Dissertations / Theses: 'Sulfid'

1

Ehm, Lars. "Hochdruckpulverdiffraktometrie an Sulfid- und Halogenid-Schichtstrukturen." [S.l.] : [s.n.], 2003. http://e-diss.uni-kiel.de/diss_766/d766.pdf.

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2

Dilner, David. "Profitability = f(G) : Computational Thermodynamics, Materials Design and Process Optimization." Doctoral thesis, KTH, Materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191243.

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The thesis starts by giving a motivation to materials modeling as a way to increase profitability but also a possibility decrease the environmental impact. Fundamental concepts of relevance for this work are introduced, this include the materials genome, ICME and of course the CALPHAD method. As a demonstration promising results obtained by an ICME approach using genetic algorithms and CALPHAD on the vacuum degassing process are presented. In order to make good predictive calculations and process models it is important to have good thermodynamic descriptions. Thus most part of the work has concerned the thermodynamic assessments of systems of importance for steelmaking, corrosion and similar processes. The main focus has been the assessment of sulfur-containing systems and thermodynamic descriptions of the Fe-Mn-Ca-Mg-S, Fe-Ca-O-S, Fe-Mg-O and Mg-Mn-O systems are presented. In addition, heat capacity measurements of relevance for the Mg-Mn-O system have been performed. To summarize the efforts some application examples concerning thermodynamic calculations related to steelmaking and inclusion formation are shown.

QC 20160829

COMPASS

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3

Schödl, Thomas. "Sulfid-Chinon-Reduktase (SQR) aus Aquifex aeolicus Gensynthese, Expression, Reinigung und biochemische Charakterisierung /." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968918344.

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4

Stauder, Stefan. "Schwefelhaltige Arsenspezies in Grundwässern." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1187198174710-08914.

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Es wurde eine Arsenkontamination von Boden und Grundwasser im Bereich einer Zellstofffabrik untersucht, die auf Ablagerungen von Eisenoxidschlacken (Rückstände aus der Pyritröstung) mit hohem Gehalt an verschiedenen Spurenelementen zurückzuführen ist. Der Standort ist dadurch gekennzeichnet, dass über viele Jahre Lösungen aus der Celluloseproduktion („Sulfitablauge“) versickerten. Hierdurch gelangten größere Mengen an Sulfat und organischen Stoffen in den Untergrund. Infolgedessen weist das Grundwasser einen stark reduzierten, sulfidischen Chemismus auf. Ein Großteil der Spurenelemente wurde aus der Schlacke im Oberboden in den darunter liegenden wassergesättigten Bereich transportiert und dort in Form von sulfidischen Niederschlägen festgelegt. Eine Ausnahme bildet Arsen, das unter den spezifischen Milieubedingungen im Schadenzentrum lösliche schwefelhaltige Verbindungen bildet (max. 4 mg As/L). Diese Arsen-Schwefel-Spezies wurden erstmals mit einer neu entwickelten IC-ICP/MS- Methode in einem Grundwasser nachgewiesen. Die Grundwasser- und Bodenuntersuchungen sowie begleitende hydrogeologische Messungen ergaben, dass die Arsen-Schwefel-Spezies innerhalb einer Fließstrecke von 30-80 m im Abstrom des Schadenzentrums vollständig immobilisiert werden. Bei der Festlegung von Arsen spielt die biologische Sulfatreduktion, die durch versickerte Sulfitablauge ermöglicht wurde, eine entscheidende Rolle. Anhand dieser Erkenntnisse wurde im Jahr 2000 ein natural attenuation-Konzept zur Sicherung des Standortes ausgearbeitet. Nach Auswertung der Ergebnisse der Standortuntersuchungen aus den Jahren 1999-2005 sowie einer Literaturrecherche zur Arsen-Schwefel-Chemie wurden die Struktur und das Verhalten der unbekannten Arsen-Schwefel-Spezies sowie die Vorgänge bei der Festlegung von Arsen im Boden genauer untersucht. Das wesentlichste Ergebnis der Arbeiten ist, dass in sulfidischen Systemen, z.B. in Grundwässern unter Sulfat reduzierenden Bedingungen, Thioarsenate gebildet werden. In Lehrbüchern und Fachpublikationen aus den vergangenen Jahrzehnten wurde bislang ausschließlich die Existenz von Thioarseniten vermutet. Ursache für die Bildung von Thioarsenaten ist eine hohe Affinität zwischen Arsen und Schwefel, die eine Oxidation von As(III) durch Anlagerung eines Schwefelatoms an dessen freiem Elektronenpaar „erzwingt“. In sulfidhaltigen Lösungen wird hierzu ein Teil des As(III) zu elementarem Arsen reduziert. Das zunächst gebildete Monothioarsenat wird weiter zu den schwefelhaltigeren Thioarsenaten sulfidiert. In sulfidischen Grundwässern bestimmen deshalb die Anionen von Oxomonothioarsenat, Oxodithioarsenat, Oxotrithioarsenat und Tetrathioarsenat das Verhalten von Arsen. Wesentlich für das Verständnis der Arsen-Schwefel-Chemie ist auch die Instabilität der As-SH-Gruppen, die entsprechend dem Dissoziationsverhalten der jeweiligen Arsen-Schwefel-Spezies gebildet werden. Dies erfolgt bei pH-Werten im Bereich von ca. 7-8,5, wobei die monomeren Anionen unter Abspaltung von Schwefelwasserstoff kondensieren. Infolgedessen muss in Grundwässern auch mit polymeren Thioarsenaten gerechnet werden. In saurer Lösung zerfallen die Thioarsenate in arsenige Säure und Schwefel bzw. fallen als Arsenpentasulfid aus. Arsen wird in sulfidischen Aquiferen als Sulfid (z.B. As4S4), als Arsenpyrit (FeAsS) oder durch Einbau von Arsen als Schwefelsubstituent in das Kristallgitter von Mackinawite bzw. Pyrit (FeS, FeS2) festgelegt. Die ermittelten Prozesse können ggf. zur Sanierung bzw. Sicherung von Standorten mit arsenhaltigen Rückständen im Boden bzw. von arsenbelasteten Grundwässern eingesetzt werden. Dabei ist auch von Bedeutung, dass Thioarsenate nach derzeitigem Kenntnisstand relativ gering toxisch sind. Im Umgang mit Thioarsenaten, z.B. auch bei der Analyse von Arsen in sulfidischen Proben, ist jedoch deren Umwandlung in arsenige Säure bei einer pH-Absenkung und auch bei Sauerstoffzutritt zu berücksichtigen. Die biologische Sulfatreduktion spielt eine wesentlich größere Rolle für die Mobilität von Arsen in Grundwässern als bisher angenommen. Im Hinblick auf die weltweit große gesundheitliche Relevanz von Arsen im Trinkwasser und auf mögliche Sanierungsverfahren sollten die Umsetzungen von Arsen unter Sulfat reduzierenden Bedingungen eingehender untersucht werden
The motivation for the thesis was a project at an industrial site conducted in 1999 to define a remediation concept for soil and groundwater contaminated with arsenic. The contamination resulted from the deposition of residuals from pyrite burning (iron oxides containing different trace elements) in the upper soil many years ago. Because of long-term pollution with process waters rich in organic substances and sulfate, the aquifer is strongly reduced (sulfidic). Most of the arsenic was transferred out of the contaminated soil into the saturated zone in a depth of 7-10 m. There it is partly immobilized as sulfide precipitations, but part of it is solved in the groundwater in form of arsenic-sulfur-complexes (up to 4 ppm). These complexes were detected for the first time in a groundwater by means of an improved IC-ICP-MS method. It was also found that approx. 80 m downstream of the contaminated spot the concentrations of arsenic in soil and groundwater were not increased. On this basis a natural attenuation concept was proposed in 2000. The data from the investigated site was evaluated and specific laboratory tests were carried out in order to identify the unknown arsenic species as well as the processes which lead to their immobilization in the aquifer. The key role of the soluble arsenic-sulfur complexes for the mobility and toxicity of arsenic in sulfate-reducing environments is commonly accepted. In the past, thioarsenites were assumed to be the existing species in sulfidic systems. In this study, however, thioarsenates were identified in solutions spiked with in arsenite and hydrogen sulfide as well as in the contaminated groundwater. The unexpected finding of an oxidation of arsenite to thioarsenates in strongly reducing systems can be explained by the high affinity between As(III) and sulfur. In sulfide containing solutions without any oxidant, arsenite therefore undergoes disproportionation to thioarsenates and elemental arsenic. This was already found out in the 19th century, but has been neglected in publications from the last decades. According to the results of this study the anions of oxomonothioarsenate, oxodithioarsenate, oxotrithioarsenate und tetrathioarsenate are the dominating arsenic species in sulfidic waters. The partitioning of the four species is governed mainly by the sulfide concentration. Beside the high affinity between arsenic and sulfur, the instability of the As-SH group is essential to understand the reactions in the arsenic-sulfur system. As soon as the arsenic-sulfur complexes form As-SH groups (according to their dissociation characteristics) they condensate in separating hydrogen sulfide. Thioarsenates form polymers in the pH range of approx. 7-8.5. Therefore beside the mentioned monomers, thioarsenate polymers can also be important in natural environments. In more acidic solutions they decay into arsenite and sulfur or precipitate as arsenic-pentasulfide. When analyzing arsenic in sulfide containing solutions, it has always to be taken into account that thioarsenates are highly sensitive to oxygen and pH. Therefore, e.g. arsenic speciation by means of HG-AAS is not suitable for sulfidic waters and can wrongly indicate a mixture of arsenite and arsenate. It has previously been supposed that the mobility as well as the toxicity of arsenic increase if the redox state decreases. For sulfidic waters the opposite is probably the case owing to the formation of thioarsenates. The toxicity of arsenite is due to the high reactivity of the As(III) towards sulfohydroxyl groups in proteins. Without a free electron pair and sulfur already incorporated, thioarsenates should be less toxic compared to arsenite. Arsenic can be mobilized out of contaminated soils in form of thioarsenates via infiltration of sulfide solutions or by input of sulfate and biodegradable organic matter. In the presence of iron, thioarsenates can be fixated in sulfidic aquifers as a minor substitute in mackinawite and biogenic pyrite or as arsenic pyrite. Bacterial sulfate reduction is a crucial factor for the mobilization and immobilization of arsenic in reduced aquifers. Considering the negative health impacts of arsenic for millions of people worldwide, as well as the implementation of the mentioned remediation strategies the arsenic-sulfur chemistry deserves closer attention

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5

Griesbeck, Christoph. "Sulfid-Chinon-Reduktase (SQR) aus Rhodobacter capsulatus physikochemische Charakterisierung und Studien zum katalytischen Mechanismus /." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963623826.

