Les activités humaines ont généré une augmentation importante de la concentration de gaz à effet de serre (GES) au cours des 150 dernières années, ce qui est relié à plusieurs problèmes environnementaux, tels que le réchauffement planétaire et les changements climatiques. Le secteur agricole contribue de 8 à 10% aux émissions totales de GES dans l'atmosphère, et les principaux GES émis sont le dioxyde de carbone (CO2), le méthane (CH4) et l'oxyde nitreux (N2O). Le contrôle et la quantification de ces émissions requièrent des technologies qui permettent de les capturer et ou les dégrader, par exemple par adsorption. L'objectif du présent projet est de caractériser des matériaux qui puissent être utilisés comme adsorbants des GES et de décrire leurs cinétiques d'adsorption afin d'avoir l'information qui permet de sélectionner des adsorbants pour capturer le CH4 et le N2O à des basses concentrations et à température et pression ambiantes. Pour adsorber le CH4, des adsorbants commerciaux et synthétiques ont été utilisés. Les adsorbants choisis ont été des zéolithes, un biocharbon conditionné au laboratoire et un ZIF (« Zeolitic imidazolate framework », ZIF-8) synthétisé au laboratoire. Ce dernier a été employé aussi pour adsorber du N2O. La capacité d'adsorption de CH4 et de N2O a été évaluée pour chaque adsorbant par de tests dynamiques d'adsorption du gaz sous conditions ambiantes. Ces matériaux ont été caractérisés physiquement et chimiquement afin de corréler leurs propriétés avec la capacité d'adsorption de CH4 et/ou de N2O. Des isothermes d'équilibre ont été utilises pour modéliser les donnés expérimentales. Parmi les différents matériaux utilisés lors de l'adsorption du CH4 à 30 ºC et à pressions partielles de CH4 inférieures à 0,40 kPa, les biocharbons présentent la capacité d'adsorption la plus élevée, suivis par le ZIF-8 et les zéolithes commerciales / Human activities contributed with a significant increase in GHG concentrations over the past 150 years and they are related to environmental issues, such as global warming and climate change. The agricultural sector contributes 8 to 10% of total GHG emissions to the atmosphere, being carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) the main GHGs emitted. The control and quantification of these emissions requires technologies which can capture and or degrade these GHG, for example by adsorption. The objective of this project is to characterize adsorbents and to describe their adsorption kinetics in order to select the most suitable for the adsorption of CH4 and N2O at low concentration and at ambient temperature. For CH4 adsorption, commercial and synthesized adsorbents were tested. The selected adsorbents were commercial zeolites, laboratory conditioned biochar and synthesized ZIF ("Zeolitic imidazolate framework"). ZIF was also used for N2O adsorption. The adsorption capacity of CH4 and N2O for each adsorbent was evaluated by dynamic adsorption tests of the gas under atmospheric conditions. These materials were physically and chemically characterized in order to correlate its properties with its CH4 and/or N2O adsorption capacity. The experimental data of gas adsorption were fitted by equilibrium isotherms. Among the different materials used for CH4 adsorption at 30 ºC and partial pressures lower than 0.40 kPa, biocharbons presented the highest adsorption capacity, followed by ZIF- 8 and commercial zeolites

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Normal";mso-tstyle-rowband-size:0;mso-tstyle-colband-size:0;mso-style-noshow:yes;mso-style-priority:99;mso-style-parent:"";mso-padding-alt:0cm 5.4pt 0cm 5.4pt;mso-para-margin-top:0cm;mso-para-margin-right:0cm;mso-para-margin-bottom:10.0pt;mso-para-margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri","sans-serif";mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;}</style><![endif]--><span lang="EN-US" style="font-size:10.0pt;line-height:115%;font-family:&quot;Cambria&quot;,&quot;serif&quot;;mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin;mso-bidi-font-family:&quot;Times New Roman&quot;">Primena različitih tretmana sa ciljem redukcije sadržaja nesaharoznih jedinjenja u melasi &scaron;ećerne repe potencijalan je metod za pobolj&scaron;anje parametara kvaliteta melase, lak&scaron;e sprovođenje procesa desaharifikacije melase i sprečavanje eventualnih nepoželjnih promena pri skladi&scaron;tenju melase. Stoga je predmet istraživanja ove disertacije redukovanje sadržaja nesaharoznih jedinjenja u melasi &scaron;ećerne repe upotrebom prirodnih adsorbenata mineralnog (različiti tipovi bentonita) i celuloznog (celuloza različitog stepena čistoće i modifikovani ekstrahovani rezanci &scaron;ećerne repe) porekla. Variranjem pH vrednosti sredine, suve materije melase i koncentracije primenjenog adsorbenta ispitan je sinergistički efekat uslova tretmana na stepen redukcije sadržaja nesaharoznih jedinjenja u melasi. Efikasnost sprovedenog tretmana utvrđena je na osnovu promena parametara kvaliteta melase i to boje, mutnoće, sadržaja saharoze, sadržaja suve materije i sadržaja pepela. </span></p><p class="MsoNormal" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;line-height:115%;font-family:&quot;Cambria&quot;,&quot;serif&quot;;mso-ascii-theme-font:major-latin;mso-hansi-theme-font:major-latin;mso-bidi-font-family:&quot;Times New Roman&quot;">Na osnovu rezultata uočava se da je pozitivan uticaj kombinovanog dejstva upotrebljenih adsorbenata i uslova tretmana najizraženiji kod mutnoće i boje melase &scaron;to potvrđuje afinitet adsorbenata ka zadržavanju i/ili vezivanju bojenih materija. Takođe, navedeni pozitivan uticaj izražen je u manjoj ili većoj meri u zavisnosti od tipa primenjenog adsorbenta ali i uslova gde je uglavnom dominantan uticaj pH vrednosti </span></p><p><!