氨基膦酸改性硅胶吸附分离铂和钯  

Sorption and Separation of Platinum and Palladium from Aqueous Solution by Aminophosphonic Acid Functionalized Silica

作　　者：徐辉[1,2] 祁光霞 孙应龙[1] 王煜[2] 韩小元[2] 梁威[2] 雷雪飞[1] 张瑞荣[2] 王毅[1] 

机构地区：[1]清华大学环境学院,北京100084 [2]西北核技术研究所,陕西西安710024 [3]北京工商大学环境科学与工程系,北京100048

出　　处：《原子能科学技术》2016年第7期1159-1165,共7页Atomic Energy Science and Technology

摘　　要：采用化学接枝法合成了氨基膦酸改性硅胶吸附剂,考察了其对溶液中铂(Pt)和钯(Pd)的吸附分离性能,测试了溶液pH值、吸附时间、初始金属离子浓度、离子强度和固液比对吸附的影响,并考察了改性硅胶吸附剂的重复使用性能。改性硅胶吸附剂对Pt和Pd的吸附主要受溶液pH值影响,而离子强度和固液比对吸附的影响不大。吸附过程符合准二级吸附动力学模型和Langmuir等温吸附方程。改性硅胶吸附剂180min时,pH=2时对Pt的平衡吸附容量为18.5mg/g,pH=6时对Pd的平衡吸附容量为29.9mg/g,利用改性硅胶吸附剂不同pH值条件下的吸附行为差异可分离回收溶液中的Pt和Pd。用5mL0.1mol/L HNO3为基质的6%硫脲溶液可实现Pt和Pd的解吸,解吸率分别为99.3%和99.2%。所合成的氨基膦酸硅胶吸附材料可回收重复使用。Aminophosphonic acid functionalized silica synthesized by chemical grafting method was utilized as the sorbent for separation of platinum（Pt）and palladium（Pd）from aqueous solution.The effects of pH,contact time,initial metal concentration,ionic strength and solid-liquid ratio on the sorption of Pt and Pd by functionalized silica were investigated.The sorption capacity is strongly dependent on pH but independenton the ionic strength and solid-liquid ratio.The sorption process fits the pseudo-secondorder kinetic model and Langmuir isotherm very well.Equilibrium sorption capacities of18.5mg/g for Pt at pH=2 and 29.9mg/g for Pd at pH=6are achieved respectively.The distinct sorption behavior of functionalized silica for Pt and Pd with pH can be used for separation of these two metal ions in aqueous solution.The sorbed Pt or Pd can be completely eluted using 6% sulfourea in 5mL 0.1mol/L HNO3.The synthesized sorbent material can be recycled and reused.

关 键 词：硅胶 氨基膦酸 吸附剂 铂 钯 

分 类 号：TL949[核科学技术—辐射防护及环境保护]