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6

Schnurbus-Duhs, Annika Jeannine [Verfasser]. "Strahlenbiologische Effekte nach Radiosynoviorthese mit Rhenium-186-Sulfid und Erbium-169-Citrat / Annika Jeannine Schnurbus-Duhs." Gießen : Universitätsbibliothek, 2013. http://d-nb.info/1065395280/34.

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7

Donner, Jan. "Aufbereitung schwefelwasserstoffhaltiger Wässer durch katalytische Oxidation an porphyrinmodifizierten kohlenstoffhaltigen Materialien." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1236021478050-88453.

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In ariden Gebieten tritt Schwefelwasserstoff häufig im Grundwasser auf, wodurch dessen Nutzung für die Trinkwassergewinnung aufgrund des störenden Geruchs und Geschmacks stark beeinträchtigt wird. Die in der Praxis oft eingesetzte Belüftung erweist sich zumeist als ineffizient und führt zu Geruchsbelästigungen in der Umgebungsluft. Das Ziel der Arbeit, die im Rahmen eines deutsch-israelischen Forschungsprojekts angefertigt wurde, bestand darin, einen wirksamen und für den praktischen Einsatz bei der Wasseraufbereitung geeigneten Katalysator zur Entfernung von Schwefelwasserstoff zu entwickeln, hinsichtlich verschiedener Verfahrensparameter und relevanter Randbedingungen durch systematische Batch- und Säulenversuche zu erproben und zu optimieren. Wichtige Kriterien zur Charakterisierung der Katalysatoren waren die Kinetik des Sulfidumsatzes, die Langzeitstabilität und die Zusammensetzung der Reaktionsprodukte. Die Nachahmung natürlich vorkommender Strukturen (z. B. Häm-Gruppe) und deren Anpassung an eine katalytische Sulfidoxidation war der Grundgedanke am Anfang der Arbeit. Entsprechende Materialien, organische Metallkomplexe (Porphyrine) auf Kohlenstoffträgern (Acetylen Black), wurden bereits erfolgreich bei der Sauerstoffreduktion in Brennstoffzellen eingesetzt. Cobalttetraphenylporphyrin (CoTPP) zeigte von allen getesteten Materialien die beste katalytische Wirksamkeit zur Sulfidoxidation. Die Sulfidumsetzung lief sowohl bei höheren pH-Werten als auch mit zunehmender Temperatur schneller ab. Anhand von Untersuchungen zum Einfluss des pH-Werts konnte bestätigt werden, dass eine katalytische Wirksamkeit nur für die Oxidation der Sulfid-Spezies HS- und S2- besteht. Mit Aktivkohle konnte ebenfalls eine katalytische Sulfidumsetzung erzielt werden, jedoch lag die Aktivität hier im Vergleich zum CoTPP deutlich niedriger. Bei allen getesteten katalytisch wirksamen Materialien entstand als vorrangiges Reaktionsprodukt Schwefel, gebildete Schwefel-Sauerstoff-Verbindungen wie Sulfat und Thiosulfat waren von untergeordneter Bedeutung. Die Untersuchungen zeigten, dass Acetylen Black aufgrund der sehr geringen Teilchengröße technisch kaum einsetzbar ist, weshalb weitere Trägermaterialien erprobt wurden. Im Gegensatz zu Aktivkohle oder Anthrazit erwiesen sich Weichfilze, insbesondere der Sigratherm Kohlenstoff-Weichfilz (KFA-Filz), als sehr gut geeignete Trägermaterialien. Beim Einsatz von Aktivkohle lagerte sich der gebildete Schwefel in den Porenräumen ab, was zu einer erheblichen Verringerung der katalytischen Aktivität führte. Dagegen wurde unter Verwendung des modifizierten Filzmaterials auch bei sehr langen Laufzeiten (bis 3000 Stunden) keine Abnahme der katalytischen Wirksamkeit beobachtet. Durch diese Katalysatormatrix konnte somit die Deaktivierung des Katalysators durch elementaren Schwefel verhindert werden. Bei abschließenden Versuchen unter Verwendung einer kleintechnischen Versuchsanlage konnte gezeigt werden, dass der Katalysator für den großtechnischen Einsatz geeignet ist. Im Vergleich zur Aktivkohle sind zwar größere Investitionskosten notwendig, andererseits können mit dem CoTPP-Material deutlich längere Laufzeiten realisiert werden. Aufgrund seiner guten technischen Handhabbarkeit ist der modifizierte KFA-Filz sowohl in kleinen dezentralen Anlagen (ländliche Siedlungen) als auch in größeren Wasserwerken einsetzbar. Zusätzliche Chemikalien sind für den Betrieb eines solchen Filters nicht erforderlich. Eine weitere Verbesserung der Sulfidentfernung wird bei langen Filterlaufzeiten durch sulfidoxidierende Bakterien bewirkt. Das Ziel, einen effizienten, technisch einsetzbaren Katalysator zur oxidativen Sulfidentfernung aus Wässern zu entwickeln, wurde somit erreicht
Hydrogen sulfide often occurs in groundwater of arid areas. Because of its malodour, H2S containing water cannot be used as drinking water without treatment. Aeration as the most common treatment technique is less effective and leads to nasty odour of ambient air. Catalytic oxidation could be an alternative. The aim of this work was to develop and to optimize a technically applicable oxidation catalyst as well as to test its applicability under practical conditions. Various N4-chelates (e. g. porphyrins), which are frequently used for the reduction of oxygen in fuel cells, were evaluated for catalytic oxidation of sulfide at selected boundary conditions and process parameters using batch and column experiments. The new catalysts should be characterized in comparison with other materials. The oxidation kinetics, the long-time stability of the catalyst and the composition of oxidation products were the main criteria used for catalyst assessment. Cobalt tetraphenylporphyrin (CoTPP) showed the highest catalytic activity of all tested materials. The rate of sulfide transformation increased significantly with increasing temperature and at pH values higher than 6. A catalyst suitable for technical use in fixed-bed reactors was obtained by coating of a supporting material (carbon felt KFA) with the active substance. For all investigated materials, sulfur was found to be the main reaction product of the sulfide oxidation. In contrast to activated carbon, which showed catalytic activity for sulfide oxidation too, modified KFA felt materials were not blocked and deactivated by formed sulfur, even after long-term use. The new catalyst is well qualified for a stable oxidation of sulfide in water. In comparison to activated carbon, higher investment costs are required, but the carbon felt supported porphyrin has a significant longer lifetime. Because of its easy use, modified KFA felt is applicable both in small local plants and in large waterworks. There is no necessity to add chemicals or to install complex control equipment. As a positive side-effect, further improvement of sulfide elimination caused by sulfide-oxidizing bacteria was found during long filter run times

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8

Stauder, Stefan. "Schwefelhaltige Arsenspezies in Grundwässern: Strukturaufklärung, Analytik und Sanierungsstrategien." Doctoral thesis, Technische Universität Dresden, 2006. https://tud.qucosa.de/id/qucosa%3A23946.