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:RelyOnVML/> <o:AllowPNG/> </o:OfficeDocumentSettings></xml><![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w:DoNotShowRevisions/> <w:DoNotPrintRevisions/> <w:DoNotShowMarkup/> <w:DoNotShowComments/> <w:DoNotShowInsertionsAndDeletions/> <w:DoNotShowPropertyChanges/> <w:HyphenationZone>21</w:HyphenationZone> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:DoNotPromoteQF/> <w:LidThemeOther>EN-US</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> <w:SplitPgBreakAndParaMark/> <w:EnableOpenTypeKerning/> <w:DontFlipMirrorIndents/> <w:OverrideTableStyleHps/> </w:Compatibility> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="&#45;-"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument></xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" DefUnhideWhenUsed="true" DefSemiHidden="true" DefQFormat="false" DefPriority="99" LatentStyleCount="267"> <w:LsdException Locked="false" Priority="0" SemiHidden="false" UnhideWhenUsed="false" QFormat="true" Name="Normal"/> <w:LsdException Locked="false" Priority="9" SemiHidden="false" UnhideWhenUsed="false" QFormat="true" Name="heading 1"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 2"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 3"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 4"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 5"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 6"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 7"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 8"/> <w:LsdException Locked="false" Priority="9" QFormat="true" Name="heading 9"/> <w:LsdException Locked="false" Priority="39" Name="toc 1"/> <w:LsdException Locked="false" Priority="39" Name="toc 2"/> <w:LsdException Locked="false" Priority="39" Name="toc 3"/> <w:LsdException Locked="false" Priority="39" Name="toc 4"/> <w:LsdException Locked="false" Priority="39" Name="toc 5"/> <w:LsdException Locked="false" Priority="39" Name="toc 6"/> <w:LsdException Locked="false" Priority="39" Name="toc 7"/> <w:LsdException Locked=&qu / <p>&nbsp;</p><p class="MsoNormal" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;line-height:115%;font-family:&quot;Cambria&quot;,&quot;serif&quot;;mso-fareast-font-family:Calibri;mso-bidi-font-family:&quot;Times New Roman&quot;">The application of different treatments aiming to reduce the content of non-sugar compounds in sugar beet molasses is a potential method for molasses quality enhancement, facilitation of molasses desugarization process and prevention of any undesirable changes during molasses storage. Therefore, the objective of this dissertation is to reduce the content of non-sugar compounds in sugar beet molasses by using natural adsorbents of mineral (different types of bentonite) and cellulosic (cellulose of different purity and modified sugar beet pulp) origin. By varying treatment conditions such as pH, molasses dry substance and the applied adsorbent concentration, the synergistic effect of the treatment conditions on the reduction efficiency of non-sugar compounds content in molasses was examined. The treatment effectiveness was determined based on changes in molasses quality parameters, namely color, turbidity, sucrose content, dry substance content and ash content.</span></p><p><!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:RelyOnVML/> <o:AllowPNG/> </o:OfficeDocumentSettings></xml><![endif]--></p><p><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w:DoNotShowRevisions/> <w:DoNotPrintRevisions/> <w:DoNotShowMarkup/> <w:DoNotShowComments/> <w:DoNotShowInsertionsAndDeletions/> <w:DoNotShowPropertyChanges/> <w:HyphenationZone>21</w:HyphenationZone> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:DoNotPromoteQF/> <w:LidThemeOther>EN-US</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> <w:SplitPgBreakAndParaMark/> <w:EnableOpenTypeKerning/> <w:DontFlipMirrorIndents/> <w:OverrideTableStyleHps/> </w:Compatibility> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="&#45;-"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument></xml><![endif]--></p><p class="MsoNormal" style="text-align:justify"><span lang="EN-US" style="font-size:10.0pt;line-height:115%;font-family:&quot;Cambria&quot;,&quot;serif&quot;;mso-fareast-font-family:Calibri;mso-bidi-font-family:&quot;Times New Roman&quot;">According to the obtained results, the positive influence of the combined effect of applied adsorbents and treatment conditions is most pronounced for molasses quality parameters turbidity and colour, which confirms the applied adsorbents affinity towards coloured compounds retention or binding. Also, the stated positive influence is expressed to a greater or lesser extent depending on the type of adsorbent used as well as the conditions applied, where the influence of pH is mainly dominant.