Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.

Dans le cadre général de la préservation des ressources naturelles, cette thèse vise la valorisation des sols urbains excavés lors des opérations de terrassements. Compte tenu de leur forte hétérogénéité et de leur histoire perturbée, les sols urbains restent assez mal caractérisés du point de vue géotechnique et environnemental. De plus leurs spécificités ne permettent pas en général d’appliquer les guides réglementaires actuellement disponibles qui ont pour objet l’encadrement de la réutilisation de matériaux dans les domaines du génie civil. La première partie du travail de thèse a consisté en une caractérisation géotechnique, chimique et minéralogiques de deux sols urbains excavés à plus d’un mètre de profondeur en région parisienne dans une zone industrielle (à Boulogne Billancourt) et dans une zone proche du périphérique parisien (à Ivry-sur-Seine). Cette étape a permis de mettre en évidence certaines caractéristiques communes : des classifications géotechniques proches (C1B5/C1A1 selon le GTR), une teneur remarquable en carbone organique, des quantités non négligeables (en contenu total) d’éléments trace métalliques et de sulfates, et enfin une composition complexe avec une composante naturelle et anthropique mise en évidence par un essai de tri importé du domaine des granulats. Cette dernière composante comprend des briques, du gypse (porteur principal du soufre et du strontium), des éléments à base de béton ainsi que des scories (magnétiques et non magnétiques), principales phases porteuses des phases métalliques et carbonées respectivement. A l’aide d’une approche en régression linéaire, la répartition des artefacts anthropiques a été évaluée dans les différents compartiments granulométriques du sol, ce qui permet d’appréhender les processus de dégradation naturels des sols urbains (fragmentation des phases accompagnée d’un transfert de polluants).Selon la réglementation environnementale basée sur des essais de lixiviation, les polluants métalliques ne montrent pas une mobilité (lixiviation) critique. Néanmoins ces sols ne sont pas considérés comme des déchets inertes du fait de leur teneur élevé en contenu total en carbone organique et d’un relargage trop élevés en sulfates (principal polluant du sol), en fluorure et en antimoine. Les performances mécaniques requises pour un usage routier après un traitement avec 5% de ciment ainsi que l’aptitude au traitement avec un traitement à 1% de chaux pour un usage en remblai ont été validées, et ce en dépit de la présence des polluants perturbateurs (notamment les sulfates). Les propriétés de perméabilité des sols urbains compactés (à l’OPN ou l’OPM) avec ou sans traitement ont permis d’étudier le transfert des polluants dans des conditions proches de celles in situ. Si le traitement à la chaux semble augmenter la perméabilité, le traitement au ciment semble fortement la diminuer sur certaines éprouvettes (absence d’écoulement sous 5 kPa de charge hydraulique). Les traitements pourraient également avoir un effet sur le relargage de certains polluants si on se base sur les résultats de test de lixiviation à pH 12 avec tantôt un effet inhibiteur (pour Ba, Sb, Mo Ni voire As), tantôt un effet activateur (pour Cu ou V voire As). Enfin, un essai d’immersion sur monolithe qui met en avant la diffusion des polluants plutôt que leur percolation sous l’effet d’une charge hydraulique complète le panel des expériences pour observer le transfert des polluants / This work fits in the protection of natural resources. It aims the valorization urban soils excavated during earthworks. Given their high degree of heterogeneity and disturbed history, urban soils remain poorly characterized from a geotechnical and environmental point of view. In addition, their specificities generally do not allow the application of currently available regulatory guides, the purpose of which is to supervise the reuse of materials in the fields of civil engineering. The first part of this work consisted of a geotechnical, chemical and mineralogical characterization of two urban soils. These soils were excavated more than one meter deep in the Paris region in an industrial area (in Boulogne Billancourt) and in an area near the Paris peripheral road (in Ivry-sur-Seine). This step made it possible to show some common characteristics: close geotechnical, gypsum (main support of sulfur and strontium), elements based on concrete and slags (magnetic and non-magnetic), important phases falling respectively to classifications (C1B5 / C1A1 according to the RTM), a remarkable content of organic carbon, significant amounts (in total content) of metallic trace elements and sulphates, and finally a complex composition with a natural and anthropogenic component evidenced by a test of sorting