發(fā)布時間：2020-12-08 11:02

　　土壤污染是當今世界關(guān)注的熱點問題。在中國,有近20%的耕地受到污染,尤其需要指出,在農(nóng)田土壤中Cd的污染指數(shù)最高為5.28,是有毒、致病的一個重要元素。鎘能通過改變植物主要的生理和代謝過程對植物造成損傷。因此,我們應(yīng)該采取環(huán)境友好的策略,來緩解Cd對土壤的污染。然而,應(yīng)用化學和機械的方法改良被金屬污染的土壤,往往比較昂貴。因此,我們需要廉價和可持續(xù)的方法來提高土壤的健康,例如種植富集金屬的植物,在污染的生態(tài)系統(tǒng)和環(huán)境中鎘的毒性水平需要采取補救措施,以保持鎘在作物中的濃度。蓖麻被認為是一種有潛力的修復重金屬污染和耐Cd脅迫的植物。與此同時,螯合劑可以通過打破土壤液相和固相之間的平衡,降低植物毒性,從而降低土壤污染。生物炭就是這種可以改良重金屬污染的良好有機材料。生物炭增加了土壤的p H以及對重金屬的吸附,因此緩解了重金屬對植物根系的毒害作用。本實驗的土樣采自武漢市的耕地土壤。風干的土壤樣品用0-400 mg kg-1的硝酸鎘處理,并在25o C培養(yǎng)。3--15 mmol kg-1EDTA、3-10 mmol kg-1NTA、10-25 mmol kg-1檸檬酸銨及3%和6%的稻草秸稈生物... 

【文章來源】：華中農(nóng)業(yè)大學湖北省 211工程院校 教育部直屬院校

【文章頁數(shù)】：118 頁

【學位級別】：博士

【文章目錄】：
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


【參考文獻】：
期刊論文
[1]Cadmium accumulation and tolerance of two castor cultivars in relation to antioxidant systems[J]. Hanzhi Zhang,Qingjun Guo,Junxing Yang,Tongbin Chen,Guangxu Zhu,Marc Peters,Rongfei Wei,Liyan Tian,Chunyu Wang,Deyun Tan,Jie Ma,Gangming Wang,Yingxin Wan.  Journal of Environmental Sciences. 2014(10)
[2]污染土壤重金屬的生物有效性和移動性評價:四種方法比較[J]. 章明奎,方利平,周翠.  應(yīng)用生態(tài)學報. 2006(08)
[3]A newly-discovered Cd-hyperaccumulator Solanum nigrum L.[J]. WEI Shuhe, ZHOU Qixing, WANG Xin, ZHANG Kaisong, GUO Guanlin & MA Lena Qiying Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.  Chinese Science Bulletin. 2005(01)
[4]鎘對植物的生理生態(tài)效應(yīng)的研究進展[J]. 張金彪,黃維南.  生態(tài)學報. 2000(03)
[5]鎘、鉛及其相互作用對小白菜生理生化特性的影響[J]. 秦天才,吳玉樹,王煥校.  生態(tài)學報. 1994(01)



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