Academic literature on the topic 'Sorption-membrane method of purification'
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Journal articles on the topic "Sorption-membrane method of purification"
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Bejanidze, Irina, Oleksandr Petrov, Volodymyr Pohrebennyk, Tina Kharebava, Nunu Nakashidze, Nato Didmanidze, Nazi Davitadze, and Anton Petrov. "Sorption of Organic Electrolytes and Surfactants from Natural Waters by Heterogeneous Membranes." Applied Sciences 10, no. 20 (October 21, 2020): 7383. http://dx.doi.org/10.3390/app10207383.
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The widespread use of surfactants increasingly requires the development and application of reliable methods for the demineralization of wastewaters, preventing environmental pollution. One of the most reliable and effective methods of demineralization of wastewaters is the electrodialysis method. Studying the behavior of large organic ions in the membrane is important for modeling cell membranes and purification of medicinal and biological preparations. The sorption characteristics of the MA-40 and MK-40 ion-exchange membranes in solutions of simple and organic electrolytes, and in a solution of the surfactant were investigated. It was found that the sorption of organic ions by membranes is mainly of an ion-exchange nature. The moisture content and elasticity of the membranes decreases in solutions of organic electrolytes, during the sorption of which the membrane becomes brittle. A study showed that in the solutions of organic electrolytes, the MA-40 membrane retains high electrochemical activity, while the MK-40 in a solution of the surfactant completely loses it. From the data obtained in this work, it is shown that organic ions do not present a hazard when water is desalted by electrodialysis, whereas sorption of surfactant ions leads to membrane poisoning.
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Busarev, Andrey, Irina Sheshegova, and Liliya Khisameeva. "Study of the processes of the purification of water from surface sources from petroleum products." E3S Web of Conferences 274 (2021): 08007. http://dx.doi.org/10.1051/e3sconf/202127408007.
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Recently, the amount of natural waters contaminated with petroleum products, which enter surface sources together with wastewater, has increased. Therefore, the issues of natural water purification of petroleum products are given great importance. Purification of natural waters from petroleum products is possible by sorption and ultrafiltration methods. Kazan State University of Architecture and Engineering conducted research on the purification of natural waters from petroleum products in adsorption filters using various sorbents, as well as membrane separators with ultrafiltration modules from various manufacturers. As a loading of sorption filters, it is recommended to use activated charcoal as a sorbent that is optimal in terms of price and quality of water purification. The membrane modules manufactured in Europe and the United States, have a high cleaning effect from petroleum products and a sufficiently high productivity. However, they are extremely expensive.
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Litynska, Marta, Tetiana Dontsova, Olena Yanushevska, and Volodymyr Tarabaka. "Development of iron-containing sorption materials for water purification from arsenic compounds." Eastern-European Journal of Enterprise Technologies 2, no. 10 (110) (April 30, 2021): 35–42. http://dx.doi.org/10.15587/1729-4061.2021.230216.
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The paper is devoted to the development of a method for obtaining and using iron-containing sorption materials for the effective removal of arsenic compounds of different oxidation states from an aqueous medium. It is known that arsenic compounds have a harmful effect on biota due to high toxicity. The paper theoretically and experimentally substantiates the choice of iron-containing materials as the main sorbent material for arsenic compounds removal from the aqueous medium. A series of iron-containing adsorbents, including powder, activated carbon-based granular and suspension sorbents, was synthesized by different methods (heterogeneous and homogeneous precipitation). Experimental studies have confirmed that the adsorption of arsenate ions on iron-containing sorption materials corresponds to the pseudo-second order of the reaction (R2=0.999), which is inherent in adsorption processes. It was determined that oxyhydroxide sorption materials obtained by the homogeneous precipitation demonstrate higher sorption activity (up to 70 mg/g for As(III) and over 70 mg/g for As(V)). It was found that activated carbon-based iron-containing sorption materials showed approximately 2 times lower efficiency than powder iron(III) oxide, iron(III) oxyhydroxide and amorphous iron(III) hydroxide. It was shown that the use of microfiltration membranes is promising for the removal of spent suspension iron-containing sorption materials. Experimental studies have confirmed that the use of the combination “fine-particle iron(III) oxyhydroxide/membrane” allows removing arsenic compounds from contaminated water to the sanitary requirements level (less than 10 μg As/l) and separating effectively the spent fine-particle sorbent from water
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STEPANOV, S. V., Yu E. STAShOK, and N. V. NOEV. "RESEARCHES ON BIOMEMBRANE PURIFICATIONAND DEMINERALIZATION OF WASTE WATERS AT SYZRAN OIL REFINERY." Urban construction and architecture 2, no. 1 (March 15, 2012): 55–58. http://dx.doi.org/10.17673/vestnik.2012.01.10.
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There are given the research results of biomembrane waste water purification at Syzran Oil Refinery and demineralization of biologically treated sewage waters by the method of reversible electrodialysis. We compared the purification efficiency on the membrane bioreactor with ethanol dosing (in order to get deeper denitrification) and without it and the purification without adding household drain as well. It is shown that biomembrane technology combined with sorption tertiary treatment makes it possible to meet the requirements of the Russian Federation norms to the quality of treated sewage. The results of the experiment on the demineralization of biologically treated sewage waters using the method of reversible electrodialysis are given. We have concluded that the recycle systems of the plant can be fed with demineralised desalted water.
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Safiddine, Leila, Hadj-Ziane Zafour, Ungarala Rao, and Issouf Fofana. "Regeneration of Transformer Insulating Fluids Using Membrane Separation Technology." Energies 12, no. 3 (January 24, 2019): 368. http://dx.doi.org/10.3390/en12030368.
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Oxidation of oil/paper insulation initiates premature aging and introduces carboxylic acids with eventual increase in oil acidity, which hampers the properties of the oil. In this paper, a membrane separation technology-based purification process for aged insulation oil has been evaluated and reported. The intent of the present study is to eliminate carboxylic acids, dissolved decay contents and other colloidal contamination present in aged oil and enhance the useful life of oil. The potential of the membrane treatment process has been demonstrated using Ultraviolet Visible Infrared Spectroscopy and Fourier Transform Infrared Spectroscopy diagnostic measurements for oil and membrane. Additionally, membrane retention properties like membrane flux, retention coefficient, sorption time and membrane mass have been analyzed to understand the treatment process. To further evaluate the performance of the membrane and effectiveness of the treatment process, acidity, dielectric dissipation factor, relative permittivity, and resistivity measurements of the oil before and after filtration have been also reported. The proposed membrane purification method has been tested for Algerian utility in-service oil samples. It is inferred that, membrane filtration method is a simple and effective method for treatment of aged oils and aids in extending the remnant life of the oil. The procedure is economically attractive because of increasing prices for transformer liquids, cost effective and environmentally sounds.