imported from the field of aggregates. This latter component comprises bricks, gypsum (main support of sulfur and strontium), concrete-based elements as well as slags (magnetic and non-magnetic), main phases respectively carrying the metallic and carbon phases. Using a linear regression approach, the distribution of anthropogenic artifacts was evaluated in the different soil size compartments, which allows understanding the natural processes of urban soil degradation (phase fragmentation accompanied by pollutant transfer).According to environmental regulations based on leaching tests, metallic pollutants do not exhibit critical mobility (leaching). However, these soils are not considered inert waste because of their high total organic carbon content and their excessive release of sulphates (the main soil pollutant), fluorine and antimony. The treatment with 1% lime for use in backfill has been validated, despite the mechanical performance required for road use after treatment with 5% cement and the suitability for treatment with the presence of disturbing pollutants (in especially sulphates). The permeability properties of compacted urban soils (OPN or OPM) with or without treatment have made it possible to study the transfer of pollutants under conditions close to those in situ. If the lime treatment seems to increase the permeability, the treatment with cement seems to strongly reduce it on certain test pieces (no flow below 5 kPa of hydraulic load). The treatments could also have an effect on the release of certain pollutants from the results of the leaching test at pH 12 with sometimes an inhibitory effect (for Ba, Sb, Mo Ni or As), sometimes an activating effect (for Cu or V or As). Finally, an immersion test on a monolith showing the diffusion of pollutants rather than their percolation under the effect of a hydraulic load completes the panel of experiments to observe the transfer of pollutants

Célèbres depuis l'accident de Seveso en 1976, les dioxines/furanes (PCCD/F) restent, malgré une forte baisse de leurs émissions, un sujet de préoccupation permanent en France et dans le monde. Le rémanence de ces composés organochlorés dans le sol et le risque toxique qu'ils représentent pour l'homme et l'environnement font que la gestion et la remédiation des sols contaminés par les PCDD/F sont devenues une priorité des industriels, législateurs et scientifiques. La phytoremédiation compte parmi les méthodes émergentes de dépollution des sols contaminés en raison de son adéquation avec le développement durable. Elle combine les capacités naturelles des plantes et de leur microbiote rhizosphérique à biodégrader les polluants organiques. Cependant, l'efficacité de cette phytotechnologie est encore souvent limitée, en particulier lorsqu'il s'agit de composés chlorés, à cause de leur récalcitrance, de leur phytotoxicité et leur faible biodisponibilité dans le sol. Ainsi, l'objectif de ce travail de thèse a consisté à étudier les performances de la phytoremédition assistée, en particulier par les champignons mycorhiziens arbusculaires, d'un sol agricole historiquement pollué par les PCDD/F prélevé sur une parcelle expérimentale située à proximité d'un ancien incinérateur. L'ensemble des résultats obtenus mettent en évidence, en particulier, le potentiel de deux espèces végétales, la luzerne et la fétuque, dans la rhizodégradation des PCCDD/F. La végétalisation du sol permet de moduler les communautés microbiennes du sol (bactéries, Archées et champignons) et notamment celles qui semblent impliquées dans la dissipation des PCCDD/F. En revanche, bien que la mycorhization agisse sur les communautés microbiennes du sol, celle-ci n'a pas eu d'impact, dans nos conditions expérimentales, sur la dissipation des PCCDD/F quelles que soit l'origine de l'inoculum utilisé et les espèces mycorhiziennes qui le compose. La dégradation de ces composés organochlorés est plus marquée dans un sol préalablement stérilisé, puis recolonisé par certaines communautés microbiennes spécifiques, impliquées dans la dissipation des PCCDD/F. L'utilisation combinée d'un mélange de rhamnolipides avec l'introduction dans le sol d'une bactérie Sphingomonas wittichii RWI, décrite pour ses capacités de dégradation des PCCDD/F, permet d'accroitre l'efficience de la rhizodégradation des PCDD/F qui se traduit par une baisse significative de la cytotoxicité du sol après phytoremédiation. / Famous since the Seveso accident in 1976, dioxins/furans (PCCD/F) remain, despite a sharp decline in emissions, a subject of permanent concern in France and in the world. The remanence of these organochlored compounds in soil and the toxic risk they represent for humans and the environment mean that the management and remediation of PCDD/F contaminated soil has become a priority for industrialists, legislators