Ce travail de thèse propose de réaliser un nanofil électrique auto-assemblé constitué de protéines. L'unité de base de ce nanofil est une protéine chimère comprenant un domaine capable de former des fibres amyloïdes (Het-s 218-289) et un domaine capable d'effectuer des transferts d'électrons (une rubrédoxine). Le premier domaine permet la réalisation d'une fibre par auto-assemblage tandis que le deuxième est exposé à la surface de cette structure. Les caractéristiques redox du domaine exposé permettent aux électrons de se déplacer d'un bout à l'autre de la fibre par sauts successifs. Un tel nanofil a été créé et caractérisé par différentes techniques biophysiques. Ensuite, la preuve de la conduction des nanofils a été apportée sur des ensembles d'objets, de manière indirecte par électrochimie, et de manière directe par des mesures tension/courant. Ces travaux ouvrent la voie à la réalisation d'objets biocompatibles, biodégradables, possédant des propriétés électroniques exploitables dans des dispositifs technologiques. / The research described in this thesis aims at creating a self-assembled nanowire only made of proteins. The building block of this wire is a chimeric protein that comprises an amyloid fibril forming domain (Het-s 218-289) and an electron transfer domain (rubredoxin). The first one self-assembles in amyloid fibrils which display the second at their surface. Redox characteristics of the exposed domain allow electrons to move from one extremity of the fibril to the other by successive jumps. Such a nanowire has been created and characterized by various biophysical experiments. Then, the conductivity of the nanowires has been demonstrated on sets of wires by electrochemistry and by direct current measurements. These experiments pave the way for future design of biocompatible and biodegradable objects that possess usable electronic properties.

This diploma thesis deals with properties of multi-materials interface composed of pure iron and Cu7Ni2Si1Cr alloy produced by SLM process. The theoretical part of thesis is focused on selective laser melting technology, and on description of defects connected with the production of SLM parts. Furthermore, one section deals with the production of multi-materials prepared by the SLM process. The experimental part of this thesis deals with selections of the SLM process parameters appropriate for bulk samples preparation. Mechanical properties were determined by the tensile tests at room temperature. Metallographic and fractographic analyses were performed for evaluation of the microstructure and description of the fracture mechanisms.

Diploma thesis deals with preparation of peripherally functionalized polydentate Schiff ligands, suitable for metal coordination, such as Fe(III) or Co(III). The compounds, formed by this functionalization using organic molecule or stable organic radical, provide coordination site for another central atom. The compounds were synthesized for their potential biological activity. The organic ligands series was prepared, and these ligands were submitted to coordination reactions with selected transition metals. The prepared compounds were characterized by nuclear magnetic resonance, mass spectrometry, electron paramagnetic resonance and X-ray structure analysis.

L’épuisement des sources d’énergie fossile et les conséquences nocives des gaz à effet de serre sur l’environnement ont accru la nécessité de l’utilisation des énergies renouvelables. Parmi les différentes sources, la biomasse possède un potentiel considérable. Ce projet de recherche vise à étudier la pyrolyse des anas de lin et du bois de hêtre, des biomasses qui se retrouvent communément dans la région Normandie, afin de produire et d’améliorer une bio-huile capable d’être utilisée comme bio-carburant dans les moteurs à combustion. L’objet de cette thèse est donc de fournir une caractérisation détaillée des produits de la pyrolyse des deux biomasses choisies et de leurs constituants purs (la cellulose, l’hémicellulose et la lignine) dans une installation semi-continue. Un traitement catalytique de désoxygénation est ensuite employé pour améliorer les propriétés des bio-huiles obtenues. Les catalyseurs utilisés sont à base de zéolithes (HZSM-5 et H-Y), des mêmes zéolithes modifiées au fer et de métaux (Pt, CoMo) supportés sur alumine. Nous avons constaté que, dans cette installation, une pyrolyse à 500 °C, sous 500 mL/min d’azote, suivie d’une désoxygénation catalytique en utilisant Fe-HZSM-5 comme catalyseur, donnait les meilleurs résultats en termes de rendement en bio-huiles et de taux de désoxygénation. L’effet d’un changement de technologie de réacteur de pyrolyse en utilisant un réacteur continu à chute sur les produits de la pyrolyse a aussi été examiné. Ce réacteur a également été couplé à une étape de traitement catalytique de désoxygénation dans un réacteur à lit fixe indépendant. Il a été aperçu qu’en dépit d’un changement de technologie de réacteur, les conditions opératoires optimales restent les mêmes avec cependant, une différence non négligeable au niveau du taux de désoxygénation. Cette différence a été attribuée à l’effet du temps de contact. Finalement, l’efficacité du catalyseur utilisé lors de la pyrolyse en continu a été suivie dans le temps. Il a été constaté qu’au cours du temps, le catalyseur démontrait une activité décroissante, indiquant qu’un phénomène de désactivation était présent. / Depleting sources of fossil fuels and harmful consequences of greenhouse gas emissions on the environment have heightened the necessity of renewable energy resources. Among the different existing sources, biomass presents a considerable potential. This research work aimed at investigating the pyrolysis of flax shives and beech wood residues, which are biomass residues commonly found in the Normandy region, so as to produce and upgrade a bio-oil capable of being used as a bio-fuel in combustion engines. The objective of this thesis was thus to provide a detailed characterisation of the products obtained from the pyrolysis of the two chosen biomasses and their pure components (cellulose, hemicellulose and lignin) in a semi-continuous system. A catalytic de-oxygenation treatment was then employed to upgrade the properties of the bio-oils obtained. The catalysts used were zeolite-based (HZSM-5 and H-Y), the latter zeolites modified by iron and metals (Pt and CoMo) supported on alumina. It was observed that, in this setup, pyrolysis at 500 °C under 500 mL/min of nitrogen, followed by a catalytic de-oxygenation using Fe-HZSM-5 as catalyst, gave the best results in terms of bio-oil yield and de-oxygenation degree. The effect, on the pyrolysis products, of changing the pyrolysis reactor technology to a continuous drop-tube reactor was also investigated. This reactor was similarly coupled with a catalytic de-oxygenation treatment step occurring in a separate fixed bed reactor. It was found that despite a change in reactor technology, the optimal operational conditions remain the same, although a non-negligible difference was noticed with respect to the de-oxygenation degree. This difference was attributed to the effect of contact time. Finally, the efficiency of the catalyst used during the continuous pyrolysis was monitored in time. It was seen that over time, the catalyst presented a diminishing activity, indicating the presence of a de-activation phenomenon.