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Lokshin, Efroim P., Olga A. Tareeva, Tatyana A. Sedneva, and Irina R. Elizarova. "METHOD OF PHOSPHORIC ACID PRODUCTION BY SORPTION CONVERSION OF APATITE CONCETRATE IN PRESENCE OF SULPHOCATIONITE IN SODIUM OR POTASSIUM FORMS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 1 (December 10, 2019): 78–85. http://dx.doi.org/10.6060/ivkkt.20206301.5851.
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The aim of the work is the continuation of the development of a new efficient hydrochemical technology for the processing of apatite concentrate, which makes it possible to produce phosphoric acid with a reduced content of impurities as a product, to use all the valuable components of apatite concentrate. The dependence of the efficiency of decomposition of apatite concentrate with a phosphate acid solution at a temperature of 20 and 50 °C in the presence of sulfate cationite КУ-2-8чС in Na+- and K+ - forms was studied. The influence of the decomposition conditions (expense and form of sorbent, the ratio of liquid: solid, the interaction temperature) on the degree of decomposition of the concentrate, the completeness of absorption by the sorbent of the metallic cations of the concentrate, the content of impurities in the resulting phosphate-acid solution, and the composition of undissolved residues are studied. The possibility of achieving a high degree of decomposition of the concentrate (up to 99.5 %) is established. High sorption efficiency of calcium and strontium (up to 90.2 and 93.4 % respectively) is shown. The sorption of REE of the cerium group was better than the REE of the middle and yttrium groups. Increasing the temperature from 20 to 50 °C reduced REE sorption by 14-170%. Aluminum, thorium and uranium were the most difficult to sorb. It has been found that effective purification of phosphoric acid from the impurity of fluorine is achieved directly in the process of decomposition. The efficiency of purification from fluorine when using a sorbent in the K+ - form is greater than when using a sorbent in the Na+- form. It is shown that the obtained acid can be purified from sodium or potassium by the electrodialysis method in a two-chamber electrodialyzer equipped with a cation exchange membrane. It is found that before electrodialysis, preliminary purification of the phosphate solution from calcium, which is obtained during the decomposition of apatite concentrate, is necessary. To this purpose, an additional purification of the phosphoric acid solution by sulphocathionite sorption has been investigated. The lower sorption from the phosphoric acid solution of Al, Ti, Fe, Th, and U is explained by the formation of stable anionic complexes or undissociated molecules by these elements. The developed technology for the production of phosphoric acid from the apatite concentrate does not require the use of sulfuric acid, has a number of other advantages. The content of impurities in the resulting phosphoric acid is much less than in the extraction phosphoric acid produced by the sulfuric acid processing of apatite concentrate.
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Cheremisina, Olga, Tatiana Litvinova, Vasiliy Sergeev, Maria Ponomareva, and Julia Mashukova. "Application of the Organic Waste-Based Sorbent for the Purification of Aqueous Solutions." Water 13, no. 21 (November 4, 2021): 3101. http://dx.doi.org/10.3390/w13213101.
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The effective purification of large-capacity wastewater from heavy non-ferrous metals and organic pollutants using inexpensive sorption technology remains a crucial task. Analyzing the current objectives of sustainable development, biochar obtained from chicken manure has prospects as a source for sorption purification of industrial wastewater. To determine the characteristics of organic material and the composition of the initial and equilibrium phases, the following analysis methods were used: volumetric, complexometric, pH-metric, X-ray fluorescence, chromatographic, spectrophotometric, luminescence-photometric and X-ray diffraction. The thermal nitrogen desorption method was used for determining the specific surface area and pore sizes with the Quantachrome Nova 1000e automatic analyzer. The sorption properties of the reprocessing product of the fresh poultry manure were investigated in relation to organic and inorganic compounds: phenols, benzene, ketones, cations of lead, mercury, manganese and iron. Based on the results obtained, technical conditions were developed for the use of the reprocessed organic waste-based product as a sorption material for household, industrial and technological wastewater purification from organic and inorganic components.
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Chuntonov, Konstantin, and Man Kyu Lee. "Mechanochemical Sorption Apparatuses." Advanced Materials Research 875-877 (February 2014): 1106–10. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1106.
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A new method of sorbent activation by its mechanical grinding directly in the purified gas medium promises a technological breakthrough in the field of manufacturing and using of high purity gases. Simple design solutions and using reactive alloys as a sorbent allow making the gas purification process controllable and reducing the cost of this process by many times as well as reducing the concentration of the impurity in the end product.
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Обуздина, Marina Obuzdina, Руш, E. Rush, Шалунц, and L. Shalunc. "Sorption Purification of Effluent Water From Heavy Metal Ions by Modified Natural Zeolites." Safety in Technosphere 6, no. 2 (August 21, 2017): 56–61. http://dx.doi.org/10.12737/article_598d7af88ce043.55438902.
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Features of sorption method of effluent water purification are considered. Analysis of technologies of effluent water purification from heavy metalsionsis presented. Physico-chemical regularities of sorption of Zn, Ni, Cu ions are investigated. As sorbents it is proposed to use zeolites of Holinsky deposits, modified by sulfur polymer, obtained from waste of epichlorohydrin production. This will allow simultaneously solving two problems: elimination of waste and wastewater purification, which is significantly advantageous from the economic point of view. Kinetic curves of sorption of Zn, Ni, Cu ions in different solution concentrations are presented. Also the adsorption process of heavy metal ions from solutions of chemically modified zeolites in the evaluation of the influence of various factors (the contact time of sorbent with solution, pH and temperature) are investigated.
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Umirova, Nilufar. "Use of glauconite as a non-reagent sorbent for the softening of drinking and boiler waters, industrial waste water." E3S Web of Conferences 216 (2020): 01147. http://dx.doi.org/10.1051/e3sconf/202021601147.
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The article discusses the sorption of purification of water bodies from impurities using natural inorganic sorbents. The availability and low cost of minerals are an important economic advantage of their use for the purification of all types of water. The article describes a method of using an effective sorbent with high ion-exchange and sorption properties for purification of light oil products, for the purification of drinking or industrial water with a high content of heave technogenic metal ions and organic substances. Based on the data obtained, conclusions are drawn about the possibility of using the studied natural mineral sorbents for the extraction of impurities from waste and natural waters.
Dissertations / Theses on the topic "Sorption-membrane method of purification"
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Літинська, Марта Ігорівна. "Видалення сполук арсену та гуматів з водного середовища." Doctoral thesis, Київ, 2021. https://ela.kpi.ua/handle/123456789/40411.
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Дисертаційна робота присвячена розробці та науковому обгрунтуванню методу для ефективного видалення сполук арсену різних ступенів окиснення та гуматів з природних вод.