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Es wurde eine Arsenkontamination von Boden und Grundwasser im Bereich einer Zellstofffabrik untersucht, die auf Ablagerungen von Eisenoxidschlacken (Rückstände aus der Pyritröstung) mit hohem Gehalt an verschiedenen Spurenelementen zurückzuführen ist. Der Standort ist dadurch gekennzeichnet, dass über viele Jahre Lösungen aus der Celluloseproduktion („Sulfitablauge“) versickerten. Hierdurch gelangten größere Mengen an Sulfat und organischen Stoffen in den Untergrund. Infolgedessen weist das Grundwasser einen stark reduzierten, sulfidischen Chemismus auf. Ein Großteil der Spurenelemente wurde aus der Schlacke im Oberboden in den darunter liegenden wassergesättigten Bereich transportiert und dort in Form von sulfidischen Niederschlägen festgelegt. Eine Ausnahme bildet Arsen, das unter den spezifischen Milieubedingungen im Schadenzentrum lösliche schwefelhaltige Verbindungen bildet (max. 4 mg As/L). Diese Arsen-Schwefel-Spezies wurden erstmals mit einer neu entwickelten IC-ICP/MS- Methode in einem Grundwasser nachgewiesen. Die Grundwasser- und Bodenuntersuchungen sowie begleitende hydrogeologische Messungen ergaben, dass die Arsen-Schwefel-Spezies innerhalb einer Fließstrecke von 30-80 m im Abstrom des Schadenzentrums vollständig immobilisiert werden. Bei der Festlegung von Arsen spielt die biologische Sulfatreduktion, die durch versickerte Sulfitablauge ermöglicht wurde, eine entscheidende Rolle. Anhand dieser Erkenntnisse wurde im Jahr 2000 ein natural attenuation-Konzept zur Sicherung des Standortes ausgearbeitet. Nach Auswertung der Ergebnisse der Standortuntersuchungen aus den Jahren 1999-2005 sowie einer Literaturrecherche zur Arsen-Schwefel-Chemie wurden die Struktur und das Verhalten der unbekannten Arsen-Schwefel-Spezies sowie die Vorgänge bei der Festlegung von Arsen im Boden genauer untersucht. Das wesentlichste Ergebnis der Arbeiten ist, dass in sulfidischen Systemen, z.B. in Grundwässern unter Sulfat reduzierenden Bedingungen, Thioarsenate gebildet werden. In Lehrbüchern und Fachpublikationen aus den vergangenen Jahrzehnten wurde bislang ausschließlich die Existenz von Thioarseniten vermutet. Ursache für die Bildung von Thioarsenaten ist eine hohe Affinität zwischen Arsen und Schwefel, die eine Oxidation von As(III) durch Anlagerung eines Schwefelatoms an dessen freiem Elektronenpaar „erzwingt“. In sulfidhaltigen Lösungen wird hierzu ein Teil des As(III) zu elementarem Arsen reduziert. Das zunächst gebildete Monothioarsenat wird weiter zu den schwefelhaltigeren Thioarsenaten sulfidiert. In sulfidischen Grundwässern bestimmen deshalb die Anionen von Oxomonothioarsenat, Oxodithioarsenat, Oxotrithioarsenat und Tetrathioarsenat das Verhalten von Arsen. Wesentlich für das Verständnis der Arsen-Schwefel-Chemie ist auch die Instabilität der As-SH-Gruppen, die entsprechend dem Dissoziationsverhalten der jeweiligen Arsen-Schwefel-Spezies gebildet werden. Dies erfolgt bei pH-Werten im Bereich von ca. 7-8,5, wobei die monomeren Anionen unter Abspaltung von Schwefelwasserstoff kondensieren. Infolgedessen muss in Grundwässern auch mit polymeren Thioarsenaten gerechnet werden. In saurer Lösung zerfallen die Thioarsenate in arsenige Säure und Schwefel bzw. fallen als Arsenpentasulfid aus. Arsen wird in sulfidischen Aquiferen als Sulfid (z.B. As4S4), als Arsenpyrit (FeAsS) oder durch Einbau von Arsen als Schwefelsubstituent in das Kristallgitter von Mackinawite bzw. Pyrit (FeS, FeS2) festgelegt. Die ermittelten Prozesse können ggf. zur Sanierung bzw. Sicherung von Standorten mit arsenhaltigen Rückständen im Boden bzw. von arsenbelasteten Grundwässern eingesetzt werden. Dabei ist auch von Bedeutung, dass Thioarsenate nach derzeitigem Kenntnisstand relativ gering toxisch sind. Im Umgang mit Thioarsenaten, z.B. auch bei der Analyse von Arsen in sulfidischen Proben, ist jedoch deren Umwandlung in arsenige Säure bei einer pH-Absenkung und auch bei Sauerstoffzutritt zu berücksichtigen. Die biologische Sulfatreduktion spielt eine wesentlich größere Rolle für die Mobilität von Arsen in Grundwässern als bisher angenommen. Im Hinblick auf die weltweit große gesundheitliche Relevanz von Arsen im Trinkwasser und auf mögliche Sanierungsverfahren sollten die Umsetzungen von Arsen unter Sulfat reduzierenden Bedingungen eingehender untersucht werden.
The motivation for the thesis was a project at an industrial site conducted in 1999 to define a remediation concept for soil and groundwater contaminated with arsenic. The contamination resulted from the deposition of residuals from pyrite burning (iron oxides containing different trace elements) in the upper soil many years ago. Because of long-term pollution with process waters rich in organic substances and sulfate, the aquifer is strongly reduced (sulfidic). Most of the arsenic was transferred out of the contaminated soil into the saturated zone in a depth of 7-10 m. There it is partly immobilized as sulfide precipitations, but part of it is solved in the groundwater in form of arsenic-sulfur-complexes (up to 4 ppm). These complexes were detected for the first time in a groundwater by means of an improved IC-ICP-MS method. It was also found that approx. 80 m downstream of the contaminated spot the concentrations of arsenic in soil and groundwater were not increased. On this basis a natural attenuation concept was proposed in 2000. The data from the investigated site was evaluated and specific laboratory tests were carried out in order to identify the unknown arsenic species as well as the processes which lead to their immobilization in the aquifer. The key role of the soluble arsenic-sulfur complexes for the mobility and toxicity of arsenic in sulfate-reducing environments is commonly accepted. In the past, thioarsenites were assumed to be the existing species in sulfidic systems. In this study, however, thioarsenates were identified in solutions spiked with in arsenite and hydrogen sulfide as well as in the contaminated groundwater. The unexpected finding of an oxidation of arsenite to thioarsenates in strongly reducing systems can be explained by the high affinity between As(III) and sulfur. In sulfide containing solutions without any oxidant, arsenite therefore undergoes disproportionation to thioarsenates and elemental arsenic. This was already found out in the 19th century, but has been neglected in publications from the last decades. According to the results of this study the anions of oxomonothioarsenate, oxodithioarsenate, oxotrithioarsenate und tetrathioarsenate are the dominating arsenic species in sulfidic waters. The partitioning of the four species is governed mainly by the sulfide concentration. Beside the high affinity between arsenic and sulfur, the instability of the As-SH group is essential to understand the reactions in the arsenic-sulfur system. As soon as the arsenic-sulfur complexes form As-SH groups (according to their dissociation characteristics) they condensate in separating hydrogen sulfide. Thioarsenates form polymers in the pH range of approx. 7-8.5. Therefore beside the mentioned monomers, thioarsenate polymers can also be important in natural environments. In more acidic solutions they decay into arsenite and sulfur or precipitate as arsenic-pentasulfide. When analyzing arsenic in sulfide containing solutions, it has always to be taken into account that thioarsenates are highly sensitive to oxygen and pH. Therefore, e.g. arsenic speciation by means of HG-AAS is not suitable for sulfidic waters and can wrongly indicate a mixture of arsenite and arsenate. It has previously been supposed that the mobility as well as the toxicity of arsenic increase if the redox state decreases. For sulfidic waters the opposite is probably the case owing to the formation of thioarsenates. The toxicity of arsenite is due to the high reactivity of the As(III) towards sulfohydroxyl groups in proteins. Without a free electron pair and sulfur already incorporated, thioarsenates should be less toxic compared to arsenite. Arsenic can be mobilized out of contaminated soils in form of thioarsenates via infiltration of sulfide solutions or by input of sulfate and biodegradable organic matter. In the presence of iron, thioarsenates can be fixated in sulfidic aquifers as a minor substitute in mackinawite and biogenic pyrite or as arsenic pyrite. Bacterial sulfate reduction is a crucial factor for the mobilization and immobilization of arsenic in reduced aquifers. Considering the negative health impacts of arsenic for millions of people worldwide, as well as the implementation of the mentioned remediation strategies the arsenic-sulfur chemistry deserves closer attention.

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9

Donner, Jan. "Aufbereitung schwefelwasserstoffhaltiger Wässer durch katalytische Oxidation an porphyrinmodifizierten kohlenstoffhaltigen Materialien." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A23632.

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In ariden Gebieten tritt Schwefelwasserstoff häufig im Grundwasser auf, wodurch dessen Nutzung für die Trinkwassergewinnung aufgrund des störenden Geruchs und Geschmacks stark beeinträchtigt wird. Die in der Praxis oft eingesetzte Belüftung erweist sich zumeist als ineffizient und führt zu Geruchsbelästigungen in der Umgebungsluft. Das Ziel der Arbeit, die im Rahmen eines deutsch-israelischen Forschungsprojekts angefertigt wurde, bestand darin, einen wirksamen und für den praktischen Einsatz bei der Wasseraufbereitung geeigneten Katalysator zur Entfernung von Schwefelwasserstoff zu entwickeln, hinsichtlich verschiedener Verfahrensparameter und relevanter Randbedingungen durch systematische Batch- und Säulenversuche zu erproben und zu optimieren. Wichtige Kriterien zur Charakterisierung der Katalysatoren waren die Kinetik des Sulfidumsatzes, die Langzeitstabilität und die Zusammensetzung der Reaktionsprodukte. Die Nachahmung natürlich vorkommender Strukturen (z. B. Häm-Gruppe) und deren Anpassung an eine katalytische Sulfidoxidation war der Grundgedanke am Anfang der Arbeit. Entsprechende Materialien, organische Metallkomplexe (Porphyrine) auf Kohlenstoffträgern (Acetylen Black), wurden bereits erfolgreich bei der Sauerstoffreduktion in Brennstoffzellen eingesetzt. Cobalttetraphenylporphyrin (CoTPP) zeigte von allen getesteten Materialien die beste katalytische Wirksamkeit zur Sulfidoxidation. Die Sulfidumsetzung lief sowohl bei höheren pH-Werten als auch mit zunehmender Temperatur schneller ab. Anhand von Untersuchungen zum Einfluss des pH-Werts konnte bestätigt werden, dass eine katalytische Wirksamkeit nur für die Oxidation der Sulfid-Spezies HS- und S2- besteht. Mit Aktivkohle konnte ebenfalls eine katalytische Sulfidumsetzung erzielt werden, jedoch lag die Aktivität hier im Vergleich zum CoTPP deutlich niedriger. Bei allen getesteten katalytisch wirksamen Materialien entstand als vorrangiges Reaktionsprodukt Schwefel, gebildete Schwefel-Sauerstoff-Verbindungen wie Sulfat und Thiosulfat waren von untergeordneter Bedeutung. Die Untersuchungen zeigten, dass Acetylen Black aufgrund der sehr geringen Teilchengröße technisch kaum einsetzbar ist, weshalb weitere Trägermaterialien erprobt wurden. Im Gegensatz zu Aktivkohle oder Anthrazit erwiesen sich Weichfilze, insbesondere der Sigratherm Kohlenstoff-Weichfilz (KFA-Filz), als sehr gut geeignete Trägermaterialien. Beim Einsatz von Aktivkohle lagerte sich der gebildete Schwefel in den Porenräumen ab, was zu einer erheblichen Verringerung der katalytischen Aktivität führte. Dagegen wurde unter Verwendung des modifizierten Filzmaterials auch bei sehr langen Laufzeiten (bis 3000 Stunden) keine Abnahme der katalytischen Wirksamkeit beobachtet. Durch diese Katalysatormatrix konnte somit die Deaktivierung des Katalysators durch elementaren Schwefel verhindert werden. Bei abschließenden Versuchen unter Verwendung einer kleintechnischen Versuchsanlage konnte gezeigt werden, dass der Katalysator für den großtechnischen Einsatz geeignet ist. Im Vergleich zur Aktivkohle sind zwar größere Investitionskosten notwendig, andererseits können mit dem CoTPP-Material deutlich längere Laufzeiten realisiert werden. Aufgrund seiner guten technischen Handhabbarkeit ist der modifizierte KFA-Filz sowohl in kleinen dezentralen Anlagen (ländliche Siedlungen) als auch in größeren Wasserwerken einsetzbar. Zusätzliche Chemikalien sind für den Betrieb eines solchen Filters nicht erforderlich. Eine weitere Verbesserung der Sulfidentfernung wird bei langen Filterlaufzeiten durch sulfidoxidierende Bakterien bewirkt. Das Ziel, einen effizienten, technisch einsetzbaren Katalysator zur oxidativen Sulfidentfernung aus Wässern zu entwickeln, wurde somit erreicht.
Hydrogen sulfide often occurs in groundwater of arid areas. Because of its malodour, H2S containing water cannot be used as drinking water without treatment. Aeration as the most common treatment technique is less effective and leads to nasty odour of ambient air. Catalytic oxidation could be an alternative. The aim of this work was to develop and to optimize a technically applicable oxidation catalyst as well as to test its applicability under practical conditions. Various N4-chelates (e. g. porphyrins), which are frequently used for the reduction of oxygen in fuel cells, were evaluated for catalytic oxidation of sulfide at selected boundary conditions and process parameters using batch and column experiments. The new catalysts should be characterized in comparison with other materials. The oxidation kinetics, the long-time stability of the catalyst and the composition of oxidation products were the main criteria used for catalyst assessment. Cobalt tetraphenylporphyrin (CoTPP) showed the highest catalytic activity of all tested materials. The rate of sulfide transformation increased significantly with increasing temperature and at pH values higher than 6. A catalyst suitable for technical use in fixed-bed reactors was obtained by coating of a supporting material (carbon felt KFA) with the active substance. For all investigated materials, sulfur was found to be the main reaction product of the sulfide oxidation. In contrast to activated carbon, which showed catalytic activity for sulfide oxidation too, modified KFA felt materials were not blocked and deactivated by formed sulfur, even after long-term use. The new catalyst is well qualified for a stable oxidation of sulfide in water. In comparison to activated carbon, higher investment costs are required, but the carbon felt supported porphyrin has a significant longer lifetime. Because of its easy use, modified KFA felt is applicable both in small local plants and in large waterworks. There is no necessity to add chemicals or to install complex control equipment. As a positive side-effect, further improvement of sulfide elimination caused by sulfide-oxidizing bacteria was found during long filter run times.

