Metallic nanoparticles (MetNPs) with unique nanoscale properties, including novel optical behavior and superparamagnetism, are continually being developed for biomedical and industrial applications. In certain biomedical applications where extended blood half-lives are required, MetNPs are surface-functionalized using polymers, proteins, and other stabilizing agents to facilitate their resistance to salt-induced aggregation. Given their colloidal stability in high ionic-strength matrices, functionalized MetNPs are anticipated to be persistent aquatic contaminants. Despite their potential environmental significance, the persistence of surface- functionalized MetNPs as individually-stabilized nanoparticles in aquatic environments is largely unknown. Further, few studies have investigated the fundamental factors that influence MetNP uptake and fate/transport processes in ecologically susceptible aquatic biota, such as filter- feeding bivalves, which ingest and accumulate a broad range of dissolved- and particulate-phase contaminants. The present study describes a comprehensive approach to prepare and rigorously characterize MetNP test suspensions to facilitate fundamental examinations of nanoparticle uptake and fate/transport processes in freshwater and marine bivalves. We demonstrate the importance of accurately characterizing test suspensions in order to better understand MetNP persistence as individually-stabilized nanoparticles within aquatic test media, and define an optical-activity metric suitable for quantifying and comparing the persistence of variable MetNP formulations as National Nanotechnology Initiative (NNI) definable nanoscale materials. We also show that individually-stabilized MetNPs of variable elemental composition, particle diameter, and surface coating are accessible to bivalves in both freshwater and marine environments. Clearance rates for MetNPs are positively related to the diameter and initial concentration of MetNP suspensions. The observed size-dependence of particle filtration rates facilitates ‘size-selective biopurification' of particle suspensions with nanoscale resolution, and may have applicability in future sustainable nanomanufacturing processes. Filtered MetNPs are retained for extended periods post-exposure primarily within the bivalve digestive tract and digestive gland, but migration to other organ systems was not observed. Clusters of MetNPs were recovered in concentrated form from excreted feces, suggesting that biotransformation and biodeposition processes will play an important role in transferring MetNPs from the water column to benthic environments. / Ph. D.

A realização dos estudos de impacto ambiental e a apresentação do respectivo relatório de impacto ambiental vinha sendo utilizada no Brasil desde a década de 70 de uma maneira não formalizada, ou seja, sem uma legislação pertinente ao assunto, com a intenção de minimizar os impactos decorrentes de empreendimentos de grande porte. Com o aumento da aplicabilidade desses estudos, foram, então, regulamentados, em nível federal, pela resolução CONAMA 001, de 23/01/1986. Para a realização do Estudo de Impacto Ambiental (EIA), deve-se desenvolver um conjunto de atividades que os respectivos órgãos licenciadores estaduais e/ou IBAMA estabelecem, geralmente denominado Termo de Referência. Considera-se que os métodos empregados nos Termos de Referência estão de acordo com as normas e recomendações das Secretarias Estaduais de Meio Ambiente e que os estudos de impacto ambiental estão sendo corretamente executados. Porém esses métodos não têm um padrão a ser seguido, podendo ocorrer possíveis erros e a não abrangência necessária das características ecológicas do meio biológico terrestre. As obras hidrelétricas, de um modo geral, produzem grandes impactos sobre o meio ambiente, que são verificados ao longo e além do tempo de vida da usina e do projeto, bem como além do espaço físico envolvido. Portanto, este trabalho visa a análise dos estudos ambientais desse tipo de atividade modificadora do meio ambiente e como eles estão sendo executados. A avaliação foi feita a partir de vários parâmetros, sendo eles metodológicos e estruturais. Foram analisados sete EIAs (Estudos de Impacto Ambiental) de empreendimentos hidrelétricos, por meio de quadros comparativos, referentes a: métodos de levantamento, habitats amostrados e resultados obtidos. As avaliações foram realizadas tendo-se por base, seis critérios: descrição dos habitats amostrados, concordância entre habitats e grupos analisados, descrição dos métodos de levantamento utilizados, utilização de métodos quantitativos, nível de identificação taxonômica e riqueza de espécies por grupo analisado. Ao término deste trabalho, foi diagnosticado a forma com que esses EIAs estão sendo executados, permitindo, possivelmente, a criação de referências para futuros trabalhos na área ambiental, com a finalidade de se obter uma melhora na qualidade dos estudos e resultados da gestão ambiental. / Environmental impact assessments (EIAs), and presentation of these reports have been used in Brazil since the 1970's in a non-formal manner, that is, without pertinent legislation to minimize the impact of large enterprises. With the rise of these studies, they were then ruled, nationally, by the CONAMA 001 resolution, 23/01/1986. To perform the EIA, a set of activities established by the respective state licensing bodies and/or IBAMA must be developed, generally named Reference Terms. The methods applied on the Reference Terms are considered to be in agreement with the regulations and recommendations of the Environment Estate Secretaries, and that the EIA are being correctly executed. However, these methods do not have a pattern to be followed, allowing possible mistakes particularly in not having the necessary span of the terrestrial biological environment and its ecological characteristics. Hydroelectric dams, generally, produce a massive impact upon the environment, and these effects last well beyond the life time of the power plant, the project and the physical space involved. Therefore, the purpose of this study is to analyze the EIA of these kinds of activities and to assess if they are being well executed. The evaluation was made using several methodological and structural parameters. Seven EIAs from hydroelectric enterprises in Cerrado were used. The results were analyzed using comparative tables, referred to: survey methods; habitats sampled; and results. The valuations were performed analyzing mainly six criteria: description of the habitats sampled, agreement between habitats and analyzed groups, description of the survey methods applied, utilization of quantitative methods to sample terrestrial biological environment, organisms identification to the species level and the richness of the group analyzed. At the end of this research, the way these EIAs are being carried on was diagnosed, allowing, possibly, the creation of reference for future environmental researches, in order to obtain an upgrade on the studies and, consequently, better results for environmental management.

