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1
Van, Wyk Albertus Maritz. "The use of crosslinked polyethylene for the manufacturing of membranes / Albertus Maritz van Wyk." Thesis, Potchefstroom University for Christian Higher Education, 1999. http://hdl.handle.net/10394/9615.
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Increasing environmental awareness over the past decade as well as stringent
environmental laws forced all factories to invest in water treatment processes for
effluent treatment before discharge or re-use. Most of these effluent treatment
processes utilize membranes as the physical. barrier for separation. The membranes
used in water applications are expensive and alternative materials and production
techniques will increase the viability of membrane separation processes.
Experiments conducted on irradiated polyethylene showed that some of its properties
were enhanced while others deteriorated. However, the enhanced properties make
the polyethylene, in particular ultra-high molecular weight polyethylene, an ideal
membrane material. The manufactured membranes were tested in extraction
experiments, and satisfactory results were obtained. Permeation studies on the
membranes compared favourably with similar studies done on commercially
available membranes. An extraction rate of 1.08 g/(m2h) nickel was achieved. A
preliminary cost evaluation showed that these membranes can be manufactured at a
low cost (R13.45/m2). and can be applied as supported liquid membranes. Future
research should focus on methods to decrease the brittleness and stiffness of the
membranes.Thesis (MIng)--PU for CHE, 1999
2
Owens, Lesley Shantell. "Fabrication, Validation, and Performance Evaluation of a New Sampling System for the In-Situ Chemical Speciation of Chromium Ions in Groundwater Using Supported Liquid Membranes (SLMs)." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/49616.
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A sampler has been fabricated to facilitate the in-situ speciation of Cr. Teflon® was selected as the material for the samplers because of its inert chemical nature. The design of the sampler is based on the Supported Liquid Membrane (SLM) extraction technique, which utilizes charged organic carrier molecules loaded onto a polymeric (Teflon®) support membrane and the principles of electrostatics to selectively transport Cr ions through an ion-pairing mechanism. Cr ions in the feed solution that have an opposite charge from the carrier molecule form an ion-pair with the carrier and are transported through the membrane and deposited into a second aqueous phase referred to as the acceptor phase. A counter-ion from the acceptor phase is exchanged for the Cr ion to complete the extraction process. Since the acceptor phase is contained in a Teflon® bottle, the SLM sampler is capable of speciation and storage of Cr ions, which is a major advantage over current speciation techniques. A food coloring test was used to check the samplers for leaks. A plastic barrier was used in place of the polymeric membrane and the acceptor phase bottle was filled with DI water. The sampler was submerged in a beaker containing food coloring and DI water. The bottle contents were checked for the presence of food coloring using UV-vis spectroscopy. The sampler was determined to be leak-free if the bottle did not contain food coloring. All systems prepared were validated upon the initial test and required no further manipulation to ensure structural soundness.
The SLM extraction technique involves two liquid-liquid extractions (LLEs). Before the samplers could be evaluated for their performance and stability in Cr speciation applications, liquid-liquid extraction studies were conducted on both systems (Cr (III) and Cr (VI)) to determine the optimal operating parameters (carrier concentration, decanol concentration, and acceptor phase concentration) of the SLM system. The selectivity of each system was also evaluated to validate proper SLM function.
The performance of the samplers was evaluated in a series of tank studies that focused on the uptake of Cr into the acceptor phase as well as the depletion of Cr ion from this phase. The goal of the performance studies was to determine the mechanical and chemical stability of the SLM samplers. As part of the validation process, selectivity studies and studies without the carrier molecule were conducted to ensure that the systems were functioning according to SLM theory. Tank studies that simulated natural sampling condition were also conducted.
The results of the tests conducted in the laboratory indicate that the SLM samplers are a stable, reliable, and viable method for Cr speciation. Future directions of this project will include the incorporation of the SLM sampler into the existing Multi-layer Sampler (MLS) technology as well as the analysis of the stability and performance of the incorporated systems in the ""in-situ speciation application.
Ph. D.
3
Hansson, Helena. "A Novel Miniaturised Dynamic Hollow-Fibre Liquid-Phase Micro-Extraction Method for Xenobiotics in Human Plasma Samples." Doctoral thesis, Stockholms universitet, Institutionen för analytisk kemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-41742.
