In this study, the Persistent Organic Pollutants (POPs) specifically / 17 Organochlorine Pesticides (OCPs) and 19 Polycyclic Aromatic Hydrocarbons (PAHs) were evaluated in the sediment samples of Balikesir (Ikizcetepeler) Dam Lake. Sixteen sampling points were chosen for determination of concentrations of OCPs and PAHs After ultrasonic bath extraction of the sediment samples GC-MS was used as analytical tool. Extraction efficiencies changes from 63.8 to 87.4% depending on the type of the POPs. Average OCP concentration was found in the range of 3.33-379 &micro / g/kg a, average PAH concentration was found in the range of 3.28-32.9 &micro / g/kg. Pollution maps regarding OCP and PAH distributions were drawn and the correlation between these two pollutant types was investigated. The quality control (QC) and quality assurance tests were applied by the analysis of standard reference materials (SRMs), surrogate standards and analysis replicates.

Soil and groundwater pollution has become a global issue since the advent of industrialization and mechanized agriculture. Some contaminants such as PAHs may persist in the subsurface for decades and centuries. In a bid to address these issues, protection of groundwater must be based on the quantification of potential threats to pollution at the subsurface which is often inaccessible. Risk assessment of groundwater pollution may however be strongly supported by applying process-based simulation models, which turn out to be particularly helpful with regard to long-term predictions, which cannot be undertaken by experiments. Such reliable predictions, however, can only be achieved if the used modeling tool is known to be applicable. The aim of this work was threefold. First, a source strength function was developed to describe the leaching behavior of point source organic contaminants and thereby acting as a time-dependent upper boundary condition for transport models. For general application of these functions dimensionless numbers known as Damköhler numbers were used to characterize the reaction of the pollutants with the solid matrix. Two functions were derived and have been incorporated into an Excel worksheet to act as a practical aid in the quantification of leaching behavior of organic contaminant in seepage water prognoses. Second, the process based model tool SMART, which is well validated for laboratory scale data, was applied to lysimeter scale data from two research centres, FZJ (Jülich) and GSF (München) for long term predictions. Results from pure forward model runs show a fairly good correlation with the measured data. Finally, the derived source term functions in combination with the SMART model were used to assess groundwater vulnerability beneath a typical landfill at Kwabenya in Ghana. The predicted breakthrough time after leaking from the landfill was more than 200 years considering the operational time of the facility (30 years). Considering contaminant degradation, the landfill would therefore not cause groundwater pollution under the simulated scenarios and the SMART model can be used to establish waste acceptance criteria for organic contaminants in the landfill at Kwabenya / Seit dem Beginn der Industrialisierung und der mechanisierten Landwirtschaft wurde die Boden- und Grundwasserverschmutzung zu einem weltweiten Problem. Einige Schadstoffe wie z. B. PAK können für Jahrzehnte oder Jahrhunderte im Untergrund bestehen. Um diese Probleme behandeln zu können, muss der Schutz des Grundwassers basierend auf der Quantifizierung potentieller Gefährdungen des zumeist unzugänglichen Untergrundes erfolgen. Risikoabschätzungen von Grundwasserverschmutzungen können jedoch durch die Anwendung prozess-basierter Simulationsmodelle erheblich unterstützt werden, die sich besonders im Hinblick auf Langzeitvorhersagen als hilfreich erweisen und nicht experimentell ermittelbar sind. Derart zuverlässige Vorhersagen können jedoch nur erhalten werden, wenn das verwendete Modellierwerkzeug als anwendbar bekannt ist. Das Ziel dieser Arbeit bestand aus drei Teilen. Erstens wurde eine Quellstärke-funktion entwickelt, die das Ausbreitungsverhalten organischer Schadstoffe aus einer Punktquelle beschreibt und dadurch als zeitabhängige obere Randbedingung bei Transportmodellen dienen kann. Im Hinblick auf die allgemeine Anwendbarkeit dieser Funktion werden als Damköhler-Zahlen bekannte, dimensionslose Zahlen verwendet, um die Reaktion von Schadstoffen mit Feststoffen zu charakterisieren. Zwei Funktionen wurden abgeleitet und in ein Excel-Arbeitsblatt eingefügt, das ein praktisches Hilfsmittel bei der Quantifizierung des Freisetzungsverhaltens organischer Schadstoffe im Rahmen der Sickerwasserprognose darstellt. Der zweite Teil dieser Arbeit beinhaltet die Anwendung des prozessbasierten und mittels Laborexperimenten validierten Modellwerkzeugs SMART für Langzeitprognosen auf der Lysimeterskala anhand von Daten zweier Forschungszentren, FZJ (Jülich) und GSF (München). Ergebnisse reiner Vorwärtsmodellierungsläufe zeigten gute Übereinstimmungen mit den gemessenen Daten. Im dritten Teil wurden die erhaltenen Quellstärkefunktionen in Kombination mit dem SMART-Modell eingesetzt, um das Grundwassergefährdungspotential unter einer typischen Deponie in Kwabenya, Ghana, einzuschätzen. Die vorhergesagten Durchbruchszeiten nach einer Leckage in der Deponie betragen über 200 Jahre bei einer Betriebszeit von 30 Jahren. Unter Berücksichtigung des Schadstoffabbaus verursacht die Deponie somit keine Grundwasserverunreinigung im Rahmen der simulierten Szenarien und das SMART-Modell kann verwendet werden, um Schadstoffgrenzwerte für organische Schadstoffe in der Deponie in Kwabenya festzulegen.