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Guschlbauer, Jannick [Verfasser], and Jörg [Akademischer Betreuer] Sundermeyer. "Organische Salze Sulfid- und Selenid-basierter Anionen: Bausteine für die Materialsynthese bi- und multinärer Metallchalkogenide / Jannick Guschlbauer ; Betreuer: Jörg Sundermeyer." Marburg : Philipps-Universität Marburg, 2020. http://d-nb.info/1203299605/34.

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Persson, Mattias. "Kostnad-nytta-analys för tungmetallrening av tvätthallsslam i fullskala." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173314.

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Examensarbetet är utfört på uppdrag av SRV Återvinning AB. SRV har en ny anläggning för att rena THS. THS är benämningen på oljehaltigt vatten från tvätthallar, gatubrunnslam och oljeavskiljare. THS är förorenat med tungmetaller. Henriksdals reningsverk är mottagare av renat vatten från SRV och har specificerat sex tungmetaller som det är önskvärt att reducera i deras tillflöde eftersom reningsverket är ReVAQ-certifierat. ReVAQ-certifieringen är till för att garantera att slammet som produceras i reningsverket håller en mycket god kvalité och kan användas för spridning på åkermark. De sex prioriterade metallerna är: bly, kadmium, krom, koppar, kvicksilver och zink. Två av reningsstegen i THS-anläggningen ingick i examensarbetets undersökning: normalisering med svavelsyra och metallutfällning med en organisk sulfid, Na3T. Faktorförsök genomfördes i THS-anläggningen för att se hur stor effekt de två undersökta reningsstegen har. Ytterligare försök genomfördes, dels för att få information om hur ett ökat THS-tillflöde påverkar reningen men även för att bekräfta att det i dagsläget inte är nödvändigt att tillsätta Na3T. Även när Na3T inte användes understeg metallhalterna i det renade vattnet Stockholm Vattens krav på processvatten från industrier. Mängden metall som släpps ut årsvis kommer, baserat på resultaten, understiga kraven från deldomen (Mål 5717-07) kungjord i miljödomstolen. Är inte Na3T behövlig tillkommer även en miljövinst genom minskade kemikalietransporter och att mindre mängd kemikalie behöver framställas. Om mottaget THS blir mer förorenat eller svårbehandlat, beroende på övrigt innehåll, än det hittills varit kan det vara nödvändigt att tillsätta Na3T för att reducera metallhalterna till önskad nivå. Normaliseringssteget fungerade inte helt tillfredsställande för alla metaller. Troligen beror det på att pH-värdet inte kan hållas tillräckligt lågt i reningssteget. Att byta doseringspumpen eller att använda mer koncentrerad svavelsyra för att kunna förbättra normaliseringssteget är inte aktuellt för SRV. Bly- och kadmiumhalterna har på renat THS-vatten flera gånger understigit kvantifieringsgränsen på 0,2 respektive 0,02 μg/l. Om kadmiumhalten i inkommande THS skulle öka drastiskt skulle eventuellt Na3T behöva tillsättas då kadmium inte bildar hydroxidfällning. Det har inte gått att påvisa att kromhalten ändras när normaliseringssteget används, men det blir en större haltändring om Na3T används. Utsläppta mängder krom per år är under kraven från miljödomstolen även om Na3T inte tillsätts. Processen behöver inte finjusteras för att fälla mer koppar eftersom haltreduktionen i alla genomförda försök har varit stor, runt 99 %. Kvicksilverhalterna har under alla försöken understigit kvantifieringsgränsen på 0,1 g per liter THS vilket är bra för alla parter (tvätthallsägare, SRV, Henriksdals reningsverk och åkermark). Zink var den, av de undersökta metallerna, som påverkades mest av ett lägre pH-värde i normaliseringssteget. Även om ett högre pH-värde används uppfyller zinkreningen nu gällande krav. Reningsresultaten stämmer även vid ett högre flöde i THS-anläggningen (8,0 m3/h). Den största arbetsmiljökonsekvensen i THS-anläggningen är exponeringsrisken för kemikalierna. Risken för att personal och obehöriga ska exponeras för använda kemikalier har begränsats men tillvägagångssättet för påfyllning av Na3T har större exponeringsrisk för kemikalien i jämförelse med övriga kemikalier. Påfyllningen av Na3T är dessutom både omständig och personalkrävande. Kemikaliekostnaden för Na3T, om den används, är cirka 100 000 kronor per år och för svavelsyran omkring 110 000 kronor, beroende på alkaliniteten hos ingående THS samt valt pH-värde i normaliseringssteget. Risken att använda kemikalierna är uppskattad till drygt 12 000 kronor årligen för Na3T respektive knappt 154 000 kronor årligen för svavelsyran. Den totala vattenvolymen till Henriksdal under 2013 var 329 000 m3 och om THS-anläggningen arbetar vid det flöde den är dimensionerad för ökar volymen med cirka 18 000 m3 per år. THS-strömmen är renare och cirka en tjugondel av de övriga strömmarna och därför blir påverkan på vattnet till Henriksdal inte speciellt stor.
This thesis is done in cooperation with SRV Återvinning AB which is a recycling company. SRV has a new plant to clean THS. THS is oily water from car washes, sludges from manholes and oil separators. THS polluted with heavy metals. Henriksdals sewage treatment plant receives the cleaned THS water. It is desirable to reduce six heavy metals in this inflow. The sewage treatment plant in Henriksdal is ReVAQ certified. The ReVAQ certification is to ensure that sludge produced in a ReVAQ certified plant is of very high quality and can be used as fertilizer on arable land. The six priority metals are: lead, cadmium, chromium, copper, mercury and zinc. Two of the new treatment steps are included in this study: normalization with sulfuric acid and metal precipitation with an organic sulfide, Na3T. DOE (Design of Experiments) were conducted in the THS facility to examine the effectiveness of the two new treatment steps. Further experiments was carried out to see how an increased feed affects the purification of THS and also to confirm that it is not necessary to add Na3T. The content of the metals in the purified water was lower than the requirements stated by Stockholm Vatten for process water from industries and the annually release of metal was lower than the requirements of an adjudication proclaimed in the Swedish Environmental Court ( Case 5717-07), even if Na3T is not used. If Na3T is not used an environmental benefit is obtained due to reduced chemical transports and smaller amount of chemicals need to be made. If the received THS becomes more polluted or more difficult to treat, depending on the other content, than the so far received THS, it may be necessary to add Na3T to reduce the metals to the desired level. The normalization step was not working satisfactory, probably due to that the pH-value cannot be kept low enough in the purification step. To replace the dosage pump or to use more concentrated sulfuric acid in order to improve the normalization step is not seen to be worth the effort. The concentrations of lead and cadmium in the purified water from THS have several times been below the limit of quantification, LOQ, (0.2 μgPb / l and 0.02 μgCd / l). Na3T can be needed if the cadmium content of incoming THS would increase drastically because cadmium does not form a hydroxide precipitation. It was not possible to prove that the normalization step contributed to a reduction of the chromium content in the THS-water, but the DOE showed that the amount of chromium was decreased if Na3T is used. The chromium content in the outgoing THS-water is below the requirements although no Na3T is added. In the experiments the purification of copper was good, the change in concentration was around 99 % and therefore the process does not need to be fine-tuned to reduce the amount of copper. The concentrations of mercury in all experiments have been below the limit of quantification (0.1 gHg /literTHS). It is good for everybody (carwash owners, SRV, Henriksdal sewage treatment plants and arable land) that the incoming content of mercury was so low that it was not possible to quantify. Zinc was the metal which was most affected by a lower pH in the normalization step. Although a higher pH was used the content of zinc in outgoing THS-water fulfilled the current requirements. The greatest working environmental risk for the workers in the plant is the risk of being exposed by chemicals. The risks for being exposed to chemicals in the THS-facility have been reduced and emergency equipment is easily accessible in the facility. The filling of Na3T was done in a different way than for the other bulk chemicals. The procedure increases the risk of chemical exposure and is both problematic and requires more staff. The chemical costs for Na3T, if used, is about 100 000 SEK per year and the cost for sulfuric acid is about 110 000 SEK per year, depending on the alkalinity and the chosen pH value in the normalization step. The risk of using chemicals is estimated to be a bit more than 12 000 SEK annually for Na3T and just under 154 000 SEK annually for the sulfuric acid. The total volume of water sent to Henriksdal in 2013 was 329 000 m3. If the THS-facility works at its dimensioned flow rate, the volume to Henriksdal is increased by approximately 18 000 m3 per year. But since the THS-stream is cleaner and about one twentieth of the other streams a larger metal reduction could be achieved by treating the other water streams more efficient.

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McGinnity, Justin. "Sulfur dioxide leaching of zinc sulfide." Curtin University of Technology, Department of Applied Chemistry, 2001. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=12896.

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Studies were conducted into the mechanism and kinetics of the dissolution of synthetic zinc sulfide and zinc concentrate in aqueous solutions containing sulfur dioxide.Experiments at ambient temperature established that the dissolution of ZnS in aqueous solutions of sulfur dioxide proceeds via acidic non-oxidative dissolution and not by direct reaction of the sulfide with S02(aq). The non-oxidative dissolution reaction generates H2S(aq) or HS-(aq) species which are thought to rapidly react with sulfurous acid species, S02(aq) or HS03-(aq), to possibly produce initially sulfane monosulfonates as intermediates, followed by sulfane disulfonates and elemental sulfur. The formation of sulfane monosulfonates is postulated based upon inhibition observed in ZnS / S02 leaches which is not attributable to either H2S(aq) or occlusion elemental sulfur.At elevated temperatures (100oC - 200oC) the rate of ZnS dissolution in sulfurous acid is affected by the thermal decomposition of sulfurous acid, which produces sulfuric acid, which leaches the mineral non-oxidatively. Increasing the temperature increases the rate of thermal decomposition of sulfurous acid and consequently, the rate of sulfuric acid formation, increasing the rate of ZnS dissolution.The kinetics of the dissolution of ZnS in solutions of sulfuric acid and sulfur dioxide were investigated at temperatures up to 200oC. At 100oC and 150oC, the dissolution of ZnS in H2SO4 was found to obey the relationd[Zn2+]/dt = kfAs[H+] krAs[H2S(aq)]1/2[Zn2+]1/2and equilibria and rate constants for the ZnS / H2S04 reaction were obtained over the range, 100oC to 200oC. The activation energies of the forward and reverse reactions were found to be 56 +/- 11 kJ mol-1 and 45 +/- 15 kJ mol-1, respectively. The equilibrium constants were 4.99x10-4, 1.26x10-3 and 2.83x10-3 at 100oC, 150oC and 200oC, respectively.In the presence of added S02, ++
at low ZnS pulp density (0.5 g L-1), the rate of ZnS dissolution in sulfuric acid increased due to the removal of H2S(aq) by reaction with S02(aq) or HS03-(aq). However the increase in rate was much less than that expected for the complete removal of H2S(aq). As with leaches of ZnS in sulfurous acid at ambient temperature, the inhibition was not attributable to the presence of residual H2S(aq) or to occlusion of unreacted ZnS by elemental sulfur, but is thought to be due to aqueous species that are like "H2S", in that they may react with Zn2+ to reprecipitate W.To this end, sulfane monosulfonates have again been postulated. The rate of ZnS dissolution, under conditions of low pulp density, was independent Of S02 concentration, suggesting that under these conditions the rate of the H2S / S02 reaction is also independent of the S02 concentration.At higher pulp densities (200 g L-1), similar to those expected in an industrial application, synthetic zinc sulfide leached rapidly in H2S04 / S02 solutions to approximately 60% zinc extraction, but was then inhibited by the large amounts of sulfur that formed. These caused agglomerates of zinc sulfide and elemental sulfur to form, even at temperatures below the melting point of sulfur, reducing the surface area of zinc sulfide available for reaction.Leaches of zinc concentrate at low pulp densities in H2S04 / S02 solutions and at temperatures above sulfur's meting point, were inhibited by the formation of molten sulfur. In contrast to synthetic zinc sulfide, zinc concentrate is readily wet by molten sulfur. Three surfactants orthophenylenediamine, quebracho and sodium ligninsulfonate were found to be reasonably effective in preventing molten sulfur from occluding the mineral surface. At high pulp densities, the H2S04 / S02 leach solution was unable to effect, the extraction of zinc from a zinc concentrate beyond approximately ++
10%.Integral S02 / H2S04 leaching of zinc concentrate was found not to be a commercial prospect. However, sidestream processing of zinc concentrate in an acid leach stage followed by reaction of generated H2S with S02 from the roasting stage to produce elemental sulfur may be viable.

