Extraction membrane

Livingston, A.G., Brookes, P.R., Biological Detoxification of a 3-chloronitrobenzene Manufacture Wastewater in an Extractive Membrane Bioreactor, Water Research, v.28, pp.1347-1354, 1994. [Pg.368]

Livingston, A.G., Extractive Membrane Bioreactors A New Process Technology for Detoxifying Industrial Waste waters, J. Chem. Tech. Biotech., v.60, pp. 117-124, 1994. [Pg.368]

Penetration enhancers are low molecular weight compounds that can increase the absorption of poorly absorbed hydrophilic drugs such as peptides and proteins from the nasal, buccal, oral, rectal, and vaginal routes of administration [186], Chelators, bile salts, surfactants, and fatty acids are some examples of penetration enhancers that have been widely tested [186], The precise mechanisms by which these enhancers increase drug penetration are largely unknown. Bile salts, for instance, have been shown to increase the transport of lipophilic cholesterol [187] as well as the pore size of the epithelium [188], indicating enhancement in both transcellular and paracellular transport. Bile salts are known to break down mucus [189], form micelles [190], extract membrane proteins [191], and chelate ions [192], While breakdown of mucus, formation of micelles, and lipid extraction may have contributed predominantly to the bile salt-induced enhancement of transcellular transport, chelation of ions possibly accounts for their effect on the paracellular pathway. In addition to their lack of specificity in enhancing mem-... [Pg.364]

Bickford and Willett [61] have reported that the filtration of soil extract solutions through a Gelman GA6 0.45pm membrane which contains a wetting agent caused interference in spectrophotometric methods for the determination of phosphate. This was due to the release of some substance from the membrane. It is recommended that low extractable membranes such as Gelman CM-450 are used for this purpose. [Pg.332]

As documented in Chapter 5, zeolites are very powerful adsorbents used to separate many products from industrial process steams. In many cases, adsorption is the only separation tool when other conventional separation techniques such as distillation, extraction, membranes, crystallization and absorption are not applicable. For example, adsorption is the only process that can separate a mixture of C10-C14 olefins from a mixture of C10-C14 hydrocarbons. It has also been found that in certain processes, adsorption has many technological and economical advantages over conventional processes. This was seen, for example, when the separation of m-xylene from other Cg-aromatics by the HF-BF3 extraction process was replaced by adsorption using the UOP MX Sorbex process. Although zeolite separations have many advantages, there are some disadvantages such as complexity in the separation chemistry and the need to recover and recycle desorbents. [Pg.203]

Elimination of coextracted materials and concentration of tetracyclines have also been accomplished using mixed-phase extraction membranes with both re-versed-phase and cation-exchange properties (294,295), or solid-phase extraction columns packed with cation-exchange materials such as CM-Sephadex C-25 (301), aromatic sulfonic acid (310), and carboxylic acid (283, 300). For the same purpose, metal chelate affinity chromatography has also been employed. In this technique, the tetracyclines are specifically absorbed on the column sorbent by chelation with copper ions bound to small chelating Sepharose fast flow column (278-281, 294-296). [Pg.987]

Succinate buffer extn, metal chelate affinity column cleanup, concn on cation-exchange extraction membrane... [Pg.995]

Brooks, P. R. Livingston, A. G. (1994). Biological detoxification of a 3-chloronitrobenzene manufacture wastewater in an extractive membrane bioreactor. Water Research, 28, 1347-54. [Pg.206]

Figure 6. Infrared spectra of dried films of (a) butyl alcohol-extracted membrane protein and (b) beef erythrocyte membranes, taken on CaF2 plates. No shoulder characteristic of the /3 conformation occurs at 1630 cmr1...

Solid-phase extraction membrane. Solid-phase extraction cartridge. [Courtesy Alhech Associates,... [Pg.644]

Solid-phase extraction uses a small volume of a chromatographic stationary phase or mole-cularly imprinted polymer23 (Box 26-2) to isolate desired analytes from a sample. The extraction removes much of the sample matrix to simplify the analysis. The opening of this chapter shows a solid-phase extraction membrane and extraction cartridges mounted on syringes. [Pg.658]

The Alkylglycosides (AGs) and Sucrose esters of fatty acids (SEFAs) are families of nonionic glycosurfactants that have been used for their ability to gently extract membrane proteins with a minimal loss of functionality. These compounds can be synthesized and purified economically, with a worldwide production of thousands of tons per year. Chemically, AGs and SEFAs are a group of uncharged amphipathic compounds that consist of an aliphatic hydrocarbon chain attached to a sugar moiety. Certain AGs and SEFAs such as dodecanoyl sucrose have enjoyed widespread use as food-grade emulsifiers and in cosmetic preparations. [Pg.380]

Tollback, J., Tamburro, D., Crescenzi, C. and Carlsson, H. (2006) Air sampling with Empore solid phase extraction membranes and online single-channel desorption/ liquid chromatography/mass spectrometry analysis determination of volatile and semi-volatile organophosphate esters. Journal of Chromatography A, 1129,1-8. [Pg.45]

S.L. Matson, Method for Resolution of Stereoisomers in Multiphase and Extractive Membrane Reactors, US Patent 4,800,162 (January, 1989). [Pg.522]

