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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Plantas para infraestrutura verde e o papel da vegetação no tratamento das águas urbanas de São Paulo: identificação de critérios para seleção de espécies / Plants for green infrastructure and the role of vegetation in urban water treatment in São Paulo: identification of criteria for species selection

Maitê Bueno Pinheiro 05 May 2017 (has links)
A cidade de São Paulo, assim como diversas cidades do mundo, enfrenta hoje sérios desafios no manejo de seus recursos hídricos, efeitos do processo de urbanização e desenvolvimento urbano que não considera as potencialidades das bases biofísicas de suas paisagens naturais, dentre eles, o tratamento da poluição das águas urbanas. Na natureza, a vegetação e a água são indissociáveis, as plantas participam da regulação do ciclo hidrológico e da manutenção da qualidade das águas através de mecanismos naturais, reconhecidos como mecanismos de fitorremediação, além de estarem diretamente relacionadas ao fornecimento de outros serviços ambientais que sustentam a vida na biosfera. Infraestrutura Verde é um conceito de rede de paisagens multifuncionais que realizam o manejo das águas das chuvas na fonte, ao mesmo tempo em que proporcionam melhorado microclima, proteção da biodiversidade, áreas de lazer e contato com a natureza, proteção contra desastres e enchentes e tratamento da poluição sem, contudo, excluir o desenvolvimento urbano. Em Berlim, Alemanha, desde o final dos anos 1980, é realizado o tratamento das águas urbanas a partir de alternativas de Infraestrutura Verde em substituição às práticas convencionais, ao passo que, em São Paulo o uso de tais alternativas é bem mais recente, integrando o Plano Diretor de Drenagem e Manejo de Águas Pluviais do município em 2010. Esta dissertação investiga o papel das plantas no tratamento das águas urbanas por tipologias de Infraestrutura Verde, sob o olhar da fitorremediação e identifica os critérios de seleção das espécies de plantas para projetos de Infraestrutura Verde na cidade de São Paulo, observando-se o estudo de caso do córrego Água Podre, bairro do Rio Pequeno, zona oeste do município. / The city of São Paulo, as many other cities around the world, is been facing serious challenges regarding their water supply management due to the urban development. The potential of the biophysical bases of their landscapes is overcome by urbanization, including the treatment of urban water. In nature, water and vegetation are indissociable. Plants participate in the regulation of the water cycle and maintenance of the water quality through natural mechanisms identified as phytoremediation processes. They are also directly related to other ecosystem services that sustain life on the biosphere. Green Infrastructure is a concept of multifunctional landscapes that manage the rainwater at the source. It also improves the microclimate, the protection to the biodiversity, provides leisure areas, protection against natural disasters and treatment of pollution, without excluding thepossibility of the development. Since the end of the 1980s, urban water treatment is used in Berlin as an alternative of Green Infrastructure, replacing conventional practices. In São Paulo the use of such alternatives is much more recent; it was integrated by the Water Management Plan in 2010. In this dissertation I investigate the role of plants in the treatment of urban waters through Green Infrastructure typologies, observing the phytoremediation processes and identifying the selection criteria of plant species for Green Infrastructure projects in the city of São Paulo. A case study of the Água Podre stream is observed; west zone of the city in Rio Pequeno district.
332

Accumulation et translocation de cinq éléments traces dans la biomasse aérienne de végétaux d’intérêt dans un contexte de phytoremédiation

Lapierre, Esther 05 1900 (has links)
No description available.
333

Estudo integrado do potencial fitorremediador da Eichhornia crassipes em ambientes naturais e sua utiliza??o para obten??o de extratos proteicos

