LIQUID EMULSION MEMBRANES - PRINCIPLES, PROBLEMS AND APPLICATIONS IN FERMENTATION PROCESSES

Liquid emulsion membranes (LEMs) have developed into a versatile techn ique for a variety of applications involving selective and controlled transport of biochemicals. Biological applications cover the controlle d delivery of drugs from capsules, detoxification of the circulatory s ystem, recovery of useful compounds from waste streams and selective s eparation of products from fermentation broths. This review traces the development of LEMs, discusses their key features, advantages and lim itations, describes methods of modelling LEM systems and highlights so me applications with industrial potential. Two kinds of LEM systems ar e considered. The first type are agitated emulsions, which are relativ ely easy to prepare and use but may be limited in their selectivity an d long-term stability. Supported liquid membranes (SLMs) are a recent development; they use porous solid supports and have excellent stabili ty and selectivity. Their chemical engineering aspects and application s in fermentation processes are considered.