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Bioanalytical chemistry is a challenging field, often involving complex samples, such as blood, plasma, serum or urine. In many applications, sample cleanup is the most demanding and time-consuming step. In the work underlying this thesis a novel dynamic miniature extractor, known as a hollow-fibre liquid-phase microextractor (HF-LPME), was designed, evaluated and studied closely when used to clean plasma samples. Aqueous-organic-aqueous liquid extraction, in which the organic liquid is immobilised in a porous polypropylene membrane, was the principle upon which the extractor was based, and this is discussed in all the papers associated with this thesis. This type of extraction is known as supported-liquid membrane extraction (SLM). The aim of this work was the development of a dynamic system for SLM. It was essential that the system could handle small sample volumes and had the potential for hyphenations and on-line connections to, for instance, LC/electrospray-MS. The design of a miniaturised HF-LPME device is presented in Paper I. The extraction method was developed for some weakly acidic pesticides and these were also used for evaluation. In the work described in Paper II, the method was optimised on the basis of an experimental design using spiked human plasma samples. Paper III presents a detailed study of the mass-transfer over the liquid membrane. The diffusion through the membrane pores was illustrated by a computer-simulation. Not surprisingly, the more lipophilic, the greater the retention of the compounds, as a result of dispersive forces. The main focus of the work described in Paper IV was to make the HF/LPME system more versatile and user-friendly; therefore, the extractor was automated by hyphenation to a SIA system.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript.
4
Yen, Pei-Shan. "Supported Liquid Metal Membranes for Hydrogen Separation." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-dissertations/480.
Full textAbstract:
Hydrogen (H2) and fuel cells applications are central to the realization of a global hydrogen economy. In this scenario, H2 may be produced from renewable biofuels via steam reforming and by solar powered water electrolysis. The purification required for fuel cell grade H2, whether in tandem or in situ within a catalytic reformer operating at 500 oC or above, would be greatly facilitated by the availability a cheaper and more robust option to palladium (Pd) dense metal membrane, currently the leading candidate. Here we describe our results on the feasibility of a completely novel membrane for hydrogen separation: Sandwiched Liquid Metal Membrane, or SLiMM, comprising of a low-melting, non-precious metal (e.g., Sn, In, Ga) film held between two porous substrates. Gallium was selected for this feasibility study to prove of the concept of SLiMM. It is molten at essentially room temperature, is non-toxic, and is much cheaper and more abundant than Pd. Our experimental and theoretical results indicate that the Ga SLiMM at 500 oC has a permeability 35 times higher than Pd, and substantially exceeds the 2015 DOE target for dense metal membranes. For developing a fundamental understanding of the thermodynamics and transport in liquid metals, a Pauling Bond Valence-Modified Morse Potential (PBV-MMP) model was developed. Based on little input, the PBV-MPP model accurately predicts liquid metal self-diffusion, viscosity, surface tension, as well as thermodynamic and energetic properties of hydrogen solution and diffusion in a liquid metal such as heat of dissociative adsorption, heat of solution, and activation energy of diffusion. The concept of SLiMM proved here opens up avenues for development practical H2 membranes, For this, improving the physical stability of the membrane is a key goal. Consequently, a thermodynamic theory was developed to better understand the change in liquid metal surface tension and contact angle as a function of temperature, pressure and gas-phase composition.
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Zou, Yiran. "Gas separation using supported ionic liquid membranes." Thesis, Queen's University Belfast, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517535.
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Maxwell, Michael. "Functionalised poly(organosiloxane)s as supported liquid membranes." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311252.
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Lantto, Jonas. "Analytical model of mass transfer through supported liquid membranes." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176912.
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This report details the development and validation of a model for the simulation of supported liquid membrane processes, as applied to the extraction of lanthanides. Supported liquid membranes are systems where two phases, usually aqueous, are separated by a third phase, typically organic, which acts as a membrane, in order to separate solutes from one phase to the other. The model employs an analytical solution to the diffusion equation for the organic phase and linear approximations of the resistances to mass transfer in the aqueous phase boundary layers. The goal of this model is to underline the importance of taking these boundary layer resistances into account.Detta arbete introducerar, deriverar och evaluerar en matematisk modell för simulering av vätskemembranprocesser, tillämpat på vätskeextraktion av lantanider. Immobiliserade vätskemembran betecknar system där två faser oftast vatten, separeras av en tredje organisk fas som agerar membran för att separera och transportera lösta komponenter från den ena vattenfasen till den andra. Modellen utnyttjar sig av en analytisk lösning till diffusionsekvationen för den organiska fasen och linjära approximationer för motstånden mot masstransport i de båda vattenfasernas gränsskikt. Målet med modellen är att understryka vikten av att inkludera dessa gränsskikt i beräkningarna.
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Aziz, Mujahid. "The recovery of copper by tubular supported liquid membranes." Thesis, Cape Peninsula University of Technology, 2006. http://hdl.handle.net/20.500.11838/894.