В дисертації теоретично (на основі літературних даних та розрахунків) та експериментально (в результаті сорбційних досліджень) обгрунтовано вибір сполук феруму, як основного сорбуючого компоненту для видалення сполук арсену з водного середовища. Різними способами (гетерогенне осадження, гомогенне осадження, гідротермальний метод) синтезовано ряд ферумвмісних сорбційних матеріалів, серед яких порошкові, зернисті на основі активованого вугілля та суспензійні сорбенти.
Визначено, що використання комбінації «дрібнодисперсний ферум(ІІІ) оксигідроксид/мембрана» дозволяє вилучати сполуки арсену з модельних та підземних вод до санітарних вимог за вихідних концентрацій арсену 500-16733 мкг/дм3 та відділяти відпрацьований дрібнодисперсний ферумвмісний сорбент від води і захищає мембрани від засмічування.
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MAIDOU, ERIC SIMON-PIERRE. "Extraction, concentration et conversion en acide lactique de lactate de sodium produit par fermentation de lactoserum." Rennes 1, 1988. http://www.theses.fr/1988REN10116.
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Saleh, Jehad. "A Membrane Separation Process for Biodiesel Purification." Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19730.
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In the production of biodiesel via the transesterification of vegetable oils, purification to international standards is challenging. A key measure of biodiesel quality is the level of free glycerol in the biodiesel. In order to remove glycerol from fatty acid methyl ester (FAME or biodiesel), a membrane separation setup was tested. The main objective of this thesis was to develop a membrane process for the separation of free glycerol dispersed in FAME after completion of the transesterification reaction and to investigate the effect of different factors on glycerol removal. These factors included membrane pore size, pressure, temperature, and methanol, soap and water content.
First, a study of the effect of different materials present in the transesterification reaction, such as water, soap, and methanol, on the final free glycerol separation was performed using a modified polyacrylonitrile (PAN) membrane, with 100 kD (ultrafiltration) molecular weight cut off for all runs at 25°C. Results showed low concentrations of water had a considerable effect in removing glycerol from the FAME. The mechanism of separation of free glycerol from FAME was due to the removal of an ultrafine dispersed glycerol-rich phase present in the untreated (or raw) FAME. The size of the droplets and the free glycerol separation both increased with increasing water content of the FAME.
Next, three types of polymeric membranes in the ultrafiltration range with different molecular weight cut off, were tested at three fixed operating pressures and three operating temperatures (0, 5 and 25oC) to remove the free glycerol from a biodiesel reactor effluent. The ASTM standard for free glycerol concentration was met for the experiments performed at 25°C. The results of this study indicate that glycerol could be separated from raw FAME to meet ASTM and EN standards at methanol feed concentrations of up to 3 mass%. The process was demonstrated to rely on the formation of a dynamic polar layer on the membrane surface.
Ceramic membranes of different pore sizes (0.05 µm (ultrafiltration (UF) range) and 0.2 µm (microfiltration (MF) range)) were used to treat raw FAME directly using the membrane separation set up at temperatures of 0, 5 and 25°C. The results were encouraging for the 0.05 µm pore size membrane at the highest temperature (25°C). The effect of temperature on glycerol removal was evident from its relation with the concentration factor (CF). Higher temperatures promoted the achievement of the appropriate CF value sooner for faster separation. Membrane pore size was also found to affect separation performance.
A subsequent study revealed the effect of different variables on the size of the glycerol droplets using dynamic light scattering (DLS). A key parameter in the use of membrane separation technology is the size of the glycerol droplets and the influence of other components such as water, methanol and soaps on that droplet size. The effect of water, methanol, soap and glycerol on the size of suspended glycerol droplets in FAME was studied using a 3-level Box-Behnken experimental design technique. Standard statistical analysis techniques revealed the significant effect of water and glycerol on increasing droplet size while methanol and soap served to reduce the droplet size.
Finally, a study on the effect of trans-membrane pressure (TMP) at different water concentrations in the FAME phase on glycerol removal using UF (0.03 µm pore size, polyethersulfone (PES)) and MF (0.1 and 0.22 µm pore sizes, PES) membranes at 25, 40 and 60°C was performed. Results showed that running at 25°C for the two membrane types produced the best results for glycerol removal and exceeded the ASTM and EN standards. An enhancement of glycerol removal was found by adding small amounts of water up to the maximum solubility limit in biodiesel. An increase in temperature resulted in an increase in the solubility of water in the FAME and less effective glycerol removal. Application of cake filtration theory and a gel layer model showed that the gel layer on the membrane surface is not compressible and the specific cake resistance and gel layer concentration decrease with increasing temperature. An approximate value for the limiting (steady-state) flux was reported and it was found that the highest fluxes were obtained at the lowest initial water concentrations at fixed temperatures.
In conclusion, dispersed glycerol can be successfully removed from raw FAME (untreated FAME) using a membrane separation system to meet the ASTM biodiesel fuel standards. The addition of water close to the solubility limit to the FAME mixture enables the formation of larger glycerol droplets and makes the separation of these droplets straightforward.
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Seira, Jordan. "Rôle de la sorption et de la biodégradation dans l'élimination de micropolluants par des procédés d'épuration biologique : application aux molécules anticancéreuses traitées par bioréacteur à membrane." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/9704/1/seira_jordan.pdf.
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Les travaux de recherche effectués dans le cadre de ce travail de thèse ont eu pour objectif de caractériser le rôle joué par les mécanismes de sorption et de biodégradation dans l’élimination de micropolluants organiques par les boues biologiques, et notamment celles de bioréacteur à membrane. La première étape a consisté en la mise au point d’une méthode d’analyse de molécules anticancéreuses depuis les phases aqueuse et solide des boues. L’extraction des molécules contenues dans la phase aqueuse a été réalisée par une combinaison de cartouches SPE permettant la récupération sélective d’espèces acides, neutres et basiques. L’extraction depuis la phase solide a été rendue possible grâce à l’utilisation de la technique sous solvant pressurisé et à chaud PLE, suivie par une étape de purification directement inspirée de la méthode développée pour la phase aqueuse. Une procédure originale de préparation d’échantillons de boues a été proposée pour estimer rigoureusement le phénomène de sorption. Le modèle de Freundlich est celui qui a donné les corrélations les plus satisfaisantes et a été sélectionné. La détermination des paramètres du modèle a mis en évidence des comportements de sorption différents pour les molécules ciblées, mais toujours caractérisés par des aptitudes de sorption faibles. La mise en relation des propriétés physico-chimiques des molécules, des boues et des paramètres de sorption n’a pas révélé de corrélations évidentes entre ces différents paramètres et ne permet pas de proposer de modèle capable de prédire la sorption en fonction des caractéristiques des boues et des polluants. La caractérisation du comportement d’un cocktail d’anticancéreux lors du traitement par un pilote de bioréacteur à membrane externe a révélé que le mécanisme majeur à l’origine de leur élimination était la biodégradation. Les interactions entre les microorganismes et les micropolluants ciblés sont liées au cométabolisme. Une étude approfondie du mécanisme a révélé que ces mêmes interactions étaient à l’origine d’une limitation de la biodégradation et doivent être intensifiées pour améliorer les performances de traitement sur ce point.