The recent discovery of high-temperature superconductivity in Fe-based materials triggered worldwide efforts to investigate their fundamental properties. Despite a lot of similarities to cuprates and MgB2, important differences like near isotropic behaviour in contrast to cuprates and the peculiar pairing symmetry of the order parameter (OP) have been reported. The OP symmetry of Fe-based superconductors (FBS) was theoretically predicted to be of so-called s± state prior to various experimental works. Still, most of the experimental results favour the s± scenario; however, definitive evidence has not yet been reported. Although no clear understanding of the superconducting mechanisms yet exists, potential applications such as high-field magnets and Josephson devices have been explored. Indeed, a lot of reports about FBS tapes, wires, and even SQUIDs have been published to this date. In this thesis, the feasibility of high-field magnet applications of FBS is addressed by studying their transport properties, involving doped BaFe2As2 (Ba-122) and LnFeAs(O,F) [Ln=Sm and Nd]. Particularly, it is important to study physical properties in a sample form (i.e. thin films) that is close to the conditions found in applications. However, the realisation of epitaxial FBS thin films is not an easy undertaking. Recent success in growing epitaxial FBS thin films opens a new avenue to delve into transport critical current measurements. The information obtained through this research will be useful for exploring high-field magnet applications. This thesis consists of 7 chapters: Chapter 1 describes the motivation of this study, the basic background of superconductivity, and a brief summary of the thin film growth of FBS. Chapter 2 describes experimental methods employed in this study. Chapter 3 reports on the fabrication of Co-doped Ba-122 thin films on various substrates. Particular emphasis lies on the discovery of fluoride substrates to be beneficial for epitaxy without compromising superconducting properties. It is worth mentioning, that a world record Tc of 28 K for Co-doped Ba-122 thin films is reported here. Chapter 4 describes high-field transport properties (up to dc 35 T) of epitaxial P-doped Ba-122 thin films prepared by MBE. Among the FBS, P-doped Ba-122 shows very high transport critical current densities, although the Tc is lower than for LnFeAs(O,F)[Ln=Sm and Nd]. Additionally, the film is microstructurally clean. These high Jc values are due to a high vortex line energy. Chapter 5 deals with transport properties of epitaxial SmFeAs(O,F) thin films. In the course of this work, a dc 45 T magnet has been used within collaboration with the National High Magnetic Field Laboratory at Tallahassee, FL, USA. SmFeAs(O,F) thin films have been prepared by molecular beam epitaxy (MBE). The investigated film shows a very high transport critical current density (Jc) of over 105 A/cm2 at 45T and 4.2K for both main crystallographic directions, which features favourable for high-field magnet applications. Additionally, by investigating the pinning properties, a dimensional crossover between the superconducting coherence length and the FeAs interlayer distance at 30-40K was observed. Chapter 6 reports on high-field transport properties of NdFeAs(O,F) thin films prepared by MBE. In this case, the transition from Abrikosov to Josephson vortices was observed around 20-30K. Additionally, the angular Jc data were scaled with the anisotropic GinzburgLandau approach. The obtained parameters at given temperature are observed to increase with decreasing temperature, which is different from Co-doped Ba-122. Chapter 7 summarises this work. / Die kürzliche Entdeckung von Hochtemperatur-Supraleitung in Fe-basierten Materialien löste weltweite Bemühungen aus, deren grundlegende Eigenschaften zu untersuchen. Neben vielen Gemeinsamkeiten mit den Kupraten und MgB2 sind wichtige Unterschiede wie nahezu isotropes Verhalten (im Gegensatz zu den Kupraten) und eine auffällige Paarungssymmetrie des Ordnungsparameters (OP) berichtet worden. Die OP-Symmetrie der Fe-basierten Supraleiter (FBS) wurde theoretisch als s± berechnet, noch bevor experimentelle Versuche unternommen wurden. Derzeit favorisieren experimentelle Ergebnisse das s±-Szenario, dennoch gibt es noch keine definitiven Nachweise. Obwohl noch kein komplettes Verständnis des supraleitenden Mechanismus existiert, wurden schon potentielle Anwendungen wie Josephson-Elemente und Hochfeldmagnete erforscht. In der Tat erschienen zahlreiche Veröffentlichungen über supraleitende Kabel, Bänder und auch SQUIDs. Diese Arbeit befasst sich mit der Durchführbarkeit von Hochfeld-Anwendungen durch die Untersuchung der Transporteigenschaften von FBS, namentlich Ba-122 und LnFeAs(O,F)[Ln=Sm und Nd]. Es ist von großer Wichtigkeit, die physikalischen Eigenschaften in einer Probenform zu untersuchen, die der Form in Anwendungen nahekommt (z.B. Dünnschichten), um dieselben Rahmenbedingungen vorgeben zu können. Es ist jedoch nicht einfach, epitaktische FBS Dünnschichten zu realisieren. Kürzlich gewonnene Erkenntnisse in der Herstellung von epitaktischen FBS-Dünnschichten ermöglichen nun ein tieferes Eindringen in die Transporteigenschaften. Die in diesen Untersuchungen gewonnenen Informationen stellen somit wichtige Argumente in der Diskussion um Hochfeld Anwendungen dar. Diese Arbeit besteht aus sieben Kapiteln: Kapitel 1 beinhaltet die Motivation dieser Arbeit, die Grundlagen der Supraleitung und eine kurze Zusammenstellung der bisherigen Arbeiten zur Dünnschichtherstellung von FBS. Kapitel 2 beschreibt experimentelle Methoden, die im Zuge dieser Arbeit verwendet wurden. Kapitel 3 berichtet von der Herstellung Co-dotierter Ba-122 Dünnschichten (Co-Ba-122) auf verschiedenen Fluoridsubstraten. Dabei wurde Augenmerk darauf gelegt, neben einem verbesserten epitaktischen Wachstum der Dünnschichten die supraleitenden Eigenschaften nicht zu beeinträchtigen. Anzumerken ist, dass in diesem Rahmen Tc-Rekord-Werte von 28 K in Co-Ba-122 erzielt werden konnten. Kapitel 4 beschreibt die Hochfeld-Transporteigenschaften epitaktisch gewachsener P-dotierter Ba-122 Dünnschichten, die