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Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, Cape Town, 2006During recent years, the use of liquid membranes has gained general interest in the treatment of effiuents where solute concentrations are low and large volumes of solutions should be processed, and, if possible, without generating any secondary waste. Liquid membrane processes have been proposed as a clean technology, owing to their characteristics, i.e. high specificity, low energy and utilization. Two liquid membrane processes have been used in metal recovery, which are the liquid surfactant membrane (LSM), which corresponds to double water-in-oil emulsion and solid . supported liquid membranes (SLM), which are made by dispersing or impregnating the extractant within the pores of in.ert solid support. Previously, the recovery of eu (IT) in a SLM system was conducted by other membrane models such as hollow fibre, spiral and flat sheet. Only a small measure of success on scale-up and industrialization of these models has been attained. One of the disadvantages of the hollow fibre system was the small lumen size through which the feed needed to pass. Pores became clogged by suspended particles because the pressure drop over the small diameter augments lower flow rates and therefore, pre-filtering is necessary (Rathore, et al., 2001). In this study the behaviour of a tubular SLM reactor with an inner diameter of the lumen approximately fifty times bigger than that of the hollow fibre are used in order to solve the problem of clogging. This tubular reactor was incorporated in to a bench scale plant and proved successful in copper extraction. By observing transient data, mass transport coefficients were determined and compared to published values.
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Yahaya, Garba Oloriegbe. "Facilitated transport in supported liquid membranes containing functionalized polyorganosiloxanes." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266467.
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Aroca, Arcaya German E. "Modelling the extraction of organic acids by supported liquid membranes." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262535.
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Vilt, Michael Edward. "Supported Liquid Membranes with Strip Dispersion for Recovery of Cephalexin." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1283447020.
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GLADDING, SARAH M. "POROUS INORGANIC SUPPORTED LIQUID MEMBRANES FOR USE IN ION CHANNELING." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109343185.
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Cao, Zishu. "Colloidal Zeolite Supported Ionic Liquid Membranes for CO2/N2 Separation." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406821911.
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Abu, Hweij Nadia. "Fabrication and characterization of polyetherimide Supported Ionic Liquid Membranes for gas separation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17867/.
Full textAbstract:
In the last decades, many studies have been addressed on the application of membrane technology in the field of gas separation. The most widespread membranes for gas separation are polymeric membranes, but several other configurations have been studied, among which heterogeneous membranes made by a polymeric support and a selective liquid, namely Supported Liquid Membranes (SLMs). Among the liquids used in this application, ionic liquids (ILs) display promising features, linked to their high viscosity, thermal stability and good affinity with CO2. For this reason, Supported Ionic Liquid Membranes (SILMs) have been widely investigated, in particular in their potentiality in CO2 removal.
The aim of this work is to study the applicability of polyetherimide (PEI) as supports for SILMs for gas separation. For this purpose, PEI porous matrix from different polymer solutions and different fabrication techniques are prepared. In particular, two phase inversion (PI) techniques have been investigated: the non-solvent induced PI and the Evaporation Induced PI. While the PEI matrixes prepared by NIPS technique present porosity of sizes of 3-5 μm suitable for the immobilization of a liquid phase, only dense structures have been obtained by solvent evaporation. Porous PEI supports are impregnated with an organic solvent (PEG 400) and an ionic liquid [bmim][BF4], leading to SLMs and SILMs, respectively. The permeability of N2, CO2, CH4, O2 and air is measured and the ideal selectivity of four gas pairs is calculated.
All membranes display separation performances which are lower than those expected by the selective liquids and that are below the state-of-the art of membrane technology for gas separation.
An analysis on the permeability of the two phases (polymer and liquid), aided by Maxwell-Wagner-Sillar theory for permeability in a heterogeneous medium, has revealed a simple but effective method to differentiate among different porous structures for SLMs and SILMs.
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Alderman, Angela. "Extraction of metals from aqueous solution using hollow fibre supported liquid membranes." Thesis, University of Hertfordshire, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332223.
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Lindegård, Boel. "Determination of amines and amine N-oxides in biological samples, particularly with supported liquid membranes for sample pretreatment." Lund : Dept. of Analytical Chemistry, Lund University, 1994. http://catalog.hathitrust.org/api/volumes/oclc/39111862.html.
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Gouveia, Andreia Sofia Ladeira dos Santos. "Facilitated CO2 separation membranes: mixing cyano and amino acid-based ionic liquids." Master's thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/13676.
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Santos, Santamaría Esther. "Separación de dióxido de carbono utilizando membranas soportadas con líquidos iónicos. Carbon dioxide separation by means of supported ionic liquid membranes." Doctoral thesis, Universidad de Cantabria, 2014. http://hdl.handle.net/10803/134723.