Inland salt lakes in Western Australia have been used by the mining industry for the disposal of excess water generated during the mining process. However, the impact of these operations on the salt lakes is poorly understood. This is mainly due to the lack of information on the biota and chemistry for the lakes. The main aim of this project was to develop a classification system for inland salt lakes of Western Australia based on abiotic and biotic factors such as sediment and water quality, invertebrates and algae to determine lakes with unique or significant features. Water and sediments collected from the salt lakes were generally characterised by an alkaline pH, high salinity and the majority of lakes being dominated by sodium and chloride. Concentrations of some metals were also high, particularly in surface water. A high degree of variation in water and sediment quality was demonstrated both within and between the study lakes. In addition, these parameters were shown to be influenced by geography, geology, stage of the hydrocycle within which the lake was sampled and the occurrence of dewatering discharge. Biota in the salt lakes must be able to cope in a harsh environment, adjusting to temporary water regime, high temperature, and high salinity. As such, the species richness of these systems is generally low. Diatoms (a group of algae) and invertebrates were investigated among the biota. A total of 56 diatom species were recorded from 24 lakes. The most common species were Amphora coffeaeformis, Hantzschia aff. baltica and Navicula aff. incertata. These species were shown to have broad tolerances to environmental variations. Sediment chemistry explained variations in diatom community structure, with zinc, moisture content and cobalt having the greatest and negative influence. / In terms of invertebrates, a total of 101 invertebrate taxa were recorded from 13 lakes in this study. Crustacea dominated and the greatest number of taxa was from the genus Parartemia. There were some differences in invertebrate community structure between lakes, most likely reflecting the high degree of speciation, and poor dispersal mechanisms of certain key species. Community structure was influenced by water quality, with phosphorus, bicarbonate and magnesium contributing to the variations in community structure. Among the 43 lakes chosen for this study a total of 17 lakes had received, or are currently receiving dewatering discharge. Sites receiving dewatering discharge generally reported higher concentrations of salts, nutrients and some metals in both water and sediments compared to natural lakes. Species richness of biota such as diatoms and invertebrates was lower at the lakes receiving dewatering discharge. However, the impact was generally localized within the pooled area of dewatering discharge. Also, despite these impacts, there appears to be signs of amelioration by flushing events. Currently there are no guidelines for water and sediment chemistry for inland salt lakes in Western Australia. Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines are the most relevant available. Concentrations of cadmium, cobalt, chromium, copper, lead, nickel and zinc in surface water of the natural inland salt lakes were shown to exceed ANZECC guideline values. / Comparison with the relevant ANZECC sediment guidelines showed that they were applicable to the salt lakes, with the exception of nickel and chromium which were naturally high in the salt lake sediments. Classification of data using multivariate analysis was done for both dry and wet phases of the hydroperiod. Six groups were delineated for the sediment and diatom data, and four groups were defined for the water quality and invertebrate data. It was common for sites from particular lakes to fall in more than one group as a result of the variability in these systems. There are a number of practical applications of this system for the mining industry and it may be used as a predictive tool for determining the impact of dewatering discharge and highlighting unique salt lakes within the Goldfields of Western Australia.

