本文選題：金屬納米顆粒 + 氧化鋼納米顆粒(CuO)��； 參考：《浙江大學》2016年博士論文

【摘要】：隨著納米科技的不斷發(fā)展,大量金屬納米顆粒在生產(chǎn)運輸、使用及處置過程中不可避免會進入土壤,對生態(tài)系統(tǒng)及人類健康造成威脅。稻田土壤作為我國典型的濕地農(nóng)田生態(tài)系統(tǒng),土壤質(zhì)量直接關(guān)系到水稻產(chǎn)量及環(huán)境健康。因此,為科學評估金屬納米顆粒的農(nóng)業(yè)生態(tài)及健康風險,推動納米科技健康可持續(xù)發(fā)展,本論文以典型金屬納米顆粒CuO NPs作為研究對象,模擬CuO NPs進入稻田土壤的環(huán)境條件,考察CuO NPs在淹水落干過程中的形態(tài)轉(zhuǎn)化及對土壤性質(zhì)及物質(zhì)組成的影響,著重探討CuO NPs對土壤微生物的毒性作用機理及對微生物群落結(jié)構(gòu)和生態(tài)功能的影響機制。主要研究結(jié)果如下：(1)闡明CuO NPs在稻田土壤中的形態(tài)轉(zhuǎn)化規(guī)律,證明CuO NPs輸入會影響稻田土壤理化性質(zhì)及物質(zhì)組成的變化。研究發(fā)現(xiàn)CuO NPs進入土壤中可迅速發(fā)生轉(zhuǎn)變,并逐漸向更穩(wěn)定的絡(luò)合態(tài)或沉淀態(tài)發(fā)展,且轉(zhuǎn)化規(guī)律與有機質(zhì)含量等土壤性質(zhì)相關(guān)。CuO NPs對稻田土壤性質(zhì)造成了不同程度的影響：其中,CuO NPs的金屬特征會影響土壤pH、Eh、Ec等環(huán)境因子的變化,而土壤吸附能力和陽離子交換能力等化學性質(zhì)未受影響；包括礦物質(zhì)、有機質(zhì)和微生物在內(nèi)的土壤固相組分均受到CuO NPs的顯著影響,且納米顆粒對微生物的影響在土壤其他組分的變化中起了關(guān)鍵作用。土壤有機質(zhì)可以在一定程度上緩解CuONPs對土壤性質(zhì)的作用效應。(2)弄清TiO2 NPs和CuO NPs分別以顆粒性質(zhì)和重金屬特性對微生物產(chǎn)生毒性的作用機理。通過對比研究發(fā)現(xiàn),CuO NPs和TiO2 NPs均會對稻田土壤微生物及其群落產(chǎn)生一定的擾動,且CuO NPs的作用強于TiO2 NPS。其中Ti02NPs對土壤酶活的影響較為復雜,對土壤微生物量及群落組成的影響較小；而CuO NPs的施加則顯著降低了土壤微生物量、酶活、微生物群落的組成及生物多樣性。通過Pearson分析納米顆粒的有效形態(tài)與微生物作用的相關(guān)性發(fā)現(xiàn),TiO2 NPs主要通過其顆粒本身的性質(zhì)影響土壤微生物,而淹水稻田土壤中的CuO NPs由于具有高度的溶解性和重金屬生物有效性,從而對土壤微生物產(chǎn)生了較大的毒害作用。此外,CuO NPs還可通過改變土壤營養(yǎng)元素的可利用能力間接影響土壤微生物的生存和發(fā)展。(3)揭示了CuO NPs作用下水稻根際微生物群落的演變規(guī)律,發(fā)現(xiàn)CuONPs顆粒及重金屬特性的微生物差異響應及其對微生物生態(tài)系統(tǒng)穩(wěn)定性的影響。利用Miseq高通量測序研究發(fā)現(xiàn),CuO NPs的不同特性對不同菌屬造成了相反的影響：由于CuO NPs的金屬毒害作用,以Chloroflexi為代表的大部分根際細菌的生長受到了CuO NPs的顯著抑制,相對豐度降低,其中參與氮循環(huán)的微生物對CuO NPs高度敏感；而包括纖維素降解菌、鐵還原菌和硫還原菌等部分細菌由于CuO NPs顆粒特性的影響,逐漸成為優(yōu)勢菌屬。CuO NPs加劇了水稻根際土壤細菌群落多樣性的消減和群落的演替,嚴重影響了根際土壤微生物生態(tài)系統(tǒng)的穩(wěn)定性。同時,水稻根際環(huán)境會影響CuO NPs對根際微生物群落的調(diào)控作用。(4)明確了CuO NPs調(diào)控水稻根際特殊微生物功能的耦合作用,從而影響了稻田土壤物質(zhì)循環(huán)。利用Q-PCR技術(shù)研究發(fā)現(xiàn)CuO NPs可以利用特殊的顆粒特性增加微生物細胞與纖維素物質(zhì)之間的接觸和附著,從而促進纖維素降解菌的活性和生長。大量的可溶性有機碳又可進一步為產(chǎn)甲烷菌、鐵還原菌等功能微生物提供豐富的碳源,同時,CuO NPs還可利用其特殊的納米顆粒特性直接參與微生物間的電子傳遞,從而促進微生物的產(chǎn)甲烷及鐵還原過程。而參與氮循環(huán)的功能微生物對CuO NPs敏感,但響應不一,并最終未影響土壤N20的排放。
[Abstract]:With the continuous development of nanotechnology, a large number of metal nanoparticles inevitably enter the soil in the process of transportation, use and disposal, which threaten the ecosystem and human health. The paddy soil is a Typical Wetland Farmland Ecosystem in China. The soil quality is directly related to the rice yield and environmental health. Therefore, it is the science of science. To assess the agro ecological and health risks of metal nanoparticles and promote the healthy and sustainable development of nanotechnology, this paper uses the typical metal nanoparticles CuO NPs as the research object to simulate the environmental conditions of CuO NPs into the paddy soil, and investigate the transformation of CuO NPs in the process of flooding and the effects on the soil properties and the composition of the soil. The toxic mechanism of CuO NPs on soil microorganism and the mechanism of influence on microbial community structure and ecological function were discussed. The main results were as follows: (1) the morphological transformation of CuO NPs in paddy soil was clarified, and it was proved that CuO NPs input would affect the changes of physical and chemical properties and material composition of paddy soil. The study found that CuO NPs was entered. It can change rapidly into the soil and gradually develop to a more stable complex or precipitation state, and the transformation law and the soil properties related to organic matter content such as the content of.CuO NPs have different effects on the soil properties of the paddy field. Among them, the metal characteristics of CuO NPs will affect the changes of environmental