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1
Pan, L. C. "Ion exchange of proteins". Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638406.
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The aims of the present work were to assess the nature and importance of the intermolecular and surface interactions in ion exchange processes at different conditions and also to develop a mathematical model for the prediction of equilibrium constants. The equilibrium uptake of two proteins (bovine serum albumin, myoglobin) on hydrophilic ion exchangers was studied at different pH values and ironic strengths. Equilibrium isotherm analysis allowed the determination of the thermodynamic equilibrium constants (K) for each condition. The affinity of the hydrophilic cellulosic ion exchanger (Whatman QA52) for bovine serum albumin was higher than for myoglobin. The maximum capacity of the ion exchanger was lower for BSA than for myoglobin under all comparable conditions. This behaviour is explained by considering the physical and chemical properties of the proteins and ion exchanger. The heats of exchange of the bovine serum albumin (BSA) at Whatman QA52 at different pH values were obtained by titration microcalorimetry (Thermometric 2277 Thermal Activity Monitor). An analysis procedure was developed to determine the standard thermodynamic functions (ΔG°, ΔH°, ΔS°) for each ion exchange process. Knowledge of these thermodynamic quantities provided further insight into the interactions that can occur during the ion exchange process. The analysis of thermodynamic data could help selection of the most effective means of manipulating process solution conditions to maximise the degree of separation. A colloid science approach for ion exchange of proteins has been developed based on electrostatic and London-van der Waals interaction energies. The approach allowed a priori prediction for the equilibrium behaviour of ion exchange of proteins at different conditions.
2
Zubair, M. "Ion exchange in chabazite". Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239984.
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Pribyl, Ondrej. "Modelling of electrochemical ion exchange". Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325234.
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4
Bayraktaroglu, Kerem. "Multicomponent Ion Exchange On Clinoptilolite". Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607580/index.pdf.
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Zeolites are crystalline, hydrated aluminosilicate minerals that are characterized by their
ability to exchange some of their constituent cations with cations in aqueous solutions,
without a major change in their crystalline structure. Clinoptilolite is the most abundant ype of zeolite and it has received extensive attention due to its favorable selectivity for mmonium and certain heavy metal cations.
The aim of this study is to investigate the binary and ternary (multicomponent) ion xchange behavior of sodium form of Gördes type clinoptilolite for ammonium,cadmium and sodium ions. For this purpose, NH4 +-Na+,Cd2+-Na+ binary systems and NH4 +-Cd2+-Na+ multicomponent system were investigated both in batch and column systems at 0.1 and 0.01 constant total normality respectively and at 250C constant temperature. As a result of binary and ternary experiments, clinoptilolite&rsquo
s affinity for both ions but greater affinity to NH4+ ion than Cd2+ ion was observed and the selectivity sequence of Gö
rdes clinoptilolite was determined as NH4+>
Cd2+>
Na+ in binary and multicomponent batch and column operations. Additionally, total ion exchange capacities and maximum exchange levels of Gö
rdes clinoptilolite for both ions were determined in batch systems whereas breakthrough capacities and column efficiencies (for three different flow rates) were determined in column systems. Finally, it was concluded that the increase of the flow rate reduced the breakthrough capacities and column efficiencies of Gö
rdes clinoptilolite for ammonium and cadmium ions in multicomponent column systems involving more than one cation.
5
Ichsan, E. A. W. "Ion exchange on chelating fibres". Thesis, University of Salford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353980.
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6
Polite, Lee Nicholas. "Studies in ion exchange chromatography". Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/54338.
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This dissertation investigates three major problems in IC, ranging from the practical to the theoretical. The first is of interest to the field of quantitative analysis. Since ion chromatography is primarily a quantitative technique, the linear range of the detector is of particular interest. The linear range was determined to be nearly five orders of magnitude for several common ions. The probes used were fluoride, chloride, sulfate, sodium, and potassium with concentrations ranging from 10 ppb to 1000 ppm. This portion of the dissertation describes the first attempt made to elucidate the linear detection range in ion chromatography using micro-membrane suppression.
The Iinearity experiments demonstrate the versatility of ion chromatography with respect to quantifiable concentrations. However, a major problem is encountered when attempting to determine a trace ion concentration in the presence of a high concentration of a similarly charged ion (matrix ion). The second part of this dissertation offers a solution to this problem. In ion chromatography, the large excess of a matrix ion affects not only the ions expected in that region of the chromatogram, but also destroys the chromatographic exchange process. One objective of this study was to develop a rapid quantitative method to determine 5 ppm chloride in the presence of 100,000 ppm sulfate. A standard anion exchange column will completely lose resolution between chloride and sulfate at a sulfate concentration of approximately 2500 ppm. The apparatus designed and built by the author uses two analytical ion—exchange columns coupled in series by a high pressure switching valve. ln order to complete the system, the author designed and built y a high pressure conductivity detector cell to monitor the conductivity of the effluent from the first column. The system works by overloading the first column and then allowing the effluent to pass onto the second column. When the trace chloride in on the second column, the first column is switched out of line. This process allows the trace chloride to be separated from the residual sulfate.