and scientists. Phytoremediation is one of the emerging depollution methods of contaminated soils due to Its suitability for sustainable development. It combines the natural capacities of plants and their rhizospheric microbiota to biodegrade organic pollutants. However, the effectiveness of this phytotechnology is still often limited, especially in the case of chlorinated compounds, due to their recalcitrance, phytotoxicity and low bioavailability in the soil. Thus, the thesis aims to study the performance of assisted phytoremission, in particular by mycorrhizal fungi, of an agricultural PCDD / F based-polluted soil from an experimental plot near an old incinerator. The results obtained show the potential of two plant species, alfalfa and tall fescue, in the rhizodegradation of PCCDD/F. Soil vegetation shows to modulate soil microbial communities (bacteria, archaea and fungi) includind those that appear to involved in the dissipation of the PCCDD/F. On the other hand, although mycorrhization affects soil microbial communities, it has not had any impact on the dissipation of PCCDD/F in our experimental conditions, whatever the inoculums origin and the mycorrhizal species which compose it. The degradation of these organochlorined compounds is more significant in a previously sterilized soil and then recolonized by specific microbial communities involved in the PCCDD/Fdissipation. The combined use of rhamnolipids mixture and Sphingomonas wittichii RWI bactrerium described for its degradation capabilities of PCCDD/F makes it possible to increase the efficiency of PCDD/F rhizodegradation which results in a significant decrease in soil cytotoxicity after phytoremediation.

Des pollutions des sols (péri)urbains et urbaines fortement peuplées en métaux et metalloïdes persistants (éco)toxiques sont couramment observées à l’échelle globale. Certains éléments (Se, Cu…) ont des rôles biologiques et par contre d’autres (Pb, Cd…) ont uniquement un impact (éco)toxique qui peut être influencé par leur spéciation et compartimentation qui modifient leurs transferts et biodisponibilité. Dans une optique de gestion des sols et d’alimentation durables, des questions scientifiques pluridisciplinaires sont à creuser concernant : (i) les mécanismes en jeu dans la biodisponibilité et l’impact sur les organismes vivants des éléments inorganiques en lien avec leur spéciation ; (ii) la co-gestion des risques environnement-santé induits par des installations industrielles classées : ICPE en France (ex. usine de recyclage de batteries) avec les riverains qui cultivent des potagers ou les employés. Dans ce contexte, ont été étudiés : (i) le transfert des métaux entre phase solide et solution du sol sous l’influence des vers de terre sur un site ICPE; (ii) le transfert et la bioaccessibilité du Se en conditions contrôlées pour 2 formes chimiques; (iii) le risque sanitaire pour les riverains d’un site ICPE qui jardinent, et les facteurs influant les plombémies des professionnels (étude statistique des données). Une review bibliographique de la qualité du manioc en lien avec les pratiques culturales et culinaires et les caractéristiques de l’environnement a finalement été réalisée pour compléter la démarche « Sciences et Société » de la thèse. L’analyse des différents isotopes du plomb dans les sols aux alentours de l’usine de recyclage a permis de conclure que 84 à 100% du plomb des sols de surface est d’origine anthropique. Un comportement d’évitement des zones les plus polluées en plomb a été observé pour l’espèce de vers de terre A. caliginosa. Le transfert racinaire, la translocation du sélénium vers le maïs et sa bioaccessibilité dans le grain sont plus élevés dans le cas du séléniate (facteur de translocation de 1.1, et bioaccessibilité humaine de 89,3%) par rapport au sélénite (0.13, et bioaccessibilité de 82,7%). L’étude de la qualité des cultures des jardins proches de l’usine (à Bazoches), en relation avec la qualité du sol (faible contamination, pH basique et teneur élevée en matières organiques qui réduisent les transferts) et de l’atmosphère a mis en évidence un transfert atmosphère-plante qui dépend du métal (le Cd est le plus biodisponible) et du végétal. Les concentrations en Pb et Cd suivent respectivement les séquences : [laitue>poireau>céleri>carotte] et [laitue>céleri>carotte>poireau]. Pour réduire l’exposition des populations, un lavage soigneux des productions avant la consommation est préconisé. / Pollution of (peri)urban soils by (eco)toxic metal(loid)s is commonly observed on a global scale. Some elements (Se, Cu ...) have biological roles and other (Pb, Cd ...) only have an (eco)toxic impact influenced by their speciation and compartmentalization that can change their transfers and bioavailability. With the perspective of sustainable management