<p>This work reports the chemical synthesis, characterisation and electrochemical application of titanium dioxide (TiO2) and iron oxide (Fe2O3) nanoparticles in the determination of phthalates. The other part of this work involved electrochemical polymerization of aniline doped with titanium and iron oxide nanoparticles for the sensor platform in the electrolytic determination of phthalates. The TiO2 and Fe2O3 nanoparticles were prepared by sol gel and hydrothermal methods respectively. Particle sizes of 20 nm (TiO2) and 50 nm (Fe2O3) were estimated from transmission electron microscopy (TEM) The other technical methods used in this study for the characterization of the TiO2 and iron oxide Fe2O3 NPs were SEM, XRD and UV- visible spectroscopy. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the nanoparticles. These electrochemical studies of the nanoparticles were performed with a Fe2O3 or TiO2/nafion/glassy carbon membrane electrode in 0.1 M phosphate buffer (pH 7.0) and 0.1 M lithium perchlorate (pH 6.8) under an aerobic condition.</p>

Supramolecular chemistry has asserted itself as a significant multidisciplinary field concerned with molecular effects afforded through non-covalent molecular interactions. The increased interest in the literature towards nanoscale devices, through modulation of molecular function, has seen the renaissance of supramolecular chemistry as function progresses from solution to surface. Heterosupramolecular chemistry follows the architectural principles of supramolecular chemistry and embraces both covalent and non-covalent interactions of condensed phase surfaces and molecular components. A modular approach to device architecture was applied as a novel method of performing photocatalysis under visible light illumination. The application of heterosupramolecular assembly to the design of photoelectrochemical cells capable of visible light induced charge separation allowed the study of interfacial processes by means of electrochemical observations. Preparation of a series of supramolecular components was undertaken as specific molecular species within a photochemical system. Starting from a synthesised bidentate ligand that incorporated an acidic functional group, 4,4'-bis(methyl)phosphonate-2,2'-bipyridine (dmpbpy) as its ethyl ester, was chelated to give the surface sensitisers, bis-(2,2'-bipyridine)-(4,4'-bis(methyl)phosphonato-2,2'-bipyridine)ruthenium(II) dichloride ([Ru(bpy)2(dmpbpy)]Cl2) and cis-bis-(4,4'-bis-(methyl)phosphonato-2,2'-bipyridine)(2,2'-bipyridine)ruthenium(II) dichloride ([Ru(dmpbpy)2(bpy)]Cl2). An electron relay moiety with an acidic functional group, 1-ethyl-1'-(2-phosphonoethyl)-4,4'-bipyridinium dichloride (EVP), was also prepared using a procedure developed by the candidate. The electronic properties of the prepared photosensitisers were examined by theoretical quantum chemical TD-DFT calculations on the molecular structures and singlet excitations were discussed in relation to experimental data. This identified that the lowest lying LUMO states were consistently occupied by 2,2'-bipyridine (bpy) and this was speculated to be a factor affecting quantum injection yields. The effect of microwave modification of colloidal TiO2 suspensions under extended periods of treatment was investigated. Nanoparticles of TiO2 were compared and contrast to similar convection hydrothermally treated TiO2 and a commercial titania product, namely Degussa P25, both of which are utilised in device fabrication. The investigation identified that extended periods of microwave hydrothermal treatment do not greatly enhance the crystallinity and primary grain size of TiO2. The heterosupramolecular assembly of a multi-component photochemical system was constructed from prepared molecular and condensed phase components. It was demonstrated that this device was capable of inducing a photochemical reaction in H2O under irradiation with  > 420 nm in the absence of an organic electron donor. Interpretation of the photocurrents obtained from this assembly provided understanding of photochemical reactions under low light intensities. Optimised conditions for the photochemical reaction was determined to be pH = 5 and illumination yielded = 0.0036% with an apparent quantum yield (AQY) = 1.6%. Photocatalytic decomposition of organic compounds in a dye-sensitised photoelectrocatalytic cell was investigated for the complete mineralisation of EDTA into CO2, H2 and simple amines and interpreted through photocurrent observations. This was extended to a broad range of organic compounds of various solution concentrations as a simulated industrial waste stream. Photooxidation gave unique photocurrent-time profiles which identified two distinct interfacial processes by mathematical treatment of photocurrent transients with a kinetic model. Kinetic parameters were proposed as a factor for qualitative discrimination of the organic compounds. The implications of these results for heterogeneous catalysis were discussed and the formation of Host-Guest complexes as a method of molecular sensing and as specific photocatalytic receptors was proposed.

