Effect of Chelates and Biochar on Cd Uptake by Castor(Ricinu

发布时间：2020-12-08 11:02

　　土壤污染是当今世界关注的热点问题。在中国,有近20%的耕地受到污染,尤其需要指出,在农田土壤中Cd的污染指数最高为5.28,是有毒、致病的一个重要元素。镉能通过改变植物主要的生理和代谢过程对植物造成损伤。因此,我们应该采取环境友好的策略,来缓解Cd对土壤的污染。然而,应用化学和机械的方法改良被金属污染的土壤,往往比较昂贵。因此,我们需要廉价和可持续的方法来提高土壤的健康,例如种植富集金属的植物,在污染的生态系统和环境中镉的毒性水平需要采取补救措施,以保持镉在作物中的浓度。蓖麻被认为是一种有潜力的修复重金属污染和耐Cd胁迫的植物。与此同时,螯合剂可以通过打破土壤液相和固相之间的平衡,降低植物毒性,从而降低土壤污染。生物炭就是这种可以改良重金属污染的良好有机材料。生物炭增加了土壤的p H以及对重金属的吸附,因此缓解了重金属对植物根系的毒害作用。本实验的土样采自武汉市的耕地土壤。风干的土壤样品用0-400 mg kg-1的硝酸镉处理,并在25o C培养。3--15 mmol kg-1EDTA、3-10 mmol kg-1NTA、10-25 mmol kg-1柠檬酸铵及3%和6%的稻草秸秆生物... 

【文章来源】：华中农业大学湖北省 211工程院校 教育部直属院校

【文章页数】：118 页

【学位级别】：博士

【文章目录】：
Abstract
Chinese abstract
Chapter I Introduction
    1.1 Cadmium pollution
        1.1.1 Impacts on humans
        1.1.2 Impacts on the plants
        1.1.3 Cd versus other heavy metals
    1.2 Biochar & crop straws role to bio availabilities of heavy metals
    1.3 Phytoremediation in Cd contaminated soils
        1.3.1 Phytoremediation techniques using chelating agents
        1.3.2 Phytoremediation and improving phytoextraction; potential for hyper andnon-hyper accumulator plant species on contaminated soil
        1.3.3 Phytoextraction
        1.3.4 Affecting phytoextraction
    1.4 Aims of study
Chapter II Material and Methods
    2.1 Plant and chelators used in this present study
    2.2 Soil collection and determination of Cd in soil and plant samples
    2.3 Sample prepration for FTIR specroscopy
    2.4 Growth parameters
    2.5 Microbial miomass （MBC） and dissolved organic carbon （DOC）
    2.6 Antioxydant enzymes extraction
    2.7 Chlorophylleand protien content
    2.8 Phytoextraction efficiency factors of plant
Chapter III Enhanced accumulation of Cd in castor （ricinus communis l.） by soil- appliedchelators
    3.1 Introduction
    3.2 Material and methods
    3.3 Results
        3.3.1 Plant Height （cm）
        3.3.2 Dry biomass production
        3.3.3 Effects of chelators on the accumulation of Cd uptake in soil
        3.3.4 Effects of the chelators on the Cd concentrations of castor plant tissue
        3.3.5 Chemical characterization of chelators in metal polluted soil
        3.3.6 Phytoremediation potential
    3.4 Discussion
    3.5 Conclusions
Chapter IV Synthetic chelating agents and metal availability in Cd polluted and non - polluted agricultural soil
    4.1 Introduction
    4.2 Material & Methods
    4.3 Statistical analyses
    4.4 Results and Discussion
        4.4.1 Concentrations of Cd and chelating agents in the Cd-polluted and non-polluted soils
        4.4.2 Chemical characterization of chelators in metal polluted soil
        4.4.3 To evaluate the microbial biomass carbon （MBC） in polluted and non-polluted soil.
        4.4.4 To assess the dissolved organic carbon （DOC） in polluted and non-polluted soil
        4.4.5 Phytoextraction potential in castor plant in Cd polluted and non-polluted soil
        4.4.6 Interaction between soil microbial carbon and available metal in Cd polluted soil
    4.5 Conclusions
Chapter V To evaluate the antioxidant enzymes using castor （Ricinus Communis L.） plant under cadmium stress
    5.1 Introduction
    5.2 Material and Methods
    5.3 Results
    5.4 Discussion
    5.5 Conclusions
Chapter VI The effects of rice straw biochar on Cd bioavailability and plant accumulationin Cd polluted soil
    6.1 Introduction
    6.2 Materials and methods
    6.3 Results and Discussion
    6.4 Conclusion
Chapter VII Concluding remarks, innovations and future perceptions
    7.1 Summary
    7.2 Principal novelty （chelators, biochar and enzyme activity）
    7.3 Future perspectives
References
Acknowledgement
Appendix


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期刊论文
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