Ce travail de recherche porte sur la mise en place d’outils permettant d’évaluer le transfert en éléments trace des sols agricoles vers les plantes. Il a été ciblé sur quatre éléments trace métalliques réglementés dans le sol et/ou la plante à savoir le cadmium, le cuivre, le plomb, le zinc, ainsi qu’un élément trace supplémentaire en voie de réglementation, l’arsenic. Dans un premier temps, un protocole d’échantillonnage a été développé afin de disposer d’un outil de diagnostic pré-récolte. Le cahier des charges a été défini de telle façon que ce protocole soit opérationnel, représentatif de la parcelle, applicable pour différentes parcelles et cultures et autorise une spatialisation de la concentration en éléments trace. Il est de type aléatoire stratifié afin de pouvoir couvrir la totalité de la surface étudiée. Dans un second temps, l’étude s’est portée sur le développement d’une méthode d’analyse des sols par électrochimie afin de disposer d’un outil d’évaluation de la biodisponibilité potentielle des éléments traces et donc du risque de transfert sol - plante. Pour ce faire, les concentrations des éléments sous leurs formes électrolabiles ont été déterminées par voltammétrie de redissolution anodique utilisant des électrodes sérigraphiées élaborées au laboratoire. La méthode a été développée et validée à partir d’une solution de sol de référence minéralisé. Elle a été par la suite appliquée à des solutions de différents sols agricoles obtenues par lixiviation selon un protocole normalisé (NF ISO 18772). / This study concerns the establishment of tools, which allow evaluating the transfer of trace elements from agricultural soils to plants. It focused on four metal trace elements regulated in soil and/or in plants, which are cadmium, copper, lead, zinc, as well as a trace element in the process of regulation, arsenic. First, a sampling protocol was developed in order to dispose of a tool of pre-harvest diagnostic. The specifications were defined such that this protocol is operational, representative of the parcel, applicable to various parcels and crops and authorizes a spatial distribution of the trace element concentration. It is based on random stratified type in order to be able to cover the whole of the considered area. Then, the study focused on the development of a soil analysis method by electrochemistry in order to dispose of a tool for assessing the potential bioavailability of trace elements and therefore the risk of the soil - plant transfer. For that, the electrolabile form concentrations of these elements were determined by anodic stripping voltammetry using screen printed electrodes produced at the laboratory. The method was developed and validated from a solution of a mineralized certified reference soil. It was subsequently applied to solutions of different agricultural soils obtained by leaching according to a normalized protocol (NF ISO 18772).

Le nombre croissant de sites affectés par la présence de matériaux technogéniques rend nécessaire l’étude du (bio)fonctionnement des Technosols, qui s’y développent. Un matériau technogénique, issu d’une ancienne friche industrielle de cokerie et présentant une multipollution en HAP et en métaux a été disposé dans des parcelles lysimétriques pour une étude in situ (site d’Homécourt, www.gisfi.fr). La caractérisation morphologique et analytique à différentes échelles du matériau initial nous a permis d’y définir, en analogie avec la classification pédologique standard, la présence (1) de constituants primaires tels que quartz, oxydes de fer, gypse et matières organiques anthropiques, (2) de pseudo-sables technogéniques, soit des laitiers, (3) d’agrégats technogéniques stables à l’eau (12% de la masse du sol) néoformés grâce au rôle agrégeant de la fraction fine (0-20µm). Matières organiques anthropiques et ETM (Zn Pb, Ba) contribuent à la formation de ces associations organo-minérales. Ce matériau d’origine anthropique, tout spécifique qu’il soit, contient des constituants minéraux et organiques capables de s’associer et donc susceptibles, au même titre que ceux des sols naturels, d’évoluer sous l’effet des facteurs pédogénétiques et former ainsi un technosol. Si les deux années d’expérimentation n’ont pas été suffisantes pour mettre en évidence une modification de la stabilité structurale de ce jeune Technosol, les résultats y soulignent l’impact des plantes colonisatrices et de la microflore rhizosphérique sur la formation d’associations organo-minérales. L’activité biologique est donc un facteur clef d’évolution de ces sols / The increasing number of sites affected by the presence of technogenic materials makes necessary the study of (bio)functioning of Technosols, developed there. A technogenic material, resulting from an old industrial coking plant and presenting a multipollution of HAP and metals was laid out in lysimetric pieces for an “in situ” study (site of Homécourt, www.gisfi.fr). The morphological and analytical characterization at different scales of initial material enabled us to define, in analogy with standard pedological classification, the presence (1) of primary constituents such as quartz, iron oxides, gypsum and anthropic organic matters, (2) of technogenic pseudo-sands, like slags, (3) of water-stable technogenic aggregates (12% of the soil mass), generated through the aggregating role of the fine fraction (0-20 µm). Anthropic organic matter and ETM (Zn Pb, Ba) contribute to the formation of these organo-mineral associations. This material of anthropic origin, while it is specific, contains mineral and organic components able to aggregate and is thus, as well as natural soils, able to develop under the influence of pedogenic factors to form a Technosol. If the two years of experimentation were not sufficient to highlight a modification of the structural stability of this young Technosol, the results underline there the impact of the colonizing plants and the rhizospheric microflora on the formation of organo-mineral associations. The biological activity is thus a key factor of evolution of these soils

