As técnicas de remediação para solos contaminados como os processos de oxidação avançados \"in situ\" visam essencialmente a mineralização dos contaminantes, reduzindo-os, em última instância, a CO2 e H2O. O objetivo deste estudo é apresentar os resultados de experimentos conduzidos para investigar como as características do solo, tais como a granulação, o teor e a natureza dos minerais argilosos, e o teor da matéria orgânica influem no desempenho da mineralização do contaminante linar alquilbenzeno no solo. Em várias partes da cidade de São Paulo há locais contaminados por esse e outros tipos de vazamentos e os responsáveis e as autoridades estão interessadas em possíveis soluções. Uma possível solução seria o tratamento in situ através dos processos de oxidação avançada. Porém, não há como decidir a priori sobre a melhor técnica, pois ela dependerá tanto do reagente empregado como do tipo de solo contaminado. Essa resposta poderá ser cientificamente fundamentada a partir de ensaios no laboratório desenhados para investigar os fatores que controlam a eficácia do processo. Os experimentos em laboratório foram conduzidos com dois tipos de solo da região metropolitana de São Paulo contaminados com linear alquilbenzeno, composto utilizado como óleo térmico em revestimentos de cabos subterrâneos de alta voltagem. Os desempenhos da mineralização com o Reagente de Fenton e Persulfato de Sódio foram avaliados na oxidação do composto linear alquilbenzeno com uma concentração inicial de 10 mg/grama de solo contaminado. Os resultados mostram uma redução considerável em massa de 82% a 85% do contaminante nos dois solos com a utilização de Persulfato de Sódio ativado termicamente e através de metal de transição \'Fe POT.2+\' disponível naturalmente no solo . O reagente de Fenton nas mesmas condições do experimento mostrou um desempenho mais limitado entre 10 % a 30% de redução em massa do contaminante. O conhecimento prévio das características do solo como o teor de argila , teor de carbono orgânico que influem fortemente os fenômenos de sorção e desorção e a composição mineralógica são variáveis importantes na definição dos reagentes e nas condições de reação de oxidação dos poluentes e contribuem na escolha mais acertada da tecnologia de remediação \'in situ\". / The remediation techniques used in contaminated soils such as \"in situ\" chemical oxidation aim essentially the mineralization of contaminants, reducing it to CO2 and H2O. The objective of this study is pointing out the results of experiments conducted to investigate how the soil characteristics such as granulometry, assay and nature of clay minerals as well as organic matter can influence in the mineralization performance of linear alkylbenzene in the soil. In some areas of São Paulo city there are contaminated sites by leakage of linear alkylbenzene and many other chemical leakages and site\'s responsible and local authorities are interested in possible technical solutions to clean it. One possible solution would be in situ treatment through advanced oxidation process; however there is no way how to decide about the best technique because it depends on contaminant substance, reagents used as well as the contaminated soil characteristics. The answer could be scientifically based on bench laboratory experiments properly designed to investigate the factors that control the process performance. The bench lab experiments were conducted with two soils sampled from metropolitan region of São Paulo and contaminated with linear alkyl benzene, used in high and medium voltage underground electrical cables. The mineralization performance was evaluated in soils contaminated with an initial concentration of 10 mg / gr of contaminated soil by oxidation of linear alkyl benzene with Fenton reagent and sodium persulfate. The final results pointed out a considerable mass reduction from 82% to 85% in both soils tested with sodium persulfate thermally activated and by naturally available transition metal \'Fe pot.2+\' in the soil. The Fenton reagent in the same experiment conditions pointed out a more limited mass reduction performance between 10% and 30%. The previous knowledge of soil characteristics such as clay assay , natural carbon content in the soil which influence the sorption / desorption phenomenon as well as the mineral composition of the soil are the key variables to define reagents and the oxidation reaction conditions which contribute to select a proper in situ chemical oxidation technology.