durch MBE hergestellt wurden. Unter den FBS zeigt P-dotiertes Ba-122 enorm hohe kritische Transport-Stromdichten, obwohl das Tc niedriger ist als bei LnFeAs(O,F)[Ln=Sm und Nd]. Der Grund dafür konnte in der hohen Flusslinienkern-Energie des P-dotierten Ba-122 ermittelt werden. Kapitel 5 behandelt Transporteigenschaften von epitaktisch gewachsenen SmFeAs(O,F)-Dünnschichten. In diesem Zusammenhang wurde ein dc-45 T-Hochfeldmagnet in Zusammenarbeit mit dem National High Magnetic Field Laboratory in Tallahassee, Florida, USA, genutzt. SmFeAs(O,F)-Dünnschichten wurden mit dem Molekularstrahl-Verfahren (MBE) hergestellt. Die Schichten zeigen sehr hohe kritische Transport-Stromdichten (Jc) von über 105 A/cm2 bei 45 T und 4.2 K für beide kristallographische Hauptrichtungen, parallel zur c-Achse und in der ab-Ebene. Diese Ergebnisse sehen sehr verheißungsvoll für eine Verwendung in Hochfeld-Anwendungen aus. Zusätzlich konnte durch die Untersuchung der Pinning-Eigenschaften ein Dimensionsübergang zwischen supraleitender Kohärenzlänge und FeAs-Ebenenabstand im Bereich 30-40 K beobachtet werden. Kapitel 6 berichtet über die Hochfeld-Transporteigenschaften von NdFeAs(O,F)-Dünnschichten, die mithilfe des MBE-Verfahrens hergestellt wurden. In diesem Falle konnte ein Ubergang von Abrikosov- zu Josephson-Flusslinien im Temperaturbereich 20-30 K beobachtet werden. Zusätzlich konnte die winkelabhängige kritische Stromdichte mit dem anisotropen Ginzburg-Landau-Ansatz skaliert werden. Die erhaltenen Parameter für verschiedene Temperaturen steigen mit fallender Temperatur. Dieses Verhalten ist gegensätzlich zu dem in Co-dotiertem Ba-122 gefundenen. Kapitel 7 gibt eine Zusammenfassung dieser Arbeit.

In this thesis, the electronic properties in superconducting LiFeAs single crystal are investigated using low temperature scanning tunneling microscopy and spectroscopy (STM/S) at various temperatures. For this purpose, the differential conductance (dI/dV) measured by STS which is directly proportional to the local density of states (LDOS) of the sample to the sub-atomic precision, is used together with the topography information. The dI/dV spectra within the ±1 V energy range reveal a characteristic feature at around -350 mV to -400 mV in stoichiometric LiFeAs. This feature seems to be a universal property among all the Fe-based high temperature superconductors, because it is also found in Fe0.965Se1.035 and NaFe0.975Co0.025As single crystals at the energy of -210 mV and -200 mV, respectively. The temperature dependent spectroscopy data averaged over a spatially fixed clean area of 2 nm × 2 nm are successfully executed between 5 K and 20 K. The two distinct superconducting phases with critical temperatures Tc = 16 K and 18 K are observed. In addition, the distance between the dip position outside the superconducting gap and the superconducting coherence peak in the spectra remains temperature independent which confirms that it is not connected to an antiferromagnetic (AFM) spin resonance. The temperature dependent spectra have been measured between 5 K and 61 K within the energy range of ±100 mV as well. The hump structure at 42 mV tends to disappear around 60 K from unknown origin. The temperature dependent quasiparticle interference (QPI) has been studied within the temperature range between 6.7 K and 25 K and analyzed by the Fourier transformation of the measured spectroscopic maps. The dispersion plots in momentum space as a function of temperature show an enhancement of QPI intensity (±5.5 mV) within the superconducting gap at the Fermi level at 6.7 K near q ~ 0. This is interpreted on the basis of Andreev bound state. In both polarities outside of this, a depletion of QPI intensity is noticed between 5.5 mV and around 9 mV. At positive energies, the QPI intensity becomes very rich above 9 mV. The size of the enhanced QPI intensity near the Fermi level, and the edge of the rich QPI intensity beyond 9 mV are found to behave like superconducting order parameter with rising of temperature. Furthermore, an energy mode peaked at around 14 mV appears in the integrated QPI intensity below superconducting Tc (6.7 K). This is consistent with the observed peak at 1st derivative of the dI/dV spectra. In both of these cases, such 14 mV peak is suppressed at normal state (25 K). This mode is therefore directly related to superconductivity in LiFeAs. The off-stoichiometric LiFeAs single crystal with superconducting Tc of 6.5 K has a 10 mV rigid band shift of the Fermi level towards electron doping. The absence of the rich QPI intensity between 9 mV and 17 mV is found compared to the stoichiometric LiFeAs, and hence the 14 mV mode is absent here. This brings us to conclude once more time that such 14 mV energy mode is relevant for superconductivity in LiFeAs.

The magnetic Fe–6.5 wt% Si powder was produced by gas atomization and its microstructure was also investigated. The secondary dendritic arm spacing (SDAS) is related to the droplet size, λ = 0.29 · D⁰·⁵, and the numerical solidification model was applied to the system, giving rise to the correlation of microstructure to the solidification process of the droplet. It is found that the solid fraction at the end of recalescence is strongly dependent on the undercooling achieved before nucleation; the chances for the smaller droplets to form the grain-refined microstructures are less than the larger ones. Furthermore, the SDAS is strongly influenced by the cooling rate of post-recalescence solidification, and the relationship can be expressed as follows, λ = 74.2 · (T)⁻⁰·³⁴⁷. Then, the growth of the SDAS is driven by the solute diffusion of the interdendritic liquids, leading to a coarsening phenomenon, shown in a cubic root law of local solidification time, λ = 10.73 · (tf)⁰·²⁹⁶.

Es wird ein auf der Submodelltechnik basierender Ansatz vorgestellt, mit dem Cord-Elastomer-Verbunde, speziell die Balgwände von Luftfedern, einer detaillierten FE-Analyse zugänglich gemacht werden können. Dieser Ansatz beinhaltet ein Globalmodell, das die gesamte Luftfeder abbildet, und zwei Submodelle, die sich auf bestimmte Ausschnitte der Balgwand konzentrieren.

