Successive applications of Bordeaux syrup, a copper fungicide widely used to control diseases on the vine, contributed to the increase in copper in large areas of vineyards in the Serra Gaúcha. Phytoremediation is a soil remediation technology that provides low environmental impact, low cost and wide public acceptance. The objective of this study is to select soil cover plants of winter and summer that are promising for phytostabilization and phytoextraction of copper in soil of Serra Gaúcha. A 'Cambissolo', was collected in the Serra Gaúcha and added different copper concentrations of 0, 100, 200, 400, 500 and 600 mg kg-1 in the form of copper chloride (66.66%) and copper sulfate (33 , 34%). In this soil, in a greenhouse were grown nine genotypes of winter cover plants: black oat (Avena stringosa Schreb) With four genotypes ("UPFA 21 Moreninha", "Vacaria", "Passo Fundo" and "IPFA 99009"), cover oat (Avena brevis L.) with genotype ("BRS Centauro"), white oat (Avena sativa L.) with three genotypes ("URS 21", "UPF 18" and "UPF 22") and hairy vetch (Vicia villosa Roth) with a 'cultivate' ("SS esmeralda") and nine genotypes of summer cover plants: pearl millet (Pennisetum glaucum L.), jack bean (Canavalia ensiforms DC), black mucuna bean (Mucuna aterrima L.), dwarf pigeonpea (Cajanus cajan L.), bahiagrass (Paspalum notatum L.), sunn hemp (Crotalaria juncea L.), gray mucuna bean (Mucuna cinereum L.), dolichos bean (Dolichos lablad L.) and sunn hemp (Crotalaria spectabilis Roth). When grown in soils with high concentrations of copper, black oat genotypes "UPFA 21 Moreninha" and white oat "URS 21" and plants jack bean and black mucuna bean produce large amounts of dry, these soils can be used as ground cover plants. The genotype "Vacaria" oat, black mucuna bean and gray mucuna bean produce high amounts of dry matter and accumulate high concentrations of copper in the root system, with potential to be used in programs phytostabilization of copper. / Aplicações sucessivas de calda bordalesa, um fungicida cúprico muito utilizado no controle de doenças na videira, contribuíram para o aumento dos teores de cobre em extensas áreas de vinhedos na Serra Gaúcha. A fitorremediação é uma tecnologia de remediação de solos que apresenta reduzido impacto ambiental, baixo custo e grande aceitação pública. O objetivo deste estudo é selecionar plantas de cobertura de solo de inverno e verão que sejam promissoras para a fitoestabilização e fitoextração do cobre em um solo da Serra Gaúcha com altos teores de cobre. Um Cambissolo foi coletado na Serra Gaúcha e foram adicionadas diferentes doses de cobre 0, 100, 200, 400, 500 e 600 mg kg-1 na forma cloreto de cobre (66,66%) e sulfato de cobre (33,34%). Neste solo, em casa de vegetação foram cultivados nove genótipos de plantas de cobertura de inverno: aveia preta (Avena strigosa Schreb.) com quatro genótipos ( Vacaria , UPFA 21 Moreninha , Passo Fundo e IPFA 99009 ), aveia para cobertura (Avena brevis L.) com o genótipo BRS Centauro , aveia branca (Avena sativa L.) com três genótipos ( URS 21 , UPF 18 e UPF 22 ) e ervilhaca peluda (Vicia villosa Roth.) com uma cultivar ( SS Esmeralda ); e nove genótipos de plantas de cobertura de verão: milheto (Pennisetum glaucum L.), feijão de porco (Canavalia ensiforms DC.), mucuna preta (Mucuna aterrima L.), feijão guandu anão (Cajanus cajan L.), pensacola (Paspalum notatum L.), (crotálaria (Crotalaria juncea L.), mucuna cinza (Mucuna cinereum L.), labe-labe (Dolichos lablad L.) e crotálaria (Crotalaria spectabilis Roth.). Quando cultivados em solos com altas concentrações de cobre, os genótipos de aveia preta UPFA 21 Moreninha e de aveia branca URS 21 e as plantas de feijão de porco e mucuna preta produzem elevadas quantidades de massa seca, podendo ser utilizadas nestes solos, como plantas de cobertura de solo. O genótipo Vacaria de aveia preta, a mucuna preta e a mucuna cinza produzem elevadas quantidades de massa seca e acumulam elevadas concentrações de cobre no sistema radicular, apresentando potencial para serem utilizadas em programas de fitoestabilização de cobre.