The Black Sea, with its oxic, suboxic and anoxic layers, provides a unique environment for studying how biological and geochemical processes affect the composition of particulate matter. The elemental composition of particles in the Black Sea is controlled by their origin and sources. Particles from rivers are dominated by aluminosilicate material that has compositions similar to the earth&rsquo / s crust. In general this material is relatively unreactive. Biological processes in the upper oxic and suboxic layers of the water column result in enrichments of elements which used as nutrients. Cu, Ba and Mo have been proposed as tracers for planktonic material and new production. Geochemical processes like manganese and iron recycling between oxidized and reduced forms, metal sulfide formation, and biogenic matter decomposition can have a large impact on the composition of particles in the suboxic and anoxic zones. The aim of this thesis was to study the composition of particles suspended in the water column of the Black Sea, in regional rivers draining into the Black Sea, and of particles deposited in these rivers and Black Sea sediments. The objectives were to determine the chemical composition and distribution of particles supplied by rivers and produced in the Black Sea, and compare with those particles buried in the sediments. The chemical distributions can help us to understand the biogeochemical processes taking place. The ultimate goal is to understand if there is a chemical signature that characterizes sediments deposited in anoxic basins that can be used to determine if ancient sedimentary rocks were deposited under such conditions. Water column filter samples were collected from the central western basin and along transects to the SW shelf regions during several research cruises of R/V Bilim and R/V Knorr in the Black Sea. Samples were taken by using both in situ large volume filtration systems and on deck vacuum filtration of discrete samples. River samples were collected by hand from the bank of four Turkish rivers and the Danube River. Sediment samples were obtained from 0 - 25 cm interval of a box core from the deep western basin. All samples were digested and analyzed by inductively coupled plasma - mass spectrometry and combination of atomic absorption (flame &amp / graphite furnace) instruments. The elements analyzed included Al, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Mo, Ag, Cd, Ba, Pb, and U. Great care was taken to avoid contamination and to obtain the highest level of precision and accuracy. The precision was typically about 5% for most elements. The accuracy, determined using standard reference materials, was also usually better than 5%. Another goal of this research was to determine the metal concentrations and best digestion methods using different types of filter materials. Blank filters were digested and analyzed and the analyses of various filter blanks are presented in the thesis. The analyses showed that the particulate matter data from Turkish Rivers were very similar to the composition of global average riverine particulate material and global average crust. The Danube River had elevated concentrations for some elements that were probably due to anthropogenic contamination. The Turkish river samples were closer to (but still higher than) the averages for the world&rsquo / s rivers but many elements in the Danube were much higher. These high values determined for major elements in the Danube samples strongly suggest considerable contamination of the Danube as compared to the Turkish Rivers. The Danube River samples were especially enriched in Pb, Zn, Ag, Cu, Cd, and Mn and slightly enriched with Cr and Ni. The first five elements, in particular, are well known indicators of pollution. The particulate matter in the water column of the Black Sea was influenced by lithogenic input from rivers, biological processes and geochemical processes. In order to examine the biogeochemical processes extensively, all the data were plotted as Metal/Al (Me/Al) ratios and compared with the ratios of the average crust and Turkish Rivers. Deviations were used to examine the anomalies due to biological and geochemical processes. In addition, the Al content of individual sample and the Me/Al ratio of crust or rivers were used to subtract the lithogenic component from the total composition. Enrichments due to biological processes were observed for Ba &gt / Fe &gt / Cr &gt / Mn &gt / Zn &gt / Ni &gt / Cu &gt / Mo &gt / V &gt / Co &gt / Cd &gt / U for the overall biogenic composition. Enrichments due to biology are most evident for Ba, Fe, Cr and Mn. This is a unique data set as there have been few previous analyses of biological enrichment for most of these elements. The results of particulate matter analyses showed that some elements including U, V, Cr, Ni, Cu, Co, Zn, Ba and Mo were enriched in the set of samples from the euphotic zone. Redox cycling in the suboxic zone was observed, as expected, for Mn and Fe, whose oxides play an important role in scavenging processes. The redox dependent processes in the suboxic &ndash / anoxic interface influence the vertical distribution of U, Ni, Co, Cu, Zn, Ba and possibly Mo, Cr and V. Elements influenced by sulfide formation in the anoxic layer are Fe, Cr, Ni, Co, Mo, and presumably Ag. The sediment data were also examined based on the same approaches. The elements Zn, Pb, U and Cd decreased with sediment depth over the top 5 cm suggesting that they were remobilized out of the sediments. In general the sediments from the Black Sea have Me/Al ratios very similar to local Turkish Rivers and average crust. There is no unique sediment signature (except possibly for Mo) indicating that these sediments were deposited under sulphidic conditions. This study does not support the hypothesis that the composition of ancient rocks can be used to characterize the environment of deposition.