Martins, Daniel Freitas Freire 24 February 2014 (has links)
Made available in DSpace on 2014-12-17T15:42:29Z (GMT). No. of bitstreams: 1 DanielFFM_TESE.pdf: 2565491 bytes, checksum: 91650e117d4deece934978a16f9a23d9 (MD5) Previous issue date: 2014-02-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study aimed to analyze the phytoremediation potential of Eichhornia crassipes in natural environments, optimize the extraction process of crude protein from plant tissue and, obtain and characterize this process in order to determine its viability of use instead of the protein sources of animal and/or human feed. For this, it has been determined in Apodi/Mossor? river water the concentration of ammonium ions, nitrite, nitrate, calcium, magnesium, potassium, iron, copper, manganese, zinc, nickel, cobalt, sodium, aluminum, c?dmium, lead, and total chromium; It was determined in plant tissue of aquatic macrophytes of Eichhornia crassipes species present in Apodi/Mossor? River the moisture content, ash, calcium, magnesium, potassium, iron, copper, manganese, zinc, nickel, cobalt, sodium, aluminum, cadmium, lead, total chromium, total nitrogen and crude protein. It was also determined the translocation factor and bioaccumulation of all the quantified elements; It was developed and optimized the extraction procedure of crude protein based on the isoelectric method and a factorial design 24 with repetition; It was extracted and characterized the extract obtained by determining the moisture content, ash, magnesium, potassium, iron, copper, manganese, zinc, nickel, cobalt, sodium, cadmium, total nitrogen and crude protein. And finally, it was also characterized the protein extract using Thermogravimetric Analysis (TG), Derived Thermogravimetric (DTG), Differential Scanning Calorimetry (DSC), Infrared Spectroscopy (FT-IR) and jelly-like electrophoresis of polyacrylamide (SDS -PAGE) to assess the their molecular weights/mass. Thus, from the results obtained for the translocation and bioaccumulation factors was found that the same can be used as phytoremediation agent in natural environments of all quantified elements. It was also found that the developed method of extraction and protein precipitation was satisfactory for the purpose of the work, which gave the best conditions of extraction and precipitation of proteins as: pH extraction equal to 13.0, extraction temperature equals 60 ? C, reaction time equals to 30 minutes, and pH precipitation equals to 4.0. As for the extract obtained, the total nitrogen and crude protein were quantified higher than those found in the plant, increasing the crude protein content approximately 116.88% in relation to the quantified contente in the vegetal tissue of macrophyte. The levels of nickel and cadmium were the unique that were found below the detection limit of used the equipment. The electrophoretic analysis allowed us to observe that the protein extract obtained is composed of low polypeptide chains by the molecular and phytochelatins, with 6 and 15 kDa bands. Analysis of TG, DTG, DSC and FT-IR showed similarities in protein content of the obtained extracts based on different collection points and 9 parts of the plant under study, as well as commercial soy protein and casein. Finally, based on all these findings, it was concluded that the obtained extract in this work can be used instead of the protein sources of animal feed should, before that, test its digestibility. As human supplementation, it is necessary to conduct more tests associated with the optimization process in the sense of removing undesirable components and constant monitoring of the water body and the raw material used / Este trabalho analisou o potencial fitorremediador da Eichhornia crassipes em ambientes naturais, otimizou o processo de extra??o da prote?na bruta do tecido vegetal e obteve e caracterizou a mesma, determinando sua viabilidade de uso em substitui??o as fontes prot?icas de ra??es animais e/ou humana. Para isso, determinou-se na ?gua do Rio Apodi/Mossor? a concentra??o de ?ons am?nio, nitrito, nitrato, c?lcio, magn?sio, pot?ssio, ferro, cobre, mangan?s, zinco, n?quel, cobalto, s?dio, alum?nio, c?dmio, chumbo e cromo total; Determinou-se no tecido vegetal das macr?fitas aqu?ticas da esp?cie Eichhornia crassipes presentes no Rio Apodi/Mossor? o teor de umidade, cinzas, nitrog?nio total e prote?na bruta e os mesmos metais determinados na ?gua. Calculou-se o fator de transloca??o e bioacumula??o de todos os elementos quantificados; Desenvolveu-se e otimizou-se o procedimento de extra??o da prote?na bruta utilizando como base o m?todo isoel?trico e um planejamento fatorial 24 com repeti??o; Extraiu-se e caracterizou-se o extrato obtido atrav?s da determina??o o teor de umidade, cinzas, nitrog?nio total e prote?na bruta e os mesmos metais determinados na ?gua. E, por fim, caracterizou-se tamb?m o extrato proteico utilizando An?lise Termogravim?trica (TG), Termogravimetria derivada (DTG), Calorimetria Explorat?ria Diferencial (DSC), Espectroscopia de Infravermelho (FT-IR) e Eletroforese em gel de poliacrilamida (SDS-PAGE) para avaliar as suas massas molares. Desta forma, a partir dos resultados obtidos para os fatores de transloca??o e bioacumula??o constatou-se que a mesma pode ser utilizada como agente fitorremediador em ambientes naturais de todos os elementos quantificados. Constatou-se ainda que o m?todo desenvolvido de extra??o e precipita??o de prote?nas foi satisfat?rio para o objetivo do trabalho, onde obteve-se as melhores condi??es de extra??o e precipita??o das prote?nas como sendo: pH de extra??o igual a 13,0; temperatura de extra??o igual a 60?C; tempo de rea??o igual a 30 minutos; e pH de precipita??o igual a 4,0. Quanto ao extrato obtido, os teores de nitrog?nio total e prote?na bruta quantificados foram superiores aos encontrados na planta, chegando a aumentar o teor de prote?na bruta cerca de 116,88% em rela??o ao teor quantificado no tecido vegetal da macr?fita. Os teores de n?quel e o c?dmio foram os ?nicos que se apresentaram abaixo do limite de detec??o do equipamento utilizado. A an?lise eletrofor?tica permitiu observar que o extrato proteico obtido ? constitu?do de cadeias polipept?dicas de baixo peso molecular e fitoquelatinas, com bandas de 6 e 15 kDa. As an?lises de TG, DTG, DSC e FT-IR permitiram constatar semelhan?as existentes no conte?do proteico dos extratos obtidos a partir de diferentes pontos de coleta e partes da planta em estudo, bem como da prote?na de soja 7 comercial e da case?na. Por fim, com base em todas essas constata??es, conclui-se que o extrato obtido no presente trabalho pode ser utilizado em substitui??o ?s fontes proteicas de ra??es animais devendo, antes disso, ser testado a sua digestibilidade. Quanto a suplementa??o humana, ? preciso a realiza??o de mais testes associados a otimiza??o do processo no sentido de remo??o dos componentes indesej?veis e constante monitoramento do corpo h?drico e da mat?ria-prima utilizada
334

