
Chapter 3 Optimization of AB 193 decolorization using RSM
    3.1 Introduction
    3.2 Materials and method
        3.2.1 Experimental reagent and apparatus
        3.2.2 Strains and culture conditions
        3.2.3 Optimization of process parameters using RSM based on BBD
    3.3 Results and discussion
        3.3.1 Box-Behnken analysis
        3.3.2 Model adequacy
        3.3.3 Effects of interactive factors in AB 193 decolorization by S.oneidensis MR-1
        3.3.4 Model validation and confirmation
        3.3.5 Conclusions
Chapter 4 Anaerobic decolorization mechanism of AB 193 by S.oneidensis MR-1 with NR as an electron mediator
    4.1 Introduction
    4.2 Materials and methods
        4.2.1 Laboratory Reagents and Apparatus
        4.2.2 Strains and Culture conditions
        4.2.3 Neutral red reoxidation assay in AB 193 decolorization
        4.2.4 EPS extraction and composition analysis
        4.2.5 Experiments of Mtr mutants and inhibitors
        4.2.6 AB 193 decolorized product analysis
    4.3 Results and discussion
        4.3.1 Oxidation-reduction change of NR by S.oneidensis MR-1 and AB 193
        4.3.2 Effects of NR on EPS secretion of S.oneidensis MR-1 during AB 193 decolorization
        4.3.3 Effects of NR on Mtr pathway of S. oneidensis MR-1 during AB 193 reduction
        4.3.4 Effects of electron transport chain inhibitors on decolorization of AB 193
        4.3.5 Analysis of the decolorized product of AB 193
    4.4 Conclusion
Chapter 5 Conclusion and Recommendation
    5.1 Conclusions
    5.2 Recommendations
References
Acknowledgement
Appendix A Instrumentation
Appendix B Reagent



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