</span></p><p><!--[if gte mso 10]><style> /* Style Definitions */ table.MsoNormalTable{mso-style-name:"Table Normal";mso-tstyle-rowband-size:0;mso-tstyle-colband-size:0;mso-style-noshow:yes;mso-style-priority:99;mso-style-parent:"";mso-padding-alt:0cm 5.4pt 0cm 5.4pt;mso-para-margin-top:0cm;mso-para-margin-right:0cm;mso-para-margin-bottom:10.0pt;mso-para-margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:"Calibri","sans-serif";mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;}</style><![endif]--></p><p><!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:RelyOnVML/> <o:AllowPNG/> 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Treatment of wastewater using magnetic technology is a rising field. In this thesis, the latest research on the subject is reviewed and several adsorbents with different coatings, which impart them unique properties, are discussed. Separation of particles from aqueous solution using magnetic technology is more convenient compared to conventional techniques, such as filtration and centrifugation. The adsorbents described in this thesis are effective for adsorption of several types of contaminants, such as heavy metals and different types of dyes.    Magnetic microspheres were synthesised using porous polystyrene microspheres as template. The microspheres were first sulfonated using chlorosulfonic acid followed by stirring in the presence of ferrous chloride which then was oxidised and magnetic nanoparticles were formed on the surface.    The sulfonated microspheres had a surface area of 420 m2/g and the magnetic 175 m2/g, indicative of Fe3O4 nanoparticles were successfully formed in the pores. The weight fraction of the Fe3O4 nanoparticles in the magnetic microspheres was 33 %.    Adsorption and desorption studies of the cationic dye, methylene blue, using mesoporous magnetic microspheres were performed. The results show that the mesoporous magnetic microspheres have good ability to adsorb methylene blue at low concentrations. In a cycle study the adsorption efficiency were nearly 100 % throughout the study. Using a 6/4 EtOH/H2O with saturated KCl solution the desorption efficiency in the cycle study were about 95 %.      The microspheres were used as carriers for TiO2 in order to overcome the problem with the separation of TiO2 from solution. The TGA results show that the microspheres contained about 12 % of TiO2. The TiO2 coated microspheres were used for the photocatalytic degradation of phenol. However, the TiO2 microspheres did not work. This was a result from that the phenol had too little contact with the TiO2. A possible way of solving this problem could be to decrease the size of the microspheres, thus increase the surface area.    Lysozyme was adsorbed and separated using the porous microspheres. The lysozyme adsorption worked best at pH 9.6, which is the pI for lysozyme. The lysozyme could be extracted from the microspheres by using a pH 13 buffer. Also, by using MeOH/H2O and EtOH/H2O solutions with saturated KCl the lysozyme could be desorbed. An adsorption and desorption mechanism was also presented. / Vattenrening med magnetisk teknologi är en ny och alltmer uppmärksammad teknik. Magnetisk separation är ett enkelt och snabbt sätt att separera något från en lösning. Magnetisk separation är mer lätthanterligt jämfört med traditionell separationsteknik såsom centrifugering och filtrering.  Med porösa polystyren mikrosfärer som mall, syntetiserades magnetiska mikrosfärer. Först så sulfonerades mikrosfärerna med klorosulfonisk syra, följt av att de rördes om i en järnkloridlösning. Magnetiska nanopartiklar bildades i porerna och på ytan av mikrosfärerna.    Sulfonerade mikrosfärerna hade en specifik ytarea på 420 m2/g och de magnetiska 175　m2/g, detta indikerar att Fe3O4-nanopartiklar bildades på ytan och i porerna. Massfraktionen av Fe3O4 var 33 %.    Adsorption- och desorptionsstudier på de magnetiska mikrosfärerna utfördes. Färgämnet metylblått användes i studien. Resultaten visade att magnetiska mikrosfärerna hade en bra adsorptionsförmåga vid låga koncentrationer av metylblått. Cykelstudier visade att adsorptionsverkningsgraden var nära 100 % under flera adsorptionscykler. Desorptionsförsök med olika lösningsmedel visade att en mättad KCl 6/4 EtOH/H2O lösning gav en desorptions-verkningsgrad på ca 95 %.   Mikrosfärerna användes som mall och kärna för att syntetisera en TiO2-fotokatalysator, detta för att överkomma problemet som finns med separation av rent TiO2 pulver från lösning. TGA resultaten visade att mikrosfärerna innehöll ca 12 % TiO2. De syntetiserade TiO2-mikrosfärerna användes till att bryta ner fenol fotokatalytiskt. Dock fungerade inte detta experiment. En anledning var att fenolen hade för lite kontakt med TiO2. En lösning på detta problem är att använda mikrosfärer med högre specifik ytarea.    Proteinet lysozym användes som modellprotein för försök att separera proteiner från lösning genom att använda porösa mikrosfärer. Resultatet visade att lysozym kunde adsorberas vid pH 9.6. Med en pH 13 buffer kunde lysozymet sedan extraheras från mikrosfärerna. En mekanism för adsorptionen och desorptionen på mikrosfärerna presenterades.