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Wu, Chen-Han, and 吳承翰. "Purification and Differentiation of Human Adipose-derived Stem cells by Membrane Filtration Method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/67816087655015721167.
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碩士國立中央大學
化學工程與材料工程研究所
100
Adipose-derived stem cells (ADSCs) are a promising cell source in regenerative medicine, of particular utility for cell therapies and tissue engineering, because adipose tissue can easily be harvested in large quantities compared to bone marrow, and ADSCs have high proliferation rates in culture. ADSCs are isolated from adipose tissue by liposuction and centrifugation followed by cultivation on cell culture dishes for at least one passage. The cultivation of cells derived from adipose tissue is necessary to purify ADSCs (i.e., “the culture method” for the purification of ADSCs) because the adipose tissue contains not only ADSCs but also adipose and other types of cells. The culture process for the purification of ADSCs requires several days, at minimum. If ADSCs can be purified from adipose tissue in a short period of time (i.e., less than 2 hrs) by using a cell purification device such as the membrane filtration method, cell therapy and tissue engineering applications using autologous ADSCs might become more efficient. Therefore, we investigated the purification of human ADSCs from a digested solution of adipose tissue by the membrane filtration method in this study, and we compared the purity of ADSCs and the differentiation ability of ADSCs into osteoblasts after purification by the membrane filtration method and the conventional cell culture method. We investigated two filtration methods to purify hADSC, i.e., batch-type and perfusion-type filtration methods. Main differences between these two filtration methods are cell flow direction to the membranes. Polyurethane foaming membranes having 5-12 μm of pore size were used as the membranes for the separation of hADSCs from human adipose tissue. The surface marker of ADSCs (e.g., CD73 and CD90) in the cells in the permeate and recovery solutions were analyzed by flow cytometry whether the mesenchymal stem cells were enriched after permeation through the membranes. The differentiation of cells into osteoblasts, which were separated by the membrane filtration method was evaluated to confirm the enriched hADSC in the permeate solution through the membranes by culture of the cells in induced medium of osteogenic differentiation. We, further, investigated the isolation of ADSCs by the membrane filtration method through surface-modified PU membranes having with various nanosegments (e.g., -NH2, -SO3H, -OH, and -COOH) and ECMs, and compared the isolation efficiency of ADSCs purified through nonmodified PU membranes and surface-modified PU membranes. We found that the cells separated through PU membranes by the perfusion method showed high popuration of ADSCs from surface marker analysis and the highest osteogenic differentiation ability.
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Chen, Li-Yu, and 陳俐伃. "Purification and Differentiation of Human Adipose-Derived Stem Cells through Silk Screen/PLGA Hybrid Membranes by Membrane Filtration Method." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/50498965500078257344.
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碩士國立中央大學
化學工程與材料工程學系
101
Human adipose-derived stem cells (hADSC) represent one of the most promising cell candidates in the field of regenerative medicine, it can easily be extracted in large amount compared to bone marrow stem cells and also exhibits a higher proliferation rate in the medium. Furthermore, hADSCs also have a high differentiation capability into mesoderm (muscle, bone, and cartilage) and ectoderm (nerves and epidermal). The cultivation of adipose tissue cells generates hADSCs with contamination of several other types of cells. Therefore, it is necessary to purify hADSCs before using hADSCs for clinical applications. Purification of hADSCs via the cell culture process requires 5-12 days by using the conventional culture method. In this study, we developed a membrane filtration method to purify hADSCs using novel membranes where the operation time is less than 30 min to purify hADSCs from adipose tissue solution. We prepared silk screen/PLGA hybrid membranes (scaffolds) by a freeze drying method where silk screens (170 mesh size) are natural and readily biodegradable protein fibers to be used for reinforcement of the membranes. PLGA has biodegradability and biocompatibility to be used to generate a sponge pore morphology of the membranes. The average pore size of the silk screen/PLGA hybrid membranes was measured to be 3.5-7µm from scanning electron microscopy. After the preparation of home-made silk screen/PLGA hybrid membranes, we investigated the purification of hADSCs from adipose tissue solution (adipose tissue-derived stromal vascular fraction [SVF]) having different cell density by the membrane filtration method and evaluated the purification efficiency of hADSCs. The mesenchymal stem cell (MSC) markers such as CD44, CD73, and CD90 expressed by hADSCs were less than 10% in the adipose tissue solution (SVF), whereas the MSC markers in the permeate solution were found to be 30-50%, indicating hADSCs were concentrated after permeation through the silk screen/PLGA hybrid membranes, when 9 ml of the adipose tissue solution having 1×106 cells/ml was permeated through the membranes. The MSC markers of the cells after 12 days of culture of the adipose tissue solution (hADSCs purified by the conventional culture method) were found to be 60-80%. The efficiency of hADSC purification in the permeation solution through the silk screen/PLGA hybrid membranes analyzed by MSC markers depended on the cell density of the adipose tissue solution. Currently 1×106 cells/ml was the optimal cell density compared to 2×106 cells/ml or 4×106 cells/ml when 9 ml of adipose tissue solution was used. It was demonstrated that more than two fold higher osteogenic gene expression, Alizarin red staining, and von Kossa staining was observed in the permeate solution compared to the adipose tissue solution (SVF) when the cells were cultured in osteogenic induction medium for 28 days. Therefore, the hADSCs were purified in the permeation solution and demonstrated a superior capacity for osteogenic differentiation than the cells in the adipose tissue solution (SVF). The polyurethane foaming membranes having pore size of 11 µm could not purify hADSCs in the permeate solution. This result indicates that the pore size and membrane material are important factors to purify the hADSCs by the membrane filtration method. It is concluded that the hADSCs can be easily isolated through the permeation through the silk screen/PLGA hybrid membranes, whereas non-hADSCs are blocked by the sieving effect of the membrane pore size and/or adhered on the membranes.
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Chuang, Kuo-Liang, and 莊國良. "Preparation of PPO/Silica mixed matrix membrane through in-situ sol-gel method for H2 purification and CO2 capture." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27621316459183464147.
