一种高选择性汞(Ⅱ) 吸附剂的制备和应用

Preparation,Properties and Application of a High Selective Solid Phase Adsorbent for Mercury(Ⅱ) 

利用两步反应法制备了溴联苯三酚红功能性硅胶(BPRSG),并通过静态平衡方法研究了该功能性硅胶对多种性质相近的金属离子的选择性吸附性能,考察了溶液pH值和搅拌时间对Hg?吸附率的影响。结果表明,在pH=7.0时,该固相萃取剂对Hg(Ⅱ)有特异的选择性吸附,可以实现与Pb(Ⅱ),Co(Ⅱ),Mn(Ⅱ),Zn(Ⅱ),Cu(Ⅱ),Cd(Ⅱ),Ni(Ⅱ)等金属离子的选择性分离,对Hg?的吸附平衡时间为30 min;最大吸附容量为4.80 mg/g。将该吸附剂制成微型固相萃取柱,用动态平衡法研究了柱流速、洗脱剂种类、洗脱速度和各种干扰离子对分离富集Hg(Ⅱ)的影响。在优化条件下,微柱对Hg?的最低富集浓度为10μg/L,富集倍率为170倍,柱容量为0.65 mg/g。20种常见离子不干扰Hg?的吸附,用1.0 mol/L醋酸即可洗脱Hg(Ⅱ),柱子可重复使用。将微柱用于环境水样中Hg?的固相萃取,回收率在95.5%～98.0%之间。

A solid phase adsorbent,bromopyrogallol red functionalized silica gel,has been prepared by two-step synthesis method.The effects of Adsorptivity performance of this functionalized silica gel for various metal ions and the solution pH value and stirred time have been investigated by static equilibrium method.It is shown that at pH 7.0,the functionalized silica gel has special selectivity for Hg2＋ in aqueous solution in the presence of other common metal ions,which makes it possible to separate Hg2＋ from Pb2＋,Co2＋,Mn2＋,Zn2＋,Cu2＋,Cd2＋,Ni2＋ and others.The Adsorptivity equilibration of this adsorbent for Hg2＋ can be achieved within 30 min,and its Adsorptivity capacity is 4.80 mg/g.Furthermore,this adsorbent has been used to prepare a mini-column for solid-phase extraction.The effects of flow rate of aqueous solution,species of eluents,elution rate and the interference of other common coexisting metal ions on the separation and enrichment of Hg2＋ have been examined by using dynamic equilibrium experiments.It is found that under optimized conditions,the minimum enrichment concentration is 10 μg/L,the enrichment factor is 170,and the column capacity is 0.65 mg/g.Twenty kinds of common ions do not interfere with the column Adsorptivity of Hg2＋,Hg2＋ adsorbed on the column can be washed out by 1.0 mol/L of acetic acid,and the column can be reused.Then,the column was used to extract Hg2＋ in environmental water samples,recoveries of 95.5%-98.0% were obtained.