Suprimento de enxofre e o estresse causado pelo excesso de zinco no capim tanzânia / Sulfur supply and stress caused by zinc excess in tanzania guinea grass

Renata Mota Lupp 27 September 2017 (has links)
O capim tanzânia (Panicum maximum cv. Tanzânia) é promissor para uso em fitorremediação, devido ao seu sistema radicular extenso, boa adaptação a variados ambientes e alto rendimento de biomassa quando bem nutrido. O enxofre faz parte de compostos essenciais ao sistema antioxidante das plantas. A toxicidade causada por alta disponibilidade de metais, como o zinco, no meio de cultivo é um problema ambiental crescente. Objetivou-se avaliar o efeito do enxofre em amenizar o estresse causado pelo excesso de zinco no capim tanzânia. O experimento foi conduzido em casa de vegetação em Piracicaba - SP, durante o verão, em delineamento de blocos casualizados em esquema fatorial fracionado, com as combinações de doses de enxofre (mmol L-1) e zinco (μmol L-1): 0,1/0,7; 0,1/500; 0,1/3000; 1,0/250; 1,0/1000; 1,9/0,7; 1,9/500; 1,9/3000; 2,8/250; 2,8/1000; 3,7/0,7; 3,7/500 e 3,7/3000. Foram avaliadas as seguintes variáveis: componentes de produção (perfilhos, folhas, área foliar, massa de parte aérea e de raízes), concentrações dos nutrientes (N, S, Ca, Mg, Cu, Fe, Mn e Zn), valor SPAD, atividades de enzimas do sistema antioxidante (GR, GPOX, APX, CAT e SOD) e concentração de prolina. A toxicidade de zinco no primeiro crescimento do capim limitou a produção de massa seca e o número total de folhas, enquanto no segundo crescimento também ocorreu limitação na área foliar e no número total de perfilhos. A concentração de enxofre na planta aumentou em função do fornecimento de enxofre e do excesso de zinco no meio de cultivo. O excesso de zinco na planta provocou desequilíbrio na nutrição da planta com os micronutrientes cobre, ferro e manganês. Os indicadores do estresse oxidativo foram sensíveis para detectar a toxicidade do zinco no capim. As reduções na concentração de prolina e nas atividades de enzimas do sistema antioxidante demonstraram o efeito do enxofre em aliviar o estresse por toxicidade de zinco no capim tanzânia. / Tanzania guinea grass (Panicum maximum cv. Tanzania) is promising for use in phytoremediation due to its extensive root system, good adaptation to diverse environments, and high biomass production when well nourished. Sulfur is part of essential compounds to the plant\'s antioxidant system. Toxicity caused by high availability of metals, such as zinc, in the growth medium is a growing environmental problem. The objective was to evaluate the effect of sulfur in mitigating the stress caused by zinc excess in tanzania guinea grass. The experiment was carried out in a greenhouse at Piracicaba, SP, during the summer, in a randomized block design with rates of sulfur (mmol L-1) and zinc (μmol L-1) of 1/0.7; 0.1/500; 0.1/3000; 1.0/250; 1.0/1000; 1.9/0.7; 1.9/500; 1.9/3000; 2.8/250; 2.8/1000; 3.7/0.7; 3.7/500 and 3.7/3000. The response variables evaluated were plant production components (number of tillers, number of leaves, leaf area, and shoots and roots dry matter), nutrient concentrations (N, S, Ca, Mg, Cu, Fe, Mn and Zn), SPAD value, activities of the antioxidant enzymes (GR, GPOX, APX, CAT and SOD) and proline concentration. Zinc toxicity in the first growth of the grass limited the dry mass production and the total number of leaves, while in the second growth also there was limitation in the leaf area and the total number of tillers. The concentration of sulfur in the plant increased as a function of sulfur supply and excess zinc in the growth medium. Excess zinc in the plant caused imbalance in plant nutrition for the micronutrients copper, iron and manganese. The indicators of oxidative stress were sensitive to detect grass toxicity by zinc. Reductions in proline concentration and enzyme activities of the antioxidant system demonstrated the effect of sulfur in alleviating the stress of zinc toxicity in tanzania guinea grass.
335