Ferritisch/martensitische Cr-Stähle und deren oxiddispersionsverfestigte Varianten gehören zu den potenziellen Konstruktionswerkstoffen für Komponenten zukünftiger kerntechnischer Einrichtungen, wie z. B. Fusionsreaktoren und Spalt-reaktoren der IV. Generation, die Strahlungsfeldern mit hohem Neutronenfluss aus-gesetzt sind. Ein Hauptproblem dieser Materialgruppen ist das Auftreten des Spröd-duktil-Übergangs und dessen maßgeblich durch die Strahlenhärtung verursachte Verschiebung zu höheren Temperaturen. In der vorliegenden Arbeit wird das Bestrahlungsverhalten von binären Fe-Cr-Modelllegierungen untersucht, die ein vereinfachtes Modell für ferritisch/martensitische Cr-Stähle darstellen. Dabei werden Bestrahlungen mit Eisenionen zur Simulation der durch Neutronen hervorgerufenen Schädigung verwendet. Die auf wenige Mikrometer begrenzte Eindringtiefe der Ionen macht es erforderlich, dass für dünne Schichten geeignete Charakterisierungsmethoden ein-gesetzt werden. Im Rahmen dieser Arbeit sind das Nano¬härte¬messungen und Transmissions¬elektronen¬mikroskopie (TEM). Im Ergebnis liegen die bestrahlungsinduzierte Härteänderung der Schicht in Ab-hängig¬keit von Chromgehalt, Bestrahlungsfluenz und –temperatur sowie, für aus-gewählte Zustände, quantitative TEM-Analysen vor. Zusammen mit begleitenden Ergebnissen von Neutronenkleinwinkelstreuexperimenten an neutronen-bestrahlten Proben der gleichen Werkstoffe ermöglichen sie die Identifizierung von bestrahlungsinduzierten Versetzungsringen und nm-großen α’-Ausscheidungen als Quellen der Strahlenhärtung. Im Rahmen eines vereinfachten Modells, das auf Orowan zurückgeht, werden die Hindernis¬stärken dieser Gitterbaufehler für das Gleiten von Versetzungen abgeschätzt. Darauf aufbauend erfolgt ausblickartig eine Erweiterung des Untersuchungsgegenstands auf komplexere Situationen hinsichtlich der Bestrahlungs-bedingungen und des Werkstoffs. Durch das Einbeziehen simultaner und sequentieller Bestrahlungen mit Eisen- und Heliumionen kann gezeigt werden, dass der Effekt von Helium auf die Strahlenhärtung von der Bestrahlungs-reihenfolge abhängt und dass der simultane Eintrag fusionsrelevanter Mengen von Helium zu einer Verstärkung der Strahlenhärtung führt, die auf einem synergistischen Effekt beruht. Für Cr-Stähle mit 9 % Cr und deren oxiddispersions-verfestigte Varianten wird kein grundlegend anderes Bestrahlungsverhalten beobachtet als für binäres Fe-9at%Cr. Es gibt jedoch Hinweise, dass Oxid-dispersionsverfestigung die Strahlenhärtung unter bestimmten Bedingungen reduzieren kann. Im Ergebnis der Arbeit zeigt sich, dass Ionenbestrahlungen in Kombination mit Nanohärtemessungen zu einem vertiefenden Verständnis der Strahlenhärtung in Werkstoffen auf Fe-Cr-Basis sowie zu einer effektiven Materialvorauswahl beitragen können. Voraussetzung ist, dass der Eindruckgrößeneffekt und der Substrateffekt auf geeignete Weise in Rechnung gestellt werden.

<p>Prisusutvo&nbsp; arsena&nbsp; u&nbsp; podzemnim&nbsp; vodama,&nbsp; koje&nbsp; se&nbsp; primenjuju&nbsp; za vodosnabdevanje stanovni&scaron;tva je globalan problem. Različiti&nbsp; konvencionalni<br />procesi&nbsp; se primenjuju&nbsp; za&nbsp; uklanjanje&nbsp; arsena iz vode, uključujući koagulaciju i<br />flokulaciju,&nbsp; sorpciju,&nbsp; membransku&nbsp; filtraciju&nbsp; i&nbsp; jonsku&nbsp; izmenu.&nbsp; Uzimajući&nbsp; u<br />obzir relativnu nisku cenu, jednostavnu kontrolu procesa i održavanje, visok<br />stepen uklanjanja arsena, sorpcija se smatra jednom od najpodobnijih tehnika<br />za uklanjanje arsena u tretmanu vode za piće. Premda su na trži&scaron;tu dostupni<br />različiti&nbsp; sorbenti&nbsp; za&nbsp; uklanjanje&nbsp; arsena,&nbsp; postoji&nbsp; potreba&nbsp; za&nbsp; iznalaženjem&nbsp; i<br />razvojem&nbsp; novih&nbsp;<em> low-cost&nbsp;</em> sorbenata,&nbsp; a&nbsp; kojima&nbsp; bi&nbsp; se&nbsp; pak&nbsp; mogao&nbsp; obezbediti<br />visok stepen uklanjanja oba oksidaciona oblika&nbsp; arsena,&nbsp; i&nbsp; As(III) i As(V). Cilj<br />ovog rada bio je usmeren na sintezu i karakterizaciju novih sorbenata na bazi<br />gvožđa&nbsp; i&nbsp; mangana&nbsp; odnosno&nbsp; Fe-Mn&nbsp; binarnog&nbsp; oksida,&nbsp; ispitivanje&nbsp; njihovog<br />potencijala&nbsp; za&nbsp; uklanjanje&nbsp; arsena&nbsp; iz&nbsp; vode&nbsp; i&nbsp; utvrđivanje&nbsp; da&nbsp; li&nbsp; novosintetisani<br />sorbenti po pitanju efikasnosti, mogu konkurisati postojećim komercijalnim i<br />&scaron;iroko kori&scaron;ćenim sorbentima u tretmanima voda.