Abstract The aim of the present study was to increase the understanding of how the cell surface properties affect the performance of unit operations used in primary protein purification. In particular, the purpose was to develop, set up and apply methods for studies of cell surface properties and cell interactions. A method for microbial cell surface fingerprinting using surface plasmon resonance (SPR) is suggested. Four different Escherichia coli strains were used as model cells. Cell surface fingerprints were generated by registration of the interaction between the cells and four different surfaces, with different physical and chemical properties, when a cell suspension was flown over the surface. Significant differences in fingerprint pattern between some of the strains were observed. The physical properties of the cell surfaces were determined using microelectrophoresis, contact angle measurements and aqueous two-phase partitioning and were compared with the SPR fingerprints. The generated cell surface fingerprints and the physical property data were evaluated with multivariate data analysis that showed that the cells were separated into individual groups in a similar way using principal component analysis plots (PCA). Studies of the behaviour of the model cells on stirred cell filtration and in an interaction test with different expanded bed adsorption (EBA) adsorbents were performed. It could be concluded that especially one of the strains behaved differently. Differences in the properties of the model cells were indicated by microelectrophoresis and aqueous two-phase partitioning which to some extent correlated with observed differences in behaviour during filtration and in an interaction test with EBA adsorbents. The impact of high-pressure homogenisation of E. coli cell extract was examined, with a lab scale and a pilot scale technique. The DNA-fragmentation, visualised with agarose gel electrophoresis, and the resulting change in viscosity was analysed. A short homogenisation time resulted in increased viscosity of the process solution that correlated with increased concentration of released non-fragmented DNA. With longer homogenisation time the viscosity decreased with increasing degree of DNA-fragmentation. The results show that strain dependant cell surface properties of E. coli may have an impact on several primary steps in downstream processing. / QC 20101129

Die vorliegende Arbeit befasst sich mit der Herstellung geformter Adsorbentien aus den Agrarreststoffen Reisstroh und Bagasse. Dazu wurde eine neue Prozessroute entwickelt, anhand welcher die Ausgangsstoffe zunächst pelletiert und anschließend pyrolysiert werden. Ziel ist es ein Produkt mit hoher mechanischer Festigkeit (Ball Pan Hardness) > 80 % und spezifischer Oberfläche > 300 m2/g zu erzeugen. Dies ist durch die Auswahl geeigneter Mischungszusammensetzungen, die Anpassungen der Pelletierparameter und des Pyrolyseregimes möglich. Zusätzliche Aktivierungsschritte führen zu einer weiteren Verbesserung der spezifischen Oberfläche. Auf Basis der experimentellen Untersuchungen wurden mittels statistischer Methoden Einfluss- und Zielgrößen in Hinblick auf die anschließende empirische mathematische Modellentwicklung ausgewählt. Damit kann die spezifische Oberfläche anhand von validierten, nicht-linearen Regressionsmodellen mithilfe von Prozessparametern abgebildet werden kann.:Abbildungsverzeichnis Tabellenverzeichnis Symbolverzeichnis 1 Einleitung 2 Grundlagen 2.1 Zusammensetzung und struktureller Aufbau biogener Reststoffe 2.1.1 Aufkommen biogener Reststoffe 2.1.2 Stoffliche Zusammensetzung biogener Reststoffe 2.1.3 Struktureller Aufbau biogener Reststoffe 2.2 Pelletierung biogener Rohstoffe 2.2.1 Wirkungsweise der Pelletierung 2.2.2 Stand der Forschung zur Einflussnahme auf die spezifischen Eigenschaften von Pellets aus biogenen Rohstoffen 2.3 Charakterisierung und Herstellung technischer Adsorbentien 2.3.1 Begriffsklärung, Einteilung und typische Eigenschaften technischer Adsorbentien 2.3.2 Stand der Forschung zu Wandlungsvorgängen und ihren Effekten bei der Herstellung kohlenstoffhaltiger Adsorbentien aus biogenen Rohstoffen 2.4 Ableitung der Aufgabenstellung zur Herstellung von geformten Adsorbentien aus Agrarreststoffen 3 Material und Methoden 3.1 Untersuchte biogene Reststoffe 3.2 Herstellung der Produkte und Begriffsklärung 3.2.1 Herstellung der Biomassepellets 3.2.2 Pyrolyse der biogenen Reststoffe und Pellets 3.2.3 Aktivierung der Biomassen und Formkohlen 3.3 Charakterisierung der Ausgangsstoffe, Zwischenprodukte und Produkte 3.3.1 Stoffliche Zusammensetzung 3.3.2 Mechanisch-physikalische Eigenschaften 3.3.3 Adsorptionsspezifische Eigenschaften 3.4 Vorgehensweise zur empirischen Modellentwicklung 3.5 Fehlerbetrachtung 