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Oen, Endre Nerhus. "Dannelse av sulfidforekomster i Reinfjord og Lokkarfjord, Seiland magmatiske provins : En svovelisotopstudie av økonomisk interessante sulfid-forekomster dannet i forbindelse med ultramafisk magmatisk aktivitet." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for geologi og bergteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24242.

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En systematisk petrografisk-geokjemisk oversikt av sulfidforekomstene i Reinfjord (Troms) og Lokkarfjord (Finnmark) i Nord-Norge blir her gitt. Hensikten med oppgaven er å øke forståelsen for geologien i området, spesielt med tanke på sulfidenes variasjon, tekstur, opptreden og opprinnelse, samt å sammenlikne sulfidforekomstene i Reinfjord med forekomstene i Lokkarfjord. Ved kartlegging og prøvetaking i felt, mikroskopering, kjemiske analyser (XRF, EPMA, ICP-MS/AES) og in situ svovelisotopanalyser (SIMS) er data samlet inn og analysert. Områdene dekket av oppgaven er begge innenfor Seiland Magmatiske Provins (Seiland Igneous Province (SIP)), en 5500 km2 stor geologisk provins bestående av omtrent 50% mafiske, 35 % ultramafiske, 10 % felsiske og 5 % alkaline bergarter. Sulfidforekomstene i Reinfjord er i forbindelse med et ultramafisk lagdelt kompleks (25 km2), mens de i Lokkarfjord er i forbindelse med en hornblendeperidotitt (2 km2). Alderen på bergartene er datert til å være 560 - 570 millioner år gamle. Tidligere undersøkelser har vist at Reinfjord består av flere lagdelte serier med tilhørende marginale soner. De lagdelte seriene viser progressivt høyere MgO-innhold fra eldst til yngst, hvor yngste intruderte serie (dunitt) sitter sentralt i komplekset. Sulfidmineraliseringene i de marginale sonene er undersøkt tidligere, men uten at det har vært utført svovelisotopstudier.Okonomisk interessante sulfider er chalcopyritt (Cu) og pentlanditt (Ni) samt Pt, Pd og Au (i ukjente mineraler). I tillegg opptrer pyrrhotitt og pyritt, samt omvandlingsmineralene markasitt og bravoittisert pentlanditt. Sulfidene sitter interstitiellt og opptrer ofte i grupper bestående av pyrrhotitt (65 %), chalcopyritt (25 %) og pentlanditt (10 %). Svovelisotopanalysen viser at gjennomsnittlig δ34S (VCDT) for Reinfjord ultramafiske kompleks (RUK) er -1,16 ? (variasjon fra -5,74 til 3,65) hvor tilsvarende gjennomsnitt for Lokkarfjord er 0,63 ? (variasjon fra -1,26 til 1,62). Dette er innenfor intervallet for typiske verdier fra mantelen (0 ? ± 2) og tyder på at svovel har sitt opphav her. Ved å kun se på tallene for de marginale sonene i Reinfjord (1,89 ? (VCDT)), som er det høyeste gjennomsnittet av prøvene fra RUK, tyder det på noe forurensing fra sidebergartene.De mest interessante funnene er gjort i forbindelse med kjerneboring (Nordic Mining, mai 2012) hvor en Ni+Cu-horisont og en PGE-horisont ble påvist i Reinfjord. Disse horisontene, sammen med sulfidmineraliseringen i Lokkarfjord, peker seg ut som mulig lovende forekomster fra et økonomisk synspunkt.

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Do, Thi Lien, Thi To Uyen Do, Thi Nhi Cong Le, Phuong Ha Hoang, and Thi Ngoc Mai Cung. "Optimization production conditions of photosynthetic purple bacteria biomass at pilot scale to remove sulphide from aquaculture pond." Technische Universität Dresden, 2018. https://tud.qucosa.de/id/qucosa%3A32725.

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For the purpose of sulphide removal in aquaculture ponds, three strains (name: TH21, QN71, QN51) were isolated and selected with the highest sulphide removal activity from Thanh Hoa and Quang Ninh coastal zones. These strains have identified and tested in a number of aquaculture ponds in different areas with good water quality results. With the objective of purple non sulfur bacteria biomass production containing 3 selected strains for wide application and suitable price for farmers, in this study, we study on optimum conditions of mixed purple non sulfur bacteria biomass production at pilot scale. The results showed that the sources of substrates were soybean meal (1g/l) and acetate (0.5g/l). These substrates are low cost, easy to find, convenient in large culture. The mixture of photosynthetic bacteria can be cultured in glass tanks, under micro aerobic and natural lighting conditions that produce highly concentrated photosynthetic bacteria and lowest rest media.
Nhằm mục tiêu xử lý sulphide trong môi trường nuôi trồng thủy sản, chúng tôi đã phân lập và lựa chọn được ba chủng vi khuẩn tía quang hợp có khả năng loại bỏ sulphide cao nhất ký hiệu TH21, QN71, QN52 từ các vùng ven biển Thanh Hóa và Quảng Ninh. Các chủng này đã được định loại và thử nghiệm tại một số ao nuôi thủy sản ở các vùng khác nhau thu được kết quả tốt về chất lượng nước. Để tạo chế phẩm vi khuẩn tía quang hợp từ 3 chủng lựa chọn được ứng dụng rộng rãi và có giá thành phù hợp cho nông hộ, trong nghiên cứu này, chúng tôi nghiên cứu tối ưu hóa các điều kiện sản xuất sinh khối hỗn hợp 3 chủng vi khuẩn tía quang hợp ở quy mô pilot. Kết quả cho thấy đã tìm kiếm được nguồn cơ chất là bột đậu tương (1g/l) và acetate (0.5g/l) là những chất có giá thành thấp, dễ tìm kiếm, thuận tiện trong nhân nuôi ở quy mô lớn. Hỗn hợp vi khuẩn tía quang hợp có thể nuôi trong các bể kính, ở điều kiện vi hiếu khí, có ánh sáng chiếu tự nhiên có thể sản xuất được chế phẩm vi khuẩn tía quang hợp có mật độ cao, cơ chất còn lại sau sản xuất là ít nhất.

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Tong, Libin. "Sulfur dispersing agents for nickel sulfide leaching above the melting point of sulfur." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/3427.

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The effects of sulfur dispersing agents (SDAs) in the oxygen pressure leaching of nickel concentrate at medium temperature were investigated. Liquid sulfur-aqueous solution interfacial tensions and liquid sulfur-sulfide mineral contact angles were measured at 140ºC, 690 kPa overpressure by nitrogen, and 1.0 mol/L NiSO₄. The effects of SDAs including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid were evaluated by the calculation of the work of adhesion in the liquid sulfur-sulfide mineral-aqueous solution systems. It was found that the sulfide mineral surface is sulfophobic at pH from 4.1 to 4.5 due to the hydrolysis of nickel (II) ions to nickel hydroxide and the deposition of nickel hydroxide on the mineral surface. These findings apply to four different sulfide mineral systems, including pentlandite, nickeliferous pyrrhotite, pyrrhotite, and chalcopyrite. Lignosulfonate, Quebracho, and humic acid were found to significantly reduce the work of adhesion indicating they should be effective SDAs. OPD is ineffective in changing the work of adhesion of sulfur on the mineral sulfides indicating that it is not a good candidate for sulfur dispersion. The adsorption behavior of SDAs, including lignosulfonate, Quebracho, OPD, and humic acid on elemental sulfur and on nickel sulfide concentrate was investigated. Lignosulfonate, Quebracho, and humic acid were characterized by their infrared spectra. The charge changes on elemental sulfur surface were characterized by the measurement of the electrokinetic sonic amplitude (ESA) in the absence or presence of SDAs. The adsorption of lignosulfonate on molten sulfur surface was calculated by the Gibbs Equation. The adsorption of lignosulfonate, Quebracho, and humic acid on the nickel concentrate was investigated at ambient temperature. The adsorption of lignosulfonate, Quebracho, and humic acid on the nickel concentrate was found to be monolayer adsorption, which was fitted to the Langmuir adsorption isotherm. Electrostatic interaction and ion-binding are the possible mechanisms for the adsorption of lignosulfonate and humic acid on the nickel concentrate. Quebracho is adsorbed on the nickel concentrate through hydroxyl and sulfonate groups. OPD cannot adsorb on the molten sulfur surface. OPD undergoes chemical change in aqueous solution in the presence of ferric at ambient temperature. Oxygen pressure leaching experiments were performed at 140 or 150ºC under 690 kPa oxygen overpressure. The particle size of the nickel concentrate was found to be an important factor in leaching. During the leaching of nickel concentrate with P₈₀ of 48 µm, the SDAs were believed to be fully degraded before nickel was fully extracted. At most 66% nickel was extracted in the presence of 20 kg/t OPD. Fine grinding (P₈₀ of 10 µm) was sufficient for 99% nickel recovery at low pulp density while at high pulp density, the nickel extraction increased from 95% to 99% with addition of SDAs. Based on the leaching results on a nickel concentrate sample (-44 µm), OPD had the effect of increasing the nickel extraction to about 99%, followed by Quebracho (83%), lignosulfonate (72%), and humic acid (61%). It is suggested that the oxidation product of OPD is effective in solving the sulfur wetting problem in leaching. 97% nickel was recovered in the presence of 5 g/L chloride ion. Chloride ion has an effect to enhance the performance of lignosulfonate under leaching conditions.