<br />Metodom&nbsp; precipitacije,&nbsp; sintetisani&nbsp; su&nbsp; Fe-Mn&nbsp; binarni&nbsp; oksidi&nbsp; sa&nbsp; različitim Fe:Mn&nbsp; molskim&nbsp; odnosima&nbsp; 1:1,&nbsp; 3:1,&nbsp; 6:1&nbsp; i&nbsp; 9:1,&nbsp; dok&nbsp; su&nbsp; kombinacijom heterogene&nbsp; nukleacione&nbsp; tehnike&nbsp; i&nbsp; precipitacije,&nbsp; sintetisana&nbsp; i&nbsp; četiri&nbsp; sorbenta magnetnih&nbsp; svojstava&nbsp; (Mag,&nbsp; Mag-Fe,&nbsp; Mag-Mn,&nbsp; Mag-FeMn).&nbsp; Modifikacijom biopolimera&nbsp; Chitosana&nbsp; i&nbsp; GAC,&nbsp; sa&nbsp; Fe-Mn&nbsp; binarnim&nbsp; oksidom,&nbsp; razvijena&nbsp; su preostala&nbsp; dva&nbsp; materijala&nbsp; Chit-FeMn,&nbsp; odnosno&nbsp; GAC-FeMn.&nbsp; Sintetisani sorbenti su karakterisani različitim tehnikama i metodama (SEM/EDS, XRD,FTIR, BET).Fizičko-hemijskom karakterizacijom sintetisanih sorbenata ustanovljeno je da se Fe-Mn binarni oksidi i magnetni materijali, karakteri&scaron;u relativno velikim specifičnim&nbsp; povr&scaron;inama&nbsp; (109-300&nbsp; m²/g)&nbsp; i&nbsp; zapreminama&nbsp; mezopora (0,144-0,403&nbsp; cm ³ /g).&nbsp; Velika&nbsp; specifična&nbsp; povr&scaron;ina&nbsp; i&nbsp; razvijena&nbsp; mikroporozna struktura uočena je kod GAC-FeMn (996 m<br />² /g; 0,394 cm^{3 /}g). U poređenju sa ostalim&nbsp; sintetisanim&nbsp; sorbentima,&nbsp; Chit-FeMn&nbsp; je&nbsp; karakterisala&nbsp; najmanja specifična&nbsp; povr&scaron;ina&nbsp; i&nbsp; zapremina&nbsp; mezopora&nbsp; (1,99&nbsp; m<br />²/g;&nbsp; 0,014&nbsp; cm ³ /g).&nbsp; XRD analiza&nbsp; Fe-Mn&nbsp; binarnih&nbsp; oksida&nbsp; ukazala&nbsp; je&nbsp; da&nbsp; je&nbsp; fazna&nbsp; struktura&nbsp; sintetisanih Fe-Mn&nbsp; binarnih&nbsp; oksida&nbsp; slična&nbsp; ferihidratu&nbsp; dok&nbsp; je&nbsp; fazna&nbsp; struktura&nbsp; magnetnih materijala ukazala na prisustvo magemita.<br />Ispitivanja kinetike sorpcionog procesa ukazala su da je mehanizam sorpcije<br />As(III)&nbsp; i&nbsp; As(V)&nbsp; na&nbsp; sintetisanim&nbsp; sorbentima&nbsp; sloţena&nbsp; kombinacija&nbsp; povr&scaron;inske<br />hemisorpcije,&nbsp; koja&nbsp; se&nbsp; odvija&nbsp; kroz&nbsp; granični&nbsp; sloj&nbsp; čestica&nbsp; sorbenata&nbsp; i unutarčestične difuzije. Tome u prilog i&scaron;li su i rezultati FTIR analize kojima<br />je potvrđeno da se sorpcija arsena na sintetisanim sorbentima ostvaruje kroz<br />interakcije hidroksilnih grupa gvožđa prisutnih na povr&scaron;ini sorbenata i arsena.<br />Dodatno, pokazano je da se za razliku od sorpcije As(V), sorpcija As(III) na sorbentima&nbsp; koji&nbsp; pored&nbsp; oksida&nbsp; gvožđa&nbsp; sadrže&nbsp; i&nbsp; okside&nbsp; mangana&nbsp; (Fe-Mn binarni oksidi, Mag-FeMn, Mag-Mn,Chit-FeMn i GAC-FeMn) odvija u dva koraka. U prvom koraku As(III) se oksiduje do As(V), dok u drugom koraku, oksidovani&nbsp; As(V)&nbsp; mehanizmom&nbsp; ligandne&nbsp; izmene&nbsp; formira&nbsp; komplekse&nbsp; na povr&scaron;ini ovih sorbenata.<br />Afiniteti sorpcije Fe-Mn binarnih oksida (na osnovu K_d vrednosti)&nbsp; za As(III) opadali su u nizu Fe-Mn 3:1 &gt; Fe-Mn 1:1 &gt; Fe-Mn 6:1 &gt; Fe-Mn 9:1 odnosno kod&nbsp; As(V):&nbsp; Fe-Mn&nbsp; 6:1&nbsp; &gt;&nbsp; Fe-Mn&nbsp; 3:1&nbsp; &gt;&nbsp; Fe-Mn&nbsp; 9:1&nbsp; &gt;&nbsp; Fe-Mn&nbsp; 1:1.&nbsp; Kod magnetnih kompozita,&nbsp; najveća K_d vrednost za As(III) i As(V) ustanovljena je kod&nbsp; Mag-FeMn.&nbsp; Uop&scaron;teno,&nbsp; Kd<br />vrednosti&nbsp; za&nbsp; As(III),&nbsp; kod&nbsp; magnetnih kompozita,&nbsp; opadale&nbsp; su&nbsp; u&nbsp; nizu:&nbsp; Mag-FeMn&nbsp; &gt;&nbsp; Mag-Mn&nbsp; &gt;&nbsp; Mag&nbsp; &gt;&nbsp; Mag-Fe, Slično, afinitet sorbenata za As(V), opadao je na sledeći način: Mag-FeMn &gt; Mag&nbsp; &gt;&nbsp; Mag-Fe&nbsp; &gt;&nbsp; Mag-Mn.