Comprendre comment les variations du climat pourraient influencer le recrutement des arbres en forêt est un défi car la germination, la croissance et la survie des semis sont particulièrement sensibles aux facteurs biotiques et abiotiques. Plusieurs modèles conceptuels généraux, (la « stress gradient hypothesis » SGH et « latitudinal herbivory theory » LHT,) suggèrent que la nature et l'intensité des interactions biotiques varient le long de gradients environnementaux. Ces modèles constituent une base théorique utile pour déterminer le rôle des interactions biotiques dans la réponse des communautés végétales aux variations du climat. Cependant, les études portant sur la SGH se sont limitées aux interactions directes entre plantes et ont négligé les interactions complexes. Les théories développées pour des niveaux trophiques supérieurs (comme la LHT) sont quant-à elles sujettes à débat et ne considèrent qu'un nombre limité d'interactions. Les interactions avec les micro-organismes du sol ont par exemple été négligées. Dans cette thèse, j'ai analysé comment les interactions directes et indirectes entre les semis, les arbres adultes, la végétation herbacée, les insectes herbivores et les pathogènes du sol varient en nature et en intensité le long de gradients climatiques. Pour explorer les interactions entre plantes, j'ai effectué une expérimentation s'appuyant sur la variabilité spatio-temporelle des conditions climatiques dans les Alpes. Les résultats montrent que les effets directs de compétition de la canopée et de la végétation herbacée augmentent avec la température. Cependant, pour les sites les plus chauds, la facilitation indirecte pourrait limiter la compétition directe des herbacées. Pour les interactions avec insectes herbivores,nous avons montré que le long de gradients d'altitude et de latitude, l'herbivorie est minimale là où les stress thermiques et hydriques est fort. Enfin, pour les interactions avec les micro-organismes du sol, nous avons mesuré en chambre de culture la survie de plantules de hêtre dans des sols, stérilisés ou non, collectés le long d'un gradient d'altitude. Les résultats montrent que les effets négatifs des micro-organismes sont plus faibles quand les communautés microbiennes proviennent de sols d'altitudes. Cette thèse suggère que les effets directs négatifs des plantes, des insectes herbivores et des pathogènes du sol sur les semis dominent dans les environnements chauds et productifs et s'atténuent dans des conditions plus froides. Les interactions indirectes semblent varier inversement et pourraient ainsi tamponner l'effet des interactions directes. / Understand how climate change could influence forest tree recruitment is a challenge because germination, seedling growth and seedling survival are especially sensitive to biotic and abiotic factors. Several conceptual models (as the “Stress Gradient Hypothesis”, SGH, and the “Latitudinal Herbivory Theory”, LHT) propose that the nature and intensity of biotic interactions vary along environmental gradients. These models constitute a useful theoretical basis to determine the role played by biotic interactions in the response of vegetation communities to climate variations. However, SGH studies have nevertheless been limited until now to direct interactions between plants and have neglected complex interactions. Theories including higher trophic levels, as the LGH, are still debated and have focused on a limited number of interactions. For example, interactions with soil biota have been neglected. In this thesis, we have analysed how direct and indirect interactions between seedlings, adult trees, ground vegetation, herbivorous insects, and soil pathogens vary in nature and intensity along climate gradients. To study interactions between plants, we established an experimentation using the spatio-temporal climatic variability in the French Alps. The results show that the direct effects of competition from adult tree canopy and ground vegetation diminish at higher altitudes. However, for warmer sites, indirect facilitation by canopy could limit direct competition by ground vegetation. To study the interactions between seedlings and herbivorous insects, we have analysed the altitudinal and latitudinal variation of herbivory on young trees across Europe. Results show that herbivory is the lowest where temperature and water stresses are strong. Finally, to study interactions with soil microorganisms, we have measured in a greenhouse the survival of European beech seedlings on soils either sterilized or not, collected along an altitudinal gradient. The results show that the negative effect of microorganisms is lower when microbe communities come from higher altitudes. The results suggest that the negative direct effects of plants, herbivorous insects and soil pathogens on seedlings are dominant in warm and productive environments and diminish in cold environments. Indirect interactions seem to vary inversely and could buffer the effects of direct interactions.

