关键词:

三辛胺, 一元羧酸, 亲油性, 表观碱度

Abstract: Extraction process based on chemical complexation is of higher capacity and selectivity for dilute polar organic solution. In this paper, phase equilibrium governing the reactive extraction of formic, acetic, propionic, butyric, valeric, monochloroacetic, dichloroacetic, trichloroacetic, glycolic, lactic and glyoxylic acids from aqueous solution into solutions of trioctyl amine (TOA) in the diluents, 1-octanol, chloroform, 4-methyl-2-pentanone (MiBK), n-hexane and tetrachloromethane were investigated. The results showed that the extractability depended on the hydrophobicity (lgP) of the acids and the acidity of the acids (pK_a). The extractability depended on the lgP for the solutes with pK_a close to each other，if otherwise depended on pK_a of the acid depended on it increased with increasing lgP of the acid and decreasing pK_a. Also, the extractability depends on diluent type and TOA concentration, and under the condition of TOA loading less than 1, the extractability in various diluents shows 1-octanol≥chloroform＞MiBK＞tetrachloromethane＞n-hexane. The specific basicity of TOA is one of the most important parameters indicating extractant dependence on solvent directly.

Key words:

三辛胺, 一元羧酸, 亲油性, 表观碱度