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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Filtration of solid and liquid aerosol particles

Scurrah, Katherine Lesley January 1999 (has links)
Fibrous filter materials are commonly adopted in a variety of industrial and domestic processes to remove fine particles. Filter performance may be assessed by two parameters: the proportion of particles passing through the media (penetration), and the resistance to gas flow through the filter (pressure drop). Another parameter, the filter lifetime, may be important where economical factors are key.
2

Lakningsförsök med furubarksflis : en utredning om utsläpp av fenolföreningar samt metallsorption

Vienola, Sari January 2007 (has links)
<p>The filters used today to purify water are often expensive and the need to find new filter materials is substantial. Studies of pine bark have shown that this is a material that may be used as an alternative to conventional filter materials, such as activated carbon. However, the study of pine bark has shown that a leakage of phenolic compounds may occur when using the material for water purification. Therefore, the purpose of this report is to investigate the release of phenols from pine bark, in order to evaluate the use of pine bark as a filter material. Another assignment is to investigate the amount of metals adsorbed by the filter material. The studies were carried out through three leaching experiments. As leachates, double deionised water and storm water were used. The phenol concentration in the leachate was determined for both double deionised water and storm water. The degree of metal sorption was measured only for the storm water. The measured phenol concentration in the double deionised water was 4.40 mg/L and in the storm water 4.81 mg/L. These concentrations exceed the Canadian guideline value, of 4.0 μg/L, more than a 1000 times. No metal sorption occurred as the metal content of the storm water was too low. Instead a release of metals from the pine bark into the eluate of the storm water occurred. The leaching attempts also resulted in a decline of the pH-values of the two different waters. The pH-values for the double deionised water and the storm water decreased from 7.0 to 4.3 and from 6.0 to 4.2 respectively. A release of phenols was ascertained with a significant difference in concentrations between double deionised water and storm water. Therefore it is not advisable to use pine bark filters for purification of water with low concentrations of metals, as the filter material may release metals into the water under such conditions.</p><p>Keywords: pine bark, phenol, filter materials, leaching, metal sorption, toxicity</p><p>Nyckelord: furubarksflis, fenol, filtermaterial, lakning, metallsorption, toxicitet</p>
3

Lakningsförsök med furubarksflis : en utredning om utsläpp av fenolföreningar samt metallsorption

Vienola, Sari January 2007 (has links)
The filters used today to purify water are often expensive and the need to find new filter materials is substantial. Studies of pine bark have shown that this is a material that may be used as an alternative to conventional filter materials, such as activated carbon. However, the study of pine bark has shown that a leakage of phenolic compounds may occur when using the material for water purification. Therefore, the purpose of this report is to investigate the release of phenols from pine bark, in order to evaluate the use of pine bark as a filter material. Another assignment is to investigate the amount of metals adsorbed by the filter material. The studies were carried out through three leaching experiments. As leachates, double deionised water and storm water were used. The phenol concentration in the leachate was determined for both double deionised water and storm water. The degree of metal sorption was measured only for the storm water. The measured phenol concentration in the double deionised water was 4.40 mg/L and in the storm water 4.81 mg/L. These concentrations exceed the Canadian guideline value, of 4.0 μg/L, more than a 1000 times. No metal sorption occurred as the metal content of the storm water was too low. Instead a release of metals from the pine bark into the eluate of the storm water occurred. The leaching attempts also resulted in a decline of the pH-values of the two different waters. The pH-values for the double deionised water and the storm water decreased from 7.0 to 4.3 and from 6.0 to 4.2 respectively. A release of phenols was ascertained with a significant difference in concentrations between double deionised water and storm water. Therefore it is not advisable to use pine bark filters for purification of water with low concentrations of metals, as the filter material may release metals into the water under such conditions. Keywords: pine bark, phenol, filter materials, leaching, metal sorption, toxicity Nyckelord: furubarksflis, fenol, filtermaterial, lakning, metallsorption, toxicitet
4

Evaluation of sorption behavior of two reactive filter materials using dual column laboratory investigation.