Comportamento de B, Zn, Cu, Mn e Pb em solo contaminado sob cultivo de plantas e adição de fontes de matéria orgânica como amenizantes do efeito tóxico / Behavior of B, Zn, Cu, Mn e Pb in contaminated soil under plant cultivation and organic matter addition for metal toxicity amelioration

Gláucia Cecília Gabrielli dos Santos 10 November 2005 (has links)
Foram conduzidos dois experimentos em casa-de-vegetação com solo contaminado acidentalmente com metais pesados. No primeiro deles objetivou-se avaliar o potencial das espécies vegetais Brassica juncea, Raphunus sativus L., Hybiscus cannabinus e Amaranthus crentus em absorver, translocar e acumular zinco, cobre, manganês, chumbo e boro na parte aérea e assim atuarem na recuperação do solo estudado. No segundo experimento avaliou-se a aplicação dos materiais orgânicos: Solomax, turfa e concentrado húmico mineral como amenizantes de toxidez dos elementos citados para Brassica juncea. Em um terceiro experimento em laboratório, avaliou-se a capacidade de retenção de zinco pelos materiais orgânicos estudados. As variáveis avaliadas foram: produção de material vegetal; quantidades absorvida e acumulada de Zn, Cu, Mn, Pb e B; índices de translocação e remoção desses elementos pelas plantas. No solo foram determinados os teores total e disponível (DTPA e CaCl2 0,01 mol L-1) de Zn, Cu, Mn e Pb. No extrato de saturação foram determinados os teores solúvel (ICP-OES) e livre (eletroforese capilar) dos elementos citados, que também foram determinados na parte aérea da Brassica juncea. Resultados das determinações analíticas também foram introduzidos no programa de especiação iônica MINTEQ. Foram avaliados ainda os efeitos dos materiais orgânicos na distribuição dos metais pesados nas frações do solo. No ajuste dos dados do experimento de retenção de zinco foi a empregado o modelo de Freundlich e calculado o coeficiente de distribuição Kd. Embora as espécies tenham sido capazes de acumular quantidades elevadas dos elementos na parte aérea, elas não puderam ser consideradas hiperacumuladoras. O Amaranthus crentus e a Brassica juncea apresentaram os maiores índices de remoção para Zn, Mn e B. Os materiais orgânicos apresentaram valores elevados de Kd refletindo a alta afinidade do zinco pela fase sólida e elevada capacidade dos materiais orgânicos em imobilizar o elemento. Os elevados coeficientes de correlação obtidos para as isotermas de adsorção indicam que o modelo Freundlich pode ser utilizado para descrever a adsorção do Zn pelos materiais. A quantidade de Zn removida pelos materiais, em termos percentuais variou com o material e com o pH, sendo favorecida nos valores mais elevados. A turfa e o concentrado húmico reduziram os teores de metais extraídos por DTPA e CaCl2 sendo esta redução refletida nos teores acumulados pela Brassica juncea, contudo esta redução não foi suficiente para impedir os efeitos fitotóxicos dos elementos. A especiação dos metais mostrou que o Zn e o Mn encontraram-se principalmente na forma livre, enquanto que o Cu e o Pb apresentaram-se complexados à matéria orgânica dissolvida. Não foram observadas correlações significativas entre os teores dos metais determinados diretamente por eletroforese capilar e indiretamente pelo programa de especiação. O fracionamento seqüencial dos metais indicou que grande parte dos metais está ligada a frações pouco disponíveis do solo. Conclui-se que a aplicação da turfa e do concentrado húmico mineral juntamente com o cultivo do Amaranthus crentus e da Brassica juncea podem auxiliar na recuperação a longo prazo de solos contaminados com Zn, Mn Pb e B. / Two pot trials were carried out using a heavy metal accidentally contaminated soil. In the first one it was evaluated the plant absorbing, translocating and accumulating power for zinc, copper, manganese, lead and boron by the following vegetal species: Brassica juncea, Raphunus sativus L., Hybiscus cannabinus and Amaranthus crentus, so they could help in the rehabilitation of the studied soil. In the second pot trial it was evaluated the application of the following organic materials: Solomax, peat, and humic mineral concentrate for heavy metal toxicity amelioration for Brassica juncea. In a laboratory experiment it was evaluated the zinc retention capacity for the above mentioned organic materials. The measured variables were plant dry matter yield, absorbed and accumulated amounts of Zn, Cu, Mn, Pb and B; the translocation index and the removal index of metal by the mentioned plant species. The total and available (DTPA and CaCl2 001 mol L-1) content of Zn, Cu, Mn and Pb, were determined in soil samples. Concerning the soil saturation extract, the soluble and free forms of the mentioned elements were determined by ICPOES and capillary electrophoresis respectively. The same metals were also determined in the plant tissue of Brassica juncea. Analytical results were introduced in the chemical equilibrium program MINTEQ in order to calculate the concentration of the free forms of Zn, Cu, Mn, and Pb. A fractioning scheme for metals in soil was carried out in order to evaluate the effect of adding sources of organic carbon. The Freundlich model was used to account for zinc adsorption by the studied organic materials and the distribution coefficient Kd was also calculated. Although the plant species were able to accumulate high amounts of metal in the aerial part, that could not be considered as a hipper-accumulation process. The highest metal removal indexes were observed for Brassica juncea and Amaranthus crentus. Organic materials showed high values of Kd, reflecting its high affinity for zinc and a great capacity of zinc immobilization as well. Freundlich model was very effective in describing the adsorption isotherms as indicated by the high determination coefficients. Zinc retention was affected by the organic material type and pH, being favored by the highest studied pH values. Peat and humic mineral concentrate reduced the amounts of metals extracted by DTPA and CaCl2 in soil but the reduction was not great enough to avoid toxic effects in plants. Zn and Mn were present mostly as free cations in soil saturation extract while Pb and Cu were complexed by dissolved organic matter. It was not detected any significant correlation between free metal contents directly determined by capillary electrophoresis and those estimated by MINTEQ. Metal sequential extraction showed that most of them occurred in the least available fractions of soil. Peat and humic mineral concentrate application to soil associated with Amaranthus crentus and Brassica juncea cultivation may be used in long term amelioration of soils contaminated with Zn, Mn, Pb and B.
336