Les sédiments urbains et résidus minier sont deux sources de pollution potentielle pour l’environnement et plus particulièrement les eaux de surfaces ou les eaux souterraines. L’altération chimique de ces interfaces solides par contact avec une source d’acidité ou d’alcalinité via l’air ou l’eau, est susceptible de se traduire par une dissolution des phases minérales et organiques et d’induire une mobilisation des éléments majeurs et traces métalliques. Ces mécanismes sont encore mal décrits et modélisés pour ce type de matrices très complexes. Cette thèse étudie donc le potentiel de mobilisation des éléments majeurs et traces métalliques de diverses interfaces carbonaté ou non carbonaté (pour l’étude du drainage minier acide et neutre contaminé). En supplément, des interfaces minérales pures ont été utilisées pour simuler en laboratoire des assemblages de phases et identifier les mécanismes croisés impliqués dans le drainage minier acide et neutre contaminé. Toutes ces matrices ont été soumises à des tests de capacité de neutralisation acido-basique (mise en contact avec une source de protons ou d’alcalinité), avec le suivi du pH (pouvoir tampon), de la conductivité et de la mobilisation élémentaire (majeurs et éléments traces métalliques). Les données expérimentales ont été modélisées avec le logiciel de spéciation géochimique PHREEQC. La combinaison des volets d’expérimentation et de modélisation, qui a très rarement été développé sur des interfaces solides aussi complexes, a permis l’identification (i) des réactions de dissolution des phases constitutives des interfaces polluées avec les réactions de sorption impliquées dans la mobilisation de leurs éléments majeurs et traces métalliques, (ii) de la spéciation des éléments majeurs et traces métalliques dans ces interfaces et dans les solutions en équilibre avec les phases solides. Ce travail de thèse permet donc d’aboutir à une méthodologie robuste, précise et réplicable permettant une caractérisation fine de la spéciation en phase liquide et solide des polluants métalliques dans les interfaces contaminées. Cette méthodologie constitue une base cruciale pour comprendre et prédire l’évolution des matières solides contaminées (sédiments urbains et déchets miniers) en fonction des différents modes de gestion : dépollution, valorisation et recyclage. / Urban sediments and mine tailings constitute two potential sources of pollution for the environment, especially surface water or groundwater. The chemical alteration of these solid matrices by contact with a source of acidity or alkalinity via air or water is likely to result in the dissolution of the mineral and organic phases and to induce the mobilization of majors and trace elements. These mechanisms are still poorly described and modeled for this type of very complex matrices. This thesis investigates potential for the mobilization of major and trace metals elements of various contaminated complex matrices, including an urban infiltration basin sediment and two carbonated and non-carbonated mining waste (for the study of contaminated acid mining drainage and contaminated neutral drainage). Besides, pure minerals were used to simulate phase mixture at the laboratory and identify the crossed mechanisms involved in contaminated acid and neutral mine drainage. All these matrices were subjected to acid-base neutralization capacity tests (solids put into contact with a source of protons or alkalinity), with monitoring of the pH (buffer capacity), the conductivity and the elemental release (major and trace metal elements). Experimental data were modeled with the PHREEQC geochemical speciation software. The combination of experimental and modeling approaches, which had very rarely been developed on such complex solid matrices, allowed the identification of (i) the dissolution reactions of the constitutive phases of the polluted matrices with the sorption reactions involved in the mobilization of their major and trace metal elements, (ii) the speciation of the major and trace metal elements in these matrices and in solution in equilibrium with the solid phases. This thesis, therefore, leads to a robust, precise and replicable methodology allowing a fine characterization of liquid and solid phase speciation of metallic pollutants in contaminated matrices. This methodology constitutes a crucial basis for understanding and predicting the evolution of contaminated solids (urban sediments and mining waste) according to different management methods: decontamination, recovery, and recycling.

