Plant-mediated synthesis of iron nanoparticles and its application in Cr(VI) and As(V) removal in aqueous medium

水是人类赖以生存和发展不可或缺的基本资源，但随着社会发展和工业化进程的加快，大量工业废水的不合理排放对水环境造成了巨大的危害，其中重金属如铬和砷的广泛使用严重影响了周边动植物及人类的生命健康。近年来，纳米铁材料特别是零价纳米铁由于其较高的反应活性和可处理污染物的多样性在环境修复领域备受关注。但是，纳米铁在应用过程中存在易被氧化、稳定性差等问题，各种改性技术往往会带来合成成本的提高。本研究针对以上问题，利用植物法还原制备纳米铁颗粒，整个制备过程绿色简便、条件温和，不需要引入其他还原剂和改性剂，对所得纳米铁颗粒进行了一系列表征，并对其在水溶液中Cr(VI)和As(V)的去除效果进行了研究。 采用...Water is essential to human survival and development, but with the development of society and the accelerated process of industrialization, the large-scale and unreasonable emission of industrial waste water causes enormous harm to the environment. The extensive use of heavy metals such as chromium and arsenic has serious impact on the surrounding flora and fauna as well as human life and health. ...学位：工程硕士院系专业：化学化工学院_工程硕士(化学工程)学号：2062013115150

Plant-mediated synthesis of silver nanoparticles and application in antibacterial fabric

纳米银是以纳米技术为基础研制而成的新型抗菌产品,由于量子效应和尺寸效应具有普通银系抗菌剂无法比拟的抗菌效果。本研究以黄芩、丁香、洋浦桃、芳樟4种植物质提取液制备银纳米颗粒,并借助于uV-VIS、TEM以及Xrd对产物进行表征,结果表明增加植物质提取液浓度或增大nA OH加入量,均有利于制得粒径较小的银纳米颗粒。SEM图片表明采用浸渍法可将所得纳米银颗粒负载于纯棉织物上,通过考察浸渍时间、温度、浴比对织物上载银量的影响,确定较优的浸渍条件为时间30 H,温度55℃,浴比为1:25。分别考察了银纳米颗粒粒径和植物质种类对所得载银织物抗菌性能的影响,发现负载到织物上的纳米银粒径越小,织物抑菌效果越好;利用本身具有抑菌效果的黄芩、丁香来制备银纳米颗粒,有利于增强所得载银织物的整体抗菌性能;4种植物质中以黄芩制得的载银织物抗菌效果最优,对金黄色葡萄球菌、大肠杆菌等实验菌株均有强烈的抑制作用。Nano silver, based on the nanoscience and nanotechnology, exhibits excellent antibacterial ability due to the quantum effect and size effect.In this work, the plant-mediated synthesis of silver nanoparticles(Ag NPs) was reported from four plants, including Scutellaria baicalensis, Syzygium aromaticum, Syzygium samarangense and Cinnamomum camphora.The as-synthesized Ag NPs were characterized by UV-Vis, TEM and XRD techniques.The results indicated that the Ag NPs tended to be smaller with the increase of biomass concentration or Na OH adding amounts.SEM images verified that the Ag NPs can be loaded onto cotton fabric through impregnation, and the optimal conditions were time of 30 h, temperature of 55℃ and liquor ratio of 1:25.Furthermore, the effects of Ag NPs size and plant species on the antibacterial ability of the resulting Ag-coated fabrics were investigated, respectively.Ag NPs loaded on the fabrics with smaller size displaied superior antibacterial activity against Escherichia coli.Moreover, Ag-coated fabrics prepared from Scutellaria baicalensis and Syzygium aromaticum extracts, which possessed own antibacterial ability, showed the cooperative antibacterial effect between biomass and nano-silver.The as-prepared fabric by the extract of Scutellaria baicalensis exhibited the best antibacterial ability with high inhibition ratio against various bacteria such as Staphylococcus aureus and Escherichia coli.国家自然科学基金项目(21206140); 厦门市科技计划项目(3502Z20133006)~