of soil and food, multidisciplinary scientific questions are digging for: (i) the mechanisms involved in the bioavailability and impact on living organisms of inorganic elements related to speciation; (ii) the co-management of environmental-health risks from industrial regulated plants (ICPE in France, such as former battery recycling plant) with residents who grow vegetable gardens or employees. In this context, were studied: (1) the transfer of metals between solid phase and soil solution under the influence of earthworms on a ICPE site; (2) the transfer and bioavailability of Se in controlled conditions for two chemical forms; (3) the health risk for the residents with gardening activities near ICPE plant and factors influencing blood lead of professionals (statistical analysis of data). A literature review of the quality of cassava in connection with the cultivation and culinary practices and characteristics of the environment was finally performed to complete the "Science and Society" process of the thesis. From the analysis of different isotopes of lead in the soil around the recycling plant it was concluded that 84 to 100% of lead in surface soils has anthropogenic origin. Avoidance behavior in the most lead polluted areas was observed for A. caliginosa earthworm species. The selenium root transfer, translocation to corn and its bioavailability in the grain are higher in the case of selenate (translocation factor of 1.1, and human bioavailability of 89.3%) compared to selenite (0.13 and bioaccessibility 82.7%). The study of crops quality in the gardens near the ICPE plant (in Bazoches), in relation to atmosphere and soil quality (low Pb contamination, alkaline pH and high organic content that reduce pollutants transfers) highlighted an atmosphere-plant transfer which depends on the metal (Cd is the most bioavailable) and plant species. Pb and Cd concentrations follow respectively the sequences: [lettuce> Leek> celery> carrot] and [lettuce> celery> carrot> leek]. To reduce population exposure, thorough washing of productions before consumption is recommended.

Two plant species including Polygonum hydropiper L. and Hymenachne acutigluma (Steud.) Gilliland were investigated in their resistance to lead (Pb) and cadmium (Cd) pollution in the soil. Lead-contaminated soil samples were collected from the lead recycling village Dong Mai, Chi Dao commune, Van Lam district, Hung Yen province, Vietnam that had Pb level up to 192,185 mg.kg-1, dry weight (DW). Cadmium-contaminated soil samples were due to supplement of CdCl2.21/2H2O to alluvial soil. Results showed that both species were highly resistant to Pb, however P.hydropiper was better. Similarly, the Cd resistance was higher for P.hydropiper than for H.acutigluma. No morpho-abnormalities of P.hydropiper regarding the impact of lead were recorded, whereas for H.acutigluma, the young leaves had white colour after two months of planting in soil containing lead levels of 192,185 mg.kg-1. The response of both species with Cd in soils included yellowing leaves, withering branches and even dying after 5-15 days exposed to Cd. Lead contents accumulated in above-ground parts of both plants were up to 4,650 and 3,161 mg.kg-1, DW, corresponding to P.hydropiper and H.acutigluma. From the research results on lead resistance and accumulation of two plant species studied, it is suggested that the two species are lead hyperaccumulators can be used for phytoremediation technology to clean contaminated soil. / Hai loài thực vật gồm nghể răm Polygonum hydropiper L. và bấc nhọn Hymenachne acutigluma (Steud.) Gilliland được nghiên cứu về khả năng chống chịu ô nhiễm chì (Pb) và cadmi (Cd) trong đất. Mẫu đất ô nhiễm chì được thu từ làng nghề tái chế chì Đông Mai, xã Chỉ Đạo, huyện Văn Lâm, tỉnh Hưng Yên, Việt Nam có hàm lượng chì lên đến 192.185 mg.kg-1, tính theo trọng lượng khô (DW). Mẫu đất ô nhiễm Cd là do được bổ sung CdCl2.21/2H2O vào đất phù sa. Kết quả cho thấy cả hai loài đều có sức chống chịu chì rất cao, tuy nhiên nghể răm có khả năng tốt hơn. Tương tự như vậy, sức chống chịu Cd của nghể răm cũng cao hơn của bấc nhọn. Không có dấu hiệu bất thường nào của nghể răm đối với tác động của chì được ghi nhận, trong khi ở bấc nhọn thì lá non có màu trắng sau hai tháng trồng trên đất có hàm lượng chì 192.185 mg.kg-1. Phản ứng của cả hai loài thực vật với Cd trong đất gồm có hiện tượng vàng lá, héo ngọn và thậm chí chết sau 5-15 ngày phơi nhiễm với Cd. Hàm lượng chì được tích lũy cao trong phần trên mặt đất của cả hai loài thực vật lên tới 4.650 và 3.161 mg.kg-1, DW, tương ứng cho loài P.hydropiper và H.acutigluma. Từ kết quả nghiên cứu về khả năng chống chịu và tích lũy chì của hai loài thực vật nghiên cứu, có thể đề xuất đây là hai loài siêu tích lũy chì có thể sử dụng trong công nghệ làm sạch đất ô nhiễm.