factors such as pH, Eh, Ec and so on, and the soil adsorption energy The chemical properties such as force and cation exchange capacity have not been affected; the soil solid components, including minerals, organic matter and microorganism, are significantly affected by CuO NPs, and the effect of nanoparticles on microbes plays a key role in the change of other soil components. Soil organic matter can mitigate CuONPs to soil to a certain extent. The effect of soil properties. (2) to clarify the mechanism of TiO2 NPs and CuO NPs to produce toxicity to microbes by particle and heavy metals respectively. Through comparative study, it is found that both CuO NPs and TiO2 NPs produce certain disturbance to the soil microorganism and its community in the paddy field, and the effect of CuO NPs is stronger than that of TiO2 NPS.. The effect of living is more complex, and it has little effect on soil microbial biomass and community composition, while the application of CuO NPs significantly reduces soil microbial biomass, enzyme activity, microbial community composition and biological diversity. The correlation between the effective morphology of nanoparticles and the effect of microbes by Pearson analysis shows that TiO2 NPs is mainly through its particles. Its own nature affects soil microbes, and the CuO NPs in the flooded paddy soil has a great toxicity to soil microbes because of its high solubility and bioavailability of heavy metals. In addition, CuO NPs can also indirectly influence the survival and development of soil microbes by changing the available energy of soil nutrient elements. 3) revealed the evolution of the rhizosphere microbial community of CuO NPs, found the response of CuONPs particles and heavy metal characteristics and their effects on the stability of the microbial ecosystem. Using Miseq high throughput sequencing, it was found that the different characteristics of CuO NPs had the opposite effect on different bacteria genera: due to CuO NPs The growth of most rhizosphere bacteria, represented by Chloroflexi, was significantly inhibited by CuO NPs, and the relative abundance was reduced. The microorganisms involved in the nitrogen cycle were highly sensitive to CuO NPs, while the cellulose degrading bacteria, iron reducing bacteria and sulfur reducing bacteria were gradually formed by the effect of CuO NPs particle properties. .CuO NPs intensifies the decline of bacterial community diversity in rhizosphere soil and succession of community, which seriously affects the stability of microbial ecosystem in rhizosphere soil. Meanwhile, the rice rhizosphere environment affects the regulation of CuO NPs on the rhizosphere microbial community. (4) it is clear that CuO NPs regulates the special microbial function of rice rhizosphere. The coupling effect affects the soil material circulation in the paddy field. Using the Q-PCR technology, it is found that CuO NPs can increase the contact and attachment between microbial cells and cellulose materials by special particle properties, thus promoting the activity and growth of cellulose degrading bacteria. The functional microorganisms such as reducing bacteria provide a rich carbon source. At the same time, CuO NPs can also use its special nano particle properties to directly participate in the electron transfer between microorganisms, thus promoting the microbial methane production and iron reduction process. The functional microorganism involved in nitrogen cycle is sensitive to CuO NPs, but the response is not one, and it does not affect the N20 row of soil in the soil. Put it.
【學位授予單位】：浙江大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：X53;X172
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本文編號：2095518