The column switching study brought to light several theoretical questions about the inner workings of the packing materials used in ion chromatography. These questions include the effects that flow rate and temperature have on capacity and efficiency in ion chromatography separations. Using chloride and sulfate as probes, the chromatographic efficiency was shown to decrease from 30° to 60° C. Even more surprising was the result that sulfate retention increased with increasing temperature while chloride retention decreased under the same conditions. Detailed studies as well as possible explanations are included in the third part of this dissertation.Ph. D.
7
McVeigh, Ryan. "Biologically enhanced ion exchange of ammonium ion using clinoptilolite". Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247390.
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Rejaldien, Moegamat Zain. "Base metal equilibrium prediction on ion exchange resin". Thesis, Cape Technikon, 2002. http://hdl.handle.net/20.500.11838/875.
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Thesis (MTech (Chemical Engineering)--Cape Technikon, Cape Town, 2002This study is the first phase of an investigation into an alternative process to recover base metals from solution, namely ion exchange. An identified ion exchange resin was employed to study the recovery of copper, nickel and cobalt from electrolytic solutions. The main focus of the investigation was the prediction of equilibrium conditions in this multi-component system using a batch configuration. In order to predict equilibrium conditions. existing multi-component isotherms such as Fritz and Schleunder were tested. It has been shown that traditional isothem15 did not accurately predict equilibrium conditions. hence the need for development of new isotherms. Essentially two approaches were followed in the development of new isotherms namely. an effective concentration approach as well as a heat transfer approach. Both yielded positive outcomes with the effective concentration approach proving to be the most accurate. In addition to these two approaches a thermodynamical approach was also tested which also showed favourable predictions for Cu loading
9
Maketon, Supachai. "Methods Development for Ion Chromatography". Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc330927/.
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Ion chromatography (IC) as developed by Small et. al. in 1975 has become an efficient and reliable analytical technique for simultaneous analysis of multiple ions in solution. The principle requirement prior to use the IC for an analysis is sample preparation; these include sample decomposition, solvent extraction, and trapping in case the target element is in the gas phase, etc. Solvent extractions for fluoride, chloride, sodium, ammonium, and potassium ions which are soluble in soils are described. Sample decompositions include silicate rocks using hydrofluoric acid for the determination of phosphorus; organic pesticides using lithium fusion technique for the determination of halide and cyanide ions are also described. After these sample preparation techniques, the aqueous solutions obtained were analyzed on the ion chromatograph for the analyses of the anions and cations mentioned above. Recovery and reproducibility of each technique is in general quite good and the comparison between the results obtained from the IC method and other instrumentation are given.
10
Pearson, C. H. G. "New ion exchange resins for ion chromatography applied to anions". Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372771.
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Forrer, Nicola. "Antibody purification with ion-exchange chromatography". Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17784.
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Watkins, E. James. "Foulant adsorption onto ion exchange membranes". Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/7062.
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Kadaifci, Bijen. "Multicomponent Ion Exchange On Zeolite 4a". Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613916/index.pdf.
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In this study binary and ternary ion exchange on Zeolite NaA using silver and cadmium ions were investigated. Ion exchange were conducted at constant temperature (25oC) and normality (0.1N) in a batch system for both binary and ternary experiments. Zeolite weights were varied between 0.1 and 1 g for binary experiments.
Thermodynamic analysis of binary ion exchange between Cd2+-Na+ and Ag+-Na+ were examined and thermodynamic equilibrium constant and Gibbs free energy were calculated. Thermodynamic equilibrium constants were found as respectively 28.2 and 300.4 for Cd2+-Na+ and Ag+-Na+ binary system. Standart free energy of Cd2+-Na+ and Ag+-Na+ binary exchange were calculated as -4.1 kJ/mol and -14.1 kJ/mol
respectively. In literature Ay (2008) calculated the Gibbs free energy for Ag+-Na+ binary system as -14.4 kJ/mol and Biskup and Subotic (2010) and Gal et al. (1970) calculated the Gibbs free energy for Cd2+-Na+ binary system as -3.7 kJ/mol and -4.4
kJ/mol respectively. It is concluded Zeolite 4A has higher affinity to silver than cadmium and selectivity sequence was found asAg+>
Cd2+>
Na+. Langmuir and Freundlich isotherms were drawn to describe experimental data. As compared the R2 of isotherms, it is clearly seen that Freundlich isotherm provides better fit for Cd2+-Na+ binary ion exchange and Ag+-Na+ binary ion exchange. The ternary ion exchange isotherms were plotted using equivalent fraction of three ions (Ag+,Na+,Cd2+) which participated in ion exchange experiments to determine selectivity of zeolite 4A for cadmium and silver. Selectivity sequence was determined as Ag+ >
Cd2+ >
Na+ for ternary ion exchange.
14
Schiewer, Silke. "Multi-metal ion exchange in biosorption". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ30375.pdf.
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Danielsson, Carl-Ola. "Continuous electropermutation using ion-exchange textile /". Stockholm : Department of Mechanics, Royal Institute of Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-359.
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Schiewer, Silke. "Multi-metal ion exchange in biosorption". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34443.
