Supported liquid membranes (SLM) utilized to separation of elements 4f and uranium

Abstract

Liquid membranes have been an emerging technique used as an alternative for the separation and preconcentration of several metallic species. It have been applied as one alternative technique in the separation of metallic ions originating from several areas of industry like the hydrometallurgical, gases separation, biotechnology, treatment of nuclear and non-nuclear waste. The recovery of those metals through that technique has good potential to reduce, in very low levels, pollutants in processes. The liquid membrane is a solution, which is an organic solvent, water immiscible and with low dielectric constant, that is used as a diluent for an extractor agent, also called the sequestering agent, loader or metal transporter, which is absorbed in the microporous of a polymeric film and actuates as solid support of the liquid membrane. The extractor agent gets the metallic ion from the feed solution liberating it on the other side of the membrane, through stripping solution. Then, the extraction and stripping of the metallic species are carried out in a single step in the process, and has this advantage in relation to the liquid-liquid extraction that requests a large number of stages to obtain products with high purity. Besides, the technique of SLM needs low capital and operational cost, low energy consumption and use of little amount of extractor agent, making possible the use of expensive extractor agents. The main objective of this research is to investigate the influence of several parameters in the process of extraction of lanthanide metals and uranium originating from a simulated radioactive waste using as polymeric support membranes, PTFE and as loader calixarenes. The calixarenes are part of a very versatile class of macrocyclic compounds that can be functionalized, being obtained like this a great variety of multifunctional receptors.