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16

Hedberg, Johanna. "Effects of meiofauna and cable bacteria on oxygen, pH and sulphide dynamics in Baltic Sea hypoxic sediment." Thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-188795.

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17

Siu, Tung. "Kinetic and mechanistic study of aqueous sulfide-sulfite-thiosulfate system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0007/MQ45585.pdf.

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18

Crowell, Brendan William. "Biological sulfur reactions and the influence on fluid flow at mid-ocean ridge hydrothermal systems." Thesis, Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-07092007-085654/.

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19

Liu, Yanan 1981. "Sulfur concentration at sulfide saturation in anhydrous silicate melts at crustal conditions." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98753.

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The sulfur concentration in silicate melts at sulfide saturation (SCSS) was experimentally investigated in a temperature range from 1250ºC to 1450ºC and a pressure range from 500 MPa to 1 GPa in a piston-cylinder apparatus. The investigated melt compositions varied from rhyolitic to basaltic. All experiments were saturated with a FeS melt. Temperature was confirmed to have a positive effect on the SCSS and no measurable pressure effect was observed. Oxygen fugacity was controlled to be either near the carbon-carbon monoxide buffer or one log unit above the nickel-nickel oxide buffer, and found to positively affect the SCSS. A series of models were constructed to predict the SCSS as a function of temperature, pressure, melt composition, oxygen fugacity and sulfur fugacity of the system. The coefficients were obtained by the regression of experimental data from this study and from data in the literature. The best model found for the prediction of the SCSS is: lnSppm =-996T+9.875+0.997lnMFM+0.1901lnf O2-0.0722&parl0;PT &parr0;-0.115lnfS2 where P is in bar, T is in K, and MFM is a compositional parameter describing the melt based upon cation mole fractions: MFM=Na+K+2 Ca+Mg+Fe2+Six Al+Fe3+.
This model predicts the SCSS in anhydrous silicate melts from rhyolitic to basaltic compositions at crustal conditions from 1 bar to 1.25 GPa, temperatures from ~1200 to 1400ºC, and oxygen fugacities between approximately two log units below the fayalite-quartz-magnetite buffer and one log unit above the nickel-nickel oxide buffer. For cases where the oxygen and sulfur fugacities cannot be adequately estimated a simpler model also works acceptably: lnSppm =-5328T+8.431+1.244 lnMFM-0.01704P T+lnaFeS where aFes is the activity of FeS in the sulfide melt and is well approximated by a value of 1. Additional experiments were performed on other basalts in a temperature range from 1250ºC to 1450ºC at 1 GPa to test the models. The model predictions and the measurements of the SCSS agree within 5%. Although I cannot fix exactly the stoichiometric coefficients of the reaction controlling sulfur dissolution, my experiments and models suggest that the solution reaction for sulfur in melts saturated with sulfide is similar to: 8FeSsulfide +3FeOsilicate+4O2-silicat e+2O2gas ⇔4S2-silicate+2S 2gas+11FeOsulfide where the subscripts indicate the phase and O 2- represents "free" oxygens in the silicate melt.
Keywords. sulfur, solubility model, dissolution mechanism, silicate melts

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Morra, Matthew John. "Gaps in the sulfur cycle : biogenic hydrogen sulfide production and atmospheric deposition /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487323583619796.

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Ji, Yijie. "Metal Organic Frameworks Derived Nickel Sulfide/Graphene Composite for Lithium-Sulfur Batteries." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron152233332526446.

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Morris, Robert Eugene. "THE CONTROL OF SULFUR EMISSIONS DURING THE ROASTING OF METAL SULFIDES (LIME, ZINC)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275396.

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23

Aguilar, Luis Felipe. "Development of Sulfur Tolerant Materials for the Hydrogen Sulfide Solid Oxide Fuel Cell." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6979.

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One of the major technical challenges towards a viable H2S//Air SOFC is to identify and develop anode materials that are electronically conductive, chemically and electrochemically stable, and catalytically active when exposed to H2S-rich environments. The corrosive nature of H2S renders most traditional state-of-the-art SOFC anode materials (Ni, Pt, Ag) useless for long-term cell performance even at very low sulfur concentrations. In my doctoral thesis work, a new class of perovskite-based anodes was developed for potential use in SOFCs operating with H2S and sulfur-containing fuels. Cermets from this family of materials have shown excellent chemical stability and electrochemical performance at typical SOFC operating conditions. As an added benefit, they appear to preferentially oxidize H2S over hydrogen, as suggested by open circuit voltage, impedance spectra, and cell performance measurements obtained using various H2S-H2-N2 fuel mixtures. Cell power output values were among the highest reported in the literature and showed no significant deterioration during 48-hour testing periods. Impedance measurements indicated overall cell resistances decreased with increasing temperature and H2S content of the fuel. This behavior is starkly different from that of contemporary SOFC anodes, where the presence of H2S usually increases overall polarization resistance and ultimately destroys the cell. Results are promising due to the drastic improvement in sulfur tolerance compared to the current generation of SOFC power systems.

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Black, Julia. "Quantifying Carbonyl Sulfide and Other Sulfur-Containing Compounds Over the Santa Barbara Channel." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/scripps_theses/998.

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Carbonyl sulfide (OCS) is emitted to the atmosphere through the outgassing of ocean surface waters. OCS is also the primary source of sulfur-containing compounds in the stratosphere and contributes to the formation of the stratospheric sulfate layer, an essential controller of the radiative balance of the atmosphere. During the 2016 Student Airborne Research Program (SARP), 15 whole air samples were collected on the NASA DC-8 aircraft over the Santa Barbara Channel. Five additional surface samples were taken at various locations along the Santa Barbara Channel. The samples were analyzed using gas chromatography in the Rowland-Blake lab at UC Irvine, and compounds associated with ocean emissions including OCS, dimethyl sulfide (DMS), carbon disulfide (CS2), bromoform (CHBr3), and methyl iodide (CH3I) were examined. Excluding OCS, the vertical distribution of marine tracers that were analyzed showed dilution with increasing altitude. For OCS, the surface samples all exhibited elevated concentrations of OCS in comparison to samples taken from the aircraft, with an average of 666 ± 26 pptv, whereas the average concentration of OCS in the aircraft samples was 581 ± 9 pptv. 2016 Surface samples were compared to surface samples from SARP campaigns between 2009-2015 taken near or within the 2016 study region. The 2009-2015 samples exhibited an average OCS concentration of 526 ± 8 pptv. It is evident that the 2016 surface samples measured higher concentrations of OCS than ever recorded during previous SARP campaigns and in comparison to global averages: 525 ± 17 pptv in the Northern hemisphere and 482 ± 13 pptv in the Southern hemisphere (Sturges et al., 2001). OCS emissions should be measured using surface samples if emission estimates from the ocean are to be evaluated since measurements from the aircraft (500 ft) are not sufficiently capturing surface concentrations. Additionally, OCS enhancements seen in 2016 had never before been detected by surface samples, revealing a potential phenomenon at work causing the elevation during this year’s campaign.

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Sweeney, Jason T. (Jason Thomas) 1971. "Novel metal oxide nanocomposites for oxygen storage, sulfur dioxide adsorption and hydrogen sulfide absorption." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/29295.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2003.
Includes bibliographical references.
Increasingly stringent regulations on automotive emissions have resulted in the need for improved pollution control technology. To reduce mobile emissions, researchers have investigated alternatives such as lean-bum engines and fuel cells. This work is focused on the synthesis, characterization and testing of novel metal oxide nanocomposites to facilitate the utilization of these technologies. In lean-bum engines, the use of adsorbents to remove NOx faces two major challenges: (1) excess hydrocarbon and CO emissions during fuel-rich pulses for adsorbent regeneration, and (2) reduced NOx adsorption efficiencies due to competitive adsorption of SO2 in the gas stream. To provide for the low-temperature oxidation of hydrocarbons and CO under a reducing atmosphere, CeO2, a well-known oxygen storage material, was modified through secondary metal oxide doping to improve thermal stability and oxygen accessibility. 20 at% substitution of Pr, Sc and Zr in CeO2 successfully promoted microstructural stability, with Ceo.8Zro0.202- retaining grain size of 30 nm even after calcination at 10000C. At high doping levels, Zr improved grain size stability further, but ZrO2 phase segregation was noted in CelxZrxO2.8 with x > 0.2. TPR experiments under 2.5% H2 in He showed that Ceo8Pr0.202- provided superior low-temperature reduction and overall reducibility amongst Ce0.8M0.2026- materials. Moreover, CelxPrxO2-8 showed increased reducibility with increasing x, achieving a maximum weight loss of 4.8% at x = 1.0. CO oxidation studies over Ceo.8M0.202-8 identified Sc and Zr doping with the lowest CO light-off temperatures (247⁰C and 264⁰C, respectively).
(cont.) For CelPrxO2- and CelxZrxO2-, low levels of doping resulted in the highest CO oxidation activity; light-off was successfully achieved at 264⁰C and 252⁰C for x = 0.4 and 0. 1, respectively. Metal oxide-based materials were developed to selectively adsorb SO2 during fuel-lean conditions and desorb SO2 during fuel-rich conditions, thereby preventing the SO2 poisoning of the NOX adsorbent. Of various simple and mixed metal oxides, the Cr203-CuO system was found to provide SO2 adsorption under oxidizing conditions at 400⁰C, and SO2 evolution under reducing conditions below 350⁰C. The CuCr20O4 phase present at the optimal Cr20O3-CuO composition gave rise to improved low-temperature CO activity, which facilitated SO2 desorption. With increased CuO content, both adsorption capacity and regenerability were increased. Through the introduction of dopants, phase-pure CuCr2yCoyO4 was obtained to allow for SO2 desorption below 300Ê»C, which corresponded well with increased CO2 evolution. By introducing excess CuO onto CuCr1.9Co0.1O4 via various synthesis routes, improved SO2 sorption characteristics were attained. In pulse adsorption/desorption studies, the CuO/ CuCr.9Co0.104 materials and CuO/CuCr204 also demonstrated excellent capacity and superior regenerability relative to the conventional CuO/A1203 adsorbent. For on-board H2 production for fuel cells, the removal of H2S is paramount to avoiding poisoning of the H2 separation membrane and the fuel cell. Conventional coarse-grained ZnO is not viable for H2S ...
by Jason T. Sweeney.
Ph.D.

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26

Lennartz, Sinikka T. [Verfasser]. "From local to global scale - marine emissions of the climate relevant sulfur gases carbonyl sulfide, carbon disulfide and dimethyl sulfide / Sinikka T. Lennartz." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1140054023/34.