Dans ce travail de thèse, les radicaux hydroxyles et sulfates, générés par les procédés électro-Fenton et électro-persulfate utilisant une anode en fer, respectivement, ont été utilisés pour la dégradation des édulcorants synthétiques et un colorant azoïque. Les études réalisées sont essentiellement concentrées sur : efficacité de dégradation, mécanismes d'oxydation, schémas de minéralisation et évolution de la toxicité lors de traitement des polluants cibles.1. Le procédé électro-Fenton a montré une grande efficacité dans la dégradation oxydative de l'Aspartame (ASP). La dégradation et la minéralisation sont essentiellement affectées par la concentration du catalyseur (Fe2+) et l'intensité du courant. La constante de vitesse absolue de la réaction d'hydroxylation de l'ASP a été déterminée comme (5,23±0,02) x 109 M-1 s-1. Les acides oxalique, oxamique et maléique ont été identifiés comme sous-produits aliphatiques. La toxicité de la solution (méthode Microtox) augment dans un premier temps et ensuite diminue progressivement lors du traitement.(2) L'édulcorant artificiel Saccarine (SAC) a été efficacement dégradée par procédé électro-Fenton avec anodes DSA, Pt et BDD. Cependant, l'utilisation de l'anode BDD a accéléré significativement la minéralisation de la SAC. Les conditions optimales pour la minéralisation efficace de la SAC étaient: [SAC]: 0,2 mM, [Fe2+] (catalyseur): 0,2 mM, [Na2SO4] (électrolyte): 0,05 M, I (courant): 200 mA et pH: 3. Les acides oxalique, formique et maléique ont été identifiés comme sous-produits aliphatiques. La mesure de la toxicité indique une augmentation en début d'électrolyse (formation des intermédiaires toxiques) et puis une diminution progressive le long du traitement.(3) L'édulcorant artificiel Sucralose (SUC) a été complètement minéralisée en 360 min de traitement par procédé électro-Fenton avec l'anode Pt ou BDD. Le taux de minéralisation est affecté par la concentration de Fe2+ et le courant appliqué. L'efficacité du courant de minéralisation diminue avec l'augmentation du courant de 100 à 500 mA avec les deux anodes. Les acides oxalique, pyruvique, formique et glycolique ont été détectés au cours du processus de minéralisation.(4) Les solutions du colorant azoïque Orange II ont été effectivement décolorées par les radicaux sulfates générés par l'activation électrochimique du peroxydisulfate (PDS) utilisant un catalyseur solide, FeOOH (procédé CE/α-FeOOH/PDS). Le pH initial a peu d'effet sur la décoloration. La méthodologie RSM (Response Surface Methodology) basée sur le modèle Box-Behnken a été appliquée pour analyser les variables expérimentales. Les résultats indiquent que le courant a un effet positif sur la vitesse de décoloration. L'interaction du dosage de l'α-FeOOH et la concentration de PDS ont des effets significatifs. Les résultats d'analyse de variance (ANOVA) ont confirmé que les modèles proposés étaient exactes et fiables pour l'analyse des variables du procédé CE/α-FeOOH/PDS. Le catalyseur solide α-FeOOH a montré une bonne stabilité structurelle et pourrait être réutilisé.(5) Les solutions d'Orange II ont été dégradés par les radicaux sulfates obtenus par le même procédé mais avec catalyseur Fe3O4 : EC/Fe3O4/PDS. La vitesse de décoloration est affecté principalement par : pH initial de la solution, densité du courant, concentration de PDS et dosage de Fe3O4. La solution a été totalement décolorée en 60 min dans les conditions suivantes: [Orange II]0: 25 mg/L, [PDS]: 10 mM, [Fe3O4]: 0,8 g/L, densité du courant (j): 8,4 mA/cm2 et pH initial: 6,0. Les expériences de recyclage ont montré que les particules de Fe3O4 étaient stables et pourraient être réutilisées. Les spectres XPS ont montré la formation de Fe(II) sur la surface des particules de Fe3O4 lors de traitement. Les principaux intermédiaires ont été séparés et identifiés par la technique GC-MS et un schéma plausible de dégradation d'Orange II a été proposé / In this paper, electro-Fenton and sulfate radical-based electro-Fenton-like processes were used to degrade artificial sweeteners and azo dye. The results obtained during the research concern the removal efficiency, the oxidation mechanism, degradation pathway and toxicity evolution of target pollutants.