四种金属氧化物纳米颗粒对农业土壤微生物的毒性研究

发布时间：2018-01-05 09:36

本文关键词：四种金属氧化物纳米颗粒对农业土壤微生物的毒性研究　出处：《北京科技大学》2017年博士论文　论文类型：学位论文

【摘要】：纳米颗粒是至少在一个方向上粒径尺寸在1-100 nm的微小粒子,尤其是指以工程应用为目的或者人工合成的微小颗粒,其在二十一世纪将对世界经济,工业和人民生活等广阔领域产生非常显著的影响。认识纳米颗粒的环境行为和生态毒性,评估其对生态环境和人类健康的潜在危害,特别是其在环境中迁移、转化、富集、吸收的作用机制,是开发和使用纳米产品的基本前提。土壤热量代谢,功能细菌和酶活力是评价纳米颗粒在农业土壤中的毒性研究是一种成功的组合,纳米颗粒在土壤中的毒性能够被测定和评估,是一种高通量的纳米颗粒毒性筛选方法。本研究选择四种金属氧化物纳米颗粒(ZnO、SiO_2、TiO_2、CeO_2)、通过土壤微生物的热量代谢、功能微生物的丰度和植物的生理状况的变化来研究纳米颗粒的环境行为,主要有以下四个方面：1、相同浓度1 mg kg~(-1)的ZnO、SiO_2、TiO_2和CeO_2纳米颗粒进入土壤后所产生的毒性因种类有很大的差异,土壤微生物热量代谢结果显示ZnO和CeO_2纳米颗粒表现出明显的抑制土壤微生物活力作用,TiO_2次之和SiO_2不明显。根据四种纳米颗粒的微量热参数P_(max)和κ值,可列出其毒性大小顺序为：ZnO CeO_2 TiO_2 SiO_2,总体上看ZnO对土壤微生物的毒性较大,SiO_2可认为基本没有毒性。2、评价了ZnO和CeO_2纳米颗粒在农业土壤生态系统中的剂量效应。根据土壤微生物的总放热量计算得出ZnO和CeO_2纳米颗粒对农业土壤的微生物活力的EC_(50)分别为103.19 mgkg~(-1)和518.49mgkg~(-1)。这为今后应用两种纳米颗粒于农药或杀虫剂中提供了参考数据。3、检测了不同粒径(9 nm、12 nm、40 nm)与不同浓度(10mgkg~(-1)、25 mgkg~(-1)、50mg kg~(-1))的SiO_2纳米颗粒对土壤的与剂量效应,结果表明SiO_2纳米颗粒对土壤微生物呈现剂量的刺激相应,证实SiO_2纳米颗粒能够提高土壤微生物的代谢能力,不具有毒性效应。4、比较了四种金属氧化物纳米颗粒对小麦生理状态影响。结果显示ZnO和CeO_2两种纳米颗粒对叶片光合作用和生长状况抑制作用较明显,TiO_2和SiO_2与对照组相比没有抑制效应；纳米颗粒的植物毒性大小与释放于溶液中的金属离子种类和数量有关。
[Abstract]:The nanoparticle is in at least one direction size in 1-100 nm micro particles, especially tiny particles or synthetic objective for engineering application, which will be on the world economy in twenty-first Century, industrial and living fields such as have a very significant impact. The toxicity of environmental behavior and ecological awareness of nanoparticles the assessment of the ecological environment and human health hazards, especially in the environment of migration, conversion, enrichment, absorption mechanism, is the basic premise of the development and use of nano products. The soil heat metabolism, functional bacteria and enzyme activity is the toxicity of nanoparticles in the evaluation of agricultural soils is a the success of the combined toxicity of nano particles in the soil can be measured and evaluated screening nanoparticle toxicity of a high-throughput method. This study selected four kinds of metal oxide nanoparticles (ZnO, SiO_2, TiO_2, CeO_2), the energy metabolism of soil microbes, environmental behavior changes in microbial abundance and physiological status of plants to study the nano particles, mainly in the following four aspects: 1, the same concentration of 1 mg kg~ (-1) ZnO, SiO_2, TiO_2 and CeO_2 nanoparticles produced after entering into the soil particle toxicity due to species have different soil microbial metabolic heat, the results showed that ZnO and CeO_2 nanoparticles showed significant inhibition of soil microbial activity, followed by TiO_2 and SiO_2 is not obvious. According to the trace thermal parameters P_ four nanoparticles (max) and kappa value, can list the toxicity order: ZnO CeO_2 TiO_2 SiO_2, on the whole the toxicity of ZnO on soil microorganisms is large, SiO_2 is considered to be no toxic.2, to evaluate the dose effect of ZnO and CeO_2 nanoparticles in the ecological system of agricultural soils according to soil microbial. The total heat release were calculated ZnO and microbial activity of CeO_2 nanoparticles on agricultural soil EC_ (50) were 103.19 mgkg~ (-1) and 518.49mgkg~ (-1). This provides reference data for the future application of.3 two nano particles in pesticides or insecticides in different particle sizes (9 nm, detection 12 nm, 40 nm) with different concentrations (10mgkg~ (-1), 25 mgkg~ (-1), 50mg kg~ (-1)) SiO_2 nano particles on the soil and dose effect, the results show that the SiO_2 nanoparticles showed a dose of soil microbial stimulation, confirmed that SiO_2 nanoparticles can improve the metabolic ability of soil microorganisms that does not have toxic effects of.4, the effect of four kinds of metal oxide nanoparticles on the physiological state of wheat were compared. The results showed that ZnO and CeO_2 two nano particles on the photosynthesis and growth of leaves of inhibition is more obvious, TiO_2 and SiO_2 compared with the control group had no inhibitory effect The phytotoxicity of nanoscale particles is related to the type and quantity of metal ions released in the solution.

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X171.5

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