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Ligmajer, Filip. "Pokročilé plazmonické materiály pro metapovrchy a fotochemii." Doctoral thesis, Vysoké učení technické v Brně. CEITEC VUT, 2018. http://www.nusl.cz/ntk/nusl-387738.

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Plazmonika, tedy vědní obor zabývající se interakcí světla s kovovými materiály, nabízí ve spojení s nanotechnologiemi nezvyklé možnosti, jak světlo ovládat a využívat. Výsledkem tohoto spojení může být například zaostřování světla pod difrakční limit, zesilování emise nebo absorbce kvantových zářičů, či extrémně citlivá detekce molekul. Tato práce se zabývá zejména možnostmi využití plazmoniky pro vývoj plošných optických prvků, tzv. metapovrchů, a pro fotokatalytické aplikace založené na plazmonicky generovaných elektronech s vysokou energií, tzv. horkých elektronech. Nejprve jsou vysvětleny teoretické základy plazmoniky a je poskytnut přehled jejích nejvýznamnějších aplikací. Poté jsou představeny tři studie zabývající se využitím plazmonických nanostruktur pro ovládání fáze a polarizace světla, pro vytváření dynamicky laditelných metapovrchů, a pro foto-elektrochemii s horkými elektrony. Společným prvkem těchto studií je pak používání pokročilých, resp. v rámci těchto oblastí netradičních, materiálů, jako např. oxidu vanadičitého nebo dichalkogenidů přechodných kovů.

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28

Šlechtová, Tereza. "Možnosti odstranění zápachu na stokové síti." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409710.

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The aim of this diploma thesis is to research the possibilities of an odor regulation in a sewerage system. The first part of the thesis is devoted to legislation in sewege odor problematics. The second part includes description of the cause of the odor and methodology related to a hydrogen sulfide elimination either from sewerage atmosphere or straight from waste water. The next part examines the results of a survey, which was given to operators of the sewerage system. The survey examined the cause of an odor, its control and possible solutions of an odor in a sewerage system. Practical part is devoted to a given geographical area, where these problems have occurred the past. In this area the measuring of hydrogen sulfide presence took place by adding chemicals into waste water. From the collected data an evaluation was made. This can serve as a possible recommendation to sewege operators.

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29

Jamieson, John William. "Tracing sulfur sources in an Archean hydrothermal system using sulfur multiple isotopes a case study from the Kidd Creek volcanogenic massive sulfide deposit /." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2697.

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Thesis (M.S.) -- University of Maryland, College Park, 2005
Thesis research directed by: Geology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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30

Lohmayer, Regina [Verfasser], and Britta [Akademischer Betreuer] Planer-Friedrich. "Importance of Sulfide, Polysulfides, and Elemental Sulfur for Abiotic and Biotic Redox Processes in Sulfur-Metal(loid)Systems / Regina Lohmayer. Betreuer: Britta Planer-Friedrich." Bayreuth : Universität Bayreuth, 2015. http://d-nb.info/1080237569/34.

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31

Bailey, Thomas. "Development of Tools for Understanding Biological Sulfur Chemistry." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20444.

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Hydrogen sulfide (H2S) is an important biomolecule for its role in mediating redox homeostasis and signaling biological processes. The study of biological sulfide is currently impeded by a lack of tools available that adequately address the questions currently facing the field. The most pressing of these questions are: how does H2S signal biological processes. To produce tools for studying H2S, chemiluminescent scaffolds were designed to study both H2S producing enzymes and directly measure free H2S. Additionally, small molecule organic persulfides were synthesized and characterized in order to study the properties and reactivity of H2S signaling species. By creating methods to directly measure biological H2S and creating model systems to investigate the active signaling species, the biological reactivity of H2S can be better understood. The luminescent methods for detecting H2S were developed in order to avoid photodecomposition inherent with fluorescent methods while still providing a spectroscopic readout for performing measurements in cells. D-cysteine concentrations can be measured using luciferin bioluminescence, and utilized to back out the H2S producing activity of DAO. Free H2S was measured using luminol derived chemiluminescence. The luminol scaffolds were studied in depth to determine what makes an H2S probe selective for H2S in order to inform the design of future H2S probes. Sulfide signaling processes were investigated using organic persulfide model systems. We found that under reducing conditions persulfides liberate free H2S, and that under basic conditions they decompose. The decomposition pathway is governed by substitution at the -carbon, which dictates the steric accessibility of the inner sulfur atom to act as an electrophile. Persulifdes do not react with acids, and are easily tagged by electrophiles to form disulfides. Persulfides are sufficiently reducing to generate NO from nitrite, facilitating cross-talk between multiple signaling species. This cross talk is mediated by formation of perthionitrite, which may function as an independent signaling species.

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32

Chin, Mian. "An atmospheric study of carbonyl sulfide and carbon disulfide and their relationship to stratospheric background sulfur aerosol." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/26226.

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33

Pahlevanzadeh, Hassan. "Solubility of the toxic gases, hydrogen sulfide and sulfur dioxide in some polar and non-polar solvents." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/5243.

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34

Nelen, Louis M. "Investigating the chemistry of H₂S/Ge(100), and Fe/Ge surfaces /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9988687.

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35

Harahuc, Lesia. "Control of iron and sulfur oxidation activities of Thiobacillus ferrooxidans and bacterial leaching of metals from sulfide ores." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0027/NQ51648.pdf.

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36

Trupiano, Vito. "EVALUATION OF OXIDIZED MEDIA FILTRATION PROCESSES FOR THE TREATMENT OF HYDROGEN SULFIDE IN GROUNDWATER." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3026.

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This study evaluated alternative sulfide treatment processes for potable water systems that rely on groundwater supplies. Research for this study was conducted at the Imperial Lakes (IL) and Turner Road (TR) water treatment plants (WTPs) in Polk County, Florida. These WTPs are in the process of refurbishment and expansion, and will require the installation of a new groundwater well. The IL and TR WTPs both rely upon groundwater sources that contain total sulfide at concentrations ranging from 1.4 to 2.6 mg/L. Sulfide is a concern because if left untreated it can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity. For this reason, the raw water will require treatment per Florida Department of Environmental Protection (FDEP) "Sulfide Rule" 62-555.315(5)(a). This rule does not allow the use of conventional tray aeration (currently in use at the IL and TR WTPs) for wells that have significant total sulfide content (0.6 to 3.0 mg/L). This research was commissioned because the potential water treatment method identified in the Sulfide Rule (i.e. forced-draft aeration) would not adequately fit within the confines of the existing sites and would pose undue burden to neighboring residents. In addition, an effective sulfide treatment process was desired that offered a low profile, did not necessitate the need for additional complex chemical feed systems, minimized the extent of electrical infrastructure upgrades, and was inexpensive to construct and operate. To meet these goals, several alternative technologies were evaluated at the desktop and bench-scale; these included anion exchange, various oxidation methods, and alternative media filtration processes. From that effort, several processes were selected for evaluation at the pilot scale: bleach (NaOCl) oxidation preceding electromedia filtration; manganese (IV) oxide (MnO2) filtration continuously regenerated with bleach; and ferrate (Fe(VI)) oxidation. Electromedia and MnO2 filtration were shown to be effective for total sulfide treatment. Both processes reduced total sulfide content to below detection levels (< 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. The use of bleach oxidation ahead of media filtration also produced finished water with low turbidity (< 1.0 NTU) as compared to conventional tray aeration and chlorination processes (6-16 NTU, as observed in this study). It was determined that the media filtration approach (electromedia and MnO2) was effective for sulfide treatment and met the County's site objectives established at the outset of the project. Ferrate was also shown to reduce total sulfide content to below detection levels (< 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. An opinion of probable capital costs for installing a sulfide oxidation/filtration process at either the Imperial Lakes or Turner Road WTP was estimated to range from roughly $830,000 to $1,100,000. That equates to a $/kgal capital cost of $0.10 to $0.32 (at 8% for 20 years). An opinion of annual probable bleach chemical costs was estimated to range from $3,500 to $9,800 for the IL WTP and $3,500 to $5,800 for the TR WTP.
M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engr MSEnvE

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37

Těšík, Jan. "Luminiscence polovodičů studovaná rastrovací optickou mikroskopií v blízkém poli." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-320110.

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This work is focused on the study of luminescence of atomic thin layers of transition metal chalkogenides (eg. MoS2). In the experimental part, the work deals with the preparation of atomic thin layers of semiconducting chalcogenides and the subsequent manufacturing of plasmonic interference structures around these layers. The illumination of the interference structure will create a standing plasmonic wave that will excite the photoluminescence of the semiconductor. Photoluminescence was studied both by far-field spectroscopy and near-field optical microscopy.

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38

Forsythe, Robert. "The Development of New Methods for Coal Sulfer Forms & Sulfur in Ash Determination." TopSCHOLAR®, 1993. https://digitalcommons.wku.edu/theses/2352.

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The development of new procedures to determine the amount and/or types of sulfur in coal and coal products is an ongoing process for coal scientists This development is driven by the problems and inconveniences of the current ASTM methods In this thesis, the work done at Western Kentucky University in the development of two new sulfur determination procedures will be described. The first procedure can be used as an alternative method for coal sulfur forms analysis with results comparable to the ASTM method. This procedure involves heating the coal samples at 365°C and 440°C for thirty minutes to selectively remove sulfur forms from the coal. The difference in the amount of sulfur remaining in the residues is the amount of pyritic sulfur in the coal This value, along with the ASTM D 2492 sulfate sulfur value can be used to calculate the amount of organic sulfur present in the coal. The second procedure described is an alternative method for measuring the amount of sulfur in coal ash. This method involves standardizing a Leco SC-432 sulfur analyzer using iron(II) ammonium sulfate and a modified weight method. The ash sample is then mixed with a carbon promoter and the total sulfur present in the ash determined. The problems encountered in the development of these two procedures and the advantages of these methods compared to the current ASTM procedures will be discussed.

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Kuba, Jakub. "Studium fotoluminiscence tenkých vrstev MoS2." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254284.

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The thesis deals with study of thin layers of transition metal dichalcogenides, especially of molybdenum disulfide. Nanostructures were fabricated on two-dimensional crystals of MoS2 and WSe2. Within followed analysis attention was paid to the photoluminescence properties. In the thesis transition metal dichalcogenides are reviewed and description of the modified process of preparation by micromechanical exfoliation is given.

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40

Kovařík, Martin. "Charakterizace elektronických vlastností nanodrátů pro elektrochemii." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-402570.