Full textAbstract:
Las últimas décadas han puesto de manifiesto la imposibilidad de trasladar la intensidad del consumo energético del mundo desarrollado a la totalidad del planeta y en consecuencia, la necesidad de un cambio global hacia una economía baja en carbono y por tanto a un modelo energético más eficiente y sostenible. Se requiere de un esfuerzo tecnológico dirigido a la reducción de las emisiones de gases de efecto invernadero, lo que implica el desarrollo de tecnologías para capturar y almacenar o valorizar dióxido de carbono (CO₂). La presente Tesis Doctoral estudia el desarrollo de nuevas membranas soportadas con líquidos iónicos para separación de CO₂ a través de un doble enfoque: desarrollo de membranas estímulo-respuesta basadas en líquidos iónicos magnéticos que presentan respuesta ante la aplicación de un campo magnético externo y membranas soportadas con líquidos iónicos basados en el anión acetato con una elevada solubilidad de CO₂, que pueden alcanzar mejores prestaciones en la separación/concentración.The last decades have shown the impossibility of transferring the energy intensity of the developed world to the entire planet and thus, the need for a global shift towards a low carbon economy and therefore, to a more efficient and sustainable energy model. A technological effort is required aimed at reducing greenhouse gas emissions, which necessarily involves the development of carbon dioxide (CO₂) capture and storage or valorization technologies. In this context, this Thesis studies the development of new supported ionic liquid membranes for CO₂ separation aiming for a dual approach: development of novel stimuli-responsive magnetic ionic liquids based membranes showing a response to the application of an external magnetic field and acetate based supported ionic liquid membranes with a high CO₂ solubility, which can achieve a better performance in its separation/concentration
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Makaka, Siphokazi. "The development of an empirical mass transfer relationship for the extraction of copper ions in a carrier facilitated tubular supported liquid membrane system." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/866.
Full textAbstract:
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Chemical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2011Treatment of waste material from mining and mineral processing is gaining increasing importance as a result of the increasing demand for high purity products and environmental concerns. Supported liquid membranes (SLMs) have been proposed as a new technology for the selective removal of metal ions from a solution. This technology can be described as the simultaneous extraction and stripping operation, combined in a continuous single process unit. Theoretically, the rate of mass transfer through SLM systems could be controlled by three resistances, namely: · Resistance through the feed-side · Resistance through the strip-side laminar layers; and · Diffusion through the membrane. It has been reported that transport resistance in the feed-side laminar layer is controlling. (Srisurichan et al, 2005:186). The objective of this research was to extract copper ions in a TSLM system, evaluate the effect of the feed characteristics on the feed-side laminar layer and determine a relationship between the applicable dimensionless numbers, i.e. Sherwood, Schmidt and Reynolds numbers. A Counter-current, double pipe Perspex bench-scale reactor, consisting of a single hydrophobic PVDF tubular membrane mounted vertically within, was used for the test work. The membrane was impregnated with LIX 984N-C and became the support for this organic transport medium. Dilute Copper solution passed through the centre pipe and sulphuric acid, as a strippant, passed through the shell side. In this test work, Copper was successfully transported from the feed-side to the strip-side and through repetitive results; a relationship between dimensionless numbers was achieved.
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Pérez, de los Rios Antonia. "Los líquidos iónicos como nuevos medios de reacción y separación en reacciones de transesterificación enzimáticas." Doctoral thesis, Universidad de Murcia, 2007. http://hdl.handle.net/10803/10937.
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El presente trabajo de Tesis tiene como finalidad analizar el potencial de los líquidos iónicos como medios de reacción y separación en reacciones de transesterificación enzimáticas. Los ILs inmiscibles con agua han resultado medios muy adecuados para llevar a cabo la síntesis de ésteres catalizada por la lipasa B de Candida antarctica (CALB), incrementando la actividad y selectividad enzimática con respecto a los valores obtenidos en disolventes orgánicos convencionales como n-hexano. El uso de líquidos iónicos miscibles con agua ha dado lugar a menores valores de actividad enzimática que n-hexano, aunque la selectividad en estos medios es mucho mayor. Los ILs se han revelado también como prometedores disolventes en su empleo en procesos de separación, más concretamente como fase líquida en membranas líquidas soportadas (SLMs). Se han desarrollado SLMs basadas en ILs altamente estables que permiten llevar a cabo la separación selectiva de sustratos y productos de reacciones de transesterificación.The main objective of this thesis is to analyze the potential use of ionic liquids as reaction and separation media in lipase-catalysed transesterification reactions. The use of ionic liquids in biocatalytic processes has been shown to be an environmentally attractive alternative to classical organic solvents. Water-immiscible ionic liquids appeared as suitable media for the transesterification reactions catalysed by Candida antarctica lipase B (CALB), increasing the activity and selectivity with respect to the values obtained with a classical organic solvent, n-hexane. The use of water-miscible ionic liquids led to lower activities than obtained in n-hexane, although the selectivity values were much higher in these media. Ionic liquids have also been shown to be promising solvents for the use in separation processes, more specifically as liquid phase in supported liquid membranes (SLMs). Highly stable SLMs based on ionic liquids have been succesfully used for the selective separation of different organic compounds which are substrates and products of transesterification reactions.
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Obón, Estrada Eleonora. "Towards the recovery of rare earth elements from end-of-life products : hydrometallurgical routes and mathematical modelling of extraction systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/669262.