In the modern practice, a sustainable development strategy in a domain of wasteutilization is shifting its focus from a general completeness of recycling to a morespecific attention to efficiently utilize elements in the wastes. This is well-illustrated bythe steelmaking slag industries. The major waste product from the steelmaking practiceis slag and its main constituents are: CaO, SiO2, Al2O3, MnO, FeO and so on. The mainfield of application for the steelmaking slags is civil engineering, especially for road andwaterway construction. However, a significant amount of the slag remains in the dumps,damaging the environment as well as requiring a land for secure storage. Efficientrecycling of these materials is of increasing interest worldwide as a result of increasingsustainability in processes with respect to increasing raw material costs and wastereduction.In order to find a practical solution, joint efforts are currently made at the RoyalInstitute of Technology, Sweden and National Metallurgical Academy of Ukraine. Theconcept is based on transformation of non-magnetic wüstite (FeO) to magneticmagnetite (Fe3O4) using an oxidizing atmosphere was proposed.In order to verify the feasibility of the proposed way of slag utilization, experiments onthe ternary CaO-FeO-SiO2 and quaternary CaO-FeO-SiO2-MnO slags systems,accompanied by thermodynamic and kinetic modelling, were performed. The crystalprecipitation during synthetic slag oxidation was observed by Confocal Scanning LaserMicroscopy (CSLM). Precipitated phases were found to be magnetite and manganeseferrite in the spinel form.Obtained magnetite and manganese ferrite can be separated from the slag by magneticseparation.The formation of nanosize manganese ferrite from the CaO-FeO-SiO2-MnO slag systemduring oxidation was investigated. Experiments were conducted in a horizontalresistance furnace in an oxidizing atmosphere (air). The final product was analysed by Xraydiffraction (XRD). The particles size of the manganese ferrite was estimated by theScherrer formula and was found to be of the order of 23-25 nm. In order to get anunderstanding of the magnetic properties of the manganese ferrite recovered from slagtreatment, it was necessary to synthesize a reference compound from pure precursors.The MnFe2O4 nanopowder was synthesized by the oxalate route. The size effects on themagnetic properties of manganese ferrite particles were investigated.IIThe potential way of the magnetite particles separation from liquid slags was investigatedby cold model studies. The experimental technique of mobilising non-conducting,nonmagnetic particles in conducting liquid in crossed electric and magnetic fields wasinvestigated in order to find the way of the particle separation from the liquidsteelmaking slags. The effects of the current density, magnetic field, size and shape ofthe particle on the particle velocity under action of the electromagnetic buoyancy force(EBF) in the electrolyte were analyzed. / QC 20100916

Le secteur industriel du traitement de surface (TS), secteur d’excellence en Bourgogne Franche-Comté, est contraint de recourir à de nouvelles méthodes d’épuration des eaux du fait d’une règlementation européenne de plus en plus stricte. En effet, notamment dans le cadre de la Directive Cadre sur l’Eau, les industriels doivent sans cesse améliorer la qualité de leurs rejets et diminuer les impacts générés par ceux-ci. Ce travail de thèse s’inscrit dans cet objectif. Ainsi, trois grands types d’investigations ont été menés : le premier a permis de définir la composition qualitative et quantitative en substances dangereuses (SD) des rejets de TS et d’étudier leur variabilité temporelle ; le second a validé des modifications d’une station physico-chimique de traitement des eaux franc-comtoise pour diminuer le flux de SD ; le dernier a proposé des solutions innovantes par bioadsorption sur des matériaux de cyclodextrine et par procédé d’oxydation avancée (POA) soit par ozone/UV, soit par l’utilisation de catalyseurs Pd-Cu pour atteindre le même objectif.[...] / The industrial sector of surface treatment (ST), sector of excellence in Bourgogne Franche-Comté, is forced to resort to new methods for water treatment due to European regulations increasingly strict. Indeed, particularly in the context of the Water Framework Directive, industries must continually improve the quality of their discharge waters and reduce the impacts generated by them. This work is part of this. Thus, three types of investigations were conducted: the first has defined qualitative and quantitative composition of hazardous substances (HS) in ST discharge waters and study their temporal variability; the second has approved changes in a physicochemical wastewater decontamination station to decrease HS water flow; the last proposed innovative solutions by biosorption on cyclodextrin materials and advanced oxidation process (AOP) by ozone / UV, or by the use of Pd-Cu catalysts to achieve the same objective.[...]