La phytoremédiation assistée par les champignons mycorhiziens à arbuscules des sols historiquement contaminés par les dioxines/furanes : Conséquences sur le microbiote du sol et sur la dissipation des polluants / Arbuscular mycorrhizal fungi - assisted phytoremediation of aged dioxin/furan-contaminated soil : Consequences on microbiota and pollutant dissipation

Meglouli, Hacène 15 September 2017 (has links)
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.
337

Silicon and tanzania guinea grass tolerance to stress by copper toxicity / Silício e a tolerância do capim-tanzânia ao estresse pela toxidez por cobre

Vieira Filho, Leandro Otávio 02 August 2018 (has links)
Whist copper (Cu) is an essential element for plants, when this element is present in excess quantities it can cause irreversible damage. This metal induces excessive production of reactive oxygen species (ROS), which damages organelles causing dysfunction. A possible means for the promotion of metal tolerance in plants is the adition of the element silicon (Si). The current study was conducted with the aim of evaluating the role of Si (0, 1 and 3 mmol L-1) on the morphologic, nutritional, metabolic and physiological responses of Panicum maximum cv. Tanzania under different Cu rates (0.3, 250, 500 and 750 μmol L-1). The grass was grown in a greenhouse under hydroponic conditions for two growth periods (33 and 30 days). Thirteen days after sowing, the seedlings were transplanted to a nutrient solution and supplied just with the Cu rate of 0.3 μmol L-1 and the set Si rates for 25 days. The remaining Cu rates were only added for a seven day period during the first growth stage. The second harvest took place 31 days after the first harvest. The experiment had six randomized blocks: three for yield, morphology and nutritional analyses and three for metabolic and physiological analyses. Plant yield, morphology and metabolic parameters were quantified in shoots and roots. Chlorophyll content index (SPAD values) and gas exchange parameters were determined in diagnostic leaves (DL), and Cu and Si concentrations were analysed from the DL and roots. The calculation of Cu and Si contents took into account the whole plant biomass. Plants exposed to Cu rates above 0.3 μmol L-1 showed low values of plant yield, morphologic parameters and SPAD, in both growth periods. Silicon supplied plants showed lower Cu concentration and content, and higher values of plant yield, morphlogic parameters and SPAD than the ones with no Si application. Silicon concentration and content were higher in plants exposed to excess Cu compared to those exposed to the control rate (0.3 μmol L-1). Gas exchange parameters in plants of the first growth were positively affected by Si supply and negatively affected by Cu rates. In the second growth, an eustress event was observed, in which plants exposed to stressing rates of residual Cu showed the highest values of gas exchange parameters and the lowest values of stress indicators. The activities of antioxidant enzymes were reduced with the increment in Cu rates. Silicon supply resulted in an increment in superoxide dismutase (SOD) activity. Tanzania guinea grass supplied with Si was able to better deal with Cu toxicity, showing increases in plant yield, morphologic and gas exchange parameters. Silicon supplied plants reduced their absorption of Cu and consequently, plants exposed to high Cu rates were still able to produce considerable biomass in the regrowth. / O cobre (Cu) é um elemento essencial para as plantas, porém, quando em excesso, pode causar danos irreversíveis às plantas. Este metal induz a produção excessiva de espécies reativas de oxigênio (ERO), que danificam organelas causando a disfunção delas. Uma possível maneira de aumentar a tolerância de plantas aos metais é o fornecimento de silício (Si). Um experimento foi conduzido com o objetivo de avaliar o papel do Si (0, 1 e 3 mmol L-1) nas respostas morfológicas, nutricionais, metabólicas e fisiológicas do Panicum maximum cv. Tanzânia sob doses de Cu (0,3, 250, 500 e 750 μmol L-1). Esse capim foi cultivado hidroponicamente em casa de vegetação por dois períodos de crescimento (33 e 30 dias). Treze dias após a semeadura, plântulas foram transplantadas para solução nutritiva, fornecendo-se apenas as doses de Si por 25 dias. A exposição ao cobre foi realizada apenas no primeiro crescimento das plantas e durou sete dias. O segundo corte ocorreu 31 dias após o primeiro corte. O experimento consistia de seis blocos completos ao acaso: três para avaliações de produção, morfologia e análises nutricionais e três para análises metabólicas e fisiológicas. A produção, a morfologia e o metabolismo das plantas foram quantificados na parte aérea e nas raízes. O índice de conteúdo de clorofila (valores SPAD) e as análises fisiológicas foram determinados nas lâminas diagnósticas (LD), e as concentrações de Cu e Si nas LD e nas raízes. Para o cálculo dos acúmulos de Cu e Si levou-se em consideração toda a biomassa da planta. Plantas expostas a doses de Cu acima de 0,3 μmol L-1 apresentaram menores valores de produtividade, parâmetros morfológicos e de SPAD. Plantas supridas com Si apresentaram menor concentração e acúmulo de Cu, e maiores valores de produtividade, parâmetros morfológicos e SPAD do que aquelas que não receberam o fornecimento de Si. A concentração e o acúmulo de silício foram maiores nas plantas expostas ao excesso de Cu do que nas expostas à dose controle de Cu (0,3 μmol L-1). Os parâmetros de trocas gasosas das plantas no primeiro crescimento foram afetados positivamente pelo Si e negativamente pelo incremento nas doses de Cu. No segundo crescimento, observou-se evento de eustresse em que plantas expostas à dose de Cu residual apresentaram os valores mais altos de parâmetros de troca gasosa e os valores mais baixos de indicadores de estresse. As atividades de enzimas antioxidantes foram reduzidas com o incremento nas doses de Cu. O suprimento de silício resultou em incremento na atividade da superóxido dismutase (SOD). O capim tanzânia suplementado com Si foi capaz de suportar melhor a toxicidade do Cu, mostrando um aumento na produção de biomassa da planta, e em parâmetros morfológicos e de trocas gasosas. As plantas suplementadas com Si reduziram a absorção de Cu e, consequentemente, plantas expostas a altas taxas de Cu e suplementadas com Si ainda foram capazes de produzir uma biomassa apreciável na rebrota.
338