Megersa, Daniel January 2015 (has links)
Phosphorous and nitrogen are vital elements for the well-being of biological life. Industrial discharges, waste water infiltration systems, conventional waste water collection and treatment systems, agricultural runoffs and landfill leachates had been emitting significant quantity of these nutrients into water bodies. These induced negative consequences to the environment including eutrophication of aquatic water bodies, toxicity to marine life and depletion of phosphate resources. Reactive filter technology is developed based on the need to remove and retain nutrients from waste water while improving the quality of effluents from emission sources. Reactive filter materials are used to build filter bed systems that treats domestic waste water, storm water, landfill leachates and contaminated subsurface water to the desired quality. In the past natural minerals such as zeolites and industrially produced polonite had been subject to laboratory study for the sorption of ammonium, heavy metals and phosphorous. The following paper is based on the results of experiment consisting of two columns packed with mordenite and polonite reactive materials filtering in series to reduce NH4 and PO4 content of a waste water. Septic tank effluent pre filtered using 0.45 μm filter is used as influent waste water into the dual columns. The dual column filtered a total of 24.07l s (372PV) and 23.42 ls (496PV) of the waste water. Sampling of the feed water and filtrates of both columns were done every second day with measurement of pH, conductivity and temperature. Analyzed samples confirmed that the dual column filtration resulted in re-moval efficiency of 84.39 % (PO4), 67.98 % (NH4) and -37.762.8 % (NOx). Filtration in the first (mordenite) column resulted in relatively larger proportion of the influent ammonium ion exchange than sorption of phosphate while the filtration in the second (polonite) column sorbed quite high amount of phosphorous than ammonium from effluent of the first column. Saturation of mordenite occurred faster even though there was sorption potential for few more of influent ammonium. All PO4 removal in mordenite column occurred above breakthrough condition. Polonite packed column was in a condition of a third of it’s saturation potential for PO4 removal at the end of the experiment. pH of samples was the parameter which is correlated significantly with filtration in polonite column than temperature and electrical conductivity. The performance of polonite was higher at higher pH than at lower pH. The mean concentrations of the dual column effluent were 0.77 mg-PO4/l and 11.13 mg-NH4/l. This is acceptable by the standards of environmental laws. The result of the experiment is valuable in prediction of performance and designing of real time filter bed.
5

Možnosti odstraňování kovů ze zdrojů pitné vody vodárenskými procesy / Possibilities of removing metals from drinking water sources by water treatment processes

Marzinová, Kristýna January 2022 (has links)
In my diploma thesis I focused on the issue of metals, their occurrence in drinking water sources in the Czech Republic and the possibility of their removal by water supply processes. Heavy metals degrade the quality of water resources, so more complex water treatment technologies are needed. The first part describes the metals, their properties, their significance and occurrence in water, then the possibility of removing metals using water supply processes. In the practical part of the diploma thesis I performed a laboratory experiment to remove iron, manganese and nickel by adsorption on selected filter materials, which are Filtrasorb F100, Filtrasorb F 400, Bayoxide E33 and GEH. The experiment was used to compare the effectiveness of selected sorption materials.
6

Bestimmung der bruch- und schädigungsmechanischen Eigenschaften keramischer Filterwerkstoffe aus Kleinstproben

Zielke, Henry 06 January 2020 (has links)
In der vorliegenden Arbeit wurden bruch- und schädigungsmechanische Eigenschaften keramischer Filterwerkstoffe, welche im Rahmen des SFB 920 entwickelt und erforscht werden, bestimmt. Es wurden zwei verschiedene Werkstoffsysteme - Aluminiumoxid und kohlenstoffgebundenes Alumniumoxid - mit entwickelten Miniaturprüfmethoden bei Prüftemperaturen bis 1500°C untersucht. Mit Hilfe des Ball-On-Three-Balls-Tests (B3B) wurde die biaxiale Festigkeit in Abhängigkeit der Prüftemperatur bestimmt. Für die kohlenstoffgebundenen Proben wurde weiterhin der Einfluss der Verkokungstemperatur als auch des Kohlenstoffgehalts auf die Festigkeit untersucht. Es konnte ein Festigkeitsmaximum ermittelt werden, wenn die Prüftemperatur der Verkokungstemperatur entspricht. Die schädigungsmechanischen Materialparameter des duktilen Verformungs- und Versagensverhalten beider Werkstoffe bei 1500°C wurden mit Hilfe von numerischen Simulationen des B3B identifiziert. Die Bestimmung der bruchmechanischen Kennwerte erfolgte mit einem Vier-Punkt-Biegeversuchsaufbaus mit Chevron-gekerbten Proben (CNB-Versuch). Numerische Untersuchungen dienten zur Bestätigung der Versuchsergebnisse und Bestimmung der Form der Rissfront sowie Risswachstum während des Versuches. / In the present work, fracture and damage mechanical properties of ceramic filter materials, which are developed and investigated within the framework of the CRC 920, are determined. Two different material systems - alumina and carbon-bonded alumina - are investigated using miniaturized test methods at temperatures up to 1500°C. The biaxial strength at different temperatures is determined using the Ball-On-Three-Balls-Test (B3B). The strength of carbon-bonded specimens is dependent on the coking temperature and the carbon content. A maximum strength can be obtained if the testing temperature equals the coking temperature. The damage-mechanical material parameters in order to describe the ductile deformation and failure behaviour of both materials at 1500°C are identified with the help of numerical simulations. The determination of fracture-mechanical properties are carried out with a four-point bending test setup with chevron-notched specimens (CNB). Numerical investigations are used to validate the test results and to simulate the shape of the crack front and crack growth during the experiment.
7

Multifunktionale Filter für die Metallschmelzefiltration - ein Beitrag zu Zero Defekt Materials: Abschlussbericht DFG Sonderforschungsbereich SFB 920