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The rare earth elements (REEs) are essential ingredients for the development of modern industry and the transition to a more sustainable economy model. The unique physicochemical features of these elements, such as their magnetism and optical properties, are greatly expanding their application. They have become key elements for the manufacture of many ordinary consumer goods like hybrid cars, fluorescent lamps or electronic devices like mobile phones or tablets. The growing popularity of the rare earth elements derivatives is leading to an increase in the global demand and the price of these elements. Unfortunately, the current availability of these resources is limited due to three main factors: their heterogeneous geological location, their low concentration in the ores, and the environmental issues related with their mining.
All these disadvantages concerning the supply of the rare earth elements have led to the study of new techniques to obtain them, such as the recycling of end-of-life products. Recycling of REEs arises as a new secondary source of supply of REEs, especially in Europe where large amounts of technological waste are generated every year. Currently, the recycling of rare earth elements represents less than 1% of the global supply. Nevertheless, some studies in the literature assume that by 2050 the recovery rate of REEs will be 90% for wind turbines, 70% for electrical vehicles and 40% for the rest of derivative products.
The research presented in this thesis relies on experimental investigation of new hydrometallurgical routes, the majority of them involving the use of ionic liquids, which could eventually be applied for the recovery of rare earth elements from end-of-life products. Matemathical modelling of the reported extraction systems has been carried out in order to provide a computational instrument that can be easily tailored for prediction of other collecting processes requiring minor adjustments.Les terres rares son ingredients essencials per al desenvolupament de la indústria moderna i la transició cap a un model econòmic més sostenible. Les seves característiques físico-químiques úniques, com el seu magnetisme i propietats òptiques, han precipitat un increment accelerat en l’aplicació d’aquests elements. Les terres rares s’han convertit en elements clau per a la fabricació de molts articles d’ús diari com per exemple, cotxes elèctrics i dispositius electrònics com telèfons mòbils i tabletes. La creixent popularitat dels productes que contenen aquests metalls està provocant un escalat en la demanda global i el preu de les terres rares. Desafortunadament, en l’actualitat, la disponibilitat d’aquests recursos a la natura és limitada degut bàsicament a tres factors: heterogènia localització geològica, baixa concentració als minerals que els contenen i inconvenients mediambientals relacionats amb la mineria. Els inconvenients relacionats amb el subministrament de les terres rares a nivell mundial han propiciat l’estudi de noves tècniques per a la obtenció d’aquests elements mitjançant el reciclatge de productes que els contenen. El reciclatge sorgeix com una font secundària alternativa a la mineria per tal d’assegurar el provisionament de terres rares especialment a Europa, on generem grans quantitats de residus tecnològics cada any. Actualment, la taxa de reciclatge de terres rares se situa per sota l'1% del subministrament global. No obstant, alguns estudis publicats en la literatura assumeixen que l’any 2050, la taxa de recuperació haurà augmentat considerablement, de manera que es reciclarà fins a un 90% de les terres rares provinents d’aerogeneradors, 70% de vehicles elèctrics i 40% de la resta de productes que contenen aquests metalls. La recerca presentada en aquesta tesi es basa, principalment, en la investigació de noves rutes hidrometal·lúrgies, la majoria d’elles utilitzant líquids iònics, que puguin ser implementades en processos de recuperació de terres rares a partir de residus tecnològics. D’altra banda, s’han elaborat models matemàtics dels sistemes d’extracció reportats que pretenen convertir-se en una eina computacional, fàcilment adaptable, per a la predicció del comportament d’extracció en d’altres processos de recuperació amb diferents condicions experimentals.
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Daniel, Carla Isabel Lopes. "Development and modulation of magnetic responsive supported ionic liquid membranes." Doctoral thesis, 2015. http://hdl.handle.net/10362/16841.
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The work presented in this thesis aims at developing a new separation process based
on the application of supported magnetic ionic liquid membranes, SMILMs, using magnetic ionic liquids, MILs. MILs have attracted growing interest due to their ability to
change their physicochemical characteristics when exposed to variable magnetic field
conditions. The magnetic responsive behavior of MILs is thus expected to contribute for
the development of more efficient separation processes, such as supported liquid membranes, where MILs may be used as a selective carrier. Driven by the MILs behavior, these membranes are expected to switch reversibly their permeability and selectivity by in situ and non-invasive adjustment of the conditions (e.g. intensity, direction vector and uniformity) of an external applied magnetic field.
The development of these magnetic responsive membrane processes were anticipated
by studies, performed along the first stage of this PhD work, aiming at getting a deep
knowledge on the influence of magnetic field on MILs properties. The influence of the
magnetic field on the molecular dynamics and structural rearrangement of MILs ionic
network was assessed through a 1H-NMR technique. Through the 1H-NMR relaxometry
analysis it was possible to estimate the self-diffusion profiles of two different model MILs, [Aliquat][FeCl4] and [P66614][FeCl4]. A comparative analysis was established between the behavior of magnetic and non-magnetic ionic liquids, MILs and ILs, to facilitate the perception of the magnetic field impact on MILs properties. In contrast to ILs, MILs show a specific relaxation mechanism, characterized by the magnetic dependence of their self-diffusion coefficients. MILs self-diffusion coefficients increased in the presence of magnetic field whereas ILs self-diffusion was not affected.
