银纳米颗粒对黄孢原毛平革菌去除重金属镉的影响及其自身在体系中的迁移转化研究

发布时间：2018-01-31 21:18

  本文关键词： 银纳米颗粒 白腐真菌 Cd(Ⅱ) 生物去除 促进作用 迁移 转化　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着越来越多的银纳米材料广泛应用于临床医疗、陶瓷材料、环保涂料、水质净化、纺织及生活日用品等各个方面,使得银纳米材料在生产、加工、使用以及废弃的过程中不可避免地释放到水体环境中。银纳米材料作为一种新的环境污染物,不仅会对水体中的生物造成影响,而且还可能影响到水体中其他环境污染物的去除。本研究选择对重金属具有较好去除作用的白腐真菌的模式菌黄孢原毛平革菌作为受试真菌,以镉为重金属的代表,研究银纳米材料对黄孢原毛平革菌去除重金属的影响,并考察其自身在体系中的迁移转化。本研究利用化学方法合成了以柠檬酸三钠为表面稳定剂的银纳米材料,且利用紫外可见分光光度分析、透射电镜分析、能谱分析、流体动力学直径分析、表面电荷分析以及X射线衍射分析对合成的银纳米材料进行表征,结果表明,本研究成功合成了粒径为24.3±0.37 nm、表面电荷为-47.2 m V的银纳米颗粒。利用该合成的银纳米颗粒对黄孢原毛平革菌去除重金属镉进行实验研究发现,低浓度(0.1~1 mg/L)的银纳米颗粒对黄孢原毛平革菌去除溶液中的Cd(Ⅱ)具有一定的促进作用,且在这个浓度范围内,该促进作用会随着银纳米颗粒浓度的增加而增强,Cd(Ⅱ)的最大的生物去除量(4.67 mg/g)在银纳米颗粒的浓度为1 mg/L时取得。而当银纳米颗粒的浓度继续增加时,该促进作用会逐渐消失,其对黄孢原毛平革菌的抑制作用开始显现。通过测定溶液中Ag~+和总银的浓度、高角环形暗场扫描透射电镜分析、能谱分析以及X射线衍射分析得知,实验中加入的银纳米颗粒在体系中发生了氧化溶解,释放出Ag~+,且最终以粒径增大的银纳米颗粒的形式迁移至黄孢原毛平革菌的菌丝表面。傅里叶变换红外光谱分析结果表明,黄孢原毛平革菌菌丝表面的羟基、氨基、羧基等官能团参与到溶液中Cd(Ⅱ)的去除以及银纳米颗粒的迁移转化过程中。
[Abstract]:As more and more silver nanomaterials are widely used in clinical medicine, ceramic materials, environmental protection coatings, water purification, textiles and daily necessities, silver nanomaterials are produced and processed. Silver nanomaterials, as a new environmental pollutant, will not only affect the organisms in the water body, but also be released into the water environment inevitably in the process of use and waste. And it may also affect the removal of other environmental pollutants in the water. In this study, the model fungus of white rot fungi with good removal of heavy metals was selected as the tested fungi. The effects of silver nanomaterials on removal of heavy metals by P. xanthosporium were studied with cadmium as the representative of heavy metals. The silver nanomaterials with trisodium citrate as the surface stabilizer were synthesized by chemical method and analyzed by UV-Vis spectrophotometry and TEM. The silver nanomaterials were characterized by energy spectrum analysis, hydrodynamic diameter analysis, surface charge analysis and X-ray diffraction analysis. The particle size is 24.3 卤0.37 nm. Silver nanoparticles with surface charge of -47.2 MV were used to study the removal of heavy metal cadmium by Phanerochaete xanthosporium. The silver nanoparticles with a low concentration of 0.1 mg / L can promote the removal of CD (鈪，

本文编号：1480025