&nbsp; U&nbsp; poređenju&nbsp; sa&nbsp; neimpregniranim,&nbsp; K_d vrednosti bile su daleko veće kod obloţenih materijala, Chit-FeMn i GAC-FeMn, &scaron;to je ukazalo&nbsp; na&nbsp; značajan&nbsp; doprinos&nbsp; Fe-Mn&nbsp; binarnog&nbsp; oksida&nbsp; adsorpcionom kapacitetu neimpregniranih medija za As(III) i As(V). U&nbsp; odnosu&nbsp; na&nbsp; ostale&nbsp; ispitivane&nbsp; anjone,&nbsp; najveći&nbsp; uticaj&nbsp; na&nbsp; sorpciju&nbsp; oba&nbsp; oblika arsena&nbsp; na&nbsp; svim&nbsp; sintetisanim&nbsp; sorbentima&nbsp; uočen&nbsp; je&nbsp; kod&nbsp; fosfata,&nbsp; dok&nbsp; je&nbsp; uticaj nitrata i hlorida, u svim slučajevima bio bez značaja. Uticaj ispitivanih anjona na&nbsp; sorpciju&nbsp; As(III)&nbsp; i&nbsp; As(V)&nbsp; na&nbsp; Fe-Mn&nbsp; binarnim&nbsp; oksidima,&nbsp; magnetnim materijalima, Chit-FeMn kao i na sorpciju As(V) na GAC-FeMn, opadao je u nizu: fosfati &gt; silikati &gt; karbonati &gt; sulfati &gt; nitrati &gt; hloridi. Slično, uticaj ispitivanih&nbsp; anjona&nbsp; na&nbsp; sorpciju&nbsp; As(III)&nbsp; na&nbsp; GAC-FeMn&nbsp; je&nbsp; opadao&nbsp; na&nbsp; sledeći način: fosfati &gt; silikati &gt; sulfati &gt; karbonati &gt; nitrati &gt; hloridi.Primenom&nbsp; sme&scaron;e&nbsp; NaCl-NaOH-NaOCl&nbsp; odnosno&nbsp; primenom&nbsp; 0,1&nbsp; M&nbsp; i&nbsp; 0,5&nbsp; M&nbsp; rastvora NaOH, ustanovljeno je da se sintetisani sorbenti mogu jednostavno i&nbsp; efikasno&nbsp; regenerisati&nbsp; i&nbsp; vi&scaron;estruko&nbsp; primeniti,&nbsp; &scaron;to&nbsp; je&nbsp; od&nbsp; izuzetnog&nbsp; značaja&nbsp; sa ekolo&scaron;kog i ekonomskog aspekta.&nbsp; Najmanje smanjenje sorpcionog kapaciteta&nbsp; i za As(III) i za As(V), nakon pet ciklusa sorpcije -desorpcije, ustanovljeno je kod binarnog oksida sa Fe:Mn molskim odnosom 3:1 i Mag-FeMn.&nbsp; Na osnovu rezultata prikazanih u ovom radu, može se zaključiti da sintetisani sorbenti,&nbsp; Fe-Mn&nbsp; binarni&nbsp; oksidi&nbsp; i&nbsp; magnetni&nbsp; kompoziti,&nbsp; posebno&nbsp; Mag-FeMn, mogu&nbsp; biti&nbsp; efikasna&nbsp; i&nbsp; ekonomična&nbsp; alternativa&nbsp; skupim&nbsp; komercijalnim sorbentima&nbsp; i&nbsp; drugim&nbsp; sofisticiranim&nbsp; tehnologijama.&nbsp; Visok&nbsp; oksidacioni&nbsp; i sorpcioni kapacitet ovih&nbsp; materijala, koji obezbeđuje istovremeno uklanjanje&nbsp; oba oksidaciona oblika arsena daje veliku prednost ovim sorbentima i čini ih veoma&nbsp; atraktivnim&nbsp; i&nbsp; obećavajućim&nbsp; u&nbsp; tretmanu&nbsp; voda.&nbsp; Dodatni&nbsp; benefit<br />magnetnih&nbsp; sorbenata,&nbsp; pre&nbsp; svega&nbsp; Mag-FeMn,&nbsp; ogleda&nbsp; se&nbsp; u&nbsp; njegovoj jednostavnoj separaciji iz vodenog medijuma i recirkulaciji u sistemu. Glavne prednosti&nbsp; sintetisanih&nbsp; Chit-FeMn&nbsp; i&nbsp; GAC-FeMn,&nbsp; ogledaju&nbsp; se&nbsp; u&nbsp; mogućnosti&nbsp; njihove primene kao efikasne filtracione ispune.</p> / <p>The&nbsp; presence&nbsp; of&nbsp; inorganic&nbsp; arsenic&nbsp; in&nbsp; groundwater&nbsp; used&nbsp; for&nbsp; drinking&nbsp; water supply&nbsp; is&nbsp; a&nbsp; global&nbsp; problem.&nbsp; Different&nbsp; techniques&nbsp; such&nbsp; as&nbsp; oxidation, coagulation,&nbsp; adsorption,&nbsp; ion&nbsp; exchange,&nbsp; and&nbsp; membrane&nbsp; filtration&nbsp; have&nbsp; been developed&nbsp; and&nbsp; applied&nbsp; for&nbsp; arsenic&nbsp; removal&nbsp; from&nbsp; aqueous&nbsp; media.&nbsp; Among these&nbsp; technologies,&nbsp;&nbsp; adsorption&nbsp; is&nbsp; regarded&nbsp; as&nbsp; one&nbsp; of&nbsp; the&nbsp; most&nbsp; promising approaches to remove arsenic from water because of its high efficiency, low cost, simplicity of operation. Although many sorbents for arsenic removal are available on the market, there is still a need to identify and develop new&nbsp; lowcost&nbsp; sorbents which are highly effective in removing both oxidation states of arsenic, As(III) and As(V). This dissertation therefore presents the synthesis and&nbsp; characterization&nbsp; of&nbsp; ten&nbsp; new&nbsp; iron&nbsp; and&nbsp; manganese&nbsp; based&nbsp; sorbents specifically developed for effective As removal. The Fe- Mn binary oxides were prepared with Fe:Mn molar ratios of 1:1, 3:1,6:1 and 9:1, while four heterogeneous magnetic composites (Mag, Mag-Fe,Mag-Mn,&nbsp; Mag-FeMn)&nbsp; were&nbsp; synthesized&nbsp; by&nbsp; combining&nbsp; the&nbsp; heterogeneous nucleation&nbsp; technique&nbsp; with&nbsp; precipitation.