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碩士國立中興大學
環境工程學系所
101
Mixed matrix membranes (MMMs) are considered as a potential candidate for membrane separation techniques due to their attractive mechanical strength, thermal stability and superior perm-selectivity properties. In general, the MMMs consist of organic polymer and inorganic particle phases. However, the permselectivity properties of MMMs are greatly influenced by both the dispersing degree of nano-particles in the continuous phase (polymers) and the interfacial adhesion between the inorganic and organic components. Therefore, the problems MMMs faced are challenging to achieve an optimized interface structure and forming composite membrane with an ultrathin and defect-free mixed matrix skin by novel preparation technology. In this study, the PPO-silica MMMs was synthesized through in-situ sol-gel method, and the effect of silica loading weight and heat treatment on the gas separation performance was investigated. The gas permeation was studied and the morphological, crystalline structure, thermal stability, and functional group of MMMs was obtained using SEM, TGA, XRD, and FTIR, respectively. The results indicate that using in-situ sol-gel method to synthesize PPO-silica MMMs is beneficial for improving nano-filler dispersion. The permeability towards H2, CO2, O2, N2, and CH4 can be enhanced without increasing selectivity slightly. Further, an improvement in adhesion between both phase and crystal structure of the polymer matrix has been observed by the recrystallization process after heat treatment, which is beneficial for diffusivity of lower molecular weight of gas components. Thus, an enhanced H2 permeability from 51.26 to 117.78 GPU and the H2/CO2 separation ratio ca. 3.6 was observed from 5 wt. % PPO-silica MMMs.
Books on the topic "Sorption-membrane method of purification"
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Ksenofontov, Boris. Biological wastewater treatment. ru: INFRA-M Academic Publishing LLC., 2020. http://dx.doi.org/10.12737/1013710.
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The training manual sets out the theoretical and practical foundations of biological wastewater treatment in both natural and artificial conditions. For in-depth study of the fundamentals of biological wastewater treatment is quite detailed sections on the basics of Microbiology. Much attention is paid to choosing the best technologies of biological wastewater treatment with effective methods of nutrient removal. In the expanded version of the methods of biological purification of wastewater using membrane bioreactors. Are extensively explored domestic and foreign experience of biological treatment of municipal and industrial wastewater.
Meets the requirements of Federal state educational standards of higher education of the last generation.
Intended for students of bachelor, master, PhD students, teachers and professionals interested in the methods of sewage purification, and it is recommended to study for the enlarged group of specialties and areas 20.00.00 "Technosphere safety and environmental engineering".
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Membrane-active peptides: Methods and results on structure and function. La Jolla, Calif: International University Line, 2009.
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Wilbert, Michelle Chapman. Evaluation of methods for monitoring the integrity of reverse osmosis membrane systems. Denver, Colo: U.S. Dept. of the Interior, Bureau of Reclamation, 2000.
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Selinsky, Barry S. Membrane Protein Protocols: Expression, Purification, and Characterization (Methods in Molecular Biology). Humana Press, 2003.
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Methods and Results in Crystallization of Membrane Proteins (Iul Biotechnology, 4). International Unversity Line, 2003.
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(Editor), A. Azzi, U. Brodbeck (Editor), and P. Zahler (Editor), eds. Membrane Proteins: A Laboratory Manual. Springer, 1987.
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Membrane Proteins: A Laboratory Manual. Springer, 1987.
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1946-, Miller Christopher, ed. Ion channel reconstitution. New York: Plenum Press, 1986.
Find full textBook chapters on the topic "Sorption-membrane method of purification"
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Albertsson, Per-Åke, Bertil Andersson, Christer Larsson, and Hans-Erik Åkerlund. "Phase Partition-A Method for Purification and Analysis of Cell Organelles and Membrane Vesicles." In Methods of Biochemical Analysis, 115–50. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2006. http://dx.doi.org/10.1002/9780470110485.ch2.
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Graeber, Elisabeth, and Volodymyr M. Korkhov. "Affinity Purification of Membrane Proteins." In Methods in Molecular Biology, 129–37. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0373-4_9.
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Rothnie, Alice J. "Detergent-Free Membrane Protein Purification." In Methods in Molecular Biology, 261–67. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3637-3_16.
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Kurien, Biji T. "Membrane Strip Affinity Purification of Autoantibodies." In Methods in Molecular Biology, 257–67. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2694-7_27.
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Byrne, Bernadette. "Expression, purification, and crystallisationof membrane proteins." In Evolving Methods for Macromolecular Crystallography, 11–23. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6316-9_2.
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Nie, Jing, and Duanqing Pei. "Expression and Purification of Membrane-Type MMPs." In Methods in Molecular Biology, 99–110. Totowa, NJ: Humana Press, 2010. http://dx.doi.org/10.1007/978-1-60327-299-5_6.
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Smith, Sinéad M. "Strategies for the Purification of Membrane Proteins." In Methods in Molecular Biology, 389–400. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6412-3_21.
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Smith, Sinead Marian. "Strategies for the Purification of Membrane Proteins." In Methods in Molecular Biology, 485–96. Totowa, NJ: Humana Press, 2010. http://dx.doi.org/10.1007/978-1-60761-913-0_29.
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Kurien, Biji T., and R. Hal Scofield. "Purification of Tryptic Digests on Polyvinylidene Difluoride Membrane." In Methods in Molecular Biology, 273–77. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-2718-0_28.
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King, Martin S., and Edmund R. S. Kunji. "Expression and Purification of Membrane Proteins in Saccharomyces cerevisiae." In Methods in Molecular Biology, 47–61. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0373-4_4.
Full textConference papers on the topic "Sorption-membrane method of purification"
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Ilin, Vadim A., Yury V. Karlin, Sergey A. Dmitriev, Natalya G. Belyanina, and Vera Eu Makeeva. "Comparative Testing of New Sorbents for LRW Purification." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4537.
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Sorption of radionuclides from various liquid radioactive wastes (LRW) is almost a traditional method, which is usually applied while developing technologies for LRW purification. There are a great number of sorbents of different kind and sorption properties, but research in developing new types of sorbents with high functional properties is still in actual state. Especially it is very important for LRW purifying technologies, which apply sorption-membrane scheme of purification. This paper is devoted to the comparative testing of new sorbents (biosorbent, fitosorbent, modified natural zeolite, and synthetic sorbent on the base of barium sulfate and some others). The aim of this testing is to determine the main properties of new sorbents and to compare them with some well-known and industrially applied ones, for example, ion exchange resins, natural zeolites and some others. All the experiments were conducted with applying real LRW and namely, radioactive evaporation bottoms from Physical Energy Institute of Obninsk town (Kaluga region) and radioactive aqueous solution from near-surface solid radioactive waste (SRW) repository drainage system of Zagorsk (Sergiev Posad town of Moscow region) branch of Moscow SIA “Radon”. Distribution coefficients of some α-, β-, γ- radionuclides at sorption in static and dynamic conditions were obtained for studied sorbents. Conclusions and some recommendations on applying the studied sorbents have been done.
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URBANAS, David, and Liudmyla MELNYK. "DESIGN OF THE REGENERATION METHOD OF HYDROXYL-CONTAINING ZIRCONIUM COMPOUNDS IN PROCESSES OF WATER PURIFICATION FROM BORON." In Conference for Junior Researchers „Science – Future of Lithuania“. VGTU Technika, 2017. http://dx.doi.org/10.3846/aainz.2017.020.
