【作者】 江辉；

【导师】 黄丹莲； 曾光明；

【作者基本信息】 湖南大学 ， 环境科学与工程， 2018， 硕士

【摘要】 随着人类工业化进程的不断加速,废弃污染物不断排放,水体污染已经成为了全世界关注的环境污染问题,其中重金属污染极其突出。如何科学有效的处理该废水污染已经成为研究热点之一。四氧化三铁磁性纳米粒子由于它强大的吸附能力和可以通过磁性分离这个优点而在水处理的平台得到广泛的关注。因此,本研究将半胱氨酸（Cys）和二氧化硅（SiO₂）成功修饰在Fe₃O₄磁性纳米材料表面。通过环境扫描电镜（ESEM）和傅里叶红外变换光谱（FTIR）分析,发现经修饰后材料具有更好的分散性,很好避免了粒子间的团聚现象;表面具有的硫基、氨基、羧基等官能团更利于铅离子的吸附,效果显著。红外光谱分析图等也很好的证实了Fe₃O₄有被很好的修饰成为了Fe₃O₄@SiO₂@Cys纳米粒子,并且粒子形成过程中其本身结构未发生改变。通过研究了pH值、使用吸附剂的量、Pb（Ⅱ）初始浓度、接触时间等因素对于吸附的影响确定了最佳吸附条件。动力学研究表明吸附更加符合准二级吸附动力学。相比Freundlich等温模型,Langmuir等温模型更能拟合Fe₃O₄@SiO₂@Cys对Pb（Ⅱ）的吸附性能。通过热力学的研究得出反应是吸热和自发的。而且吸附剂相比镉、铜和锌离子表现出对铅离子对好的吸附效果。另外,研究四氧化三铁和半胱氨酸以及氧化石墨烯的制备出的复合材料对于铅离子的吸附,研究了pH值、使用吸附剂的量、Pb（Ⅱ）初始浓度、接触时间等因素对于吸附的影响,展现出来比单独材料的更强大的吸附能力,同时还具备磁性分离的特性。更多还原

【Abstract】 Recent industrial and urban activities have led to a rapid expansion of a wide range of pollutant in surface and groundwater.Water pollution has become a global environmental pollution.Heavy metals releasing to the environment cause serious environmental and health risks.Consequently,the need for contaminants removal has become a must.Fe₃O₄ magnetic nanoparticles attracted much attention and brought new platforms for water treatment take advantage of the surface effect and strong adsorption of heavy metals and it had an incomparable advantage that it could be very readily separated from aqueous solution by permanent magnet.In our study,Fe₃O₄ was successfully prepared by the immobilization of SiO₂ and L-Cysteine,which was confirmed by ESEM and FTIR.So the adsorption result was much more better and the immobilization process did not significantly result in the phase change of Fe₃O_4.Showd by external magnetic field,Fe₃O₄@SiO₂@CysNPs can separate from the solution quickly.The effect of various parameters such as pH,adsorption dosage,contact time and initial Pb（Ⅱ）concentration on the efficiency of adsorption process were evaluated.The adsorption kinetics fitted well to the pseudo-second-order model with correlation coefficients greater than 0.999.The best interpretation for the equilibrium data were given by Langmuir isotherm.The thermodynamic analysis of equilibrium suggested that the adsorption of Pb（Ⅱ）was spontaneous and endothermic in nature.Compared with other several kinds of heavy metal ions like Cu（Ⅱ）Cd（Ⅱ）and Zn（Ⅱ）,the adsorbent showed the better adsorption capacity for Pb（Ⅱ）.The desorption and regeneration studies indicated that Fe₃O₄@SiO₂@Cys could be employed repeatedly.In addition,a novel ternary magnrtic consisting of reduced graphene oxide,L-Cysteine and Fe₃O_4.The influence of pH value,dosage of adsorbent,initial concentration and contact time were investigated via batch experiments.The results show thatnot only the adsorption of GO@Fe₃O₄@Cys very strong,but also easy to be separated.更多还原