Vegetation establishment is one of the major rehabilitation methods that are used to stabilize, cover, to minimize, mitigate or remove the contaminants from tailings storage facilities (TSF’s). Phytostabilization is a useful mechanism by which plants limit the contamination of natural systems with toxic elements. For successful occurrence of phytostabilization on mine tailings, it is vital to establish plant species that can survive the hostile conditions of the substrate. Major problems encountered with vegetation covers is the lack of natural soil properties e.g. soil structure, organic carbon and also hostile chemical conditions. Only a few species are tolerant to the different negative properties of the tailings. The main aim of this project is to identify plant species that can be used for vegetative rehabilitation of nine different types of tailings material including gypsum, gold, platinum, kimberlite, coal, fluorspar and andalusite tailings. The ability of 28 different plant species to survive in the tailings was assessed by statistically calculating the growth potential of the species and summarizing the data in graphs and an index table that calculates a specific merit value for each of the tailings-species combinations. The various plant stress factors that the species exhibited were also documented. Finally, the results were correlated with a soil physical and -chemical baseline study of the tailings to provide insight into successes and failures of certain species. The final results identified various successful tailings-species combinations, as well as failures. The index table proved to be a useful tool to identify suitable species for establishment on various tailings. The baseline study of the different tailings could be used to explain why certain species could be established successfully, as well as the reason why some species did not survive. / M (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Vegetation establishment is one of the major rehabilitation methods that are used to stabilize, cover, to minimize, mitigate or remove the contaminants from tailings storage facilities (TSF’s). Phytostabilization is a useful mechanism by which plants limit the contamination of natural systems with toxic elements. For successful occurrence of phytostabilization on mine tailings, it is vital to establish plant species that can survive the hostile conditions of the substrate. Major problems encountered with vegetation covers is the lack of natural soil properties e.g. soil structure, organic carbon and also hostile chemical conditions. Only a few species are tolerant to the different negative properties of the tailings. The main aim of this project is to identify plant species that can be used for vegetative rehabilitation of nine different types of tailings material including gypsum, gold, platinum, kimberlite, coal, fluorspar and andalusite tailings. The ability of 28 different plant species to survive in the tailings was assessed by statistically calculating the growth potential of the species and summarizing the data in graphs and an index table that calculates a specific merit value for each of the tailings-species combinations. The various plant stress factors that the species exhibited were also documented. Finally, the results were correlated with a soil physical and -chemical baseline study of the tailings to provide insight into successes and failures of certain species. The final results identified various successful tailings-species combinations, as well as failures. The index table proved to be a useful tool to identify suitable species for establishment on various tailings. The baseline study of the different tailings could be used to explain why certain species could be established successfully, as well as the reason why some species did not survive. / M (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

La phytostabilisation est une méthode de gestion de sites pollués par des éléments traces métalliques (ETM) grâce à une approche verte. Les champignons mycorhiziens, associés aux racines, peuvent contribuer au potentiel de phytostabilisation des arbres en réduisant notamment le transfert des ETM vers les parties aériennes. Dans le cadre du projet BIOFILTREE, plusieurs approches sont mises en oeuvre afin de sélectionner des espèces fongiques performantes en phytostabilisation. Tout d'abord, afin de cibler des espèces d'intérêt, les communautés fongiques associées aux racines de divers clones de peupliers sur un site pollué sont analysées. Tous les peupliers sont colonisés par des champignons ecto-, endomycorhiziens et endophytes. Cependant, des spécificités d'hôtes sont observées parmi ces communautés, avec notamment un champignon majoritaire du genre Hebeloma qui ne s'associe pas avec tous les génotypes. Ensuite, plusieurs campagnes de prélèvements de champignons sur divers sites pollués ont permis d'isoler des souches particulièrement tolérantes aux ETM. De très fortes variations intra- et interspécifiques sont observées lors de ces tests. En parallèle, des approches ciblées de caractérisation fonctionnelle de gènes