硫酸铵-溴化四丁基铵-水体系液液萃取分离汞

Liquid-liquid extraction of mercury(Ⅱ) with ammonium sulfate-tetrabutylammonium bromide-water system

研究了用硫酸铵-溴化四丁基铵（TBAB）-水体系进行液液萃取分离汞（Ⅱ）与常见离子的条件。试验发现，TBAB的水溶液在硫酸铵的作用下盐析，形成了液一液两相，在pH1～6的克拉克-鲁布斯缓冲溶液中，汞（Ⅱ）被萃取到上层TBAB相，其他共存离子Zn^2＋，Cu^2＋，Ni^2＋，Co^2＋，Mn^2＋，Fe^3＋不被萃取。对合成水样中汞（Ⅱ）与其他离子形成的二元混合体系及多元混合体系的研究发现，其他离子的存在对所建方法萃取汞（Ⅱ）不产生干扰，从而实现了汞（Ⅱ）与常见离子的定量分离。

The extraction separation behavior of mercury（Ⅱ） with （NH4）2SO4- tetrabutylammonium bromide-water system and the conditions for the separation of mercury（Ⅱ） from other metal ions were studied. The results showed that the salting-out of TBAB in aqueous solution occurs under the action of ammonium sulfate, forming both phase liquid and liquid. Hg^2＋ is selectively extracted into upper phase （TBAB phase） in the Clark-Lubs buffer solution at pH 1-6. In the same condition, other ions including Zn^2＋ ,Cu^2＋ , Ni^2＋ , Co^2＋ , Mn^2＋ , Fe^3＋ could not be extracted. The binary and multiple mixed system that synthesized from mercury（Ⅱ） and other ions were studied, and it was found that the presence of other ions did not interfere with the extraction of mercury（Ⅱ）. Mercury（Ⅱ） can be separated from other common ions quantitatively.