(1) Electro-Fenton process was a effective method for the degradation of ASP in water. The removal and mineralization rate was affected by the Fe2+ concentration and applied current. The absolute rate constant of hydroxylation reaction of ASP was (5.23 ± 0.02) × 109 M–1 S–1. Short-chain aliphatic acids such as oxalic, oxamic and maleic acid were identified as aliphatic intermediates in the electro-Fenton process. The bacteria luminescence inhibition showed the toxicity of ASP solution decreased after it reached a maximum during the first period of the oxidation reaction.(2) Artificial sweetener SAC could be degraded effectively by electro-Fenton process with a DSA, Pt or BDD anode. However, the using of BDD anode could accelerate the mineralization of SAC. The optimal conditions for SAC removal were SAC concentration 0.2 mM, Fe2+ concentration 0.2 mM, Na2SO4 concentration 50 mM, applied current 200 mA and initial pH 3.0. Oxalic, formic, and maleic acid were observed as aliphatic byproducts of SAC during electro-Fenton process. The bacteria luminescence inhibition showed the toxicity of SAC solution increased at the beginning of electrolysis, and then it declined until the end of the reaction.(3) Artificial sweetener Sucralose could be completely mineralized in a 360 min reaction by electro-Fenton process with a Pt or BDD anode. The mineralization rate was affected by the Fe2+ concentration and applied current. The mineralization current efficiency (MCE) decreased with rising applied current from 100 to 500 mA with both Pt and BDD anode. Oxalic, pyruvic, formic and glycolic acids were detected during the oxidation of sucralose.(4) Orange II was effectively decolorized by EC/α-FeOOH/PDS process. The initial pH of Orange II solution had little effect on the decolorization of Orange II. RSM based on Box-Behnken statistical experiment design was applied to analyze the experimental variables. The response surface methodology models were derived based on the results of the pseudo-first-order decolorization rate constant and the response surface plots were developed accordingly. The results indicated the applied current showed a positive effect on the decolorization rate constant of Orange II. The interaction of α-FeOOH dosage and PDS concentration was significant. The ANOVA results confirmed that the proposed models were accurate and reiable for the analysis of the varibles of EC/α-FeOOH/PDS process. The catalystα-FeOOH showed good structural stability and could be reused.(5) Aqueous solutions of Orange II have been degraded effectively in the EC/Fe3O4/PDS process. The decolorization rate was affected by the initial pH of Orange II solution, current density, PDS concentration and Fe3O4 dosage. Orange II can be totally decolorizated in a 60 min reaction when initial Orange II concentration was 25 mg/L, PDS concentration was 10 mM, Fe3O4 dosage was 0.8 g/L, current density was 8.4 mA/cm2 and initial pH was 6.0. Recycle experiments showed Fe3O4 particles were stable and can be reused. XPS spectrum indicated Fe(II) was generated on the surface of Fe3O4 particles after reaction. The main intermediates were separated and identified by GC-MS technique and a plausible degradation pathway of Orange II was proposed

Magister Scientiae - MSc / This work reports the chemical synthesis, characterisation and electrochemical application of titanium dioxide (TiO2) and iron oxide (Fe2O3) nanoparticles in the determination of phthalates. The other part of this work involved electrochemical polymerization of aniline doped with titanium and iron oxide nanoparticles for the sensor platform in the electrolytic determination of phthalates. The TiO2 and Fe2O3 nanoparticles were prepared by sol gel and hydrothermal methods respectively. Particle sizes of 20 nm (TiO2) and 50 nm (Fe2O3) were estimated from transmission electron microscopy (TEM) The other technical methods used in this study for the characterization of the TiO2 and iron oxide Fe2O3 NPs were SEM, XRD and UV- visible spectroscopy. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the nanoparticles. These electrochemical studies of the nanoparticles were performed with a Fe2O3 or TiO2/nafion/glassy carbon membrane electrode in 0.1 M phosphate buffer (pH 7.0) and 0.1 M lithium perchlorate (pH 6.8) under an aerobic condition. / South Africa