In order to understand the reasons underlying the magnetic dependence of MILs
self-diffusion, studies were performed to investigate the influence of the magnetic field
on MILs’ viscosity. It was observed that the MIL´s viscosity decreases with the increase
of the magnetic field, explaining the increase of MILs self-diffusion according to the
modified Stokes- Einstein equation.
Different gas and liquid transport studies were therefore performed aiming to determine
the influence of the magnetic behavior of MILs on solute transport through SMILMs.
Gas permeation studies were performed using pure CO2 andN2 gas streams and air, using a series of phosphonium cation based MILs, containing different paramagnetic anions.
Transport studies were conducted in the presence and absence of magnetic field at a
maximum intensity of 1.5T. The results revealed that gas permeability increased in the
presence of the magnetic field, however, without affecting the membrane selectivity. The increase of gas permeability through SMILMs was related to the decrease of the MILs viscosity under magnetic field conditions.(...)
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Hsiang, Yin Hou, and 侯翔殷. "Facilitated transport of xylene isomers through supported liquid membranes containing cyclodextrins." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/66608217223407888958.
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碩士長庚大學
化學工程研究所
90
The separations of xylene isomers using carrier-contained supported liquid membranes was studied at 25℃. The carriers investigated include β-cyclodextrin (β-CD) and its Hydroxypropyl derivatives.The extraction equilibria of xylene isomers and aqueous cyclodextrins solutions were studied first. Then, a supported liquid membranes with and without containing cyclodextrins were used to facilitated mass transfer mechanism of xylene isomers through supported liquid membranes. The extraction extraction experiments indicate that the xylene the solubility and complexation constants of xylene and CDs increase with increasing the concentration of cyclodextrins in the aqueous phase .Increasing hydroxypropyl substitutions also help xylenes dissolve in organic phase and their complex formations with CDs. The mass transfer and separation of xylene isomers through supported liquid membranes by using cyclodextrins was investigated. The diffusivity coefficients of xylene isomers increased by six times compared with no carrier addition. The selectivity was 3.05 for β-CD, 3.55 for Hp-β-CD (MS=0.6) and 3.35 for Hp-β-CD (MS=1.0).
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Chen, Chia-Nan, and 陳嘉南. "Separation of Amino Acids Using Non-dispersive Supported and Emulsion Liquid Membranes." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/70137479781688454540.
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碩士元智大學
化學工程學系
93
The recovery and separation of amino acids from aqueous solutions by using a hollow fiber membrane module have been studied in this paper. Due to the zwitterionic character of amino acids, they had specific isoelectric points (pI). Amino acids could exist as the cationic or anionic form by adjusting the pH value less and greater than their isoelectric points in aqueous solutions. Therefore, a cation-exchange carrier, D2EHPA, may be applied to extract anionic forms of amino acids and to separate two amino acids. About the selectivity of binary amino acids, it was found that the larger the pH value, the larger the selectivity (1 < pH < 7). It was also found that the larger the concentration of D2EHPA in the organic phase, the larger the recovery. The hollow fiber experiments were performed by changing the pH value, the D2EHPA concentration, the acidity of strip phase, the concentration ratio of L-phenylalanine and L-aspartic acid in the feed phase, and the flow rate of all phase. It was shown that an increase of D2EHPA concentration in the organic phase and the concentration of the acid in the strip phase would enhance the selectivity. The increase of pH value in the feed phase and the ratio of [Asp]aq/[Phe]aq in the feed phase would enhance separation factor. The selectivity was in the range 1.3 ~ 18.5 .
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Ramakanth, C. "Studies On Copper Extraction With 5-Dodecylsalicyl Aldoxime In Supported Liquid Membranes." Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1864.
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Gaolape, Kefilwe Precious. "Determination of quinolones in bovine kidney using hollow-fiber supported liquid membrane extraction prior to liquid chromatography tandem mass spectrometry." Diss., 2017. http://hdl.handle.net/10500/24958.