4 Diskussion der experimentellen Ergebnisse 4.1 Charakterisierung der eingesetzten Rohstoffe 4.2 Auswahl geeigneter Mischungszusammensetzungen und Pelletierbedingungen zur Herstellung von Formkohlen 4.3 Einfluss der Pyrolysebedingungen auf die Eigenschaften der Formkohle 4.3.1 Einfluss des Pelletwassergehaltes auf die spezifische Oberfläche der Formkohlen 4.3.2 Einfluss des Pyrolyseregimes auf die spezifische Oberfläche der Formkohlen 4.4 Einfluss von Aktivierungsschritten auf die Eigenschaften der Formaktivkohlen 4.4.1 Einfluss der chemischen Aktivierung der Biomassen 4.4.2 Einfluss der Aktivierung der Formkohlen 5 Empirische mathematische Modellentwicklung 5.1 Auswahl relevanter Einflussgrößen und Zielgrößen für die empirische Modellentwicklung 5.2 Modellentwicklung zur Abbildung der spezifischen Oberfläche anhand ausgewählter Einflussgrößen 6 Zusammenfassung und Ausblick 7 Literatur 8 Anhang A. Recherche zur Zusammensetzung ausgewählter Agrarreststoff B. Übersicht über ausgewählte, wissenschaftliche Veröffentlichungen zur Herstellung von Biomassepellets C. Übersicht über ausgewählte, wissenschaftliche Veröffentlichungen zur Aktivierung von (pyrolysierten) Agrarreststoffen D. Übersicht über ausgewählte, wissenschaftliche Veröffentlichungen zur Herstellung (geformter) Kohlenstoffadsorbentien aus Reisstroh und Bagasse E. Übersicht über die Ball Pan Hardness und spezifische Oberfläche kommerziell erhältlicher Form(aktiv)kohlen F. Übersicht über die genutzten Messgeräte und die zugehörigen Messfehler G. Zusammensetzung der Aschen aus Bagasse und Reisstroh H. Übersicht über ausgewählte Charakteristika der hergestellten Formkohlen und kommerziell erhältlicher Produkte

Le but principal de cette étude était la recherche de structures optimales de charbons activés capables d"atteindre l'objectif de stockage d'hydrogène fixé par le département de l"énergie américain (DOE) pour les applications mobiles en utilisant l"adsorption physique à la température ambiante et aux pressions en-dessous de120 bars. L'hydrogène est destiné à être stocké dans une cuve rempliée d"adsorbants et doit être utilisé dans les véhicules alimentés principalement par des piles à combustible. Les adsorbants à base de carbone connus ont une capacité de stockage faible. Par conséquent, dans ce travail, j'ai défini les paramètres responsables de l'insuffisance de capacité de stockage de ces matériaux. Une attention particulière a été accordée à la géométrie locale des pores des adsorbants. J'ai étudié la structure locale des pores des adsorbants à base de carbone et je présente le principe de la conception d"architectures tridimensionnelles de nouvelles structures de carbone ainsi que la capacité d'adsorption de l'hydrogène par ces structures, lesquelles constituent une classe prometteuse de matériaux pour le stockage d'hydrogène et qui n'ont pas été étudiées jusqu'ici. Hormis la maximisation de la densité de l'hydrogène absorbée par cette famille de structures, mon but était de caractériser l'adsorption dans cette nouvelle catégorie d'adsorbants. Cela permet d"apporter des informations quant à la méthodologie à utiliser pour ajuster les propriétés physiques de ces matériaux afin d'optimiser leurs propriétés de stockage. Les résultats obtenus semblent montrer que cet objectif est atteint et confirment que mon approche constitue une bonne base pour de futures recherches. / The main goal of research presented in this thesis has been a search for optimal carbon-based porous structure capable to achieve the hydrogen storage capacity defined by US Department of Energy (DOE) for mobile applications at room temperature by adsorption at medium-level pressures below 120 bars. The hydrogen is assumed to be stored in a tank filled with adsorbents to be used in transport application, mainly fuel-cell driven vehicles. The known carbon-based adsorbents have low storage capacity. Therefore in this work, I have defined the basic parameters which are responsible for the capacity deficiency of such materials. Special attention has been paid to local pore geometry of adsorbents. I have investigated the pore local structure of carbon-based adsorbents and I present the basis of design and hydrogen adsorption capacity in three-dimensional architecture of new carbon frameworks, a promising class of potential hydrogen storage materials that have not been studied so far. Apart from maximizing the density of hydrogen taken up by this family of structures, I have aimed at characterization of this new category of adsorbents. This is hoped to lead to a guidance how their physical properties can be designed, or `tuned', to optimize their storage properties, and the obtained results seem to achieve this aim and thus provide a good basis for future research.