Two plant species including Polygonum hydropiper L. and Hymenachne acutigluma (Steud.) Gilliland were investigated in their resistance to lead (Pb) and cadmium (Cd) pollution in the soil. Lead-contaminated soil samples were collected from the lead recycling village Dong Mai, Chi Dao commune, Van Lam district, Hung Yen province, Vietnam that had Pb level up to 192,185 mg.kg-1, dry weight (DW). Cadmium-contaminated soil samples were due to supplement of CdCl2.21/2H2O to alluvial soil. Results showed that both species were highly resistant to Pb, however P.hydropiper was better. Similarly, the Cd resistance was higher for P.hydropiper than for H.acutigluma. No morpho-abnormalities of P.hydropiper regarding the impact of lead were recorded, whereas for H.acutigluma, the young leaves had white colour after two months of planting in soil containing lead levels of 192,185 mg.kg-1. The response of both species with Cd in soils included yellowing leaves, withering branches and even dying after 5-15 days exposed to Cd. Lead contents accumulated in above-ground parts of both plants were up to 4,650 and 3,161 mg.kg-1, DW, corresponding to P.hydropiper and H.acutigluma. From the research results on lead resistance and accumulation of two plant species studied, it is suggested that the two species are lead hyperaccumulators can be used for phytoremediation technology to clean contaminated soil. / Hai loài thực vật gồm nghể răm Polygonum hydropiper L. và bấc nhọn Hymenachne acutigluma (Steud.) Gilliland được nghiên cứu về khả năng chống chịu ô nhiễm chì (Pb) và cadmi (Cd) trong đất. Mẫu đất ô nhiễm chì được thu từ làng nghề tái chế chì Đông Mai, xã Chỉ Đạo, huyện Văn Lâm, tỉnh Hưng Yên, Việt Nam có hàm lượng chì lên đến 192.185 mg.kg-1, tính theo trọng lượng khô (DW). Mẫu đất ô nhiễm Cd là do được bổ sung CdCl2.21/2H2O vào đất phù sa. Kết quả cho thấy cả hai loài đều có sức chống chịu chì rất cao, tuy nhiên nghể răm có khả năng tốt hơn. Tương tự như vậy, sức chống chịu Cd của nghể răm cũng cao hơn của bấc nhọn. Không có dấu hiệu bất thường nào của nghể răm đối với tác động của chì được ghi nhận, trong khi ở bấc nhọn thì lá non có màu trắng sau hai tháng trồng trên đất có hàm lượng chì 192.185 mg.kg-1. Phản ứng của cả hai loài thực vật với Cd trong đất gồm có hiện tượng vàng lá, héo ngọn và thậm chí chết sau 5-15 ngày phơi nhiễm với Cd. Hàm lượng chì được tích lũy cao trong phần trên mặt đất của cả hai loài thực vật lên tới 4.650 và 3.161 mg.kg-1, DW, tương ứng cho loài P.hydropiper và H.acutigluma. Từ kết quả nghiên cứu về khả năng chống chịu và tích lũy chì của hai loài thực vật nghiên cứu, có thể đề xuất đây là hai loài siêu tích lũy chì có thể sử dụng trong công nghệ làm sạch đất ô nhiễm.