石墨烯—磺胺嘧啶单一及复合污染对小麦的毒性效应研究

发布时间：2018-05-29 06:56

本文选题：石墨烯 + 磺胺嘧啶　；参考：《河南师范大学》2017年硕士论文

【摘要】：纳米材料由于其独特的物理化学性质,被广泛应用于材料、电子、污染修复、化妆品、医药等各个领域。随着纳米材料使用量的不断增大,其在环境中不可避免的会与其他污染物产生复合作用。磺胺类药物是我国生产和使用量最大的抗生素之一,已有研究表明,其在环境中有一定的残留并且对植物的生长具有一定的毒性。为评估环境中纳米材料和磺胺嘧啶(Sulfadiazine,SD)的对生态系统造成的潜在风险,选取了还原石墨烯(reduced graphene oxide,rGO)和氧化石墨烯(graphene oxide,GO)两种不同的纳米材料,结合SD,探究其单一及复合对植物发芽和生长的生态毒性效应。主要研究结果如下:通过急性毒性实验和植物生长实验,探究了rGO/GO-SD单一及复合污染对小麦发芽和生长的生态毒性。研究结果表明:单一污染下,随着SD浓度的增加,对植物的生长抑制率增强;rGO单一胁迫下,整体上表现为促进植物的生长,但在rGO浓度为200mg/L时,对植物根部生长产生了轻微的抑制;GO单一污染下,作物芽伸长抑制率随GO浓度的增大而减小,根伸长抑制率和生长期根部和地上部生长抑制率随GO浓度的增加,抑制率增大。复合污染下,SD起主导作用,即同一rGO/GO浓度下,随着SD浓度的增大,抑制作用增强,rGO整体上降低了SD对植物生长的毒害作用,GO的存在整体上增大了SD对植物生长的毒害作用。GO对植物生长的毒性大于rGO,可能原因是GO在植物根部的大量吸附,影响植物根的生长。rGO-SD单一及复合污染条件下,在不同时期,植物体内的MDA含量以及抗氧化酶系统变化规律亦不同。植物根/芽中MDA含量随SD浓度的增大,含量增多,地上部MDA含量先升高后降低;生长期根部MDA含量随rGO浓度的增大而减少。复合污染条件下,根部MDA含量均在SD浓度为50 mg/L时达到最大。植物体内抗氧化酶系统随污染物浓度的变化,整体变化规律不明显。GO-SD单一及复合污染条件下,GO单一胁迫下,生长期根部MDA含量显著低于地上部MDA的含量,根部MDA含量与对照差异不显著;根和芽中POD酶活性随GO浓度的增大,其活性先增强后降低。复合污染作用下,根系MDA含量随SD浓度的增大而增加,而发芽期芽中MDA和生长期地上部MDA呈现相反的规律。无论是SD单一还是SD-GO复合污染下,植物体内SOD酶活性整体上处于激活状态,且随SD浓度的增大,活性增强;而POD酶活性在植物发芽期处于激活状态,随SD浓度的增大而增强,而生长期植物地上部中POD酶活性整体上低于对照,处于抑制状态。
[Abstract]:Nanomaterials, due to their unique physical and chemical properties, are widely used in materials, electronics, pollution remediation, cosmetics, medicine and other fields. With the increasing use of nanomaterials, it is inevitable to compound with other pollutants in the environment. Sulfonamides are one of the most widely used antibiotics in China. Some studies have shown that sulfonamides have some residues in the environment and are toxic to the growth of plants. To assess the potential risks to the ecosystem of nanomaterials and sulfadiazine (SDD) in the environment, two different nanomaterials, reduced graphene oxidego and graphene oxidegox oxide, were selected. The ecological toxicity effects of SDs on plant germination and growth were studied. The main results are as follows: through acute toxicity test and plant growth experiment, the ecological toxicity of single and compound rGO/GO-SD pollution on wheat germination and growth was studied. The results showed that under single stress, the growth inhibition rate of plants increased with the increase of SD concentration. Under single stress, the growth of plants was promoted, but when the concentration of rGO was 200mg/L, the growth of plants was enhanced. The inhibition rate of shoot elongation decreased with the increase of go concentration, and the inhibition rate of root elongation and root and shoot growth increased with the increase of go concentration. Under the compound pollution, SD played a leading role, that is, under the same concentration of rGO/GO, with the increase of the concentration of SD, The inhibitory effect of rgo on the whole decreased the toxicity of SD to plant growth. On the whole, it increased the toxicity of SD to plant growth. The toxicity of go to plant growth was greater than that of rGO.This may be due to the large amount of adsorption of go on the root of plant. The changes of MDA content and antioxidant enzyme system in plant were different in different periods under the condition of single or complex pollution. The content of MDA in root / bud increased with the increase of SD concentration, but the content of MDA in shoot increased first and then decreased, and the content of MDA in root decreased with the increase of rGO concentration in the growing period. Under the condition of compound pollution, the content of MDA in roots reached the maximum when the concentration of SD was 50 mg/L. The total change of antioxidant enzyme system in plant was not obvious with the change of pollutant concentration. Under single stress of GO-SD and compound pollution, the MDA content of root was significantly lower than that of MDA in shoot. The content of MDA in root was not significantly different from that of control, and the activity of POD enzyme in root and bud increased firstly and then decreased with the increase of go concentration. Under the compound pollution, the content of MDA in root increased with the increase of SD concentration, but the MDA in the bud and the MDA in the shoot in the germinating stage showed the opposite rule. Under the condition of single SD or SD-GO compound pollution, the activity of SOD enzyme in plant was activated as a whole, and increased with the increase of SD concentration, while the activity of POD enzyme increased with the increase of SD concentration in the germination period. However, the activity of POD enzyme in the shoot was lower than that in the control, and it was in a state of inhibition.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X503.231

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