Le aflatossine sono potenti sostanze cancerogene presenti in natura. L'aflatossina b1 viene poco degradata nel rumine ed è escreta nel latte come aflatossina M1 con un carry over del 1-3%. Nel presente lavoro è stata studiata l'apparizione delle aflatossine nel sangue conseguente all'ingestione orale di un bolo contaminato per verificare come queste tossine sono assorbite nel tratto digestivo delle vacche da latte. La comparsa nel plasma e nel latte attraverso una mucosa tipicamente non di assorbimento per determinare il possibile meccanismo che regola l'assorbimento delle aflatossine è stato un ulteriore oggetto di studio. Un'altra prova è stata effettuata con vacche da latte per studiare il carry-over dell'aflatossina B1 nel latte in relazione al livello produttivo e alle cellule somatiche, come indicatore di processi infiammatori nella mammella. La capacità sequestrante di diversi tipi di adsorbenti è stata comparata in prove in vitro condotte in differenti condizioni sperimentali. Anche il comportamento del complesso aflattosina-adsorbente nel tratto digestivo di vacche in lattazione è stato studiato in vivo per mezzo della misurazione della presenza di aflatossina M1 nel latte. Una prova in vivo è stata effettuata per verificare l'effetto che la pellettatura o la semplice miscelazione di adsorbenti nei mangimi può avere nel migliorare l'efficienza di sequestro. / Aflatoxins are the most potent natural carcinogenic compound present in nature. Aflatoxin B1 is poorly degraded in the rumen and is excreted in milk as aflatoxin M1 with a carry-over rate of 1-3%. The present work investigated rate and schedule of aflatoxins plasma appearance following an oral contaminated bolus to verify how these toxins are absorbed in the gastro-intestinal tract of dairy cows. Aflatoxins plasma and milk appearances were also investigated using a non-absorbing mucosa to understand the possible aflatoxins absorption mechanism through mucous membranes. A trial was carried out in lactating dairy cows to study the carry over of ingested aflatoxin B1 in milk as aflatoxin M1 in relation to milk yield and somatic cells count, the latter as indicator of udder inflammatory processes. sequestering capacity of different kinds of mycotoxins sequestering agents were compared in vitro trial carried out at different experimental conditions. The behaviour of the aflatoxins-adsorbents complexes through digestive tract of lactating dairy cows were also investigated in vivo by measuring appearance of aflatoxin M1 into milk. An in vivo trial was conducted to verify if effect of pelletizing or simply mixing processes is useful to improve mycotoxins sequestering agents efficacy in dairy cow nutrition.

Microorganisms are able to produce a wide variety of volatile organic compounds. This thesis deals with sampling, analysis and identification of such compounds, produced by microorganisms commonly found in buildings. The volatiles were sampled on adsorbents and analysed by thermal desorption cold trap-injection gas chromatography, with flame ionization and mass-spectrometric detection. The injection was optimized, with respect to the recovery of adsorbed components and the efficiency of the chromatographic separation, using multivariate methods. Eight adsorbents were evaluated with the object of finding the most suitable for sampling microbial volatiles. Among the adsorbents tested, Tenax TA proved to have the best properties for the purpose. Some carbon-containing adsorbents, e.g., Tenax GR and Carbopack B, showed a catalytic effect on thermal decomposition of some compounds, mainly terpene derivatives. Five fungal species, Aspergillus versicolor, Pénicillium commune, Cladosporium cladosporioides, Paecilomyces variotii and Phialophora fastigiata, and anactinomycete, Streptomyces albidoflavus, were cultivated on various artificial media and/or building materials. Cultivation was performed in culture flasks, provided with air inlet and outlet tubes. Humidified air was constantly led through the flasks, and samples were taken by attaching adsorbent tubes to the outlet tubes of the flasks. The cultivation medium proved to be of vital importance for metabolite production, quantitatively as well as qualitatively. For Streptomyces albidoflavus the effect of medium, cultivation temperature, and oxygen and carbon dioxide levels in the supplied air on the production of volatiles, was studied using multivariate techniques. The medium and the temperature exerted the largest influence, but the oxygen and carbon dioxide levels also affected the amounts of some metabolites produced. The produced volatile metabolites were identified by mass spectrometry and reference compounds. Alcohols, ketones, sulphur compounds and terpenes were most frequently found, but hydrocarbons, ethers and esters were also produced by some species. Among the most commonly produced metabolites, which are also suggested as potential indicator substances for excessive growth of microorganisms in buildings, were 3-methyl-1-butanol, 2-methyl-1-butanol, 3-methyl-2-butanone, 3-methyl-2-pentanone, dimethyl disulphide, -methylfuran, 2,5-dimethylfuran and geosmin. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 5 uppsatser.</p> / digitalisering@umu