La contamination des sols agricoles par la chlordécone menace la durabilité de l’élevage de plein air aux Antilles. Afin de maintenir ce dernier tout en protégeant les consommateurs de denrées animales d’origine terrestre, plusieurs stratégies sont étudiées. Ces travaux de thèse sont focalisés sur l’une d’entre elles qui consiste à séquestrer la chlordécone afin de réduire significativement sa biodisponibilité pour l’animal. La démarche expérimentale a été réalisée par étape, elle s’appuie sur trois piliers : des matières séquestrantes carbonées de type biochar ou charbon activé, l’utilisation de sols artificiels et sur le concept de biodisponibilité relative pour évaluer les performances de séquestration. Les essais conduits avec du charbon activé (à base de noyaux de dattes, de coco ou de lignite) ont montré une séquestration de la chlordécone en milieu aqueux ou chez l’animal, mais pour ce dernier cela ne fonctionne que si la chlordécone et la matrice séquestrante ont eu un temps de contact prolongé (ou maturation) avec l’ingestion par l’animal. Ces résultats montrent l’intérêt d’une séquestration in situ, à savoir directement dans le sol contaminé susceptible d’être ingéré par les animaux. Comme le charbon activé a un coût élevé, des matières carbonées a priori moins coûteuses ont été testées : des biochars à base de diverses essences de bois. Ces biochars produits à deux températures de pyrolyse (500 et 700°C) ont été caractérisés d’un point de vue physique (porosité) et sélectionnés via un test in vitro de disponibilité environnementale. Les tests in vivo (sur porcelets) n’ont pas montré que ces biochars sélectionnés étaient aptes à séquestrer efficacement la chlordécone, puisque la biodisponibilité relative n’était pas différente de un (référence = sol standard sans matière organique). La présence de tourbe dans le sol artificiel ne s’oppose pas au piégeage par les matrices carbonées exogènes. Le test in vitro utilisé et le test in vivo donnent des tendances équivalentes de réduction de la biodisponibilité relative, ce qui est intéressant dans une logique de validation du test in vitro. Ces résultats positifs montrent que la stratégie de séquestration par des matériaux hautement carbonés est possible, requiert des propriétés de microporosité et d’accès aux pores proches de celles d’un charbon activé, mais contingents des conditions expérimentales mises en œuvre ils doivent être poursuivis et validés sur des sols dits naturels / The contamination of agricultural soils by chlordecone threatens the sustainability of outdoor farming in the West Indies. In order to maintain the latter while protecting consumers of terrestrial animal products, several strategies are being studied. This thesis is focused on one of them which consists of sequestering chlordecone in order to significantly reduce its bioavailability for the animal. The experimental approach was carried out in stages, based on three pillars: biochar or activated carbon as sequestering materials, the use of artificial soils and the concept of relative bioavailability to assess sequestration performance. Tests conducted with activated charcoal (based on dates kernels, coconut or lignite) have shown that chlordecone is sequestered in an aqueous medium or in animals, but for the latter it only works if chlordecone and sequestering matrix had a prolonged contact time (or maturation) with ingestion by the animal. These results show the interest of in situ sequestration, ie directly in the contaminated soil likely to be ingested by the animals. As activated charcoal has a high cost, a priori less expensive carbonaceous materials have been tested: biochars based on various wood species. These biochars produced at two pyrolysis temperatures (500 and 700 ° C) were characterized from a physical point of view (porosity) and selected via an in vitro environmental availability test. In vivo tests (on piglets) did not show that these selected biochars were able to effectively sequester chlordecone, since the relative bioavailability was not different from one (reference = standard soil without organic matter). The presence of peat in the artificial soil does not prevent trapping by exogenous carbonaceous matrices. The in vitro test used and the in vivo test give equivalent tendencies to reduce the relative bioavailability, which is interesting in a logic of validation of the in vitro test. These positive results show that the strategy of sequestration by highly carbonaceous materials is possible, requires properties of microporosity and access to pores close to those of an activated carbon, but contingent on the experimental conditions implemented, they must be continued and validated on natural soils