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The regeneration method of zirconium hydroxide sorbent spent in the boron sorption process by diluted solution of acids as well as the principle recycling diagram of the formed regenerating solution by the nanofiltration process with the OPMN-P membrane were proposedin this work. The permeate obtained can be used as a boron-containing microfertilizer (ammonium salt + boron) after it has been neutralised with ammonium hydroxide. Zirconium-containing concentrate may be reused for sorbent preparation. The effectiveness of separation of the regenerating solution components by nanofiltration is demonstrated by high values of zirconium rejection coefficient in this process (RZr ~98– 99%) and low values of boron rejection coefficient (RB ~12%). In this case the specific performance of the membrane is about 50 dm3/m2·h.
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Lin, Yamin, Mengmeng Zheng, Jiamin Gao, Xin Zhao, Wei Gong, Yun Yu, and Juqiang Lin. "A serum analysis method combining membrane protein purification with surface-enhanced Raman spectroscopy for noninvasive prostate cancer detection." In Optics in Health Care and Biomedical Optics XI, edited by Qingming Luo, Xingde Li, Ying Gu, and Dan Zhu. SPIE, 2021. http://dx.doi.org/10.1117/12.2600128.
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Alrehili, Mohammed, Mustafa Usta, Nawaf Alkhamis, Ali Anqi, and Alparslan Oztekin. "Gas Separation by Using Spiral Wound Membrane." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51852.
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Spiral wound membrane is used in several industrial purification processes such as desalination, food industries and gas separation. It has been shown that membrane performance could be greatly enhanced by momentum mixing in the feed channel induced by spacers. Square shaped spacers will be considered in inline geometries for the Reynolds number, Re, of 300 and 500. A separation of CO2 from CH4 will be investigated. A computational fluid dynamics simulation will be conducted for flows of a binary mixture of CO2 and CH4. The mass flux through the membrane will be determined based on the local partial pressures of each species, the permeability, and the selectivity of the membrane. Shear Stress Transport turbulence model will be employed to capture the steady state velocity and concentration field. The transient effect on the momentum mixing will be studied using lattice Boltzmann method. Two dimensional nine velocity directional, D2Q9, lattice arrangement with multi-relaxation time (MRT) lattice Boltzmann method is used to simulate transient flow field while single relaxation time (SRT) lattice Boltzmann method is employed to simulate concentration field for Re = 100 and 300. The bounding surfaces are treated as impermeable walls for simulations conducted using the lattice Boltzmann method. The results predicted by lattice Boltzmann and SST turbulence model agree well.
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Bienz, D., T. Wager, and K. J. Clemetson. "ISOLATION AND CHARACTERIZATION OF HUMAN PLATELET MEMBRANE GLYCOPROTEINS Ia AND IIa." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643910.
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Glycoproteins (GP) Ia and IIa are relatively minor components of the platelet surface with similar molecular properties. Nieuwenhuis et al. (Nature 319, 470-72, 1985) described a patient whose platelets show no response to collagen. The correlating lack of GPIa in the platelets of this patient suggests this glycoprotein being the receptor for collagen. Santoro (Cell, 46, 913-20, 1986) described a 160 kDa glycoprotein that binds to collagen in the presence of MG2 + and is possibly identical with GPIa. The role of GPIIa is still unknown but a similar molecule has also been found on endothelial cells. It has been suggested that GPIa and GPIIa are complexed with a further membrane component GPIc. The two glycoproteins show only slight difference in molecular weight, isoelectric point and in their affinity for various lectins. As a result they coisolate using most separation techniques.GPIa is usually associated with the cytoskeleton while GPIIa is mostly found in the soluble phase. GPIa is dissociated from the cytoskeleton by addition of 2% SDS (final conc.) and sonication. Performing Triton X-114 phase partition, GPIIa is found in the detergent phase. After the detergents of the GPIa and GPIIa enriched protein solutions are exchanged with the non-ionic octanoyl-N-methyl glucamide, the glycoproteins are further purified by affinity chromatography on wheat germ agglutinin-Sepharose followed by Lens culinaris lectin-Sepharose both of which bind GPIa and GPIIa. A major contaminant during the purification is GPIb. Final purification of GPIa and GPIIa was obtained by preparative SDS-PAGE using electroelution into a membrane trap. Latest results show an enrichment of GPIa and a lack of GPIb in pseudopodes, isolated by the method of Rotman et al. (Proc. Natl. Acad. Sci. USA, 4357-61, 1982).
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Zhang, Zhien, Yunfei Yan, Junlei Wang, Li Zhang, Yanrong Chen, and Shunxiang Ju. "Analysis of CO2 Capture From Power-Plant Flue Gas Using the Membrane Gas Absorption (MGA) Method." In ASME 2015 Power Conference collocated with the ASME 2015 9th International Conference on Energy Sustainability, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/power2015-49026.
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Currently membrane gas absorption (MGA) is a novel approach for gas separation. In the present work, a wide-ranging 2D mathematical model for CO2 absorption from the N2/CO2 mixture is proposed. Single solvents [H2O, ethylenediamine (EDA), diethanolamine (DEA), monoethanolamine (MEA), piperazine (PZ)] and blended solvents [DEA/PZ] were used as the absorbents. The non-wetting mode for the membrane contactor was considered in the calculations. The effects of gas concentration and velocity, and liquid concentration and velocity on CO2 removal were observed. The simulation results were verified with the experimental data showing a good agreement. The modeling results indicate that gas concentration and velocity have a negative effect on the capture process, while liquid concentration and velocity enhance CO2 capture. Also, it is noted that PZ has the best absorption performance than other single absorbents. The chemical solvents are much better than the physical solvent for the absorption of CO2. For mixed absorbents based on amine solutions, the CO2 removal efficiency could be about 20% higher than that of the single solutions. Thus, this model could provide the optimum operating conditions for acid gas absorption in the hollow fiber membrane module. It is also proved that the MGA approach exhibits a good potential in power-plant waste gas purification.
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Wicki, A. N., A. Walz, and K. J. Clemetson. "IDENTIFICATION OF GLYCOPROTEIN lb IN “IN VITRO” TRANSLATES FROM ISOLATED HUMAN PLATELET mRNA." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643628.