Fundação de Apoio a Pesquisa e à Inovação Tecnológica do Estado de Sergipe - FAPITEC/SE / The presence of high concentrations of toxic metals in water bodies requires a constant search for new and more effective methods to treat industrial waste. The present work proposes a technique for the removal of chromium present in leather tannery effluent, using a hybrid magnetic adsorbent, CoFe2O4/NOM, synthesized using an environmentally friendly procedure. Salts of the metals (Co and Fe) were used as precursors and natural organic matter (NOM) was used as the gelification agent, replacing the traditional reagents that are toxic and expensive. Comparisons were made of CoFe2O4/NOM produced at ambient temperature (FeAMB) and the materials produced after calcination at 200 (Fe200), 400 (Fe400), and 800 °C (Fe800). The materials were analyzed by X-ray diffractometry and infrared spectroscopy, which revealed the presence of NOM in the structure of the material, together with the formation of cobalt ferrite, hence confirming the suitability of the new synthesis route. Adsorption tests, performed as a function of pH and time, showed the effectiveness of FeAMB at the natural pH of the effluent (pH 4.2), while at pH 6.0 the removal percentages were approximately 94, 100, 98, and 89% for FeAMB, Fe200, Fe400, and Fe800, respectively, with corresponding equilibration times of 60, 120, 120, and 60 minutes, respectively. Kinetics assays showed that high adsorption of 70-87% was achieved after only 20 minutes. The adsorption kinetics could be fitted using a pseudo-second order model, and the likely removal mechanism was electrostatic attraction between carboxylate groups and the cationic chromium species CrOH2+ and Cr(OH)2 +. Amongst the adsorbents studied, the FeAMB/NOM hybrid material was especially attractive because it did not require heat treatment and showed high removal capacities during five reuse cycles, ranging from 96% in the first cycle to 82% in the fifth cycle. The residues remaining after the reuse cycles, comprising the FeAMB hybrid saturated with chromium (FeAMB_Sat) and the desorbed chromium solution (dried and calcined at 500 °C, denoted CrD), showed excellent catalytic activity in the reduction of 4-nitrophenol to 4-aminophenol, the latter being an important compound used in the synthesis of pharmaceuticals and corrosion inhibitors. The conversion rates and times were 99.9% and 55 seconds for vi FeAMB_Sat, and 99.9% and 3 seconds for CrD. A magnetic hybrid material (denoted FeSF) was also synthesized replacing the analytical grade iron salt precursor by a ferric sulfate solution derived from the treatment of iron ore mining waste. This hybrid was highly efficient as an adsorbent, with 98% removal of chromium present in an industrial effluent in only 20 minutes. The technique described here contributes to the development of industrial symbiosis since it uses materials prepared using natural substances and enables the reuse of waste in the production cycle. The procedure is a technologically viable alternative for the remediation of metal-contaminated effluents. / O aumento da concentração de metais tóxicos nos corpos hídricos impulsiona uma busca constante por tratamentos eficientes para remediar resíduos industriais. Portanto, neste trabalho é proposto a remediação do cromo existente em efluente industrial de curtimento de couro utilizando um adsorvente híbrido magnético, CoFe2O4/MON, sintetizado por uma rota modificada, eco-amigável. Utiliza-se como precursores sais dos metais de interesse e a matéria orgânica natural (MON) como substância gelificante, em substituição aos reagentes tradicionais que são tóxicos e de alto custo. Para fins comparativos, a CoFe2O4/MON obtida à temperatura ambiente (FeAMB) foi calcinada a 200 (Fe200), 400 (Fe400) e 800°C (Fe800) e a formação do material foi confirmada por difratometria de raios x, que indicou também, simultaneamente, com o infravermelho, a presença da MON na estrutura do material, a formação da ferrita de cobalto e assim, a eficácia da rota de síntese proposta. Os ensaios de adsorção em função do pH e do tempo, evidenciaram a eficiência da FeAMB, no pH natural do efluente (4,2), enquanto que para os demais, no pH 6,0; com percentuais de remoção de aproximadamente 94, 100, 98 e 89% para FeAMB, Fe200, Fe400, Fe800, respectivamente, e tempos de equilíbrio de 60, 120, 120 e 60 minutos. Entretanto, com apenas 20 minutos de ensaios cinéticos houve uma alta resposta de adsorção, entre 70-87%. A cinética de adsorção ajustou-se melhor ao modelo de pseudo-segunda ordem e o possível mecanismo de remoção ocorre por atração eletrostática entre os grupos carboxilatos e as espécies catiônicas do cromo, CrOH2+, Cr(OH)2 +. O material híbrido FeAMB/MON destaca-se entre os demais adsorventes em estudo por não ter sido submetido a tratamento térmico e porque apresentou uma elevada capacidade de remoção após ser submetido a cinco ciclos de reutilização, variando de 96% no primeiro ciclo para 82% no quinto ciclo. Os resíduos decorrentes dos ciclos de reutilização, o híbrido FeAMB saturado com cromo (FeAMB_Sat) e a solução de cromo dessorvido, seca e calcinada a 500°C (CrD), apresentaram excelentes potenciais catalíticos na redução do 4- nitrofenol a 4-aminofenol, o qual é um importante insumo para a síntese de produtos farmacêuticos e inibidores de corrosão. A taxa e o tempo de conversão da redução, foram de 99,9% e 55 segundos para FeAMB_Sat e 99,9% e 3 segundos para CrD. De modo eminente, também foi sintetizado um material híbrido magnético substituindo o precursor sal de ferro em grau analítico por solução de sulfato férrico oriunda de um resíduo tratado da mineração de ferro, denominado FeSF. Este híbrido revelou uma eficiência notável como adsorvente, pois o percentual de remoção de cromo presente em efluente industrial foi de 98% em apenas 20 minutos. Diante disso, o presente estudo contribuiu para a prática da simbiose industrial ao propor o emprego de substâncias naturais na elaboração de materiais, bem como a reutilização dos resíduos, e sua reinserção no ciclo produtivo desenvolvendo uma alternativa tecnologicamente viável para remediação de metais.

