Supported liquid membrane treatment

T0174 Commodore Separation Technologies, Inc., Supported Liquid Membrane T0176 Concurrent Technologies Corporation, Acid Extraction Treatment System (AETS)... 

Hill, C., Dozol, J.-F., Lamare, V., Rouquette, H., Eymard, S., Tournois, B., Vicens, J., Asfari, Z., Bressot, C., Ungaro, R., Casnati, A. Nuclear waste treatment by means of supported liquid membranes containing calixcrown compounds. J. Incl. Phenom. Maerocyclic Chem. (1994), 19 (1—4), 399 -08. 

Teramoto, M., Fu, S.S., Takatani, K., Ohnishi, N., Maki, T., Fukui, T., and Arai, K., Treatment of simulated low level radioactive wastewater by supported liquid membranes Uphill transport of Ce(III) using CMPO as carrier. Sep. Purif. Tech., 1999, 18 57-69. 

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. 

Takeuchi, H., Takahashi, K., Nakano, M. (1990). Separation of heavy metals from aqueous solutions by hoUow-fiber type supported liquid membranes in a continuous regenerating mode. Water Treatment, 5, 222-36. 

Chaudry, M. A., Bukhari, N., Mazhar, M., Abbasi, W. (2007). Coupled transport of chromium(III) ions across triethanolamine/cyclohexanone based supported liquid membranes for tannery waste treatment. Sep. Purif. Technol., 55, 292-9. 

The range of apphcations of supported liquid membranes (SLMs) in the wastewater treatment is comparable to the ELM (Section 3), with respect to the range of chemicals that have been treated using this technology. This section, therefore, has a structure that is analogical to Section 3. 

Synthesis of Phosphoric Acids and Their Derivatives. - A series of monoalkyl and dialkyl phosphorus acid chiral esters have been synthesised for use as carriers for the transport of aromatic amino acids through supported liquid membranes. The compounds acted as effective carriers but enantio-separation was at best moderate. A range of phosphono- and phosphoro-fluoridates have been prepared by treatment of the corresponding thio- or seleno- phosphorus acids with aqueous silver fluoride at room temperature (Scheme 1). In some cases oxidation rather than fluorination occurred. Stereospecifically deuterium-labelled allylic isoprenoid diphosphates, e.g. (1), have been synthesised from the corresponding deuterium-labelled aldehyde by asymmetric reduction, phosphorylation and Sn2 displacement with pyrophosphate (Scheme 2). ... 

The main application of this technology for metal extraction will probably be in the treatment of effluents and wastewaters as shown by the many research papers that have been published. This is particularly true of the supported liquid membrane because of the many modules required to treat significant volumes of feed solution. This then creates a large capital expenditure, aud, although lifetimes of polymeric membranes have now been increased considerably, the initial outlay will probably be too great for the value of any benefits or metal recovered. However, if this process can be used for high-value products, then the expenditure can be more easily justified— hence, the potential use of such systems for recovery of pharmaceutical compounds. 

Pancharoen, U., Poonkum, W. Lothongkum, A.W. (2009) Treatment of arsenic ions from produced water through hollow fiber supported liquid membrane. Journal of Alloys and Compounds, 482, 328-334. 

Zhu, G. Li, B. (1990)A study of water uptake in supported liquid membranes. Water Treatment, 5,150-156. 

Vicens and coworkers (Chapter 26) report the use of novel calix-fcw-crown ether compounds as carriers in a supported liquid membrane system for the removal of cesium from nuclear waste water. Decontamination factors of greater than 20 are obtained in the treatment of synthetic acidic radioactive wastes. Very good stability (over 50 days) and high decontamination yields are achieved. 

Calix[4]-W5-crowns 1-7 are used as selective cesium-carriers in supported liquid membranes (SLMs). Application of the D esi diffusional model allows the transport isotherms of trace level Cs through SLMs (containing calix[4]-6/5-crowns) to be determined as a function of the ionic concentration of the aqueous feed solutions. Compound 5 appears to be much more efficient than mixtures of crown ethers and acidic exchangers, especially in very acidic media. Decontamination factors greater than 20 are obtained in the treatment of synthetic acidic radioactive wastes. Permeability coefficient measurements are conducted for repetitive transport experiments in order to determine the SMLs stability with time. Very good results (over 50 days of stability) and high decontamination yields are observed with l,3-calfac[4]-Aw-crowns 5 and 6. 

Nuclear Waste Treatment by Means of Supported Liquid Membranes Containing Calixcrown Compounds ... 

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