Phytostabilization of mine tailings covered with fly ash and sewage sludge

Neuschütz, Clara January 2009 (has links)
Establishing plant communities is essential for the restoration of contaminated land. As potential cover materials, fly ash and sewage sludge can prevent formation of acid mine drainage from sulfidic mine waste. The aim of the thesis was to i) screen for plants that can be established in, and prevent leakage of metals and nutrients from sludge on top of ash and tailings, and ii) investigate root growth into sealing layers of ash and sludge. Analyses were performed under laboratory, greenhouse and field conditions using selected plant species to examine the release of Cd, Cu, Zn, N, and P from the materials. Plant physiological responses and interactions with fly ash were also investigated. The data show that plants can decrease metal and nutrient leakage from the materials, and lower the elemental levels in the leachate, but with varying efficiencies among plant species. Plants capable of taking up both nitrate and ammonium were more efficient in preventing N leakage compared with those taking up primarily ammonium. Fast growing plants could raise the pH in acidic sludge leachate, but the initial pH decrease and N leakage was not counteracted by plants. Germination in fresh sludge was problematic, but enhanced by aeration of the sludge. In general, the accumulation of metals in plant shoots was low, especially if ash was located below the sludge. Fresh ash was phytotoxic (e.g., high alkalinity, salinity and metal levels) and induced the activity of stress-related enzymes in shoots. In sealing layers of aged and cured ash, roots could grow if the penetration resistance was low, or into the surface of stronger layers if the surface had become pulverized. The roots caused dissolution of calcium-rich minerals, possibly by exudation of saccharides. Addition of sludge to an ash layer increased root growth, likely due to decreased bulk density and pH, and nutrient addition. In conclusion, with selected plant species and a properly constructed cover, metal and nutrient leaching from the materials and root growth into the sealing layer can be restricted.
339

Phytoremediation of pharmaceuticals with salix exigua

Franks, Carmen G., University of Lethbridge. Faculty of Arts and Science January 2006 (has links)
Municipal treated wastewater entering rivers contain biologically active pharmaceuticals capable of inducing effects in aquatic life. Phytoremediation of three of these pharmaceuticals and an herbicide was investigated using Sandbar willow (Salix exigua) and Arabidopsis thaliana. Both plants were effective at removing compounds from solution, with removal of 86% of the synthetic estrogen, 17α-ethynylestradiol, 65% of the anti-hypertensive, diltiazem, 60% of the anti-convulsant, diazepam (Valium®), and 51% of the herbicide atrazine, in 24 hours. Distribution of compounds within roots and shoots, in soluble and bound forms, differed among compounds. Uptake and distribution of pharmaceuticals within the study plants confirmed pharmaceutical behaviour can be predicted based on a physiochemical property, their octanol-water partitioning coefficients. An effective method for detection of 17α-ethynylestradiol within surface water using solid phase extraction and gas chromatography-mass spectrometry was developed. Previously unreported breakdown of 17α-ethynylestradiol into another common estrogen, estrone, during preparative steps and gas chromatography was resolved. / xv, 216 leaves ; 29 cm.
340

Molecular biodiversity of microbial communities in polluted soils and their role in soil phytoremediation

