茶皂素强化黑麦草修复芘—镉污染土壤及污染物形态转化机制

发布时间：2018-04-08 11:40

本文选题：茶皂素　切入点：黑麦草　出处：《上海大学》2015年硕士论文

【摘要】：表面活性剂强化植物修复是对重金属和有机污染修复的有效手段,在污染修复领域具有广阔的应用前景,但目前尚未完全弄清其修复机制。本文从表面活性剂强化植物对土壤中污染物不同形态转化及提高生物可利用形态的角度进行研究。选择了四种表面活性剂,通过模拟土壤环境,筛选出40 mg L-1的茶皂素与供试植物黑麦草强化修复芘和镉单一与复合污染土壤。研究了茶皂素在单一和复合污染土壤中对污染物的增溶作用、污染物不同形态之间的相互转化关系、单一和复合污染物之间的相互作用、黑麦草对污染物的富集降解效果、植物的过氧化氢酶(CAT)和过氧化物酶(POD)活性、土壤微生物活性、土壤脱氢酶(DHA)和多酚氧化酶(PPO)活性和茶皂素及污染物对黑麦草根和叶的微观结构的影响。(1)从四种表面活性剂中筛选出茶皂素40mg kg-1进行修复实验。茶皂素对Cd和芘都有很好的增溶作用,促进Fe-Mn氧化态Cd和碳酸盐结合态Cd向可交换态Cd转化,促进吸附态芘向生物可利用态芘转化。在复合污染土壤中,Cd的存在会促进芘的增溶作用,芘抑制Cd的增溶作用。(2)污染物对种子萌发具有一定的胁迫作用,但不影响植物的正常萌发。添加40mg kg-1的茶皂素可以增加植物的生物量,促进其对芘和Cd的降解与富集,提高植物中的CAT和POD酶活性及土壤中的DHA和PPO酶活性,增强植物的抗逆性和自我保护机制。添加茶皂素使土壤中可利用态污染物含量增多,促使土壤中微生物活性增加,提高微生物协同植物降解和富集污染物,加快植物和微生物降解和富集土壤中污染物的过程。Cd和芘的富集部位主要集中在黑麦草的根部,Cd在土壤中有向下迁移作用。(3)通过SEM扫描电镜观察茶皂素强化修复后的植物根和叶的微观结构。当植物受到污染物胁迫之后,会产生防御机制,在叶或根的表面分泌白色颗粒物,或者在根的表面产生褶皱和突起来保护植物的基本生理特征。添加茶皂素会活化污染物,加快植物修复进程。茶皂素作为生物可降解表面活性剂,在污染物修复领域将具有非常好的应用前景。本文研究了茶皂素强化黑麦草对芘、镉污染土壤修复的强化作用及污染物形态转化机制,为表面活性剂强化植物修复技术的发展和应用提供了支持。
[Abstract]:Surfactant enhanced phytoremediation is an effective method for remediation of heavy metals and organic pollutants. It has a broad prospect of application in the field of pollution remediation, but its remediation mechanism has not been fully understood.In this paper, the surface active agent was used to enhance the transformation of different forms of pollutants in soil and to improve the bioavailable forms.Four surfactants were selected. By simulating the soil environment, 40 mg L-1 tea saponin and ryegrass were selected to strengthen the remediation of pyrene and cadmium single and compound contaminated soil.The solubilization of tea saponin in single and compound polluted soil, the relationship between different forms of pollutants, the interaction between single and complex pollutants, and the enrichment and degradation effect of ryegrass on pollutants were studied.The activities of catalase (CAT) and peroxidase (POD) in plants, soil microbial activity,Soil dehydrogenase (DHA) and polyphenol oxidase (PPO) activities and the effects of tea saponin and its pollutants on the microstructure of ryegrass roots and leaves.Tea saponin has a good solubilization effect on both CD and pyrene. It can promote the conversion of Fe-Mn oxidized CD and carbonate bound CD to exchangeable CD and adsorbed pyrene to bioavailable pyrene.The existence of CD in compound polluted soil could promote the solubilization of pyrene. Pyrene inhibited the solubilization of CD. 2) pollutants had a certain stress effect on seed germination, but did not affect the normal germination of plants.Tea saponin supplemented with 40mg kg-1 could increase the biomass of plants, promote the degradation and enrichment of pyrene and CD, increase the activities of CAT and POD in plants and DHA and PPO in soil, and enhance the resistance and self-protection mechanism of plants.The addition of tea saponin increased the content of available pollutants in soil, promoted the microbial activity in soil, and enhanced the biodegradation and accumulation of pollutants by microbes.Accelerated degradation and enrichment of pollutants in soil by plants and microorganisms. CD and pyrene enrichment sites are mainly concentrated in the roots of ryegrass. CD has downward migration in the soil.) the enhanced remediation of tea saponin was observed by SEM scanning electron microscope.The microstructures of the roots and leaves of the later plants.When plants are stressed by pollutants, they produce defense mechanisms, secreting white particles on the surface of leaves or roots, or ruffling and protruding on the surface of roots to protect the basic physiological characteristics of plants.Adding tea saponin activates pollutants and speeds up the process of phytoremediation.Tea saponin, as a biodegradable surfactant, will have a good application prospect in the field of pollutant remediation.The enhancement effect of tea saponin on remediation of pyrene and cadmium contaminated soil and the mechanism of transformation of pollutants form were studied in this paper, which provided support for the development and application of surfactant enhanced phytoremediation technology.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X173

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