La disponibilité de la ressource en eau potable est en train de diminuer dans diverses régions, en lien avec la demande croissante d'eau douce, de la demande en produits alimentaires (Agriculture et élevage) et des effets des changements climatiques au niveau mondial à cause de la croissance démographique. Les pratiques agricoles inadaptées peuvent conduire à des pollutions des eaux superficielles et souterraines par des pesticides, des produits pharmaceutiques, des métaux, des nutriments, ou des sédiments et colloïdes. L'augmentation de la demande en produits animaliers est un des principaux facteurs qui conduisent à l'augmentation de l'utilisation d'antibiotiques, notamment de la famille des sulfonamides comme le sulfametoxazole (SMX). Malgré les grandes quantités de SMX utilisées tant en santé humaine qu'animale, et malgré le risque de contamination des ressources en eau associés à ce type de molécule, leur devenir dans les sols est encore mal compris et est peu documenté. C'est dans ce contexte que nous avons entrepris l'étude des interactions physico-chimiques, la dégradation, l'impact et le transfert du SMX dans deux sols aux propriétés physico-chimiques similaires mais issus de zones géographiques différentes (Recife, Brésil et Mâcon, France), et présentant différents contextes climatiques (tropical et tempéré) et différents usages (urbain et agricole). L'étude des interactions physico-chimiques a consisté à caractériser les processus de sorption et leurs cinétiques ainsi que l'effet du pH des sols, en lien avec l'ionisabilité de la molécule de SMX (2 pKa). La dégradation (biotique et abiotique) de la molécule antibiotique a été évaluée pour 3 concentrations différentes (10-3, 10-4 et 10-5M) pour évaluer l'effet des propriétés des sols sur la toxicité et la biodisponibilité du SMX. Les sols de Macon et Recife non contaminés au SMX présentent une biodiversité importante et semblable comme l'ont montré les indices de Shannon (H') et de Simpson. L'addition d'antibiotiques aux 2 sols modifie rapidement leur biodiversité microbienne et induit des changements de structures et de composition de la communauté bactérienne. Une bactérie du genre Arthrobacter est spécifiquement stimulée dans les deux sols par l'ajout de SMX, mais elle n'est pas cultivable, en revanche, nous avons pu isoler une souche de Burkholderia fortement stimulée par la présence de l'antibiotique, qui représente plus de 30% de la communauté bactérienne et qui présente des capacités de dégradation de l'antibiotique très importantes. La dégradation du SMX dans les deux sols s'avère rapide à faible concentration (10-5M) et plus lente (Mâcon) voire inexistante (Recife) à plus forte concentration (10-3M). La mobilité du SMX a été évaluée par des essais de transport en colonnes de sols remaniés conduites à 0,2; 0,45 et 0,7 mL.min-1. Les concentrations en SMX étant déterminées par HPLC-UV. L'identification des processus hydrodynamiques dans les deux sols et des processus de transfert du SMX a été réalisée avec le modèle de convection - dispersion avec retard (CDE sous CXTFIT). Les cinétiques de sorption ont été bien décrite avec un modèle de second ordre et le SMX suit une adsorption de type Langmuir. La mobilité du SMX s'est avérée plus importante dans le sol de Mâcon que dans le sol de Recife en lien avec une plus forte teneur en oxydes de fer très réactifs dans ce dernier, suggérant un risque plus élevé de contamination des eaux naturelles dans le cas du sol de Mâcon. Ce risque est toutefois contrebalancé par la faible persistance dans les deux sols du SMX qui, à faible concentration, est rapidement dégradé. Mots clés : Sol, antibiotique, Sulfametoxazol, sorption, transport, dégradation, impact, polluants émergents / The availability of fresh water in various regions, has been decreasing due to the increasing demand of water resources, the growing demand for food (agriculture and livestock) and the effects of climate change on a global level due to global population growth. Inadequate agricultural practices can lead to pollution of surface and groundwater with pesticides, pharmaceuticals, pollutants, nutrients and sediments, since the main entry of these products into the environment is resulting from their use in human