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Platelet membrane glycoproteins play a crucial role in platelet adhesion and activation. To understand how they function it is of great importance to know their amino acid sequences and structures. It is rather difficult to purify membrane glycoproteins in amounts that are sufficient to determine their amino acid sequences by protein sequencing techniques. The easier way seems to be molecular cloning of the genes for these proteins.Metabolically stable mRNA derived from nucleated megakaryocytes is known to be present in the anuclear human platelets. We have developed a purification method for the isolation of platelet mRNA. Starting with 100 units of blood platelets we isolated 0.5 mg of mRNA by guanidine chloride/lithium chloride/phenol extraction. Crude mRNA as well as oligo-dT purified, polyadenylated mRNA, was assayed for protein synthesis in a reticulocyte lysate translation system in the presence of different labelled amino acids. SDS-PAGE of nonreduced and reduced samples of the translation products showed molecular masses up to at least 200 kDa. Immunoprecipitation and affinity column chromatography with poly- and monoclonal anti platelet glycoprotein lb antibodies showed that a protein with a molecular mass of 60 kDa crossreacting immunologically with glycocalicin is specifically recognized by these antibodies. The 60 kDa protein seems to be the nonglycosylated form of GPIbケ.
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Oviroh, Peter Ozaveshe, Sunday Temitope Oyinbo, Sina Karimzadeh, and Tien-Chien Jen. "Multilayer Separation Effects on MoS2 Membranes in Water Desalination." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-69156.
Full textAbstract:
Abstract Climate change and its related effects are imposing severe stress on the current freshwater supplies. This has been exacerbated due to the growth in population, rapid industrialization, and increased energy demand. Increased water requirement is a global challenge. Although more than 70% of the Earth is covered by water, much of it is unusable for human use. Freshwater reservoirs, ponds, and subterranean aquifers account for just 2.5% of the world’s overall freshwater availability. Unfortunately, these water supplies are not very unevenly spread. Therefore, the need to augment these supplies through the desalination of seawater or brackish water. Reverse osmosis (RO) is currently the most widespread method of desalination. However, the unit cost of water is still high partly due to the thin-film composite (TFC) polymer membranes used in the current desalination system. Thus the need for low-cost nanomaterials for Water Desalination and Purification. A promising way to meet this demand is to use two-dimensional (2D) nanoporous materials such as graphene and MoS2 to minimize energy consumption during the desalination process. New nanotechnology methodologies that apply reverse osmosis have been developed. Among some of these technologies is using 2D materials such as graphene and MoS2, which have been studied extensively for water desalination. Single-layer nanoporous 2D materials such as graphene and MoS2 promises better filtrations in the water channel. Although single-layer MoS2 (SL_MoS2) membrane have much promise in the RO desalination membrane, multilayer MoS2 are simpler to make and more cost-efficient. Building on the SL_MoS2 membrane knowledge, we have used the molecular dynamics method (MD) to explore the effects of multilayer MoS2 in water desalination. This comparison is made as a function of the pore size, water flow rate and salt rejection. In addition, we also looked at the effect of the increased interlayer spacing between layers of the nanoporous 2D membrane and then made the comparison. The ions rejection follows the trend trilayer> bilayer> monolayer from results obtained, averaging over all three membrane types studied for the MoS2, the ions rejection follows the trend trilayer > bilayer > monolayer. We find that the thin, narrow layer separation plays a vital role in the successful rejection of salt ions in bilayers and trilayers membranes. These findings will help build and proliferate tunable nanodevices for filtration and other applications.
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Ilin, V., Yu Karlin, A. Laurson, Eu Volkov, and S. Dmitriev. "Possible Approach to Cleaning “Problematic” LRW With Large Contents of Suspended Particles, Oils and Other Organic Substances." In The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7146.
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A general structural scheme for cleaning “problematic” liquid radioactive wastes (LRW) containing a large amount of suspended particles, oils and other organic substances has been proposed. The technological scheme includes two main stages: 1) separation of suspended particles, oil product emulsions and the larger part of colloidal particles from LRW by filtration, 2) purification of radioactive waters from radionuclides by membrane-sorption to the levels of radiation safety norms applied. The filtration stage is considered as a three-step process of “problematic” LRW treatment including: 1) “problematic” LRW extraction from storage tanks with a robot type device intended for washing out the bottom sediment (slurry), 2) separation of suspended particles, oil product emulsions and larger part of colloidal particles from LRW by filtration through porous or gauze diaphragms of 0.1 to 10 μm pores (cells) in size, 3) concentration of separated slurry up to 100–200 g/l. Two main options of the membrane-sorption technologies, AQUA-EXPRESS and Reverse Osmosis, for LRW purification have been considered. Two possible options of porous or gauze diaphragms productivity and lifetime increase between their surface regenerations have been shown: 1) possibility of an oxidizer introduction into initial LRW, 2) possibility to rotate a filtering element (disk or cylinder type).
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Emori, Kanako, Tatsuma Miura, and Akio Yonezu. "Large Deformation Behavior of Porous Polymer Materials With 3D Random Pore Structure: Experimental Investigation and FEM Modeling." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-11143.
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Abstract This study investigates the deformation behavior of porous polymer materials with 3D random pore structure. The test sample has sub-micron-sized pores with an open cellular structure, which plays a critical role for water purification. The base polymer is PVDF (polyvinylidene difluoride). First, the surface and cross section of the sample are observed using FESEM to investigate the microstructure (cell size and geometry of the cell ligament, etc). Next, uni-axial tensile loading is carried out for polymeric membrane and it is found that the membranes underwent elasto-plastic deformation. In order to establish a numerical model, finite element metod (FEM) is employed. Using a software of Surface Evolver, 3D random pore structure is created in the representative volume element (RVE). The established computational model can predict both elastic deformation and plastic deformation. Furthermore, viscoplastic deformation behavior (i.e. time-dependent deformation and creep deformation) is investigated, experimentally and numerically. In particular, creep compliance is measured, and we investigate the effect of applied loading on creep deformation behavior. Using the time–temperature–stress superposition principle (TTSSP), we obtain a new master curve, which covers higher stress level, and successfully establish an FEM model of creep deformation of the test sample. The present model enables the prediction of the macroscopic and microscopic deformation behavior of the porous materials, by taking into account of 3D random pore structure.
Reports on the topic "Sorption-membrane method of purification"
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Husson, Scott M., Viatcheslav Freger, and Moshe Herzberg. Antimicrobial and fouling-resistant membranes for treatment of agricultural and municipal wastewater. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598151.bard.