L’enjeu actuel autour de la gestion des MIDND est de valoriser, dans la mesure du possible, les mâchefers sur les chantiers routiers à maîtrise d’ouvrage publique ou privée, tout en tenant compte de la réglementation en vigueur et en réalisant un suivi rigoureux dès l’élaboration jusqu’à leur mise en place. Un des freins de la valorisation des MIDND est relatif aux critères de qualité de plus en plus contraignants. Parmi les polluants potentiels qui peuvent entrainer des restrictions environnementales d’utilisation, les éléments trace métalliques (ETM), dont le comportement en fonction des paramètres que sont la maturation et la granulométrie reste peu connu, sont des plus préoccupants. Dans cette thèse, l’approche développée a permis de définir les conditions favorables au relargage des ETM suivants : Cu, Cr, Pb, Sb, Ni et Zn. La démarche scientifique s’articule autour de trois grands axes : Le premier axe concerne le développement d’une méthode de caractérisation pertinente des MIDND (notamment de la fraction organique et de la fraction minérale polluante) afin de pouvoir mieux juger de leurs qualités. La matrice initiale d’étude prélevée sur un site industriel ainsi que ses fractions granulométriques, ont été finement analysée, tant d’un point de vue physico-chimique qu’en ce qui concerne leur comportement environnemental. La modélisation géochimique basée sur ces données physicochimiques et de lixiviation permet d’identifier des phases majoritaires et de simuler le comportement du matériau dans la perspective de prévoir l’évolution du MIDND en conditions spécifiques de stockage ou de valorisation. Le deuxième axe décrit l’impact des conditions de maturation, et du fractionnement granulométrique sur l’évolution de la qualité des MIDND. Trois différentes conditions de maturation (naturelle sur plate-forme; accélérée sur petit tas; forcée) ont été étudiées. Les résultats montrent que les changements dans la composition chimique et minéralogique des MIDND étudiés et de leurs fractions granulométriques sont plus significatifs lorsque la maturation progresse. La maturation naturelle accélérée et la carbonatation forcée limite la lixiviation du Cu, du Pb et du Zn. Au contraire, la lixiviation du Cr, de Sb, des Cl- et des SO42- augmente lorsque le pH diminue. Le troisième axe est dédié à l’étude de l’utilisation des MIDND comme matière première secondaire dans un scénario de valorisation alternatif aux utilisations en sous-couches routières classiquement pratiquées. Le scénario consiste à incorporer les MIDND dans un coulis auto-compactant utilisable pour l’élargissement de chaussées ou le comblement de fossés. Une formulation a pu être définie. La conformité des performances mécaniques, géotechniques et environnementales aux spécifications d’usage normalisées, est encourageante pour les potentiels utilisateurs des MIDND en technique routière. / Current challenge of Municipal Solid waste Incineration (MSWI) bottom ash management lays in its valorization, mainly to be used in road construction projects. The process must take into account environmental regulations and conduct rigorous monitoring from production to utilization. One constraint in the assessment of MSWI bottom ash is related to quality criteria which is becoming more restrictive. Among potential pollutants that can cause environmental use restrictions are metal trace elements (MTE), whose behavior based on weathering and grain size is not yet well known and represent one of greatest concern. In this thesis, the developed research approach defined the favorable conditions for Cu, Cr, Pb, Sb, Ni and Zn release. The aforementioned approach is based on three pillars: The first pillar focuses on the development of a pertinent characterization method for bottom ash (including the polluting organic and mineral fraction) aiming at a better assessment of its properties. The initial study matrix, taken from an industrial site, was carefully analyzed from both, physico-chemical and environmental performances. Geochemical modeling based on physico-chemical and leaching data, allowed to identify the main mineral phases and to simulate material behavior with the purpose of predicting the evolution of MSWI bottom ash in specific storage or valorization conditions. The second pillar describes the impact of weathering conditions and size partitioning on MSWI bottom ash quality evolution. Three different weathering conditions (natural on industrial scale heap; accelerated on small heap; and forced) were studied. The results showed that changes in the chemical and mineralogical composition of MSWI bottom ash as well as in its size fractions are more significant when the weathering proceed. The natural accelerated weathering and the forced carbonation limited the leaching of Cu, Pb and Zn, whereas, the leaching of Cr, Sb, Cl and the SO42- increased as pH decreased. The third pillar focuses on the study of MSWI bottom ash alternative utilization as secondary raw material for the typically practiced road sub-layers construction. It consisted of incorporating MSWI bottom ash in a self-compacting material used for pavement sub-layer or coated road shoulders structures. A formulated material was obtained by mixing MSWI bottom ash, water and cement as a hydraulic binder. The results of the mechanical, geotechnical and environmental assessment are promising for MISWI bottom ash potential use in road construction.