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Focus of this study was on the development of one of the faster, simpler, cost effective and environmentally friendly sample pre-treatment techniques which employs a supported liquid membrane, in this case a Hollow-fiber supported liquid membrane (HF-SLM) for determination of seven (7) quinolone antibiotics (enrofloxacin, ciprofloxacin, danofloxacin, difloxacin, norfloxacin, nalidixic acid and sarafloxacin) in bovine kidney samples followed by LC-MS/MS analysis. The key parameters of the method were optimized and the method was validated following the 2002/657 EC guidelines. The optimum HF-SLM conditions were therefore; NaH2PO4 as a donor phase at pH 7, 0.1% formic acid at pH 3 as acceptor phase. Triethylamine was the optimized liquid membrane and the stirring time was optimized at 1 hour. Separation of the 7 quinolones including 3 internal standards (enrofloxacin-d5, norfloxacin-d5 and difloxacin-d3) was carried out on a Phenomenex Kinetex 2.6 μm XB-C18, 100 mm x 4.6 mm, 100Å column. Validation parameters such as Correlation coefficients (r2) ranging from 0.9714-0.9975 were obtained, while limit of detection (LOD) ranged between 3-39 ug kg-1 and limit of quantification (LOQ) ranged between 10-130 ug kg-1. The obtained limits at which it can be concluded with an error probability of α = 95% that a sample is non-compliant (CCα) ranged from 28 – 422 ug kg-1 while CCβ; the smallest content of the substance that may be detected, identified or quantified in a sample with an error probability of β = 95%, ranged from 29 – 454 ug kg-1. The method was found to be reproducible with CVs ≤ 23 %. The tested samples from Botswana local abattoirs showed no presence of quinolone antibiotics when the method was applied to real bovine kidney samples. Hollow-fiber supported liquid membrane can therefore be used for extraction of biological samples since it is a “greener technique” which uses less solvent which are less harmful to the environment when disposed as compared to dispersive Solid Phase Extraction (dSPE).Chemistry
M. Sc. (Chemistry)
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Lin, Jian-Hau, and 林劍壕. "Studies on the Transport and Separation of Copper(Ⅱ) and Cadmium(Ⅱ) Ions by Supported Liquid Membranes." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/467ca7.
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碩士國立臺北科技大學
化學工程所
94
In this research, the transportation and separation of copper(2+) and cadmium(2+) ions in sulfate solutions through a supported liquid membrane were studied at 25℃. The carrier in the supported liquid membrane was di(2-ethylhexyl)- phosphoric acid (D2EHPA) dissolved in kerosene. We investigated the phenomena during the transport processes in supported liquid membrane based on the experimental one. The experimental results of supported liquid membrane indicated that the overall permeabilities of copper(2+) and cadmium(2+) were correlated with the pH value of feed phase, the carrier concentration in liquid membrane, and the ratios of metal ions concentrations in the feed solutions. Besides, it showed that the cadmium(2+) had higher initial permeability than the copper(2+). The initial permeability of both copper(2+) and cadmium(2+) increased with increasing of the initial pH of feed solution while the initial permeability of cadmium(2+) increased very fast. The initial permeability of copper(2+) and cadmium(2+) increased with increasing of the carrier concentration. In addition, changing the feeding fluid copper and cadmium concentration ratio, the experimental results showed that copper and the cadmium penetration coefficient all decreases accordingly. This indicates that here exists competition between copper(2+) and cadmium(2+) ions. As for separation effect the experimental results show that changing the pH value of feed phase, the carrier concentration in liquid membrane, or the ratios of metal ions concentrations in the feed solutions, essentially caused no big the values change of the membrane factor. And, furthermore, there factors did not change with time obviously.
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Wallace, Sean Maurice. "Supported liquid membranes with macrocyclic carriers mimicking the metal uptake mechanisms of microorganisms for determination of metal speciation /." Diss., 1996. http://catalog.hathitrust.org/api/volumes/oclc/36390732.html.
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吳文馨. "Efficiency and kinetic studies on extraction separation of Zn(II) and Cd(II) ions in supported liquid membranes." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/19214230681213907628.
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碩士元智大學
化學工程學系
90
Some effluents discharged form electroplating and the fluorescence dyeing industries often include Zn2+ and Cd2+. A supported liquid membrane (SLM) was used to separate Zn2+ and Cd2+ from such synthetic solutions. The extraction equilibrium of Zn2+ and Cd2+ and the kinetics of SLM with the acidic extractants di(2-ethylhexyl)phosphoric acid (D2EHPA) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (PC88A) and the basic extractant tri-octyl methylammonium chloride (Aliquat 336) in kerosene were investigated. The compositions of the extracted species for the extraction of Zn2+ and Cd2+ with D2EHPA (0.1 mol/dm3) and PC88A (0.2 mol/dm3) were determined. D2EHPA (HX) with Zn2+ form , D2EHPA with Cd2+ form and , PC88A (HY) with Zn2+ from and , PC88A with Cd2+ form and . The extraction equilibria of Zn2+ and Cd2+ from chloride solutions with Aliquat 336 were determined to be and , respectively. From the experimental data of using the acidic extractants, the extraction efficiency increased with increasing initial pH values; and the extraction efficiency of Zn2+ was better than that of Cd2+. The flux of Zn2+ increased with increasing extractant concentration. In the binary system of Zn2+/Cd2+, the separation factor increased by increasing metal concentration ratios. In the case of basic extractant, the extraction efficiency of Cd2+ was better than that of Zn2+. When Zn2+/Cd2+ is 7 ( b = 1), neither of it is easy to separate in the binary system with the increasing metal concentration ratios. The increase in extractant concentration cannot lead to and without increased flux of Cd2+. The theoretical values calculated from the mass transfer model considering the extraction chemistry and mass transfer coefficient were compared with experimental results. The error was less than 5%.