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Elektrochemické metody nacházejí využití v mnoha aplikacích (např. senzorice, skladování el. energie nebo katalýze). Jejich nespornou výhodou je nízká finanční náročnost na přístrojové vybavení. Abychom lépe porozuměli procesům probíhajícím na elektrodách, je dobré znát elektronickou pásovou strukturu materiálu elektrody. Úkolem této práce je vyhodnotit výstupní práci a pozici hrany valenčního pásu nových materiálů pro elektrody, konkrétně cínem dopovaného oxidu india pokrytého nanotrubicemi sulfidu wolframičitého. Ultrafialová fotoelektronová spektroskopie a Kelvinova silová mikroskopie jsou metody použité pro tuto analýzu. Zvláštní důraz je kladen na přípravu vzorků elektrod pro měření, aby nedošlo k nesprávné interpretaci výsledků vlivem vnějších efektů jako je např. kontaminace nebo modifikace povrchu.

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41

Hall, Donald Lewis. "Fluid evolution during metamorphism and uplift of the massive sulfide deposits at Ducktown, Tennessee, U.S.A." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54186.

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The Ducktown mining district, located in the southeastern corner of Tennessee within the Blue Ridge Province of the southern Appalachians, contains some of the largest metamorphosed pyrrhotite-pyrite-rich massive sultide deposits in the Appalachian-Caledonian orogen. Oxygen isotope temperatures of 530±20°C are consistent with previous estimates based on mineral thermobarometers (540±40°C; 6-7 kb) suggesting that minerals attained oxygen isotopic equilibrium during peak metamorphism and underwent little retrograde exchange. Fluid inclusion and petrologic data do not support the previous interpretation that low δ¹⁸O zones near orebodies are synmetamorphic, rather, a premetamorphic origin is indicated. Integrated fluid/rock ratios were low enough during and after metamorphism that premetamorphic spatial variations in δ¹⁸O were retained. However, hydrogen and carbon isotopes were homogenized throughout the area during or before metamorphism. The low δ¹⁸O zones surrounding the orebodies appear to have formed during sea—fIoor hydrothermal activity associated with ore deposition. The δ¹⁸O value of the fluid responsible for ore deposition, assuming a temperature of 300°C, is calculated to be -1 to +2 per mil, consistent with the interpretation that the ore fluid was modified seawater. Calculation of theoretical C-O-H-S fluid speciation suggests that the fluid in equilibrium with clinopyroxene-bearing rocks was essentially H₂O+CO₂with XCO₂ = 0.10. However, primary fluid inclusions located in clinopyroxene contain signifticant quantities of CH₄. This discrepancy is explained by hydrogen diffusion into primary fluid inclusions and subsequent conversion of CO₂ to CH₄ during uplift in response to an fH₂ gradient between inclusion and matrix fluids. Low δD values of primary fluid inclusions are consistent with diffusive addition of isotopically light hydrogen after trapping. Secondary inclusions in metamorphic quartz record a complex uplift history involving a variety of fluids in the C-O-H-N-salt system. lsochores calculated for these inclusions constrain the uplift path to have been initially concave toward the temperature axis. Over the pressure range 2.3 to 1.0 kb the uplift path became nearly isothermal at 215±20°C. lmmiscible H₂O-CH₄-N₂-NaCl fluids present during the isothermal stage of the uplift history were derived during Alleghanian thrusting by expulsion of pore fluids and maturation of organic matter in lower plate sedimentary rocks proposed to underlie the deposits. Average uplift rates of 0.1 mm/yr are suggested by the uplift path and available geochronologic data.
Ph. D.

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42

Friedman, Carrie T. 1972. "Analysis of stable sulfur isotopes and trace cobalt on sulfides from the TAG hydrothermal mound." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/53034.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1998.
Includes bibliographical references (leaves 86-90).
by Carrie T. Friedman.
M.S.

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43

Lamanna, William Christopher. "Functional characterization of the novel heparan sulfate 6O-endosulfatases Sulf1 and Sulf2." Göttingen Cuvillier, 2008. http://d-nb.info/989809897/04.

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44

Anglen, Brandy Lynn. "Contrasting sulfur isotopic characteristics for sulfate and sulfide in water and sediment profiles from three lakes in Taylor Valley, Antarctica." [Bloomington, Ind.] : Indiana University, 2005. http://wwwlib.umi.com/dissertations/fullcit/3183912.

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45

Chauk, Shriniwas S. "High-pressure high-temperature control of Hydrogen Sulfide, Sulfur Dioxide and Selenium from fuel/flue gas using Ca-based sorbents /." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488186329503714.

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46

Li, Wen. "Synthesis and solubility of arsenic tri-sulfide and sodium arsenic oxy-sulfide complexes in alkaline sulfide solutions." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44546.

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Alkaline sulfide leaching (ASL) at approximately 100 ºC has been used to selectively extract arsenic and antimony from enargite and tetrahedrite concentrates. Sodium thio-arsenate has been postulated to crystallize from alkaline sulfide leaching solutions upon cooling. However, literature data on the solubility of sodium thio-arsenate as well as proof of its crystallization from ASL solutions is scant. In this thesis, the solubility of leach-produced and synthetic sodium thio-arsenate is studied. To determine arsenic solubility in ASL solutions, sodium thio-arsenate and sodium arsenic oxide sulfide complexes are synthesized by various means and characterized by EDX, QXRD, and ICP. The synthesis of amorphous As₂S₃, sodium arsenic oxy-sulfide complexes, and sodium thio-arsenate is first presented. For amorphous As₂S₃ synthesis, the effect of concentration of sodium sulfide (0.1 M) and hydrochloric acid (1 M), temperature (40 ~ 60 ºC), and aging time (48 hours) was optimized. The solubility of synthetic sodium arsenic oxy-sulfide complexes and sodium thio-arsenate in ASL solutions increases significantly as temperature is increased to 95 ºC. More importantly, the solubility of sodium thio-arsenate at certain temperatures is significantly affected by the concentration of sodium hydroxide and sulfide in solution. Due to the common ion effect, if NaOH and HS- concentrations are very high, the solubility of sodium thio-arsenate decreases. Enargite leaching tests were done to characterize the precipitate that occurred upon cooling and to verify the arsenic saturation point, which should be between 38.5 ~ 58 g/L (0.51 M ~ 0.78 M) As depending on the NaOH and HS- concentration. Comparison with solubility experiments of pure sodium thio-arsenate shows that arsenic solubility in ASL solutions is supersaturated. However, direct comparison of saturation in ASL solutions and the solubility as obtained by the synthetic solutions/crystallites prepared here is not possible given the complex nature of the ASL crystallites that appear not to contain the often discussed “sodium thio-arsenate”.

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47

Meyer, Amanda Lynn. "Biogeochemistry of Sulfur Isotopes in Crystal Lake, Clark County, West-Central Ohio." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1420911116.

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48

Babcock, Kevin Brian. "Alkali carbonate-sulfide electrolytes for medium temperature hydrogen sulfide removal." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/12959.

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Hao, Yong. "Sulfur Based Electrode Materials For Secondary Batteries." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2582.

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Developing next generation secondary batteries has attracted much attention in recent years due to the increasing demand of high energy and high power density energy storage for portable electronics, electric vehicles and renewable sources of energy. This dissertation investigates sulfur based advanced electrode materials in Lithium/Sodium batteries. The electrochemical performances of the electrode materials have been enhanced due to their unique nano structures as well as the formation of novel composites. First, a nitrogen-doped graphene nanosheets/sulfur (NGNSs/S) composite was synthesized via a facile chemical reaction deposition. In this composite, NGNSs were employed as a conductive host to entrap S/polysulfides in the cathode part. The NGNSs/S composite delivered an initial discharge capacity of 856.7 mAh g-1 and a reversible capacity of 319.3 mAh g-1 at 0.1C with good recoverable rate capability. Second, NGNS/S nanocomposites, synthesized using chemical reaction-deposition method and low temperature heat treatment, were further studied as active cathode materials for room temperature Na-S batteries. Both high loading composite with 86% gamma-S8 and low loading composite with 25% gamma-S8 have been electrochemically evaluated and compared with both NGNS and S control electrodes. It was found that low loading NGNS/S composite exhibited better electrochemical performance with specific capacity of 110 and 48 mAh g-1 at 0.1C at the 1st and 300th cycle, respectively. The Coulombic efficiency of 100% was obtained at the 300th cycle. Third, high purity rock-salt (RS), zinc-blende (ZB) and wurtzite (WZ) MnS nanocrystals with different morphologies were successfully synthesized via a facile solvothermal method. RS-, ZB- and WZ-MnS electrodes showed the capacities of 232.5 mAh g-1, 287.9 mAh g-1 and 79.8 mAh g-1 at the 600th cycle, respectively. ZB-MnS displayed the best performance in terms of specific capacity and cyclability. Interestingly, MnS electrodes exhibited an unusual phenomenon of capacity increase upon cycling which was ascribed to the decreased cell resistance and enhanced interfacial charge storage. In summary, this dissertation provides investigation of sulfur based electrode materials with sulfur/N-doped graphene composites and MnS nanocrystals. Their electrochemical performances have been evaluated and discussed. The understanding of their reaction mechanisms and electrochemical enhancement could make progress on development of secondary batteries.

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Huang, Shanshan. "Nanoparticulate nickel sulfide." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54754/.

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Nickel sulfide possesses a variety of typical structures and stoichiometries that distinguish itself from iron sulfide and exhibits unique roles in the prebiotic reactions which are proposed to be involved in the origin of life. Nickel sulfide precipitate is hydrated and nanocrystalline, modelled as a 4 nm sphere with a 1 nm crystalline and anhydrous NiS (millerite) core, surrounded by a hydrated and defective mantle phase. It is a metastable but fairly robust structural configuration. It may be formulated as NiSxFbOx approximates to 1.5 and decreases on heating. The fresh nanoparticulate nickel sulfide precipitates undergo structural transformation from the initial millerite-like NiS to the more crystalline polydymite-like Ni3S4. This reaction is accompanied by the formation of a less crystalline Ni3S2 (heazlewoodite) phase. The reaction, happening in ambient conditions, occurs more readily for the solids precipitated from acidic environments (i.e., pH 3) and may be facilitated by the hydrogen and water bonding contained in this material. The performance of nickel sulfide and iron sulfide precipitates is investigated in the formaldehyde world under ambient and sulfidic environments which mimic the ambient ancient Earth environments to some extent. The catalytic capacity of the metal sulfides is not obvious in these experiments. An interesting finding is that, trithiane, the cyclic (SCH2)3, also suppresses the pyrite formation and thus promotes the greigite formation in the reaction between FeS and H2S. This provides another cause for the greigite formation in the Earth sedimentary systems and adds information to the origin-of-life theory in the iron sulfur world. Voltammetry experiments reveal that the nickel-cysteine complex lowers the overpotential for molecular H2 evolution in sea water to -1.53 V under ambient conditions. This catalytic property of the abiotic nickel-cysteine complex apparently mimics the Ni-S core in some hydrogenase enzymes functioning in physiological conditions. This bridges the abiotic and biotic worlds and supports the idea that life originated in the prebiotic ancient ocean.

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Dissertations / Theses on the topic 'Sulfid'

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