Hassan, Saad El Din 07 1900 (has links)
Les métaux lourds (ML) s’accumulent de plus en plus dans les sols à l’échelle mondiale, d’une part à cause des engrais minéraux et divers produits chimiques utilisés en agriculture intensive, et d’autre part à cause des activités industrielles. Toutes ces activités génèrent des déchets toxiques qui s’accumulent dans l’environnement. Les ML ne sont pas biodégradables et leur accumulation cause donc des problèmes de toxicité des sols et affecte la biodiversité des microorganismes qui y vivent. La fertilisation en azote (N) est une pratique courante en agriculture à grande échelle qui permet d’augmenter la fertilité des sols et la productivité des cultures. Cependant, son utilisation à long terme cause plusieurs effets néfastes pour l'environnement. Par exemple, elle augmente la quantité des ML dans les sols, les nappes phréatiques et les plantes. En outre, ces effets néfastes réduisent et changent considérablement la biodiversité des écosystèmes terrestres. La structure des communautés des champignons mycorhiziens à arbuscules (CMA) a été étudiée dans des sols contaminés par des ML issus de la fertilisation à long terme en N. Le rôle des différentes espèces de CMA dans l'absorption et la séquestration des ML a été aussi investigué. Dans une première expérience, la structure des communautés de CMA a été analysée à partir d’échantillons de sols de sites contaminés par des ML et de sites témoins non-contaminés. Nous avons constaté que la diversité des CMA indigènes a été plus faible dans les sols et les racines des plantes récoltées à partir de sites contaminés par rapport aux sites noncontaminés. Nous avons également constaté que la structure de la communauté d'AMF a été modifiée par la présence des ML dans les sols. Certains ribotypes des CMA ont été plus souvent associés aux sites contaminés, alors que d’autres ribotypes ont été associés aux sites non-contaminés. Cependant, certains ribotypes ont été observés aussi bien dans les sols pollués que non-pollués. Dans une deuxième expérience, les effets de la fertilisation organique et minérale (N) sur les différentes structures des communautés des CMA ont été étudiés. La variation de la structure de la communauté de CMA colonisant les racines a été analysée en fonction du type de fertilisation. Certains ribotypes de CMA étaient associés à la fertilisation organique et d'autres à la fertilisation minérale. En revanche, la fertilisation minérale a réduit le nombre de ribotypes de CMA alors que la fertilisation organique l’a augmenté. Dans cette expérience, j’ai démontré que le changement de structure des communautés de CMA colonisant des racines a eu un effet significatif sur la productivité des plantes. Dans une troisième expérience, le rôle de deux espèces de CMA (Glomus irregulare et G. mosseae) dans l'absorption du cadmium (Cd) par des plants de tournesol cultivés dans des sols amendés avec trois niveaux différents de Cd a été évalué. J’ai démontré que les deux espèces de CMA affectent différemment l’absorption ou la séquestration de ce ML par les plants de tournesol. Cette expérience a permis de mieux comprendre le rôle potentiel des CMA dans l'absorption des ML selon la concentration de cadmium dans le sol et les espèces de CMA. Mes recherches de doctorat démontrent donc que la fertilisation en N affecte la structure des communautés des CMA dans les racines et le sol. Le changement de structure de la communauté de CMA colonisant les racines affecte de manière significative la productivité des plantes. J’ai aussi démontré que, sous nos conditions expériemntales, l’espèce de CMA G. irregulare a été observée dans tous les sites (pollués et non-pollués), tandis que le G. mosseae n’a été observé en abondance que dans les sites contaminés. Par conséquent, j’ai étudié le rôle de ces deux espèces (G. irregulare et G. mosseae) dans l'absorption du Cd par le tournesol cultivé dans des sols amendés avec trois différents niveaux de Cd en serre. Les résultats indiquent que les espèces