Stripping dispersion hollow fiber liquid membrane containing PC-88A as carrier and HCl for transport behavior of trivalent dysprosium

摘要

The transport of Dy(3+) through stripping dispersion hollow fiber liquid membrane system (SDHFLM) containing dispersion phase with HCl solution as stripping solution and 2-ethyl hexyl phosphoric acid-mono-2-ethyl hexyl ester (PC-88A) dissolved in kerosene as membrane solution, has been studied. Many factors of the interface chemical reaction and composition of the liquid membrane including pH value, initial concentration of Dy(3+), different ionic strength of feed phase, volume ratio of membrane solution to stripping solution (O/W), HCl concentration, carrier concentration, different stripping agents of dispersion phase, hydrodynamic characteristic (flow rates, stability) and hollow fiber structure parameters (inner diameter of fibers, membrane thickness, porosity, etc.) on Dy(3+) transport with SDHFLM were investigated. The advantages of SDHFLM compared to the traditional HFLM was investigated too. Experimental results indicated that the optimum transport conditions of Dy(3+) were that HCl concentration was 4.00 mol/L, PC-88A concentration was 0.150 mol/L, O/W was 0.5 in the dispersion phase, and pH value was 5.00 in the feed phase. Ionic strength had no obvious effect on transport of Dy(3+). When initial Dy(3+) concentration was 1.50 x 10(-4) mol/L, the transport efficiency of Dy(3+) was up to 95.4% in 170 min. The kinetic equation was developed in terms of the law of mass diffusion and the theory of interface chemistry. The results were in good agreement with the literature data. (C) 2011 Elsevier B.V. All rights reserved.