Extraction of hexavalent chromium ions with polyurea microcapsules
Extraction of hexavalent chromium ions with polyurea microcapsules
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聚脲微胶囊萃取六价铬离子
DOI：
10.1016/0376-7388(93)e0172-g
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发表时间：
1994
影响因子：
9.5
通讯作者：
N. Yan
中科院分区：
文献类型：
--
作者：
P. Ni;Ming;N. Yan
研究了聚脲微胶囊对水溶液中金属离子的萃取。实验结果表明，以N235为萃取剂包埋微胶囊时，对铬(VI)的萃取速度远快于对钴(II)和铜(II)的萃取。在试验的萃取剂中，三辛胺(TOA)的萃取剂效果最好。当以磷酸三丁酯(TBP)为萃取剂时，由于油/水界面的界面张力较低，微胶囊的平均直径较小。微胶囊的萃取率随料液pH的降低而增加，随微胶囊中TOA浓度的增加而增加。甲苯-2，4-二异氰酸酯与二乙烯三胺的摩尔比在1 4~1 8之间变化时，微胶囊的萃取率下降，说明膜配方对膜的传质有影响。提高溶出液的pH值可以促进微胶囊中铬离子的溶出。
The extraction of metal ions from aqueous solutions has been studied using polyurea microcapsules. Experimental results showed that when N235 was used as an extractant encapsulated with the microcapsules, the extraction rate for chromium (VI) was much faster than that for cobalt (II) and copper (II). Among the extractants tested, trioctylamine (TOA) gave the best results. When tributyl phosphate (TBP) was used as an extractant, the mean diameter of the microcapsules was smaller due to the lower interfacial tension at the oil/water interface. The extraction rate increased with a decrease in pH in the feed solution, but increased with an increase in TOA concentration in the microcapsules. When the molar ratio of tolylene 2, 4-diisocyanate to diethylene triamine for preparing the microcapsules was varied from 1 4 to 1 8, the extraction rate decreased, indicating that the membrane formulation had impact on the mass transfer across the membrane. The stripping of the chromium ions from the microcapsules can be promoted by raising the pH in the stripping solution.