&nbsp; The&nbsp; remaining&nbsp; two&nbsp; materials, Chit-FeMn&nbsp; and&nbsp; GAC-FeMn,&nbsp; were&nbsp; created&nbsp; by&nbsp; modifying&nbsp; the&nbsp; Chitosan&nbsp; and GAC&nbsp; biopolymers&nbsp; with&nbsp; Fe-Mn&nbsp; binary&nbsp;&nbsp; oxide&nbsp; (Chit-FeMn&nbsp; and&nbsp; GAC-FeMn).Multiple&nbsp; techniques&nbsp; were&nbsp; applied&nbsp; to&nbsp; determine&nbsp; the&nbsp; physical&nbsp; and&nbsp; chemical characteristics&nbsp; of&nbsp; the&nbsp; resulting&nbsp; sorbents&nbsp; (including&nbsp; SEM/EDS,&nbsp; XRD,&nbsp; FTIR and BET analyses). In order to establish which sorbents show&nbsp; the greatest promise for application during&nbsp; drinking&nbsp; water&nbsp; treatment,&nbsp; the&nbsp; sorption&nbsp; capacity&nbsp; of&nbsp; the&nbsp; sorbents,&nbsp; theAs(III)&nbsp; and&nbsp; As(V)&nbsp; sorption&nbsp; mechanisms,&nbsp; and&nbsp; the&nbsp; impact&nbsp; of&nbsp; various&nbsp; factors relevant to arsenic sorption, including the regeneration potential and the reuse potential of the sorbents, were all investigated in&nbsp; batch experiments. During the physical characterisation, the Fe-Mn binary oxides and magnetic materials&nbsp; were&nbsp; found&nbsp; to&nbsp; have&nbsp; relatively&nbsp; large&nbsp; specific&nbsp; surface&nbsp; areas (109-300 m 2 /g) and mesopore volumes (0.144-0.403 cm 3 /g).&nbsp; A large specific surface&nbsp; area&nbsp; and&nbsp; microporous&nbsp; structure&nbsp; was&nbsp; observed&nbsp; for&nbsp; GAC-FeMn&nbsp; (996 m 2 /g;&nbsp; 0.394&nbsp; cm 3 /g).&nbsp; In&nbsp; comparison&nbsp; with&nbsp; the&nbsp; other&nbsp; synthesized&nbsp; sorbents,&nbsp; Chit-FeMn has the smallest specific surface area and pore volume (1.99 m 2 /g; 0.014&nbsp; cm 3 /g).&nbsp; XRD&nbsp; analyses&nbsp; of&nbsp; the&nbsp; Fe-Mn&nbsp; binary&nbsp; oxides&nbsp; indicated&nbsp; that&nbsp; the phase&nbsp; structure&nbsp; of&nbsp; the&nbsp; synthesized&nbsp; Fe-Mn&nbsp; binary&nbsp; oxides&nbsp; was&nbsp; similar&nbsp; to ferrihydrate,&nbsp; while&nbsp; the&nbsp; phase&nbsp; structure&nbsp; of&nbsp; the&nbsp; magnetic&nbsp; materials&nbsp; showed&nbsp; a good agreement with the XRD diffractogram of maghemite. Investigations into As sorption process kinetics have shown that the sorption mechanism&nbsp; for&nbsp; both&nbsp; As(III)&nbsp; and&nbsp; As(V)&nbsp; on&nbsp; the&nbsp; synthesized&nbsp; sorbents&nbsp; is&nbsp; a combination&nbsp; of&nbsp; surface&nbsp; hemisorption,&nbsp; which&nbsp; takes&nbsp; place&nbsp; through&nbsp; the boundary&nbsp; layer&nbsp; of&nbsp; sorbent&nbsp; particles,&nbsp; and&nbsp; intracellular&nbsp; diffusion.&nbsp; The&nbsp; FTIR analyses&nbsp; confirmed&nbsp; that&nbsp; arsenic&nbsp; sorption&nbsp; was&nbsp; accomplished&nbsp; through&nbsp; the interactions&nbsp; of&nbsp; the&nbsp; hydroxyl&nbsp; groups&nbsp; of&nbsp; iron&nbsp; present&nbsp; on&nbsp; the&nbsp; surface&nbsp; of&nbsp; the sorbents and arsenic. In contrast to the sorption of As(V), it was also shown that&nbsp; As(III)&nbsp; sorption&nbsp; onto&nbsp; sorbents&nbsp; containing&nbsp; manganese&nbsp; oxides&nbsp; (Fe-Mn binary&nbsp; oxides,&nbsp; Mag-FeMn,&nbsp; Mag-Mn,&nbsp; Chit-FeMn&nbsp; and&nbsp; GAC&nbsp; -FeMn)&nbsp; takes place in two steps. In the first step As(III) is oxidized to As(V), while in the second&nbsp; step,&nbsp; the&nbsp; oxidized&nbsp; As(V)&nbsp; forms&nbsp; complexes&nbsp; on&nbsp; the&nbsp; surface&nbsp; of&nbsp; the sorbents via ligand exchange. The&nbsp; Fe-Mn&nbsp; binary&nbsp; oxide&nbsp; sorption&nbsp; capacities&nbsp; (expressed&nbsp; as&nbsp; Kd values)&nbsp; for As(III)&nbsp;&nbsp; followed the trend Fe-Mn 3:1 &gt; Fe-Mn 1:1 &gt; Fe-Mn 6:1 &gt; Fe-Mn 9:1, whereas the&nbsp; As(V) trend was Fe-Mn 6:1 &gt; Fe-Mn 3:1 &gt; Fe-Mn 9:1 &gt; Fe-Mn 1:1. In the magnetic&nbsp; composites, the largest&nbsp; Kd value for As(III) and As(V) was&nbsp; obtained&nbsp; for&nbsp; Mag-FeMn.&nbsp; Generally,&nbsp; the&nbsp; Kd values&nbsp; for&nbsp; As(III)&nbsp; in&nbsp; the magnetic composites decreased in the series: Mag-FeMn &gt; Mag-Mn &gt; Mag &gt; Mag-Fe.&nbsp; Similarly,&nbsp; the&nbsp; affinity&nbsp; of&nbsp; the&nbsp; sorbents&nbsp; for&nbsp; As(V)&nbsp; was&nbsp; as&nbsp; follows: Mag-FeMn&nbsp; &gt;&nbsp; Mag&nbsp; &gt;&nbsp; Mag-Fe&nbsp; &gt;&nbsp; Mag- Mn.