Aneziris, Christos G. 06 February 2024 (has links)
Die Sicherheit von Straßen-, Schienenfahrzeugen sowie von Flugzeugen erfordert hochbelastbare Bauteile aus Stahl, Eisen, Aluminium und Magnesium. Während des Herstellungsprozesses können Verunreinigungen in der Metallschmelze auftreten, die zu Defekten in Form von Einschlüssen führen. Die Reduzierung oder Entfernung dieser Einschlüsse ist schwierig oder manchmal sogar unmöglich. Der Sonderforschungsbereich 920 „Multifunktionale Filter für die Metallschmelzefiltration – ein Beitrag zu Zero Defect Materials“ konzentrierte sich auf die Erforschung einer neuen Generation von Metallqualitäten – auch beim Recycling – durch Schmelzefiltration mit überlegenen mechanischen Eigenschaften für höchstbeanspruchbare Komponenten in Sicherheits- und Leichtbaukonstruktionen. Der SFB 920 wurde von 2011 bis 2023 an der Technischen Universität Bergakademie Freiberg von der Deutschen Forschungsgemeinschaft (DFG) gefördert (Projektnummer 169148856 – SFB 920) und nach 12 Jahren intensiver Forschungsarbeit erfolgreich beendet. Der Abschlussbericht des SFB 920 fasst die wichtigsten Publikationen und ausgewählte Ergebnisse zusammen.:1 Zusammenfassung / Summary 1 2 Die 50 wichtigsten veröffentlichten Ergebnisse 2 2.1 Publikationen mit wissenschaftlichen Qualitätssicherung 2 2.2 Weitere Publikationen und öffentlich gemachte Ergebnisse 4 3 Übersicht der Teilprojekte 5 4 Wissenschaftliche Entwicklung des Sonderforschungsbereichs 7 4.1 Einleitung, Vision und Thesen 7 4.2 Ausgewählte Ergebnisse 8 4.2.1 „Stahlschmelze-Filtration“ 8 4.2.2 „Aluminiumschmelze-Filtration“ 16 4.2.3 „Magnesiumschmelzefiltration“ 17 4.2.4 Beiträge der Simulation 18 4.2.5 Harz- und pechfreies Bindemittel für umweltfreundliche, reaktive Filter 20 4.2.6 Generatives Hybrid-Flammspritzverfahren 20 4.2.7 Transferprojekte 21 4.2.8 Zusammenfassende Bemerkungen 22 4.2.9 Management der Forschungsdaten 24 4.2.10 Literatur 24 4.3 Wissenschaftliche Veranstaltungen und Wissenschaftskommunikation 26 4.4 Nationale und internationale Kooperationen 28 5 Schwerpunktbildung und internationale Sichtbarkeit 31 / The safety of road and railway vehicles as well as aircrafts requires highly stressable components made of steel, iron, aluminum and magnesium. During the production process, contaminations can occur in the metal melt, which lead to defects in the form of inclusions. Reducing or removing these inclusions is difficult or sometimes impossible. The Collaborative Research Center 920 “Multi-functional filters for metal melt filtration – a contribution towards zero defect materials” focussed on research into a new generation of metal qualities - also during recycling - via melt filtration with superior mechanical properties for use in high-demand construction materials and light-weight structures. The CRC 920 was funded by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) from 2011 to 2023 at the Technische Universität Bergakademie Freiberg (Project-ID 169148856 – SFB 920) and was successfully completed after 12 years of intensive research work. The final report of the CRC 920 presents the most important publications and selected results.:1 Zusammenfassung / Summary 1 2 Die 50 wichtigsten veröffentlichten Ergebnisse 2 2.1 Publikationen mit wissenschaftlichen Qualitätssicherung 2 2.2 Weitere Publikationen und öffentlich gemachte Ergebnisse 4 3 Übersicht der Teilprojekte 5 4 Wissenschaftliche Entwicklung des Sonderforschungsbereichs 7 4.1 Einleitung, Vision und Thesen 7 4.2 Ausgewählte Ergebnisse 8 4.2.1 „Stahlschmelze-Filtration“ 8 4.2.2 „Aluminiumschmelze-Filtration“ 16 4.2.3 „Magnesiumschmelzefiltration“ 17 4.2.4 Beiträge der Simulation 18 4.2.5 Harz- und pechfreies Bindemittel für umweltfreundliche, reaktive Filter 20 4.2.6 Generatives Hybrid-Flammspritzverfahren 20 4.2.7 Transferprojekte 21 4.2.8 Zusammenfassende Bemerkungen 22 4.2.9 Management der Forschungsdaten 24 4.2.10 Literatur 24 4.3 Wissenschaftliche Veranstaltungen und Wissenschaftskommunikation 26 4.4 Nationale und internationale Kooperationen 28 5 Schwerpunktbildung und internationale Sichtbarkeit 31

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