Afin de satisfaire la demande croissante des systèmes de traitement de l'air, des procédés commerciaux basés sur la photocatalyse par TiO2 ont été commercialisés. Récemment le problème de la désactivation de ces systèmes a attiré l'attention des industriels ainsi que des chercheurs. Les Siloxanes Méthyliques Volatils (SMVs) présents dans l'air auraient été identifiés comme une source majeure contribuant à cette désactivation. Par ailleurs, dans les centres de stockage des déchets, la valorisation du biogaz nécessite de recueillir et de traiter le biogaz issu des déchets organiques en vue de produire de l'énergie renouvelable et inoffensive pour l'environnement. A nouveau, les SMVs ont été identifiés comme un frein principal au développement de cette filière, ces derniers conduisant après oxydation à des dépôts de silice abrasifs dans le moteur. Les difficultés de mesure des SMVs aussi bien dans le biogaz que dans l'air ambiant ainsi que l'évaluation de leur impact sur les systèmes photocatalytiques ou dans les procédés de valorisation du biogaz constituent par conséquent un vrai défi. Afin de répondre à ces problématiques, ce travail comporte trois volets principaux : Le premier volet est dédié à la mise au point d'une méthode de mesure des siloxanes méthyliques volatils dans le biogaz et dans l'air ambiant. Pour ce faire nous avons choisi de mettre en place un système d'échantillonnage des SMVs basé sur leur piégeage et préconcentration sur un support solide suivi d'une désorption thermique ou chimique (extraction par solvant) avant leur analyse par GC-MS. Puisqu'aucune étude systématique sur le choix des supports n'est relatée dans la littérature, nous avons comparé plusieurs types d'adsorbants en déterminant le volume de perçage pour chacun des SMVs afin de choisir le (les) meilleur(s). Le second volet est consacré à l'évaluation des teneurs en SMVs dans le biogaz ainsi que dans l'air ambiant en différents endroits. Une méthode d'analyse des SMVs fiable a été développée qui a permis de confirmer les résultats précédents obtenus au laboratoire en ce qui concerne le choix des adsorbants pouvant piéger quantitativement les SMVs. Enfin, dans le troisième volet, l'impact des SMVs sur les systèmes photocatalytiques en choisissant comme molécule modèle l'octaméthylcyclotétrasiloxane (D4) a été étudié / In order to address the growing demand for indoor air treatment, many commercial systems based in the potocatalytic degradation using TiO2 have reached the market. Recently, deactivation of these systems has been observed. Some of the potentially most important deactivation pollutants are volatile methyl siloxanes (VMS), which are becoming more and more abundant indoor and in ambient air. Moreover, the increasing interest in the utilization of biogas to generate renewable energy (production of heat or electricity), has created significant concerns about the presence of VMS in the biogas. During biogas combustion, VMS are oxidized to abrasive microcrystalline silica that causes serious damage to gas engines, thus reducing the economic benefits of using biogas. Hence, it is essential to be able to measure the concentration of such VMS in ambient air and in biogas by a reliable method, as well as to study their impact on the photocatalytic systems. To address these issues, this work has three main parts: The first part is dedicated to the development of a method for measuring volatile methyl siloxanes in biogas and in ambient air. We have chosen sampling gas through sorbent tube followed by thermal desorption or chemical desorption (solvent extraction) and analysed using GC-MS. Since no systematic study on the choice of materials is related in the literature, we compared several types of adsorbents based on the determination of the VMS breakthrough volume (BV), in order to choose an appropriate adsorbent and to obtain accurate quantification of VMS. The second part is devoted to the evaluation of VMS in biogas and in ambient air at different sites. A reliable analytical method has been developed, and results are in agreement with the previous results obtained in the laboratory regarding the choice of adsorbents. Finally, in the third part, for a better understanding of the impact of VMS on photocatalytic systems, D4 was chosen as a VMS model compound as it is one of the most important VMS