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Biosorption, a process of passive metal binding to biomass, may be used for purification of metal bearing effluents. This work investigates the binding of heavy metal ions (Cd, Cu, Zn), light metal ions (Ca, Na) and protons to biomass of the brown alga Sargassum.The mechanism of metal binding was confirmed to be ion exchange. A novel multi-component sorption isotherm model for cation binding was derived to aid in predicting the biosorption performance of the new biosorbent. This model considers chemical binding to free sites on the biomass and ion exchange (1:2 stoichiometry for divalent ions). It is based on chemical equilibrium constants and assumes competition of all cations for the same binding sites. Two main binding sites (carboxyl and sulfate) were characterized in terms of their respective quantities and pK$ rm sb{a}.$ Only two model parameters had to be determined for each metal cation (binding constants) and one additional parameter for each binding site (site quantity).
The two-site model successfully described metal and proton binding at different pH in mono- and di-metal systems. It was possible to predict the complete equilibrium sorption state, residual metal concentration in solution and metal uptake by the biosorbent, from the known initial state for varying amounts of biomass and different initial pH values. In order to account for the effect of ionic strength and electrostatic attraction, the above mentioned biosorption model was expanded by incorporating a version of the Donnan model and/or a Gouy-Chapman double layer model. The charge density of the biomass was characterized and intrinsic binding constants were derived. Correlations to account for biosorbent particle swelling were established. For the specific case of linear increase of swelling with the number of free sites, an explicit sorption isotherm equation was derived that includes the Donnan model in an easy-to use-way.
Using the parameters obtained from pH titrations at different ionic strength, it was possible to predict the effect of ionic strength on Cd binding. The influence of Ca on Cd binding was predicted from experiments with Cd and Ca, respectively, in mono-metal systems.
17
Chandrapalan, P. "Surface modification of ion exchange membrane". Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249383.
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Obermoller, H. D. "Uranium Isotope Separation by Ion Exchange". Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518938.
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Addison, Paul A. "A study of ion exchange equilibrium". Thesis, University of Canterbury. Chemical and Process Engineering, 1990. http://hdl.handle.net/10092/7508.
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A study has been made of methods for the characterization and prediction of ion exchange equilibria. Methods which took account of the thermodynamic non-idealities present in ion exchange systems were found to provide the best results.
A characterization method which used the extended Debye-Hückel relation and the Wilson equation to estimate solution and resin phase activity coefficients, respectively, was developed. A simplifying reciprocal relationship between a pair of Wilson interaction parameters was hypothesized and was found to give results which were not significantly different from those yielded by the more complicated expression, even though the number of parameters had been reduced from three to two. The reciprocity hypothesis was able to be justified in terms of commonly made approximations.
By its application to the characterization of a number of ternary equilibria, the Hála constraint relating three pairs of Wilson interaction parameters, previously only applied to vapour-liquid equilibrium, was found to be equally useful for ion exchange purposes.
Predictions of ternary ion exchange equilibria were successfully made using the Wilson parameters and thermodynamic equilibrium constants obtained from binary characterizations. Only slight reductions in the quality of prediction were evident when the reciprocal relation and the Hála constraint were included in the predictive algorithm, even though the number of parameters used was reduced from eight to four. When data from only two of the three constituent binary systems were used to predict a ternary system, best results were obtained when the two pairs used both contained the most favourably selected ion in the ternary system.
A CSTR technique for the measurement of ion exchange equilibrium isotherms was designed, built and tested. The method had the particular advantages that it was continuous and enabled on-line acquisition and analysis of results by computer. Only one experimental run was necessary to obtain a complete binary ion exchange isotherm. The uncertainty in computed resin phase compositions was found to compare very favourably with those arising from other methods. Measurements were made of the kinetics of the CSTR process and of the transient behaviour of the ion selective electrode used to ascertain solution phase compositions. Both of these were found to have a significant effect at low concentrations, and appropriate adjustments to measured data were made. It was recommended that these corrections may be avoided by use of a lower feed flowrate at the expense of a longer run time, necessitating the installation of a pump capable of delivering flowrates below those used in this work.
Reproducible results were obtained for the Na+/H+ exchange on Dowex 50W-X8 at 0.1 N total solution concentration and a temperature of 20°C. The results did not, however, agree with some previously published data for the same system. This discrepancy was thought to be due to a difference in the mean resin particle size between the two sets of experiments. Batch measurements were made, and confirmed the binary isotherm measured by the CSTR.
20
Kier, D. "Ion-exchange for radioactive waste treatment". Thesis, University of Salford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376870.
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Herbas, Mélodie. "Ion exchange to cope with decommissioning". Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/ion-exchange-to-cope-with-decommissioning(fd150782-5021-4243-8d30-f3dcfec9abec).html.