de CMA ont un potentiel différent pour atténuer la toxicité des ML dans les plantes hôtes, selon le niveau de concentration en Cd. En conclusion, mes travaux suggèrent que le G. irregulare est une espèce potentiellement importante pour la phytoextration du Cd, alors que le G. mosseae pourrait être une espèce appropriée pour phytostabilisation du Cd et du Zn. / Trace metals (TM) are continually world-wide added to soils through the intensive use of mineral fertilizers and agriculture chemicals, together with industrial and other activities generating toxic wastes. Problems associated with metal-contaminated soil exists because TM are not biodegradable. TM that accumulate in soils affect the biodiversity of soil microorganisms. Nitrogen (N) fertilization is a widespread practice to increase soil fertility and crop production. However, the long-term use of N fertilization causes many detrimental effects in the environment. The intensive use of N fertilization increase TM input in soils, and in extreme cases, N fertilization result in TM pollution of the surrounding soil and water and increase TM concentration in plant tissues. In addition, the long-term use of N fertilizers changes and declines the biodiversity of above and underground ecosystems. The community structure of arbuscular mycorrhizal fungi (AMF) was investigated in TM contaminated and long-term N fertilized soils. In addition, the role of different AMF species in TM uptake or sequestration was investigated. In the first experiment, AMF community structure was analyzed from non-contaminated and TM contaminated sites. We found the diversity of native AMF was lower in soils and plant roots harvested from TM polluted soils than from unpolluted soils. We also found that the community structure of AMF was modified by TM contamination. Some AMF ribotypes were more often associated with TM contaminated sites, other ribotypes with uncontaminated sites, while still other ribotypes were found both in polluted and unpolluted soils. In the second experiment, the effect of different organic and mineral N fertilization on AMF community structure was investigated. Variation in root-colonizing AMF community structure was observed in both organic and mineral fertilization. Some AMF ribotypes were more affiliated to organic fertilization and other to mineral fertilization. In addition, mineral fertilization reduced AMF ribotypes number while organic fertilization increased AMF ribotypes number. In this experiment, it was demonstrated that change in root-colonizing AMF community structure had a significant effect on plant productivity. In the third experiment, the role of different AMF species (G. irregulare and G. mosseae) in TM uptake by sunflower plants grown in soil amended with three different Cd levels was evaluated. It was demonstrated that AMF species differentially affected TM uptake or sequestration by sunflower plants. This experiment supported a different effect of AMF in TM uptake based on Cd concentration in soil and the AMF species involved. Our research demonstrated that TM and N fertilization affected and shifted AMF community structure within roots and soils. It was shown that change in root-colonizing AMF community structure significantly affected plant productivity. In this study, it was showed that the AMF species G. irregulare was recorded in all uncontaminated sites while G. mosseae was the most abundant AMF species in TM contaminated sites. Therefore, the role of G. irregulare and G. mosseae in Cd uptake by sunflower plants grown in soils amended with three different Cd levels was investigated. The results indicated that AMF species mediate different mechanisms to alleviate TM toxicity in host plants, depending on AMF species and soil Cd level involved. We hypothesize that G. irregulare is a potentially important species for Cd phytoextration processes, while G. mosseae might be a suitable candidate for Cd and Zn phytostabilization processes.

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