and veterinary medicine. Increased demand in livestock is one of the factors that led to an increased use of antibiotics, such as sulfamethoxazole, and despite the large amount of sulfamethoxazole that is used both in human medicine and in veterinary medicine, and the risk of contamination of aquifers associated this molecule, its fate in soil is still unclear and poorly documented. Thus, the physico-chemical, biological interactions were studied, the impact associated with bacterial resistance and the transport of sulfamethoxazole (SMX) in two different soils but have similar particle size characteristics, the soils are of different geographical origins (Recife, Brazil and Macon, France), uses (urban and rural) and climatic conditions (tropical and temperate). The sorption tests were divided into kinetics of sorption isotherm and sorption in function of pH, since sulfamethoxazole is an ionizable molecule. The biodegradation tests were performed at three different concentrations of sulfamethoxazole (10-3, 10-4 and 10-5 M) to evaluate the effect of soil characteristics and concentration of the SMX on biodegradation of SMX molecule. The soils untreated, Macon and Recife, have an equivalent diversity, according to the calculation of the Shannon index (H ') and Simpson index. Assays of miscible displacement in soil columns with KBr and sulfamethoxazole were satisfactory for flow rates 0.2; 0.45 and 0.7 mLmin-1. The concentration of sulfamethoxazole was determined by high performance liquid chromatography (HPLC). Identification of the mechanisms involved in the transport process and the determination of parameters hidrodispersive soil through the elution curves of KBr and sulfamethoxazole were performed using the CDE model (convection-dispersion) through CXTFIT program. Sorption kinetics was best described with the second-order model and the sorption isotherms were linear. The CDE model adequately represents the experimental data of the elution curves of the sulfamethoxazole. The soil Recife, relative to Macon, had the lowest risk of groundwater contamination existing in this region / A disponibilidade de água doce, em diversas regiões, vem diminuindo em função docrescimento da demanda de recursos hídricos, do crescimento da demanda poralimentos (agricultura e pecuária) e dos efeitos da mudança climática em nível mundialdevido ao crescimento da população mundial. As práticas agrícolas inadequadas podemlevar à poluição das águas superficiais e subterrâneas com pesticidas, fármacos,poluentes, nutrientes e sedimentos. O aumento da demanda na pecuária é um dos fatoresque conduziu a um aumento do uso de antibióticos, como o sulfametoxazol, e apesar dagrande quantidade utilizada tanto na medicina humana como na veterinária, e do riscode contaminação dos aquíferos associados a essa molécula, seu destino no solo aindanão está claro e é pobremente documentado. Os objetivos deste trabalho foram estudaras interações físico-químicas e biológicas, o impacto associado à resistência bacteriana eo transporte do sulfametoxazol (SMX) em dois solos distintos, embora comcaracterísticas granulométricas semelhantes. Os solos são de diferentes origensgeográficas (Recife, Brasil e Macon, França), usos (urbano e agrícola) e condiçõesclimáticas (tropical e temperada). Os ensaios de sorção foram divididos em: cinética,isoterma de sorção e sorção em função do pH, uma vez que o sulfametoxazol é umamolécula ionizável. Os ensaios de biodegradação foram realizados em trêsconcentrações diferentes do sulfametoxazol (10-3, 10-4 e 10-5M) para avaliar o efeito dascaracterísticas dos solos e da concentração do SMX sobre a biodegradação da moléculado SMX. Os solos não tratados Macon e Recife têm uma diversidade equivalente,segundo o cálculo do índice de Shannon (H'), e do índice de Simpson. Os ensaios dedeslocamento miscível em colunas de solo com o KBr e o sulfametoxazol foramsatisfatórios para as vazões de 0,2; 0,45 e 0,7 mL.min-1. A identificação dosmecanismos envolvidos no processo de transporte e a determinação dos parâmetroshidrodispersivos dos solos, através das curvas de eluição do KBr e do sulfametoxazol,foram realizadas utilizando o modelo CDE (convecção-dispersão). A cinética de sorçãofoi melhor descrita com o modelo de segunda ordem e as isotermas de sorção foram nãolineares. O modelo CDE representou adequadamente os dados experimentais das curvasde eluição do sulfametoxazol. O solo Recife, em relação ao Macon, apresentou o menorrisco de contaminação do lençol freático existente nessa região.