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This PhD project studied the caesium and strontium removal capacities of six nanoporous materials. Indeed, it was linked in with the SIXEP plant present at Sellafield site, UK, which is currently using natural clinoptilolite, originally mined from the Mojave Desert, to remove radioactive caesium and strontium ions from wastewater effluents. At the moment the feeds entering the SIXEP plant correspond to the best working conditions for clinoptilolite. As the feeds are moving toward more acidic pH and complex solutions and as clinoptilolite works at neutral pH, new nanoporous materials are required. This project had been divided into sub-projects, which all had the same purpose of finding the best material for caesium and strontium removal under complex solutions. The first part of the PhD focused on the synthesis of CST, SNT, ETS-4 and ETS-10 materials following literature reviews. The two last materials studied were provided by Fortum Power and Heat Oy for CsTreat material and by Sellafield Ltd for clinoptilolite material. The second part of the PhD consisted in studying the exchange capacities for caesium and strontium ions for each material studied under batch conditions using several water compositions relevant to Sellafield Ltd. Each water composition had different competing ions or pH and were used to classify the materials between them. From that it was found that Clinoptilolite stays the best materials for caesium and strontium removal. The third part of the project was the gamma irradiation of the materials. This irradiation had an aim to check the stability of the structure of the studied materials under gamma irradiation. The materials were exposed to four different gamma doses which were 0.5; 1; 3 and 6 MGy, the last one corresponding to the maximum dose were structural changes could happen. This revealed that all the materials, except ETS-4 material, were stable under gamma irradiation and that no structural changes were observable. The fourth part of the project was an extension of the third part in which the materials were Cs exchanged before being gamma irradiated to a dose of 6 MGy. This showed that the caesium exchange process is not affected by radiation. Finally, the unexchanged materials were alpha irradiated using a 15 MeV He2+ beam at the Dalton Cumbria Facility. Two irradiations were performed on CsTreat, CST, ETS-4, ETS-10 and clinoptilolite material. It was found that all the materials were damaged by alpha irradiation and displayed amorphous framework To resume, it appeared that clinoptilolite still stays one of the best materials for the removal of caesium and strontium ions in a wide range of wastewater composition. Additionally, it was discovered that ETS-10 material could be a good alternative to clinoptilolite material as its structure is stable under gamma irradiation and it displayed good exchange capacities when competing ions were present in the feeds. CST could also be a substitute as it shows good ion exchange properties under a broad range of pH. SNT material was great for strontium removal while CsTreat was working well for caesium removal. Even though ETS- 4 revealed good ion exchange capacities they were lower than clinoptilolite, ETS- 10 or CST materials.
22
Coker, Eric Nicholas. "Ion exchange studies of microporous solids". Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/47815.
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Ma, Yiu Wa. "Fixed bed removal of heavy metal ions by chelating ion exchange". Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491880.
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Column runs with varied operation conditions of flowrate, feed concentration and particle size have been conducted to observe the sorption of nickel, copper and zinc by the chelating resin. They all show a typical constant-pattern, steep curve in the first part of the breakthrough curve and the slope would dramatically reduce at a breakpoint such that it would take extremely long time to reach 100% breakthrough level. ~ The Modified Bed Depth Service Time (BDST) model incorporated with a timedependent bed capacity has been used together with the Empty Bed Residence Time (EBRT) model to analyze the fixed bed performance under different operating conditions. The Homogeneous Surface Diffusion Model (HSDM) and the Shrinking Core Diffusion . Model (SCDM) have been applied to- model the fixed bed performance. Due to the dramatic change in the slope, the first and second parts of the breakthrough curves need to be modeled separately. Comparing the two models, SCDM is more appropriate to explain the sorption of metal ions into the chelating resin. The research has suggested the existence of a Na-loaded outer shell and a H-loaded inner core in the chelating resin. When the moving boundary progresses from the outer shell into the inner core, there is a remarkable change in the ion exchange process, resulting in different kinetics. This explains the sharp change in the slope of the experimental breakthrough curves. A new version of SCDM has been developed to model the progression of the moving boundary inside the resin for the successive resin layers along the whole resin column so as to predict the column' s solid and liquid phase concentration profiles. The new SCDM has. the flexibility of varying the portion of the outer shell so that the behavior of resins with different resin Na contents can be predicted.
24
Adams, Robert Jonathan Watt. "The extraction of caesium and cobalt(II) from solution using inorganic ion exchangers in electrochemical ion exchange". Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385171.
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Houghton, Mark Phillip. "Polymer-supported reactions using ion-exchange resins". Thesis, Lancaster University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255343.
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Abonijim, M. N. "Ion exchange properties of poly(vinylimidazoline) resins". Thesis, University of Salford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381642.
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Harsa, Sebnem. "Studies on the ion-exchange of pectinase". Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303734.
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Willett, Thomas Clifford. "Magnetic adsorbents displaying switchable ion-exchange behaviour". Thesis, University of Birmingham, 2009. http://etheses.bham.ac.uk//id/eprint/507/.
