Development of a Photo-Fenton Catalyst Supported on Modified Polymer Films:Preparation, Characterization and Implication for Water Decontamination by Solar Photocatalysis

The work presented in this thesis is a part of the European project INNOWATECH. The global objective of this project was to provide effective technological solutions for the treatment of industrial wastewater, to propose new concepts in wastewater treatment with potential benefits for the protection of the environment. In particular photo-assisted Fenton oxidation was investigated. It is a promising technology to decontaminate industrial wastewater as it makes use of the natural energy that provides the sun, abundant chemicals (iron ions and hydrogen peroxide) and does not produce toxic waste. Apart from short detour about homogenous photo-Fenton reaction (chapter 2) where the influence of pollutant physico-chemical properties on reactivity is studied, this thesis focuses on photo-Fenton treatment using a new solid catalysis. The immobilization of iron oxide on a suitable support is a strategy proposed to overcome the practical limitation related to homogeneous photo-Fenton treatment (i.e. the limited operational pH range and the problems caused by the separation of catalyst from the effluent). The preparation and the surface characterization of new photo-Fenton catalysts based on iron oxide supported on modified polymer films is described in chapters 3 and 4. The photocatalytic activities of prepared materials were evaluated mainly toward organic pollutant degradation both at laboratory (chapter 3-5) and at pilot (chapter 6) scales. In detail, chapter 2 focuses on the effect of contaminant physico-chemical properties on the reactivity via photo-assisted Fenton catalysis. Several para-substituted phenols were used in order to cover a wide range of electronics effects. Many physico-chemical descriptors were correlated with the initial Fenton and photo-Fenton degradation rates (r0). Electronic descriptors such as calculated zero point energy (Ezero) and energy of the highest occupied orbital were found to be the most adequate to predict Fenton and photo-assisted Fenton reactivity. The preparation of iron oxide-coated polymer films is described in chapter 3. Polyvinyl fluoride (PVF) film surface was functionalized by different methods, either by Vacuum-UV radiation, radio-frequency plasma, photo-Fenton oxidation or TiO2 photocatalysis. These pre-treatments were performed to increase iron oxide adhesion to polymer surface. Afterward the functionalized polymers films were immersed in an aqueous solution for the deposition of iron oxide layer by hydrolysis of FeCl3. The catalytic activities of resulting materials were compared during hydroquinone degradation in presence of H2O2 and under simulated solar light illumination. The most efficient and stable catalyst obtained was prepared by means of TiO2 photocatalytic functionalization of polymers followed by iron oxide coating (leading to so called Pf-TiO2-Fe oxide), therefore this preparation procedure was selected in chapters 4-6. Chapter 4 focuses on the study of the mechanisms involved during the preparation and use of Pf-TiO2-Fe oxide. In particular, the modifications induced by TiO2 photocatalysis on polymer surface such as oxygen group formation and deposition of TiO2 particles were characterized by x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and UV-visible spectrophotometry. The photocatalytic activity of Pf-TiO2-Fe oxide in presence of H2O2 and under simulated solar light radiation was evaluated toward HQ degradation. The occurrence of important synergistic effects between TiO2 and iron oxide was discussed. Finally, the effect of preparation parameters on photocatalytic activity of Pf-TiO2-Fe oxide/H2O2/light system was determined allowing the optimization of preparation procedure. Hence highly efficient photocatalysts for hydroquinone degradation and E. Coli inactivation were obtained. The degradation of hydroquinone and nalidixic acid (NA) mediated the system Pf-TiO2-Fe oxide/H2O2/light was examined (chapter 5). The contribution of homogeneous photo-Fenton oxidation in the degradation process was determined and the mechanisms involved in iron leaching are discussed. Besides, the effect of operational parameters on degradation rates was assessed. The rates are independent on initial pH and NaCl presence but were enhanced by increasing temperature. Long-term stability of Pf-TiO2-Fe oxide was evaluated by repetitive nalidixic acid degradation runs. The adaptation of Pf-TiO2-Fe oxide to pilot scale in a compound parabolic collector (CPC) solar photoreactor is described in chapter 6: solar photocatalytic degradation of phenol, nalidixic acid, mixture of pesticides, and another of emerging contaminants, in water was investigated. The influences of operational pH and pollutant structure on the degradation rates were evaluated. It was found that compounds with chelating moieties (or carboxylic acids) were the most quickly removed by Pf-TiO2-Fe oxide/H2O2/light and allowed the photo-Fenton catalyst to be efficient at higher pH values