&nbsp; In&nbsp; comparison&nbsp; to&nbsp; the&nbsp; nonimpregnated&nbsp; materials,&nbsp; the&nbsp; Kd values&nbsp; were&nbsp; much&nbsp; higher&nbsp; for&nbsp; the&nbsp;&nbsp; boated materials,&nbsp; Chit-FeMn&nbsp; and&nbsp; GAC-FeMn,&nbsp; demonstrating&nbsp; the&nbsp; significant advantage&nbsp; Fe-Mn&nbsp; binary&nbsp; oxides&nbsp; provide&nbsp; in&nbsp; increasing&nbsp; As(III)&nbsp; and&nbsp; As(V)&nbsp; adsorption capacities. One&nbsp; of&nbsp; the&nbsp; most&nbsp; problematic&nbsp; limiting&nbsp; factors&nbsp; in&nbsp; applying&nbsp; adsorption technologies during drinking water treatment is the presence of other water constituents which interfere with the adsorption process.&nbsp; Investigations into the inhibitory effect of competive anions on the adsorption of both forms of arsenic&nbsp; revealed&nbsp; that&nbsp; phosphates&nbsp; were&nbsp; the&nbsp; worst&nbsp; offenders&nbsp; in&nbsp; terms&nbsp; ofreducing&nbsp; the&nbsp; arsenic&nbsp; removal&nbsp; efficacy&nbsp; of&nbsp; sorbents&nbsp; investigated.&nbsp; From&nbsp; the largest&nbsp; to&nbsp; the&nbsp; smallest&nbsp; negative&nbsp; influence&nbsp; of&nbsp; the&nbsp; anions&nbsp; investigated,&nbsp; for As(III)&nbsp; and&nbsp; As(V)&nbsp; adsorption&nbsp; on&nbsp; Fe-Mn&nbsp; binary&nbsp; oxides,&nbsp; magnetic&nbsp; materials and Chit-FeMn, as well as As(V) adsorption on GAC-FeMn, the order was: phosphates &gt; silicates &gt; carbonates &gt; sulfates &gt; nitrates &gt; chlorides, with the presence&nbsp; of&nbsp; the&nbsp; latter&nbsp; two&nbsp; anions&nbsp; proving&nbsp; almost&nbsp; irrelevant&nbsp; to&nbsp; the&nbsp; As adsorption&nbsp; process.&nbsp; Similarly,&nbsp; the&nbsp; negative&nbsp; influence&nbsp; of&nbsp; anions&nbsp; on&nbsp; As(III) sorption on GAC-FeMn was: phosphates &gt; silicates &gt; sulphates &gt; carbonates &gt; nitrates &gt; chlorides. Another&nbsp; issue&nbsp; with&nbsp; applying&nbsp; adsorption&nbsp; in&nbsp; real&nbsp; treatment&nbsp; conditions&nbsp; is&nbsp; the need to regularly&nbsp; regenerate and/or replace the spent sorbent. In this work, a simple&nbsp; and&nbsp; efficient&nbsp; process&nbsp; for&nbsp; sorbent&nbsp;&nbsp; rfegeneration&nbsp; is&nbsp; demonstrated.&nbsp; This regeneration&nbsp; process&nbsp; can&nbsp; be&nbsp; applied&nbsp; to&nbsp; the&nbsp; sorbents&nbsp; investigated&nbsp; multiple times, and uses an NaCl-NaOH-NaOCl mixture, or 0.1 M and 0.5 M NaOH solutions.&nbsp; This&nbsp; finding&nbsp; is&nbsp; of&nbsp; great&nbsp; importance&nbsp; from&nbsp; an&nbsp; ecological&nbsp; and economic point of view. The minimum reduction in the sorption capacity for both As(III) and As(V), after five sorption-regeneration cycles, was found in&nbsp; the&nbsp; binary&nbsp; oxide&nbsp; with&nbsp; a&nbsp; 3:1&nbsp; Fe:Mn&nbsp; molar&nbsp; ratio&nbsp; and&nbsp; Mag-FeMn.&nbsp; Arsenic sorption&nbsp; behaviour&nbsp; was&nbsp; also&nbsp; investigated&nbsp; using&nbsp; real&nbsp; groundwater&nbsp; samples, with the results demonstrating the great potential of 3:1 Fe-Mn binary oxide and Mag- FeMn. However, Chit-FeMn and GAC-FeMn were less effective at adsorbing As from the groundwater samples.Based on the results presented in this dissertation, it can&nbsp; be concluded that the synthesized&nbsp; sorbents,&nbsp; especially&nbsp; the&nbsp; Fe-Mn&nbsp; binary&nbsp; oxides&nbsp; and&nbsp; magnetic composites,&nbsp; and&nbsp; Mag-FeMn&nbsp; in&nbsp; particular,&nbsp; can&nbsp; be&nbsp; efficient&nbsp; and&nbsp; economical alternatives&nbsp; to&nbsp; expensive&nbsp; commercial&nbsp; sorbents&nbsp; and&nbsp; other&nbsp; sophisticated&nbsp; As removal&nbsp; technologies.&nbsp; The&nbsp; high&nbsp; oxidation&nbsp; and&nbsp; sorption&nbsp; capacity &nbsp; of&nbsp; these materials,&nbsp; which&nbsp; ensure&nbsp; the&nbsp; simultaneous&nbsp; removal&nbsp; of&nbsp; arsenic&nbsp; with&nbsp; both oxidation states, is a large advantage for these sorbents and makes them very attractive&nbsp; and&nbsp; promising&nbsp; for&nbsp; application&nbsp; in&nbsp; drinking&nbsp; water&nbsp; treatment.&nbsp; An additional&nbsp; benefit of the magnetic sorbents, primarily Mag-FeMn, is the ease with&nbsp; which&nbsp; they&nbsp; may&nbsp; be&nbsp; separated&nbsp; from&nbsp; the&nbsp; aqueous&nbsp; medium,&nbsp; allowing&nbsp; for simple&nbsp; recirculation within a system. Similarly,&nbsp; the main advantages of&nbsp; the synthesized Chit- FeMn and GAC-FeMn are reflected in their application as effective filtration media.</p>