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Peng, Chen-Yu, and 彭振育. "The Extraction and Separation of Platinum(II) and Palladium(II) Using Basic Extractants and Supported Liquid Membranes and to Explore the Life Cycle Assessment Study of the Environmental Impact Factor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/q9ryjm.
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博士國立臺北科技大學
工程科技研究所
102
This study employed a tri-n-octyl/decyl amine (Alamine 336) as an extractant dissolved in kerosene to extract Platinum (II) and Palladium(II) from HCI solution at 25°C. Both of the extraction equilibrium and kinetic study were evaluated according to the experimental data to describe the transport phenomena of Platinum (II) and Palladium(II) in the separation process of supported liquid membrane(SLM). The experiments of different stripping reagents such as HCI, NaCl, KCl, BaCl2, AlCl3, and thiourea were compared, respectively; and the optimal status was determined. The results showed that the extraction distribution ratios are proportional to the extractant concentration and disproportional to chloride ion concentration. By graphical analysis, the compositions of palladium complexes in organic phase and equilibrium constant of recovered extraction reaction were examined. Finally, the recovery efficiency of palladium(II) in acidic chloride solution was determined. The alkaline extractant, i.e., Alamine 336, were selected and used in the extraction process to recover the palladium (II) from HCl solution. The results indicated that the extraction distribution of palladium (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Alamine 336 complexes (i.e., and ) were found to be K20 = 2.61×103 and K21 = 2.47×104 (kmol/m3)?1, responsively. The extraction of platinum (II) from HCl solution was carried out using the alkaline extractant, i.e., Alamine 336. The results indicated that the extraction distribution of platinum (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. However, the extraction distribution of platinum (II) decreased as the increase of chloride concentration. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pt-Alamine 336 complexes (i.e., and ) were found to be = 7.76×103 and = 5.38×103(kmol/m3)?1, responsively. The extraction of palladium (II) from HCl solution was carried out using the alkaline extractant, i.e., Alamine 336. The results indicated that the extraction distribution of palladium (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. However, the extraction distribution of palladium (II) decreased as the increase of chloride concentration. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Alamine 336 complexes (i.e., ) were found to be K20 = 4.68×103. In addition, the extraction of platinum (II) from HCl solution was carried out using the alkaline extractant, i.e., Alamine 336. The results indicated that the extraction distribution of platinum (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. However, the extraction distribution of platinum (II) decreased as the increase of chloride concentration. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Alamine 336 complexes (i.e., ) were found to be K20 = 3.11×104. Furthermore, the extraction of both platinum (II) and palladium (II) were carried out from HCl solution using the alkaline Alamine 336 extractant. The results indicated that the extraction distribution of platinum (II) and palladium (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. However, the extraction distribution of both platinum (II) and palladium (II) decreased as the increase of chloride concentration. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Alamine 336 complexes (i.e., and ) were found to be = 2.91×103, with a slope of = 2.48×104 (kmol/m3)?1. In the case of platinum (II), the equilibrium constants of organic phases of Pt-Alamine 336 complexes (i.e., and ) were found to be = 7.76×103, with a slope of = 5.38×103 (kmol/m3)?1. According to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Alamine 336 complexes (i.e., and ) were found to be = 2.91×103, with a slope of = 2.48×104 (kmol/m3)?1. In the case of palladium (II), the equilibrium constants of organic phases of Pt-Alamine 336 complexes (i.e., and ) were found to be = 7.76×103, with a slope of = 5.38×103 (kmol/m3)?1. The extraction of both platinum (II) and palladium (II) were carried out from HCl solution using the alkaline Aliquat 336 extractant. The results indicated that the extraction distribution of platinum (II) and palladium (II) for organic and water phases increased as the increases of the concentration of Alamine 336 extractant. However, the extraction distribution of both platinum (II) and palladium (II) decreased as the increase of chloride concentration. In the case of palladium (II), according to the results from graphical presentation and numerical analysis, the equilibrium constants of organic phases of Pd-Aliquat 336 complexes (i.e., ) were found to be = 5.41×103. On the other hand, in the case of platinum (II), the equilibrium constants of organic phases of Pt-Aliquat 336 complexes (i.e., ) were found to be = 6.41×104. Lastly, the environmental impacts of the extraction process was assessed using Umberto software. The inventory data for extraction process including amounts of chemical consumption was gathered in this study to quantify the environmental impacts of the proposed extraction process.