impliqués dans l'homéostasie au zinc sont mises en oeuvre chez Laccaria bicolor, un champignon ectomycorhizien modèle. L'homéostasie aux ETM est liée entre autres à l'activité des transporteurs des familles ZIP (Zrt-, Irt- related Protein) et CDF (Cation Diffusion Facilitator). L'étude des membres de ces deux familles a permis d'affiner la compréhension des mécanismes d'absorption et de séquestration des ETM dans les hyphes des champignons ectomycorhiziens / Phytostabilization is a gentle management option for sites polluted by trace elements (TE). Mycorrhizal fungi could assist plants in stabilizing pollutants by increasing the soil-prospected volume and by immobilizing MTE in their hyphae. Within the BIOFILTREE project, several approaches were used to select fungal strains that could be used for enhancing the phytostabilization process. Firstly, the mycorrhizal status of roots of three poplar clones from a TE-polluted site and the fungi associated with the roots were analyzed. The roots were colonized by endomycorrhizal, ectomycorrhizal, and endophytic fungi. Our data also revealed some specific trends, i.e. Hebeloma species was not associated with all poplar genotypes. Secondly, several fungal strains were isolated from polluted sites and their in vitro tolerance to TE was tested. There was a strong inter- and intra-specific variation in metal tolerance. In a greenhouse study, two poplar clones were inoculated with an endomycorrhizal inoculum and grown on a TE-polluted soil. A slight modification in TE accumulation in shoots was observed. In parallel, the role of ZIP (Zrt-Irt- like Proteins) and CDF (Cation Diffusion Facilitator) proteins in TE homeostasis/tolerance was also studied in the ectomycorrhizal model fungus Laccaria bicolor. The corresponding proteins were functionally characterized by the use of different approaches (yeast complementation, GFP-chimeric proteins, transcript analyses, cell metal content analyses). This study allowed us to better understand the mechanisms underlying zinc uptake and compartmentation in the hyphae of this fungus

Ce travail a comme objectif d’explorer le potentiel de bioremédiation de plantes et de rhizobactéries pour la réhabilitation des sols de sites miniers dans la région de Marrakech. Nous avons isolé des souches rhizosphériques et nodulaires des racines de fève et de plantes indigènes des sites miniers Draa Sfar et Kettara. Plusieurs isolats ont montré une bonne tolérance aux ETM allant jusqu’à 25 mg/l de Cu, 200 mg/l de Pb et 150 mg/l de Zn. Les souches tolérantes aux métaux ont fait l’objet de criblage pour déterminer leurs caractères PGPR (production d’exopolysaccharides, sidérophores, AIA et activité antifongique). En présence du sol minier amendé avec le sol agricole, la fève a montré une capacité à accumuler les métaux différemment d’un métal à l’autre. Le Pb a été peu mobile dans les parties aériennes des plantes, et n’a pas atteint les graines. Le Zn a été le métal le plus transloqué vers les parties aériennes bien que sa quantité soit importante au niveau des racines. Le Cu a été accumulé plutôt dans les racines des plantes. Le Zn et le Cu ont été transloqués aux graines mais à des teneurs significativement faibles. L’inoculation par les bactéries PGPR a permis de mieux accumuler le Cu dans les plantes notamment dans la partie racinaire. L’inoculation mixte PGPR-rhizobia a amélioré l’absorption du Zn dans les plantes notamment dans la partie aérienne. Les analyses in natura sur ces sites miniers fortement contaminés par des métaux lourds indiquent que le microbiote a évolué, devenant tolérant à la pollution à long terme par les métaux lourds et adapté aux plantes indigènes elles-mêmes capables de tolérer et d'accumuler les métaux lourds. / This work aims to explore the potential of plant and rhizobacteria for bioremediation in mining soil in Marrakech region. Rhizospheric and nodules strains were isolated from faba bean roots and native plants growing in Draa Sfar and Kettara mining sites. Several isolates showed good tolerance to metals up to 25 mg/l of Cu, 200 mg/l of Pb and 150 mg/l of Zn. The tolerant strains to metals were screened for their PGPR characteristics (production of exopolysaccharides, siderophores, IAA and antifungal activity). In mining soil amended with agricultural soil, faba bean showed an ability to accumulate metals differently. Pb was not very mobile in shoots, and did not reach the seeds. Zn was the most translocated metal to the aerial parts although its amount was important in roots. Cu was accumulated rather in the roots of plants than shoots. Zn and Cu were translocated to seeds but at significantly lower levels. The inoculation with PGPR bacteria allowed Cu to accumulate better in plants, particularly in roots. Whereas the PGPR-rhizobia mixed inoculation improved the absorption of Zn in plants, especially in shoots. In natura investigation of mining sites heavily contaminated with heavy metals (HMs) indicates that microbiota has evolved, becoming tolerant to long-term HMs pollution and adapted to indigenous plants themselves able of tolerating and accumulating HMs.