Capillary electrophoresis (CE) coupled to MS has the advantage of high resolution and soft ionization for biomolecules, which may be used to differentiate post-translational modifications and variants of intact proteins and oligonucleotides. Different modes of CE (capillary zone electrophoresis, capillary isoelectric focusing, capillary electrochromatography, micellar electrokinetic chromatography, nonaqueous capillary electrophoresis) to MS as well as online preconcentration techniques (transient capillary isotachophoresis, solid-phase extraction, membrane preconcentration) are used to compensate for the restricted detection sensitivity of the CE methodology [77, 78]. [Pg.174]

PME MASE Polymeric membrane extraction, Membrane-assisted sorbent extraction Nonporous Aqueous/polymer/aqueous Organic/polymer/aqueous Aqueous/polymer/organic... [Pg.448]

Utilization of an extraction membrane as analyte collecting medium in combination with thermal desorption Thermal Membrane Desorption Application - TMDA)... [Pg.462]

Membrane bioreactors have been reported for the production of diltiazem chiral intermediate with a multiphase/extractive enzyme membrane reactor [15, 16]. The reaction was carried out in a two-separate phase reactor. Here, the membrane had the double role of confining the enzyme and keeping the two phases in contact while maintaining them in two different compartments. This is the case of the multiphase/ extractive membrane reactor developed on a productive scale for the production of a chiral intermediate of diltiazem ((2R,3S)-methylmethoxyphenylglycidate), a drug used in the treatment of hypertension and angina [15]. The principle is illustrated in... [Pg.399]

Livingston, A.G., Arcangeli, J.P., Boam, T., Zhang, S., Marangon, M. and Freitas, L.M. (1998) Extractive membrane bioreactors for detoxification of chemical industry wastes process development Journal of Membrane Science, 151, 29. [Pg.532]

It may also be economical to remove the inhibitory product directly from the ongoing fermentation by extraction, membranes, or sorption. The use of sorption with simultaneous fermentation and separation for succinic acid has not been investigated. Separation has been used to enhance other organic acid fermentations through in situ separation or separation from a recycled side stream. Solid sorbents have been added directly to batch fermentations (18,19). Seevarantnam et al. (20) tested a sorbent in the solvent phase to enhance recovery of lactic acid from free cell batch culture. A sorption column was also used to remove lactate from a recycled side stream in a free-cell continuously stirred tank reactor (21). Continuous sorption for in situ separation in a biparticle fermentor was successful in enhancing the production of lactic acid (16,22). Recovery in this system was tested with hot water (16). [Pg.655]

Reverse osmosis also serves some of the waste management and resource recovery needs in the metals and metal finishing industry. Effluent streams from mining and plating operations containing heavy metals, acids, and other chemicals can be treated with reverse osmosis to recover both the metal as its salt, and purified water for reuse. For metal ion recovery from dilute solutions, however, reverse osmosis faces competition from conventional solvent extraction, membrane-based solvent extraction, and its variant, coupled transport (see Section V.F.3). [Pg.381]

Solvent extraction Podbielniak extraction Membrane solvent extraction Coupled transport Minimum emulsification and associated entrainment loss Enhanced selectivity and concentration... [Pg.396]

Is this a plausible premise In order to approach this question, we can assume that the mixture of organic compounds in carbonaceous meteorites such as the Murchison meteorite resembles components available on the early Earth through extraterrestrial infall. A series of organic acids represents the most abundant water-soluble fraction in carbonaceous meteorites [ 15,67,68]. Samples of the Murchison meteorite were extracted in an organic solvent commonly used to extract membrane lipids from biological sources [69,70]. When this material was allowed to interact with aqueous phases, one class of compounds with acidic properties was clearly capable of forming membrane-bounded vesicles (Fig. 7). [Pg.18]

However, it can be assumed for most electrochemical applications of ionic liquids, especially for electroplating, that suitable regeneration procedures can be found. This is first, because transfer of several regeneration options that have been established for aqueous solutions should be possible, allowing regeneration and reuse of ionic liquid based electrolytes. Secondly, for purification of fiesh ionic liquids on the laboratory scale a number of methods, such as distillation, recrystallization, extraction, membrane filtration, batch adsorption and semi-continuous adsorption in a chromatography column, have already been tested. The recovery of ionic liquids from rinse or washing water, e.g. by nanofiltration, can also be an important issue. [Pg.319]

This study focuses firstly on the transfer of regeneration principles as they have been developed in the field of water-based electroplating and of purification options for ionic liquids as they are experienced in other fields of ionic liquid application. A number of purification procedures for fresh ionic liquids have already been tested on the laboratory scale with respect to their finishing in downstream processing. These include distillation, recrystallization, extraction, membrane filtration, batch adsorption and semi-continuous chromatography. But little is known yet about efficiency on the technical scale. Another important aspect discussed is the recovery of ionic liquids from rinse or washing water. [Pg.333]

The first step for the design of an EMR is to select the type of reactor. Extractive membrane reactors are desirable when one of the substrates or products is poorly soluble in aqueous solution or when an undesirable by-product has to be separated, as the membrane acts as a solvent extraction step [99]. Immobilized enzyme reactors are usually applied with materials that enable enhancement of enzymatic stability or preserve enzyme from deactivation by a direct contact with an organic solvent [99]. Finally, direct-contact membrane reactors are the most versatile alternative in processes with soluble compounds. [Pg.260]

Ra determination in environmental samples (highly saline thermal waters) by ICP-QMS with ultrasonic nebulization has been described by several working groups. Radium was preconcentrated and isolated from the matrix elements by selective extraction using a radium specific solid phase extraction membrane disk designed for radioactive counting methods as proposed by... [Pg.419]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...