A realização dos estudos de impacto ambiental e a apresentação do respectivo relatório de impacto ambiental vinha sendo utilizada no Brasil desde a década de 70 de uma maneira não formalizada, ou seja, sem uma legislação pertinente ao assunto, com a intenção de minimizar os impactos decorrentes de empreendimentos de grande porte. Com o aumento da aplicabilidade desses estudos, foram, então, regulamentados, em nível federal, pela resolução CONAMA 001, de 23/01/1986. Para a realização do Estudo de Impacto Ambiental (EIA), deve-se desenvolver um conjunto de atividades que os respectivos órgãos licenciadores estaduais e/ou IBAMA estabelecem, geralmente denominado Termo de Referência. Considera-se que os métodos empregados nos Termos de Referência estão de acordo com as normas e recomendações das Secretarias Estaduais de Meio Ambiente e que os estudos de impacto ambiental estão sendo corretamente executados. Porém esses métodos não têm um padrão a ser seguido, podendo ocorrer possíveis erros e a não abrangência necessária das características ecológicas do meio biológico terrestre. As obras hidrelétricas, de um modo geral, produzem grandes impactos sobre o meio ambiente, que são verificados ao longo e além do tempo de vida da usina e do projeto, bem como além do espaço físico envolvido. Portanto, este trabalho visa a análise dos estudos ambientais desse tipo de atividade modificadora do meio ambiente e como eles estão sendo executados. A avaliação foi feita a partir de vários parâmetros, sendo eles metodológicos e estruturais. Foram analisados sete EIAs (Estudos de Impacto Ambiental) de empreendimentos hidrelétricos, por meio de quadros comparativos, referentes a: métodos de levantamento, habitats amostrados e resultados obtidos. As avaliações foram realizadas tendo-se por base, seis critérios: descrição dos habitats amostrados, concordância entre habitats e grupos analisados, descrição dos métodos de levantamento utilizados, utilização de métodos quantitativos, nível de identificação taxonômica e riqueza de espécies por grupo analisado. Ao término deste trabalho, foi diagnosticado a forma com que esses EIAs estão sendo executados, permitindo, possivelmente, a criação de referências para futuros trabalhos na área ambiental, com a finalidade de se obter uma melhora na qualidade dos estudos e resultados da gestão ambiental. / Environmental impact assessments (EIAs), and presentation of these reports have been used in Brazil since the 1970's in a non-formal manner, that is, without pertinent legislation to minimize the impact of large enterprises. With the rise of these studies, they were then ruled, nationally, by the CONAMA 001 resolution, 23/01/1986. To perform the EIA, a set of activities established by the respective state licensing bodies and/or IBAMA must be developed, generally named Reference Terms. The methods applied on the Reference Terms are considered to be in agreement with the regulations and recommendations of the Environment Estate Secretaries, and that the EIA are being correctly executed. However, these methods do not have a pattern to be followed, allowing possible mistakes particularly in not having the necessary span of the terrestrial biological environment and its ecological characteristics. Hydroelectric dams, generally, produce a massive impact upon the environment, and these effects last well beyond the life time of the power plant, the project and the physical space involved. Therefore, the purpose of this study is to analyze the EIA of these kinds of activities and to assess if they are being well executed. The evaluation was made using several methodological and structural parameters. Seven EIAs from hydroelectric enterprises in Cerrado were used. The results were analyzed using comparative tables, referred to: survey methods; habitats sampled; and results. The valuations were performed analyzing mainly six criteria: description of the habitats sampled, agreement between habitats and analyzed groups, description of the survey methods applied, utilization of quantitative methods to sample terrestrial biological environment, organisms identification to the species level and the richness of the group analyzed. At the end of this research, the way these EIAs are being carried on was diagnosed, allowing, possibly, the creation of reference for future environmental researches, in order to obtain an upgrade on the studies and, consequently, better results for environmental management.

No description available.

No description available.

