Liquid membrane technology

PhenoHc-based resins have almost disappeared. A few other resin types are available commercially but have not made a significant impact. Inorganic materials retain importance in a number of areas where synthetic organic ion-exchange resins are not normally used. Only the latter are discussed here. This article places emphasis on the styrenic and acryHc resins that are made as small beads. Other forms of synthetic ion-exchange materials such as membranes, papers, fibers (qv), foams (qv), and Hquid extractants are not included (see Extraction, liquid-liquid Membrane technology Paper.). 

Z. M. Gu, A New Liquid Membrane Technology-Electrostatic Pseudo-liquid Membrane, J. Membrane Sdence, Vol. 52, No. 1, p. 44,1990. 

Yang, Q. and Kocherginsky, N.M. (2006) Copper recovery and spent ammoniacal etchant regeneration based on hollow fiber supported liquid membrane technology From bench-scale to pilot-scale tests. Journal of Membrane Science, 286, 301. 

Marr R and Kopp A. Liquid membrane technology—a survey of phenomena, mechanisms, and models. Int Chem Eng 1982 22 44—60. 

Noble RD and Way JD. Liquid membrane technology—an overview. In Noble RD, Way ID, eds. Liquid Membranes, Theory and Applications. American Chemical Society, ACS symposium series 347, 1986 1-26. 

Two commercial size plants for groundwater treatment based on liquid membrane technology in general, and the supported liquid membrane using hollow fibers in particular, were built and operated in Baltimore, U.S.A. Specifically, the purpose of the two plants is for hexavalent chromium cleanup. One plant went into commercial operation in March 1999 and the other approximately about a year later. The liquid membrane system in these two plants is able to reduce metal-ion concentration from 100-1000 ppm range to approximately 0.05 ppm and, meanwhile, produce a concentrated chromium solution, which is the spent strip solution, at approximately 20% Cr (VI). This concentration is suitable for sale for reuse. 

Treatment of Cyanide-Containing Waste Water from Gold Mine Operation by Liquid Membrane Technology. News release in Kexue Bao (Newspaper of Science), China, October 16, 1987. 

Kocherginsky, N. M., Yang, Q., Seelam, L. (2007). Recent advances in supported liquid membrane technology. Sep. Purif. Technol., 53, 171-77. 

Liquid membrane technology has been applied to a great extent for separation of mixtures of saturated and aromatic hydrocarbons. Investigations reveal that the LSM process offers potential for dearomatization of petroleum streams like naphtha and kerosene to meet product specifications for naphtha cracker feedstock and aviation kerosene, respectively [25, 63, 85, 144-146]. The separation is based on a simple permeation technique and occurs due to the difference in solubility and diffusivity of permeating species through the membrane. Kato and Kawasaki [70] conducted studies on the enhancement of hydrocarbon permeation by the use of a polar additive like sulfolane or triethyl glycol. Sharma et al. [147] enhanced the selectivity of the membrane by several orders with the addition of a carrier. Chakraborty et al. [85] used cyclodextrins to enhance the separation factor and removal efficiency of aromatic compound. 

Manipulation by the carrier concentration (and therefore, by the LMF potential), by the volume of the circulating bulk LM solution, or by both, enables to obtain selectivity that is as close to its highest level as necessary for the process developed. It is one of the biggest advantages of the BAHLM system in comparison with other liquid membrane technologies. 

Here, a review on supported ionic liquid membrane technology including issues such as methods of preparation and characterization, stability, transport mechanisms and applications is presented. 

Liquid membrane technology Is Introduced and Is Identified as a subset of membrane science. A tutorial section discusses configurations, transport mechanisms, experimental techniques, and a survey of basic theoretical approaches. The concepts of reactive liquid membranes which combine traditional unit operations such as extraction or absorption with stripping are discussed. The chapters to follow in this volume are summarized and the subject of each la placed In perspective to the field of liquid membrane technology. 

This volume Is divided Into three sections theory, carrier chemistry, and applications. The theory section Includes chapters which thoroughly describe the theory and analysis of various liquid membrane types and configurations (107-110) The carrier chemistry section contains two articles on the use of macrocycles for cation separations (111-112). The applications section begins with a survey article which thoroughly reviews the liquid membrane applications In the literature and discusses both potential and commercial aspects of liquid membrane technology. The remaining articles discuss both gas phase (113-115) and liquid phase transport (116-117). 

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