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Magnetic bioseparations based on non-porous adsorbents offer a low-fouling alternative to the porous materials required by conventional adsorbent separation techniques. Interest in magnetic bioseparations has been limited by the high cost of suitable magnetic absorbents. In this study a variety of techniques - including Ce(IV) initiation, surface ATRP and sulfonyl activation – were used to graft ion-exchanging polyelectrolyte surfaces on low cost non-porous polyvinyl alcohol-magnetite supports. Grafting of poly(2-vinyl pyridine) and poly(methacrylic acid) was fully characterised using solid and liquid state FTIR. Dense polyelectrolyte layers were seen, with Ce(IV) grafted layers accounting for up to 49% of grafted support mass. Values for ATRP and tresyl activations were 41% and 25% of support mass respectively. These included layers which correspond to the brush regime (2R\(_f\)/D > 8), as determined by Flory Radius calculations. The above matrices were subsequently analysed with bind and elute studies using a model mixture of acidic and basic proteins. Switchable ion-exchange behaviour was demonstrated, with anion binding capacity >25 mg/g support at pH 5 and cation binding >25 mg/g seen for Ce(IV) grafted supports. Improved elution by pH was also seen, with up to 73% of bound lysozyme removed during a single elution at pH 5.
29
Harries, Richard R. "Water purification by ion exchange mixed beds". Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/18591.
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Ion exchange is used extensively for the removal of ionised impurities found in natural waters. The final stage in the production of ultra pure water is normally a bed of mixed anion and cation exchange resins. Three areas within the operating cycle of a regenerable mixed bed - resin separation, resin mixing and anion exchange kinetics - have been investigated. Complete separation of the two resins by backwashing, prior to chemical regeneration, is necessary to prevent the subsequent release of trace impurities into the purified water. Various published models of particle segregation by backwashing were examined but none accurately described the separation of two ion exchange resins with similar bead size distributions and densities. A new model has been proposed based on variations in fluidised bed porosity combined with overlapping bulk circulation cells of particles. A graphical technique has been developed to predict resin separability and the predictions compared with practical data. The effects of variations in bead size, bead density, backwash flow rate and temperature have been calculated. The variations in bead density with ionic form and polymer/matrix type of the exchanger have been measured. Following regeneration the resins are remixed by air agitation of a resin/water slurry. A mechanism to describe the progressive stages of air mixing has been proposed, based on bubble transport and bulk circulation of resin beads. The subsequent sedimentation of the resins was also considered. Laboratory and full scale studies confirmed the predicted effects of mixing fault conditions, particularly re-separation of the mixed resins. A mass transfer equation has been developed to describe the leakage of influent ions through a column of exchange resins. In conjunction with laboratory column tests the equation has been used to investigate the influence on anion exchange of polymer/matrix type, influent anion and the presence of foulants on the resin beads. Sulphate and phosphate ions exchange more slowly than monovalent chloride and nitrate ions. On a fouled exchanger the rate of sulphate exchange deteriorates more rapidly and seriously than for chloride exchange. This has been attributed to steric hindrance of the divalent sulphate ion. A laboratory method has been developed for the routine assessment of mixed bed anion exchangers and the prediction of their performance potential in service, with particular application to condensate purification for boiler feedwater.
30
Ahmed, Manzoor. "Modelling the ion exchange equilibria of proteins". Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242335.
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Coetzee, Johannes Wilhelm. "The ion exchange phenomenon of acetylene black". Thesis, Cape Technikon, 1996. http://hdl.handle.net/20.500.11838/909.
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Thesis (MTech (Chemical Engineering)--Cape Technikon, Cape Town,1996Acetylene Black IACB) IS a pure form of carbon which is used in the battery, plastics, printing and rubber industries. It is extensively used in the battery industry to absorb electrolyte and to lower the electrical resistance of dry cell batteries. It is the attempt of this thesis, to investigate the surface characteristics '---------._-- -,- ...• -...•--- .. ------.. _.. --- "'- and structure of ACB by using it as an adsorbent for cyanide complexes, in particular gold cyanide. The thesis is predominantly aimed at identifying the mechanism of metal cyanide adsorption onto ACB, viz. ion exchange and/or physical adsorption. In order to quantify the mechanism of adsorption, comparative studies with other adsorbents currently used in the mining industry, such as activated carbon, were conducted. These studies revealed various similarities in the metal adsorption process between ACB and activated carbon, thus indicating physical adsorption rather than ion exchange to be the dominant mechanism for metal adsorption from solution. The rate of metal adsorption onto acetylene black was relatively fast compared to activated carbon. Furthermore, adsorption profiles revealed that intraparticle diffusion was negligible when a metal was adsorbed onto ACB from solution. This indicates that acetylene black has a predominantly amorphous structure, although X-ray diffractrometry indicates a certain degree of graphitisation associated with ACB. The small surface area of ACB, together with the lack of intraparticle diffusion, resulted in the rapid attainment of the equilibrium metal loading on ACB. Moreover, this equilibrium metal loading was far less than that of activated carbon and ionexchange resin. While pH, temperature and strong oxidizing agents had a marked effect on the adsorption profile of metal cyanides onto ACB, the effect of oxygen enrichment and organic solvents was negligible. Furthermore, the adsorption of gold onto ACB is best explained by a Freundlich-type isotherm. As is the case with activated carbon and ion exchange resin, gold is eluted from ACB by a NaOH solution. It was also found that the elution efficiency is influenced by a change in temperature. Changes in operating variables in the production of ACB had an effect on the absorption stiffness of the product. Both an increase in acetylene feed rate and operating temperature reduced the absorption stiffness of the product.
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Tailony, Ra'uf. "Ion exchange glass strengthening using microwave processing". University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1449764292.