This dissertation describes electrochemical oxidation of Padan 95 SP on Boron-doped diamond (BDD) electrode mainly by •OH radicals (which was measured by indirect method, i.e: the formation of 2-Hydroxylterephthalic acid (2-HTA)), Electro-Fenton and the combination with adsorption technology for increasing total organic carbon (TOC) removal efficiency. In this study, the formation of 2-HTA on BDD electrode via the reaction between terephthalic acid (TA) and •OH as a method to quantify hydroxyl radical formation was investigated. The degradation of Cartap in Padan 95SP (95 % Cartap) on BDD was investigated. Operating parameters such as applied current density, types of electrolyte and initial concentration of Padan 95SP were varied in order to determine their effect on the degradation efficiency of Cartap. The concentration of Cartap was determined by UV-Vis spectroscopy according to 5,5-Dithiobis-(2-nitrobenzoic acid) (DTNB) procedure. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC-MS) were used to characterize the commercial Padan 95SP and the formation of by-products. The optimal conditions for Cartap degradation by electrochemical process have been established: concentration of electrolyte: 0.05 M Na2SO4, initial concentration of Padan 95SP: 300 mg·L-1, pH = 3, current density: j = 20 mA·cm-2. At this condition, Cartap decreases to 41 %, TOC decay reaches 8 %. To increase TOC decay at higher Padan 95 SP concentration in aqueous solution, the combination technique of electrochemical process with other techniques was proposed, e.g.: Electro-Fenton technique, pre-oxidizing by NaOCl or the Electro-Adsorption combination. In the Electro-Fenton technique, we investigated the influence of factors such as the presence of NaOCl in pretreatment of process, affects of H2O2 concentration, Fe2+ dosage, co-catalysts metals ion and pH. The efficiency shows approximately 80 % of TOC removed at 700 mg·L-1 Padan 95 SP. The combination of electrochemical with adsorption method shows the efficient removals of TOC and Padan 95SP (95 % Cartap) based on reagents oxidation in electrochemical process and adsorption of granular activated carbon (GAC), respectively. The influence of factors such as supporting electrolytes, flow rate, bed height, recycling number as well as initial concentration were investigated in order to determine their effects on TOC removal. The efficiency of this combination shows approximately 75 % of TOC and more than 90 % of Cartap removed at 700 mg·L-1 Padan 95 SP. Fourier Transform Infrared (FT-IR) and (Brunauer–Emmett–Teller) BET surface analysis were applied to investigate GAC before and after usage. The results have shown that the application of electrochemical technique with other methods can be the potential option for treatment of wastewater containing Padan 95 SP. / Diese Dissertation befasst sich mit der Reduktion des gesamten organischen Kohlenstoffs (TOC) aus wässriger Lösung, die Padan 95 SP enthält. Als Methoden zur Minimierung von TOC wurden die elektrochemische Oxidation von Padan 95 SP auf Bor-dotierter Diamant (BDD) Elektroden durch •OH Radikale, Elektro-Fenton und die Kombination mit Adsorptionstechnologien verwendet. Die •OH Radikale wurden dabei durch indirekte Methoden, z. B. die Bildung von 2-HTA gemessen. Zur Quantifizierung der Hydroxylradikalbildung wurde in dieser Studie die Bildung von 2-Hydroxylterephthalsäure (2-HTA) an BDD-Elektroden über die Reaktion zwischen Terephthalsäure (TA) und •OH untersucht. Weiterhin befasst sich die Arbeit mit dem Abbau von Cartap in Padan 95SP (95% Cartap) auf BDD über die Reaktion zwischen Cartap und Hydroxylradikalen. Betriebsparameter wie die angewandte Stromdichte, die Elektrolytarten und die Anfangskonzentration von Padan 95SP wurden variiert, um ihre Wirkung auf die Abbaueffizienz von Cartap zu bestimmen. Die Konzentration von Cartap wurde mittels UV-Vis-Spektroskopie mit dem 5,5-Dithiobis-(2-Nitrobenzoesäure) (DTNB) Verfahren bestimmt. Hochleistungs-Flüssigkeitschromatographie (HPLC) und Gaschromatographie/Massenspektrometrie (GC-MS) wurden verwendet, um das kommerziell erhältliche Padan 95SP und die Bildung von Nebenprodukten