L’Union européenne et la Suisse : recherches sur l’institutionnalisation d’une relation entre l’UE et un État tiers

The relationship between Switzerland and the European Union can bedescribed as a tension between the interiority and the exteriority of the former to the latter.This ambivalence is emphasised by the effect of the passage of time. The interactionbetween objectivism and subjectivism can explain both the legal analysis of this tension asthe evolution of the relationship. One can point to the existence of a legal objectivizationphenomenon linked to the use of European Union law in order to determine the applicablelaw between the two parties. This phenomenon extends to the institutional part of therelationship as well: the ongoing negotiations are to strengthen the homogeneity of the lawapplied in the EU-Switzerland relationship by aligning it on European Union law. However,the evolution of this objectivization phenomenon is limited. The evolution of thegroup/ensemble formed by the European Union and Switzerland has an innate boundaryas it is lacking its own “idée d’oeuvre”, thus following that of the European Union. Thetension between the ongoing objectivization phenomenon and its innate limits seems toreflect the issue of political liberty. As the group/ensemble is still evolving and raisespolitically related issues, political liberty cannot unfold.La relation entre l’Union européenne et la Suisse est celle d’une ambivalenceentre l’intériorité et l’extériorité de la Suisse par rapport à l’Union européenne, tension querend prégnant l’effet de l’écoulement du temps. Une analyse de l’interaction entre lesubjectivisme et l’objectivisme caractérisant cette relation permet d’expliquer juridiquementcette tension, et de qualifier le développement de la relation Suisse-UE. Il existe entrel’Union européenne et la Suisse un phénomène d’objectivisation du droit, profondément liéà l’utilisation du droit de l’Union européenne pour fonder les règles applicables. Cephénomène se prolonge au niveau institutionnel : les négociations en cours visent àrenforcer l’homogénéité du droit de la relation Suisse-UE sur le droit de l’UE. Pourtant, cephénomène d’objectivisation se heurte à certaines limites : l’ensemble formé entre l’Unioneuropéenne et la Suisse ne peut prétendre qu’à un développement intrinsèquement limité,parce qu’il ne bénéficie pas d’une « idée d’oeuvre » propre, mais emprunte celle del’Union européenne. La tension résultant entre le maintien dans le temps d’un phénomèned’objectivisation et les limites inhérentes de l’objectivité possible, semble alors être lamanifestation de la liberté politique, qui se pose dans un ensemble qui se construit, sanspouvoir se déployer dans la mesure du commun

Marché intérieur et intégration économique

Analyse des déterminants politique dans la construction jurisprudentielle du marché intérieur

Marché intérieur et intégration économique

Analyse des déterminants politique dans la construction jurisprudentielle du marché intérieur

Information Theory Filters for Wavelet Packet Coefficient Selection with Application to Corrosion Type Identification from Acoustic Emission Signals

The damage caused by corrosion in chemical process installations can lead to unexpected plant shutdowns and the leakage of potentially toxic chemicals into the environment. When subjected to corrosion, structural changes in the material occur, leading to energy releases as acoustic waves. This acoustic activity can in turn be used for corrosion monitoring, and even for predicting the type of corrosion. Here we apply wavelet packet decomposition to extract features from acoustic emission signals. We then use the extracted wavelet packet coefficients for distinguishing between the most important types of corrosion processes in the chemical process industry: uniform corrosion, pitting and stress corrosion cracking. The local discriminant basis selection algorithm can be considered as a standard for the selection of the most discriminative wavelet coefficients. However, it does not take the statistical dependencies between wavelet coefficients into account. We show that, when these dependencies are ignored, a lower accuracy is obtained in predicting the corrosion type. We compare several mutual information filters to take these dependencies into account in order to arrive at a more accurate prediction