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Can, Özge Ülkü Semra. "Ion exchange in natural zeolite packed column/". [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/kimya/T000607.pdf.
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Cao, Liming. "Protein Separation with Ion-exchange Membrane Chromatography". Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-050405-174109/.
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McKevitt, Bethan Ruth. "Removal of iron by ion exchange from copper electrowinning electrolyte solutions containing antimony and bismuth". Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/427.
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In order to increase the current efficiency in copper electrowinning tankhouses, iron can be removed from the electrolyte using ion exchange. While this is a proven technology, very little data is available for the application of this technology to copper electrowinning electrolytes containing antimony and bismuth.
The feasibility of utilizing iron ion exchange for the removal of iron from copper electrowinning electrolytes containing antimony and bismuth was studied in the laboratory. Apicolylamine, a sulphonated diphosphonic, an aminophosphonic and three sulphonated monophosphonic resins were tested. The picolylamine resin was found to be completely impractical as it loaded high levels of copper. All the phosphonic resins tested loaded an appreciable amount of antimony, however, only the aminophosponic resin loaded an appreciable amount of bismuth.
Tests to determine whether or not the sulphonated monophosphonic Purolite S957 resin would continue to load antimony with time and, hence, reduce the resin's ability to remove iron gave inconclusive results. In the event that the resin's ability to remove iron is hampered due to antimony loading, testing has shown that the resin performance may be restored via a regeneration with a solution containing sulphuric acid and sodium chloride.
A case study for the application of this technology to the CVRD Inco CRED plant has shown that, while iron removal by ion exchange is technically feasible, it will upset the plant's acid balance in electrolyte. Therefore, an acid removal process would need to be implemented in tandem with an iron ion exchange system. Additionally, preliminary calculations suggest that a system with a single ion exchange column may have difficulty removing sufficient iron for the CRED design conditions. Therefore, consideration should be given to the possibility of utilizing a two column system (one column loading, one column stripping).
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Huang, Julie Shiong-Jiun. "Ion Chromatography of Soluble Cr(III) and Cr(VI)". Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc500410/.
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Ion chromatography coupled with a conductivity detector was used to investigate the analysis of Cr(III) and Cr(VI) in aqueous samples. An IC methodology for Cr(III) was developed using a cation column and an eluent containing tartaric acid, ethylenediamine, and acetonitrile at pH 2.9. The detection limit of this method can reach 0.1 ppm level with good precision. Several operational parameters were evaluated during the regular use of the method. Comparison of the IC method with AA method showed good agreement between the two methods. The anion exchange column was used for Cr(VI) determination. The best results were obtained with an eluent containing sodium gluconate, borate buffer, glycerin, and acetonitrile. The retention time for the Cr207 2 - sample was 11 min. and the calibration curve was linear between 1.0 and 100 ppm.
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El-Masri, Nasrein. "Ion-association complexes of thallium and mercury with rhodamine 6G in aqueous solution". Scholarly Commons, 1988. https://scholarlycommons.pacific.edu/uop_etds/2170.
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CHARBEL, MARIA Y. "Estudo para a remocao de fluoreto em aguas e efluentes". reponame:Repositório Institucional do IPEN, 1990. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10235.
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Made available in DSpace on 2014-10-09T12:36:21Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:59:29Z (GMT). No. of bitstreams: 1 03871.pdf: 2892098 bytes, checksum: 5369857479c6fb9952c9855c38d0ee35 (MD5)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Borghi, Andrea. "Cellulose hollow fibers membranes for ion-exchange chromatography". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20289/.
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The development of an efficient and cost-effective purification process is the objective of protein separation. Usually, the most common procedure is chromatography, typically performed in a packed bed column; however, the cost is relatively high.
Nowadays, one of the most interesting and promising method is the employment of particular membranes, the hollow fibers, in the standard chromatographic operations. Hollow fibers membranes were developed in the 1960s, specifically for reverse osmosis; nonetheless, they are now largely applied in both liquid and gaseous applications.
In this project, the preparation of cellulose hollow fibers, exploited for ion-exchange chromatography, was studied during a five months internship at the King Abdullah University of Science and Technology (KAUST) in the group of Professor Suzana Nunes.
The hollow fibers were prepared, dissolving cellulose in 1-Ethyl-3-methylimidazolium diethyl phosphate (EMIM DEP), an ionic liquid commonly used as green solvent for cellulose.
After a first research, regarding the performance of flat sheet membrane obtained by phase inversion, in which permeance and rejection were investigated using bovine serum albumin (BSA), the second phase of the project was the optimization of cellulose hollow fibers. Steps of the procedure included: a prior functionalization and application in ion-exchange chromatography. Ion exchange hollow fibers were, indeed, prepared reacting the cellulose with 1,4-butane sultone, and checked for proper functionalization by FTIR.
The ion-exchange fibers were primarily characterized in bind and elute mode using pure lysozyme solutions. The Tris buffer, chosen for equilibration and adsorption, was optimized in terms of molarity and pH.
The values of static binding capacity resulted in promising and comparable to that of the commercial ion-exchange membrane.
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Karlsson, Stefan. "Modification of Float Glass Surfaces by Ion Exchange". Doctoral thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-18447.
