非離子活性劑雲點萃取菲的研究

Abstract

本文中採用兩種非離子型乙氧基化醇界面活性劑，Tergito 15-S-7與Neodol 25-7為萃取劑從水相萃取菲。兩種活性劑分子中含有相近的碳原子和乙氧基數，但□基位於碳鏈的不同位置。Tergitol 15-S-7為仲醇。萃取過程基於兩個活性劑的雲點現象。為使萃取實驗在皺溫下進行，實驗下採用硫酸鈉或磷酸鈉降低活性劑的雲點溫度，因此，鹽的加入強化了萃取過程。實驗結果表明增加鹽的濃度，或降低活性劑濃度可減小活性劑相的體積，從而提高菲的富集指數。在實驗中，菲的回收率可高於96%。

Extraction and preconcentration of the model polycyclic aromatic hydrocarbon (PAH), phenanthrene, in aquenous solutions by two different kinds of nonionic ethoxylated alcohols, Tergitol 15-S-7 and Neodol 25-7, as extractants was studied at ambient temperature (22℃)。Both surfactants have almost the same numbers of hydrocarbons and ethylene-oxide (EO) units, but differ in the location of the alcohols. Neodol 25-7 is a primary alcohol, while Tergitol 15-S-7 is secondary one. The extraction process is based on the clouding phenomena of these two nonionic surfactants. Addition of sodium sulfate or sodium phosphate could decrease the cloud point temperatures of the surfactant solutions below the ambient temperatures, so that the cloud-point extraction process could be facilitated. Increasing the salt concentration or decreasing the surfactant concentration could improve the preconcentration factor, which is attributable to the decrease in the volume of surfactant-rech phase. Consequently, the recovery efficiency higher than 96% was achieved for phenanthrene in aqueous solution.