beim Abbau von Cartap zu charakterisieren. Die optimalen Bedingungen für die Cartap-Degradation durch den elektrochemischen Prozess wurden festgelegt: Konzentration des Elektrolyten: 0.05 M Na2SO4, Padan 95SP Anfangskonzentration: 300 mg·L-1, pH = 3, Stromdichte: j = 20 mA·cm-2. Unter diesen Bedingungen sinkt Cartap auf 41% und der TOC erreicht 8 % des jeweiligen Ausgangswertes. Um den TOC-Zerfall bei höher Padan 95 SP Konzentration in Wasser zu erhöhen, wurde die Kombination des elektrochemischen Prozesses mit anderen Techniken vorgeschlagen, z.B.: Elektro-Fenton-Technik, Oxidation mit NaOCl, oder die Kombination des elektrochemischen Prozesses mit einem Adsorptionsprozess. Bei der Elektro-Fenton-Technik wurde der Einfluss von Faktoren wieder Anwesenheit von NaOCl in der Prozessvorbehandlung, Auswirkungen der H2O2-Konzentration, Fe2+-Dosierung, Metallionen als Cokatalysatoren und der pH-Wert der Lösung untersucht, um die Wirkung auf die Abbau-Effizienz für Cartap zu bestimmen. Es konnten mit dieser Methode rund 80 % TOC, ausgehend von 700 mg·L-1Padan 95SP, entfernt werden. Die Kombination des elektrochemischen Prozesses mit einer Adsorptionsmethode ermöglicht eine effiziente Entfernung von TOC und Padan 95SP (95% Cartap). Dies basiert auf der Oxidation und anschließender Adsorption auf granularer Aktivkohle (GAC). Der Einfluss von Faktoren wie Leitelektrolyten, Flussrate, Betthöhe, Recyclingzahl sowie die Anfangskonzentration von Padan 95 SP wurde untersucht, um deren Auswirkungen auf die TOC Entfernung zu bestimmen. Durch die Kombination konnten so 75% desTOC und mehr als 90% Cartap bei 700 mg·L-1Padan 95 SP entfernt werden. Fourier-Transformations-Infrarot (FT-IR) und BET-Oberflächenanalyse wurden angewendet, um GAC vor und nach der Verwendung zu untersuchen. Die Ergebnisse haben gezeigt, dass die Kombination des elektrochemischen Prozesses mit anderen Methoden eine potentielle Option für die Behandlung von Abwasser, das Padan 95 SP enthält, sein kann.

Im Rahmen der vorliegenden Arbeit wurden zwei verschiedene Klassen oxidischer Nanomaterialien nasschemisch synthetisiert und strukturell-morphologisch charakterisiert. Zum einen betrifft dies TiO2-, TiO2/SiO2-, Ag/TiO2- und Pd/TiO2-Sole, welche die photokatalytisch aktive Modifikation Anatas in nanokristalliner Form enthalten und über einen solvothermalen Sol-Gel-Prozess hergestellt werden konnten. Im Hinblick auf eine potentielle Anwendung in der Desinfektionstechnologie und für den Abbau organischer Umweltschadstoffe wurde die photokatalytische Aktivität von Pulvern und Beschichtungen auf Textil durch E. coli-Abtötung bzw. Modellfarbstoffabbau untersucht. Im Weiteren wurde die antimikrobielle Aktivität pyroelektrischer LiNbO3- und LiTaO3-Pulvermaterialien unter zyklischer thermischer Anregung nachgewiesen. Diese als Pyroelektrokatalyse bezeichnete Nutzung des pyroelektrischen Effektes in einem katalytischen bzw. elektrochemischen Prozess ist dabei von grundlegender Neuheit. Aufsetzend auf den physiko-chemischen Grundlagen dieses Phänomens wurde eine Hypothese des Mechanismus entwickelt und in Analogie zur Photokatalyse diskutiert. / This thesis deals with two classes of oxidic nanomaterials that were synthesized by chemical solution routes and characterized with respect to structure and morphology. Sols of TiO2, TiO2/SiO2, Ag/TiO2 and Pd/TiO2 containing the photocatalytically active modification anatase in nanocrystalline form were prepared via a solvothermal sol-gel process. With regard to potential application in disinfection and environmental remediation technology the photocatalytic activity of powders and coatings on textile was investigated by means of E. coli decomposition and organic dye degradation. Further the antimicrobial activity of pyroelectric LiNbO3 and LiTaO3 powder materials under cyclical thermal excitation was demonstrated. In this context the application of the pyroelectric effect in a catalytic or electrochemical process – termed as pyroelectrocatalysis – is of fundamental novelty. Based on the physico-chemical principles of the phenomenon a hypothesis of the mechanism was developed and discussed in analogy with photocatalysis.