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Glass is a common material in each person’s life, e.g. drinking vessels, windows, displays, insulation and optical fibres. By modifying the glass surface it is possible to change the performance of the entire glass object, generally known as Surface Engineering. Ion exchange is a convenient technique to modify the glass surface composition and its properties, e.g. optical, mechanical, electrical and chemical properties, without ruining the surface finish of the glass. This thesis reports the findings of two different research tasks; characterisation of the single-side ion exchange process and the novel properties induced. The characterisation of the ion exchange process was mainly performed by utilising a novel analytical equipment: the Surface Ablation Cell (SAC), allowing continuous removal of the flat glass surface by controlled isotropic dissolution. SAC-AAS has provided concentration vs. depth profiles of float glass ion exchanged with K+, Cu+, Rb+ and Cs+. In addition, SEM-EDX has provided concentration vs. depth profiles of Ag+ ion exchanged samples and validation of a copper concentration vs. depth profile. From the concentration vs. depth profiles, the effective diffusion coefficients and activation energies of the ion exchange processes have been calculated. Depending on the treatment time and treatment temperature, penetration depths in the range of 5-10 μm (Rb+, Cs+), 20-30 μm (K+, Cu+) and 80-100 μm (Ag+) can be readily obtained. The effective diffusion coefficients followed the order Ag+>K+>Cu+>Rb+>Cs+. This is in accordance with the ionic radii for the alkali ions (K+<Rb+<Cs+) but reverse for the noble metal ions (Cu+<Ag+). The glass properties modified by single-side ion exchange have mainly been characterised by UV-VIS spectroscopy and flexural strength measurements. Cu+ and Ag+ ion exchange give rise to surface colouration, Cu+ copper-ruby and Ag+ yellow/amber. The surface-ruby colouration was found to depend on the residual tin ions in the tin-side of the float glass. The flexural strength was studied using the coaxial double ring-test method which also was suitable for holed specimens. The flexural strength of K+ ion exchanged float glass samples was found to substantially increase compared to untreated.
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Noutsios, Peter C. "Optical vertical couplers by ion exchange in glass". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40415.
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Planar and channel optical waveguides fabricated by field-assisted $K sp+$-$Na sp+$ ion exchange in soda-lime glass are studied. An optical characterization of planar surface guides for a given set of fabrication conditions has been performed to determine the refractive index profile. Parallel to this, the ion-exchange diffusion process has been modelled numerically to predict the concentration profile of these waveguides. Direct measurements of the profiles using electron microprobe analysis has been carried out.The results of the characterization were used in the design and fabrication of a novel vertically integrated optical directional coupler. This device, composed of single-mode surface and buried ion-exchanged waveguides, allows for the optical fiber coupling to the buried guide and efficient power transfer to the surface guide, where the light can be detected by a modelled $GaAs$ photodetector. An improved version of the device using a sputtered $Al sb2O sb3$ surface guide allows for edge coupling to the detector. Calculations of the $GaAs$ absorption coefficient show an optimum behavior for a given thickness of $Al sb2O sb3$.
An implicit finite-difference vector beam propagation method (FD-VBPM), that was improved to account for graded-index profiles, has been developed and used in the design of both directional-coupler structures. Finally, a three-dimensional FD-VBPM algorithm was implemented for the channel-guide version of the improved coupler.
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Leonard, Danièle. "Adsorption of bile acids by ion-exchange resins". Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74309.
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The interactions of cholestyramine with bile acids in aqueous buffer solutions were studied by in vitro adsorption experiments. Application of the Donnan theory, which is based on ion partitioning between two phases, indicates that the adsorption is an ion-exchange process--the bile acid anion displaces the chloride counter-ion of cholestyramine. Donnan considerations indicate that the bile acid in the resin phase exists in two forms, bound and unbound, but at higher Ceq the bound form is increasingly favoured. Since the concentrations of bound bile acid in the resin phase are above the critical micellar concentration, micelle-type ordering is occurring. It is also possible that the unbound bile acid in the resin phase aggregates to form "regular" micelles. The micellization promotes the partitioning of glycocholic acid into the resin phase, explaining the ability of cholestyramine to adsorb glycocholic acid significantly, in vitro.Ion-exchange resins were prepared by solid phase peptide synthesis with active sites chosen to resemble those of cholestyramine. They were produced by coupling 4-(aminomethyl)benzoic acid, 4-aminophenylacetic acid or 4-(aminomethyl)phenylacetic acid to the backbone. The ion-exchange resins were prepared both as primary amines and in the quaternized form. The cholestyramine-like sorbents were synthesized with systematic changes in the structure, to determine which structural parts of cholestyramine are involved in the adsorption process. As compared to cholestyramine, both sets of resins were remarkably ineffective in adsorbing bile acids in vitro. It was found that the nature of the backbone determines the accessibility to the active site; that the resins with the methylene group positioned between the phenyl group and the amino group have higher adsorption capacity for glycocholic acid; and that quaternization increases the adsorption capacity. The two latter observations indicate the importance of the basicity of the active site. Therefore, in cholestyramine, the backbone is such that it permits the transfer of ionic species and the quaternary ammonium group is involved in the interaction with bile acids.