Durch die Zunahme der Biogasproduktion in den letzten Jahren hat sich auch die Menge von Gärprodukten, die verbleibenden Rückstände, entsprechend erhöht. In Deutschland fallen jährlich mehr als 50 Millionen Tonnen Gärprodukte an, die als Dünger verwendet werden. Damit werden Nährstoffe in den Kreislauf landwirtschaftlicher Ökosysteme zurück-geführt. Allerdings sind die agroökologischen Wirkungen noch nicht hinreichend erforscht. Aus diesem Grund wurden die folgenden Parameter untersucht: Einfluss von trockenen und flüssigen Gärprodukten auf dem Ertrag von drei ausgewählten Fruchtarten im Vergleich zu oder in Kombination mit Mineraldünger in On-Farm Versuchen; Wachstum, Entwicklung und Ertrag von zwei ausgewählten Fruchtarten im Vergleich zu Mineraldünger, Gülle und Stallmist in einer vollständig randomisierten Blockanlage; Einfluss auf ausgewählte Bodenlebewesen im Vergleich zu Mineraldünger, Gülle und Stallmist in einer vollständig randomisierten Blockanlage. Zusätzlich wurde die Mineralisierung von flüssigen und festen Gärprodukten im Vergleich zu Gülle und Stallmist untersucht, um Effekte der verschiedenen Düngestoffe auf die Humusbildung unter kontrollierten Bedingungen zu bestimmen. / With the increase of biogas production in recent years, the amount of digestates or the remaining residues increased accordingly. Every year in Germany more than 50 million tons of digestates are produced, which are used as fertilizer. Thus nutrients return into the circulation of agricultural ecosystems. However, the agro-ecological effects have not been deeply researched until now. For this reason, the following parameters were quantified: the influence of dry and liquid fermentation products on the yield of three selected crops in comparison to or in combination with mineral-N-fertilizers in on-farm experiments; the growth, development and yield of two selected crops in comparison to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design; selected soil organisms as compared to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design. In addition, the mineralization of dry and wet digestates in comparison with liquid manure and farmyard manure was investigated in order to evaluate the effects of different fertilizers on the humus formation under controlled conditions.

No description available.

Les substances per- et polyfluoroalkylées (PFAS) représentent une large classe de composés chimiques synthétiques produits depuis plus de 60 ans. Les PFAS les plus couramment détectés à travers le monde dans la faune et les humains, le sulfonate de perfluorooctane (PFOS) et le perfluorooctanoate (PFOA), ont été classés comme polluants organiques persistants (POP) et sont responsables de nombreux effets sur la santé. Le PFOS et le PFOA sont inscrits à la convention de Stockholm à l'annexe B et à l'annexe A respectivement à partir de 2009 et 2020. En raison de sa persistance et de son potentiel de bioaccumulation, le PFOS a été progressivement retiré de la production aux États-Unis entre 2000 et 2002, inclus dans la liste « d'élimination virtuelle » au Canada et interdit dans les pays européens. Une fois rejetés dans l'environnement, les PFAS se comportent généralement très différemment de ce que l'on attend habituellement d'un POP. Ces travaux de recherche ont été entrepris afin de documenter les niveaux des PFAS historiques et nouvellement identifiés dans diverses matrices pertinentes pour l’exposition humaines, notamment l'eau potable et diverses espèces de poissons du Canada. Un autre objectif était d’évaluer l'influence de l’effluent d’une station d'épuration des eaux usées municipales sur les signatures isotopiques δ15N et les PFAS de deux poissons du fleuve, le doré jaune (Sander Vitreus) et le doré noir (Sander Canadensis). Ces travaux ont nécessité la mise en œuvre de méthodes d’analyse par chromatographie liquide et spectrométrie de masse à haute résolution. Enfin, une évaluation du risque lié à l’exposition au PFOS/PFOA pour l’environnement et les humains a été conduite. / Abstract: Per- and polyfluoroalkyl substances (PFAS) represent a broad class of synthetic chemicals produced over the past 60 years. The most commonly detected PFASs across the globe in various of wildlife, and humans, perfluorooctane sulfonate (PFOS), and perfluorooctanoate (PFOA), have been classified as persistent organic pollutants (POP), bioaccumulative and causing many health outcomes. PFOS and PFOA are listed to the Stockholm convention in Annex B and Annex A respectively in 2009 and 2020. Due to its persistence and bioaccumulation potential, PFOS was phased out of production in United States during 2000-2002, included in the “virtual elimination” list in Canada, and banned in European countries. Once released to the environment, PFASs generally behave very differently from what is usually expected for a POP. Here, we documented the levels of legacy PFASs and newly identified PFASs in drinking water, as well as in fish species from the Canadian environment. Another research objective was to evaluate the influence of a municipal wastewater treatment plant (WWTP) effluent on the δ15N isotopic signatures and PFAS levels in two fish species, Walleye (Sander vitreus) and Sauger (Sander canadensis). Analyses required the use of liquid chromatography high-resolution mass spectrometry. Finally, a risk assessment of PFOS/PFOA exposure to the environment and humans was conducted. Keywords: Targeted PFAS, suspect PFAS, δ15N, drinking water, fish, biota, environment, AFFF, high resolution mass spectrometry, risk assessment, Canada.