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This research project introduced a novel membrane coating strategy to combat biofouling, which is a major problem for the membrane-based treatment of agricultural and municipal wastewaters. The novelty of the strategy is that the membrane coatings have the unique ability to switch reversibly between passive (antifouling) and active (antimicrobial) fouling control mechanisms. This dual-mode approach differs fundamentally from other coating strategies that rely solely on one mode of fouling control. The research project had two complementary objectives: (1) preparation, characterization, and testing of dual-mode polymer nanolayers on planar surfaces and (2) evaluation of these nanolayers as membrane modifiers. The first objective was designed to provide a fundamental understanding of how polymer nanolayer chemistry and structure affect bacterial deposition and to demonstrate the reversibility of chemical switching. The second objective, which focused on membrane development, characterization, and testing, was designed to demonstrate methods for the production of water treatment membranes that couple passive and active biofouling control mechanisms. Both objectives were attained through synergistic collaboration among the three research groups. Using planar silicon and glass surfaces, we demonstrated using infrared spectroscopy that this new polymer coating can switch reversibly between the anti-fouling, zwitterion mode and an anti-microbial, quaternary amine mode. We showed that switching could be done more than 50 times without loss of activity and that the kinetics for switching from a low fouling zwitterion surface to an antimicrobial quaternary amine surface is practical for use. While a low pH was required for switching in the original polymer, we illustrated that by slightly altering the chemistry, it is possible to adjust the pH at which the switching occurs. A method was developed for applying the new zwitterionic surface chemistry onto polyethersulfone (PES) ultrafiltration membranes. Bacteria deposition studies showed that the new chemistry performed better than other common anti-fouling chemistries. Biofilm studies showed that PESultrafiltration membranes coated with the new chemistry accumulated half the biomass volume as unmodified membranes. Biofilm studies also showed that PES membranes coated with the new chemistry in the anti-microbial mode attained higher biofilm mortality than PES membranes coated with a common, non-switchablezwitterionic polymer. Results from our research are expected to improve membrane performance for the purification of wastewaters prior to use in irrigation. Since reduction in flux due to biofouling is one of the largest costs associated with membrane processes in water treatment, using dual-mode nanolayer coatings that switch between passive and active control of biofouling and enable detachment of attached biofoulants would have significant economic and societal impacts. Specifically, this research program developed and tested advanced ultrafiltration membranes for the treatment of wastewaters. Such membranes could find use in membrane bioreactors treating municipal wastewater, a slightly upgraded version of what presently is used in Israel for irrigation. They also may find use for pretreatment of agricultural wastewaters, e.g., rendering facility wastewater, prior to reverse osmosis for desalination. The need to desalinate such impaired waters water for unlimited agricultural use is likely in the near future.
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Yalovsky, Shaul, and Julian Schroeder. The function of protein farnesylation in early events of ABA signal transduction in stomatal guard cells of Arabidopsis. United States Department of Agriculture, January 2002. http://dx.doi.org/10.32747/2002.7695873.bard.
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Loss of function mutations in the farnesyltransferase β subunit gene ERA1 (enhanced response to abscisic acid), cause abscisic acid hypersensitivity in seedlings and in guard cells. This results in slowed water loss of plants in response to drought. Farnesyltransferase (PFT) catalyses the attachment of the 15-carbon isoprenoid farnesyl to conserved cysteine residues located in a conserved C-terminal domain designated CaaX box. PFT is a heterodimeric protein comprised of an a and b sununits. The a subunit is shared between PFT and geranylgeranyltransferase-I (PGGTI) which catalyses the attachemt of the 20-carbon isoprenoid geranylgeranyl to CaaX box proteins in which the last amino acid is almost always leucine and in addition have a polybasic domain proximal to the CaaL box. Preliminary data presented in the proposal showed that increased cytoplasmic Ca2+ concentration in stomal guard cells in response to non-inductive ABA treatements. The goals set in the proposal were to characterize better how PFT (ERA1) affects ABA induced Ca2+ concentrations in guard cells and to identify putative CaaX box proteins which function as negative regulators of ABA signaling and which function is compromised in era1 mutant plants. To achieve these goals we proposed to use camelion Ca2+ sensor protein, high throughput genomic to identify the guard cell transcriptome and test prenylation of candidate proteins. We also proposed to focus our efforts of RAC small GTPases which are prenylated proteins which function in signaling. Our results show that farnesyltransferaseprenylates protein/s that act between the points of ABA perception and the activation of plasma membrane calcium influx channels. A RAC protein designated AtRAC8/AtRop10 also acts in negative regulation of ABA signaling. However, we discovered that this protein is palmitoylated and not prenylated although it contains a C-terminal CXXX motif. We further discovered a unique C-terminal sequence motif required for membrane targeting of palmitoylatedRACs and showed that their function is prenylation independent. A GC/MS based method for expression in plants, purification and analysis of prenyl group was developed. This method would allow highly reliable identification of prenylated protein. Mutants in the shared α subunit of PFT and PGGT-I was identified and characterized and was shown to be ABA hypersensitive but less than era1. This suggested that PFT and PGGT-I have opposing functions in ABA signaling. Our results enhanced the understanding of the role of protein prenylation in ABA signaling and drought resistance in plants with the implications of developing drought resistant plants. The results of our studies were published 4 papers which acknowledge support from BARD.
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Barefoot, Susan, Benjamin Juven, Thomas Hughes, Avraham Lalazar, A. B. Bodine, Yitzhak Ittah, and Bonita Glatz. Characterization of Bacteriocins Produced by Food Bioprocessing Propionobacteria. United States Department of Agriculture, August 1992. http://dx.doi.org/10.32747/1992.7561061.bard.
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Objectives were to further characterize activity spectra of dairy propionibacteria bacteriocins, jenseniin G and propionicin PLG-1, purify them, examine the role of cell walls in resistance, examine their interactions with cytoplasmic membrane, explain producer immunity, and clone the responsible genes. Inhibitory spectra of both bacteriocins were further characterized. Propionicin was most effective in controlling Gram-positive, rather than Gram-negative organisms; it controlled growth of sensitive cells both in a culture medium and a model food system. Jenseniin inhibited yogurt cultures and may help prevent yogurt over-acidification. Both were active against botulinal spores; jenseniin was sporostatic; propionicin was sporicidal. Jenseniin was produced in broth culture, was stable to pH and temperature extremes, and was purified. Its molecular mass (3649 Da) and partial amino acid composition (74%) were determined. A blocked jenseniin N-terminus prevented sequencing. Methods to produce propionicin in liquid culture were improved, and large scale culture protocols to yield high titers were developed. Methods to detect and quantify propionicin activity were optimized and standardized. Stability of partially purified propionicin was demonstrated and an improved purification scheme was developed. Purified propionicin had a 9328-Da molecular mass, contained 99 amino acids, and was significantly hydrophobic; ten N-terminal amino acids were identified. Propionicin and Jenseniin interacted with cytoplasmic membranes; resistance of insensitive species was cell wall-related. Propionicin and jenseniin acted similarly; their mode of action appeared to differ from nisin. Spontaneous jenseniin-resistant mutants were resistant to propionicin but nisin-sensitive. The basis for producer immunity was not resolved. Although bacteriocin genes were not cloned, a jenseniin producer DNA clone bank and three possible vectors for cloning genes in propionibacteria were constructed. In addition, transposon Tn916 was conjugatively transferred to the propionicin producer from chromosomal and plasmid locations at transfer frequencies high enough to permit use of Tn916 for insertional mutagenesis or targeting genes in propionibacteria. The results provide information about the bacteriocins that further supports their usefulness as adjuncts to increase food safety and/or quality.