Computer modelling showed that the cholestyramine pendants are close to one another and are separated by benzene rings, thus leaving too little space between them to allow a bile acid molecule to interact with the benzene rings. Therefore, the bile acids must interact with the quaternary ammonium group, leaving the bile acid molecule inside the cavity where they interact with one another to form micelles. The possible modes of interactions of bile acids with the synthesized resins are more numerous since the pendants are not as close together. (Abstract shortened by UMI.)
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Forster, Christine. "Aspects of charge exchange in ion-atom collisions". Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6189/.
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The straight line semi-classical Impact Parameter method has been modified for use with classical trajectories. Ion-atom collisions have been modelled using wavefunctions expanded in terms of atomic basis states which were centred on either the target or projectile ions. Total and differential charge exchange cross-sections are presented for (^4)He(^++) and (^4)He(^+) collisions within the centre of mass energy range 0.21 kev < E(_em) < 2.5 keV. Results using curved and straight line paths are compared with data from other authors. Significant trajectory effects were found at the lower energies in the range. The curved trajectory results were lower than those from the straight line model and also lower than previous calculations carried out. At higher energies in the range there was good agreement between straight line and curved trajectory models and previous work. Differential cross-sections were found to be sensitive to the trajectories employed, and comparisons have been made with previous work. Total, state specific and differential cross- sections for charge exchange are presented for Be(^++) and H collisions using a five state basis, within the centre of mass energy range 0.111 keV < E(_em) < 0.4444 keV. There was reasonable agreement between the straight line results and previous work. There were significant trajectory effects for all the final charge transfer states. Results are presented for low-energy collisions between positively charged muons and atomic hydrogen. An eight state basis has been used. Direct excitation cross sections for n = 2 atomic states and charge transfer cross sections to Is and n = 2 have been calculated. The effect on the cross sections of using different internuclear potentials has been examined. Trajectory effects were small for charge transfer to Is but were more pronounced in the direct excitation and charge exchange cross- sections to n = 2. These results have been compared to those obtained for curved trajectory H(^+) and H collisions at the same relative velocity, to assess the validity of velocity scaling. It was found that velocity scaling was reliable for charge transfer to Is and for total electron capture cross-sections. However, it was progressively inaccurate for direct excitation and for electron capture into excited states for µ(^+) impact energies of less than 300 eV. These results are discussed and suggestions for further work are made.
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Parker, Karen Elizabeth. "Calculating ion exchange parameters from pure clay assemblages". Thesis, University of Birmingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422780.
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Emms, Tony. "Ion exchange and separations in high silica zeolites". Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244886.
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Price, S. G. "Kinetics of ion exchange in a chelating resin". Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234132.
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Addo, Martin Adomako. "Developments in ion exchange media for protein separation". Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760580.
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Ntemi, Pascal Vitalis. "Taste masking of clarithromycin with ion exchange resins". Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/65178.
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Dzyazko, Yu S., L. N. Ponomareva, Yu M. Volfkovich, V. N. Belyakov, V. E. Sosenkin, N. F. Nikolskaya, N. N. Scherbatyuk i Yu A. Litvinenko. "Hybrid organic-inorganic nanocomposites for ion-exchange processes". Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20577.
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Two types of composite ion-exchangers, which are based on strongly acidic gellike cation-exchange resin and zirconium hydrophosphate, have been obtained. The first group contains both inorganic nanoparticles and their aggregates, the second one contains only aggregates. Analysis of differential porogrammes obtained with a method of standard contact porometry allowed us to estimate porous structure both of polymer
matrix and inorganic constituent. Each stripe of the porogrammes has been related to structure element of polymer and ZrPh. Geometrical globular model has been applied to estimate a size of nanoparticles. A size of the nanoparticle size was shown to depend on their location: it reaches 16 nm, if the globules are placed in clusters of the polymer matrix, and 36 nm for aggregated nanoparticles in macropores. The results have been
confirmed by data of scanning and transmission electron microscopy. Modification of ion-exchange resins causes transformation of porous structure of labile polymer matrix.
The transformation occurs both at nano- and micro-levels. Recommendations regarding to structure of composite ion-exchangers for different applications are given.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20577
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Amini, Adib. "The Sustainability of Ion Exchange Water Treatment Technology". Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6640.
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This research investigated using a life cycle environmental and economic approach to evaluate IX technology for small potable water systems, allowing for the identification and development of process and design improvements that reduce environmental impacts and costs. The main goals were to evaluate conventional IX in terms of life cycle environmental and economic sustainability, develop a method for improving designs of IX systems from a environmental and economic sustainability standpoint, evaluate potential design improvements, and make the research findings accessible to water professionals through user-friendly tools and frameworks that take into account their feedback. This research provides an understanding, from the perspective of life cycle environmental impacts and costs, of the tradeoffs between various reactor designs of IX, the effects of scale, key contributors to impact and cost, design trends that improve sustainability, and how combined cation anion exchange compares to conventional IX. Furthermore, tools were developed that can be used to identify design choices that improve sustainability of IX systems. These tools were made into a user-friendly format to better bridge the gap between research and practice.