The health of the Baltic Sea is negatively affected by hazardous substances such as metals and persistent organic pollutants (POPs), which include legacy pollutants that were banned decades ago, but still circulate in the ecosystem. Elevated levels of legacy pollutants, identified by HELCOM as key hazardous substances, have been found in accumulations of fibrous sediments, so-called fiberbanks and fiber-rich sediments, which derive from old pulp mills along the Swedish north coast. The fiberbanks are deposited in shallow water and bathymetrical models show evidence of their erosion, potentially caused by propeller wash, submarine landslides and gas ebullition. This thesis addresses the potential dispersal of key substances from three fiberbank sites located in a non-tidal Swedish estuary, in which metals and POPs are present in concentrations that may pose a risk for benthic organisms. Metals and POPs are partitioned to organic material and, as expected, show the highest partitioning coefficients (KD) in fiberbanks that have higher TOC levels compared to adjacent areas with fiber-rich sediments (natural clay sediments mixed up with fibers) or relatively unaffected postglacial clays. However, many analytes were found to be present in quantifiable concentrations in pore water, which indicates diffusion of substances from the solid phase to the aqueous phase. To assess the dispersive influence of an abrupt erosional event on dispersion, metals were measured in undisturbed bottom water and in bottom water disturbed by artificial re-suspension of fibrous sediments. The bioavailable, dissolved fraction of metals decreased in bottom water after re-suspension, probably due to the particle concentration effect. In contrast, the total concentrations of metals and number of quantifiable metals increased with particle concentration caused by re-suspension. At one station, the total concentration of chromium (Cr) was elevated to a level where it may lower the ecological status of the water body during periods of substantial erosion (e.g. spring floods or submarine landslides). Analyses of disturbed bottom water revealed, however, that minerogenic particles were preferentially re-suspended compared to organic. This suggests that physical erosion and re-suspension of fiberbank sediments might have a larger effect on dispersal of metals than on POPs. / TREASURE

La question des détritus marins de plastique et de leur impact sur l'environnement prend de l’ampleur. Il a été démontré que 80% des plastiques sont issus de sources terrestres, tandis que 20% viennent des côtes et mers. De nombreux auteurs soulignent un problème environnemental sérieux lié à l'absorption de POP (Polluants Organiques Persistants) par les débris plastiques, initiant ainsi une source potentielle de contamination de la chaîne alimentaire. Tous les auteurs attribuent la fragmentation en « microplastiques » (taille < 5mm) à des phénomènes liés à la dégradation, en particulier sous UV sans l’avoir jamais réellement ni démontré ni analysé. Les rivières constituant alors un vecteur privilégié de transport des déchets terrestres vers les mers et océans, nous avons décidé de mettre en évidence (et de quantifier) la présence de microplastiques dans une rivière réputée « sauvage » comme l’Allier. Au laboratoire, nous mettons au point des protocoles de simulation de la fragmentation des plastiques sous irradiations UV de différentes matières plastiques dans l'eau (douce). Nous analysons aussi bien les molécules chimiques issues de la dégradation des plastiques et transférées dans le milieu aqueux que les modifications moléculaires que peut subir le matériau. / The question of marine litter and their environmental impact gains importance. It was shown that 80% of plastics results from terrestrial sources, while 20% come from coastlines and seas. Many authors point to a serious environmental problem involved to the absorption of POPs (persistent organic pollutants) by plastic detritus, thus initiating a potential source of contamination of the food chain. All authors attribute the fragmentation to "microplastic" (size < 5mm) to phenomena related to degradation, under UV without ever having demonstrated or analysed it. The rivers constituting then a privileged vector of transport of the terrestrial waste towards the seas and oceans, we decided to highlight (and quantify) the presence of microplastics in a river known as "wild" as the Allier. At the laboratory, we develop simulation protocols for the fragmentation of plastics under UV irradiation of various plastic materials in fresh water. We analyse both the chemical molecules resulting from the degradation of plastics and transferred to the aqueous medium as well as the molecular changes that can undergo the material.