Sur le site de la friche industrielle de l'Escalette dans le parc national des Calanques (Marseille), une réflexion alliant écologie de la restauration et phytoremédiation est menée dans le but d'optimiser les fonctions écosystémiques qui limitent les transferts d'éléments traces métalliques et métalloïdes (ETMM) des sols. Une caractérisation in situ de la composition et la structure des communautés végétales natives et spontanées a été menée sur des sites fortement contaminés, permettant de sélectionner des plantes tolérantes. La réponse de deux espèces pérennes natives à l'hétérogénéité de la contamination des sols en ETMM a été évaluée in situ, notamment via l'analyse des interactions sol-plantes microorganismes de la zone rhizosphérique. Enfin, des essais de restauration écologique des communautés végétales natives, basés sur la capacité de plantes natives tolérantes à stabiliser les ETMM et les dynamiques de résilience des communautés végétales, ont été menés sur une zone fortement contaminée. Les résultats indiquent qu'un siècle de contamination en ETMM a affecté de façon significative les communautés végétales en terme de composition, diversité et structure. Ils mettent en évidence une tolérance des plantes natives impliquant des microorganismes symbiotiques. Les résultats préliminaires des essais de restauration écologique confirment le choix d'espèces natives pour relancer une dynamique de végétation sur sols très contaminés et l’importance de créer des microsites favorables dans des milieux (semi-)arides hétérogènes. Ils apportent une contribution au développement d'écotechnologies pour la restauration des sols contaminés dans un contexte méditerranéen. / On the Escalette brownfield, included in the area of the Calanques National Park (Marseille, southeastern France), a research project combining restoration ecology and phytoremediation is carried out, in order to optimize the ecosystem functions which limit the transfers of metals and metalloids (MM) and to restore the functions of the contaminated soils. We developed an in situ characterization approach of the composition and structure of plant communities that grow on MM contaminated sites. This enabled the selection of native plants, tolerant to high concentrations of MM. In a second step, the response of two native perennial species to surface and depth heterogeneity of MM soil contamination was evaluated in-situ, regarding the soil-plant-microorganism interactions at the rhizosphere level. Finally, ecological restoration trials of native plant communities were carried out in a polluted hotspot, based on the ability of native plants to stabilize MM and the resilience dynamics of plant communities.The results indicated that a century of MM pollution pressure produced a significant correlation with plant community dynamics in terms of composition, diversity and structure. They showed that the tolerance of native plants involves symbiotic microorganism interactions. Preliminary results from ecological restoration trials confirmed the method for native plants species selection to recover a vegetation dynamic on highly polluted soils and the importance of creating favorable microsites in heterogeneous (semi-)arid environments. They contribute to the development of ecotechnologies for the restoration of contaminated soils in a Mediterranean context.

Les objectifs de cette thèse ont été de contribuer à l'évaluation des niveaux de contamination en éléments traces métalliques et métalloïdes (ETMM) des sols du site de l'ancienne fonderie de plomb de l'Escalette (sud-est de Marseille), d'en approcher les processus de transport et transfert dans l'environnement en particulier leurs mobilités dans le sol et leurs transferts aux plantes. La contribution à l'établissement d'une cartographie de la contamination sur un périmètre plus vaste que celui de l'usine (zone des Calanques) a permis de mettre clairement en évidence l'impact de cette dernière. Sur le site industriel, les formes et niveaux de contamination des sols diffèrent d'une zone à l'autre. Les sols formés en surface des crassiers se caractérisent par leurs fortes teneurs en Cu, Zn et Pb, dont les fractions mobilisables sont notables (2 à 30%), l'influence des scories est nette. Les sols prélevés à proximité de la cheminée présentent les plus fortes contaminations en Pb, Sb et As, avec de 10 à 30% de fractions mobilisables. Cette contamination est liée aux émissions anciennes via la cheminée rampante mais aussi à la dégradation de cette dernière. Le potentiel de libération des éléments As et Sb des sols de ces 2 zones conduirait à leurs stockages dans des décharges pour déchets dangereux. Les essais de solubilisation en milieu acide ont mis en évidence des risques pour la santé par ingestion concernant Pb et As. Les zones en proche périphérie de l'usine sont moins impactées mais sont néanmoins considérées comme fortement contaminées. G. alypum et R. officinalis, présentes sur le site, sont tolérantes aux ETMM et peuvent les accumuler. / The overall objective of this thesis was to contribute to the assessment of the level of contamination by trace metals and metalloids (TMM) on the site of Escalette (a former lead smelter in southeastern Marseille). The study of TMM transfer and transport processes on this site, taking into account their mobility in the soil and their transfer to plants, was a specific objective. The mapping of TMM contamination in an extended area around the factory site (on Calanques zone) has clearly highlighted the impact of the former industry. So, on the Escalette site, forms and levels of soil contamination differ from one area to another. Soils formed on the surface of the slag deposits are characterized by high levels of Cu, Zn and Pb, whose mobilizable fractions are significant (2-30%), showing a clear influence of slag. Soils collected near a chimney creeping uphill the slope, present the highest contamination levels in Pb, Sb and As, with from 10 to 30 % of mobilizable fractions. This contamination is linked to emissions through the damaged chimney but also to the degradation of this latter. The potential release of As and Sb from the soils of these two areas requires that these soils must be disposed of in landfills for hazardous wastes and their solubilization in acid medium have highlighted the health risks by ingestion for Pb and As. On areas in near periphery of the smelter, soils are less affected but must be still considered heavily contaminated. G. alypum and R. officinalis were observed on the site. They are tolerant and can accumulate TMM. Concentrations in roots were significantly correlated with the concentrations in soils, except for Cu.

