Membrane Extraction Hybrid Membrane Systems

The combinations of liquid membrane extraction (usually mediated by specific ion exchange extrac-tant/carrier) with ion exchange membranes in some

Feed solution

Cation exchange membrane (OEM)

Liquid membrane

Cation exchange membrane (CEM)

Receiving solution

M*—^^

M*/ H* )

H+/ M+

— H+

Ion Carrier Ion exchange transport exchange

Figure 5 Scheme of membrane hybrid system composed of two cation exchange membranes and the liquid membrane containing an ionic carrier (C). Coupled countertransport of M 3 and H 3 cations. (From Wodzki R, Szczepanski P and Pawlowski M (1999) Recovery of metals from electroplating waste solutions and sludge. Comparison of Donnan dialysis and pertraction technique. Polish Journal of Environmental Studies 8(2): 111 -124.)

Ion Carrier Ion exchange transport exchange

Figure 5 Scheme of membrane hybrid system composed of two cation exchange membranes and the liquid membrane containing an ionic carrier (C). Coupled countertransport of M 3 and H 3 cations. (From Wodzki R, Szczepanski P and Pawlowski M (1999) Recovery of metals from electroplating waste solutions and sludge. Comparison of Donnan dialysis and pertraction technique. Polish Journal of Environmental Studies 8(2): 111 -124.)

relatively new membrane systems have been called membrane hybrid systems (MHS). The scheme of cation transport in a simple MHS is depicted in Figure 5. The MHS operation involves a series of ion exchange-diffusion processes (ion exchange membrane) as well as permeation through a liquid membrane. The presence of an ion exchange membrane at a particular interface stabilizes the liquid membrane and enhances the interfacial ion exchange reactions because of high, and specific, sorption of certain ions by the membrane polyelectrolyte. The long term and stable operation of a liquid membrane system can be achieved with the MHS idea. The selective and active transport of metal cations, inorganic anions and some carboxylic acids has been reported. It is worth noting that these systems can be regarded as biomimetic, which means that they correspond to a cellular envelope of Gram-positive bacteria composed of an ion exchange polymer membrane (cell wall) and a quasi-liquid membrane (cytoplasma membrane).

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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