Pollution of soil by trace metals has become one of the biggest global environmental challenges resulting from anthropogenic activities, therefore, restoration of metal contaminated sites needs due attention. The use of phytoremediation technologies as nature-based solution to pollution, could support successful implementation of green economic development strategies; with economically affordable and environmentally friendly benefits. The present investigation employed an exploratory study on the phytoremediation potentials of three selected native plants; Phytolacca dodecandra (L’Herit), Adhatoda schimperiana (Hochst) and Solanum incanum L, dominating areas close to heavy metal contamination sources; in metropolitan centers of Addis Ababa. In this work, concentration of six heavy metals of interest chromium (Cr), lead (Pb), cadmium (Cd), nickel (Ni) copper (Cu) and zinc (Zn) were examined in soil and in different tissues (leaves, stems and roots) of selected plants (both seedlings and mature plants), in dry and rainy seasons using atomic absorption spectrophotometer. Efficiency of phytoremediation is discussed based on calculated values of Bio-concentration Factor (BCF), Translocation Factors (TF) and Bioaccumulation Coefficient (BAC). Phytolacca dodecandra showed BCF, TF and BAC > 1 for Zn, Pb, Ni, Cu and Cd Adhatoda schimperiana gave BCF, TF and BAC > 1 for Zn, Cu, Ni and Cr; likewise, BCF, BAC and TF values of > 1 were noted in Solanum incanum for Zn, Cu, Pb and Ni. Based on these scenarios, the three plants could be utilized for phytoextraction of contaminated soil. Conversely, BCF and BAC for Cr levels in tissues of Phytolacca dodecandra were all < 1, which indicates unsuitability for phytoremediation of Cr in contaminated soils. Besides, Adhatoda schimperiana retained Pb and Cd in their roots showing root BCF > 1, while BAC and TF < 1, which highlights its suitability for phytostabilization. Moreover, BCF, TF and BAC values of < 1 noted for Cr and Cd in Solanum incanum reveal that Solanum incanum may not be a good candidate for remediation of Cr and Cd contaminated environments. In conclusion, results from this study revealed that the selected plants can accumulate substantial amounts of the above trace metals in their tissues and can serve as prospective phytoremediators of most of these metals. Phytoextraction and phytostabilization were the main mechanisms of remediation in this study. / Environmental Sciences / Ph. D. (Environmental Sciences)

Det här arbetet ger en orientering i växters olika förmågor att rehabilitera miljöskador och belyser möjligheten att använda växternas essentiella och varierande förmågor i miljöarbetet. De ämnen som har skadlig inverkan på miljön kallas för miljögifter. Både globalt och i Sverige har omloppet av många miljögifter ökat markant de senaste århundradet. Växter kan användas för att rena förorenad mark. De olika processerna när växter renar mark, vatten och luft från föroreningar samlas under begreppet fytoremediering. Det finns olika metoder och reningsprocesser inom fytoremediering. Växter kan dels ta upp och lagra föroreningar, bryta ned dem till ofarliga beståndsdelar samt förhindra så att de inte sprider sig ut i ekosystemet. I det här examensarbetet har föroreningssituation vid järnvägsstationen i Ockelbo använts som exempel för att konkretisera fytoremediering till en specifik plats. En beskrivning av de till platsen relaterade föroreningarna arsenik, bly, kadmium, kvicksilver, koppar, zink, PAH (polycykliska aromatiska kolväten) och olja presenteras tillsammans med aktuella fytoremedieringsmetoder och grödor för respektive förorening. Som slutsats bedöms fytoremediering vara möjligt för järnvägsstationen i Ockelbo. Fördelar och nackdelar med fytoremediering på stationen lyfts fram och möjliga parallella användningsområden medan fytoremedieringen pågår diskuteras. Vidare diskussion förs kring fytoremediering, miljöfrågor och rådande regelverk och logistik i Sverige. Arbetet innefattar ett förslag till utformning av fytoremediering på stationsområdet. Förslaget inkluderar ett växtval av olika fytoremedieringsgrödor lämpliga för platsen.