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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.
41

Efeito de pontas de pulverização e de arranjos populacionais de plantas de Eichhornia crassipes (Mart.) Solms., Salvinia auriculata Aubl. e Pistia stratiotes L. na deposição de calda de pulverização

Marchi, Sidnei Roberto de [UNESP] 16 March 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-03-16Bitstream added on 2014-06-13T20:00:32Z : No. of bitstreams: 1 marchi_sr_dr_botfca.pdf: 984466 bytes, checksum: 1469adadcc88f867eee451598ff9f2f3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo avaliar a quantidade de calda de pulverização depositada na água e em folhas de Eichhornia crassipes (Mart.) Solms, Salvinia auriculata Aubl e Pistia stratiotes L. em condições variáveis de arranjos populacionais e dois tipos de pontas de pulverização (ConeJet TXVK-8 e TeeJet DG 11002 VS). Para tanto, foi conduzido um experimento em caixas d água composto por três Situações distintas. Na Situação Aguapé, além da proporção de dominância total correspondente à cobertura de 100% da caixa d água pelas plantas de aguapé, foram utilizados os arranjos (ou proporções) com as espécies de salvinia ou alface d água a 75%:25%, 50%:50%, 25%:75%. Adotou-se as mesmas proporções na Situação Salvínia e na Situação Alface d água, sendo que cada Situação foi determinada pela predominância total de salvínia ou alface d água, respectivamente, na caixa d água. Uma densidade tripla, onde as três espécies foram igualmente dispostas na proporção de 33,33%, foi utilizada como testemunha. Soluções dos corantes Amarelo Tartrasina FDC-5 a 3.500 ppm e Azul Brilhante FDC-1 a 1.000 ppm foram utilizados como traçadores para as pontas TXVK-8 e DG 11002VS, respectivamente. A pulverização de ambas soluções foram efetuadas na mesma unidade experimental, com um intervalo de 30 minutos entre si, através de um pulverizador costal pressurizado com CO2 e calibrado de modo a proporcionar um volume de aplicação aproximado de 200 L/ha. Amostras de água dos reservatórios foram coletadas antes e após as aplicações com o objetivo de avaliar a quantidade de calda de pulverização que não atingiu o alvo. Imediatamente após a coleta da 2 água, as plantas presentes nos reservatórios foram lavadas com água destilada até remoção total dos corantes depositados nas folhas. Placas de plástico contendo... / The present research had as objective to quantify the spray deposition on water and leaves of water hyacinth (Eichhornia crassipes (Mart.) Solms), water fern (Salvinia auriculata Aubl.) and water lettuce (Pistia stratiotes L.) according to various population arrangements and two nozzle type (ConeJet TXVK-8 and TeeJet 11002VS). The trial was carried out under reservoirs conditions using three different Situations. At Water hyacinth Situation, besides the total dominancy proportion equivalent to 100% of reservoir covering by water hyacinth plants, it was used three others combinations involving water hyacinth and water fern or water lettuce plants, as following: 75%:25%, 50%:50% and 25%:75%. The same combinations were also used at Water Fern Situation and Water Lettuce Situation, being each Situation determined by total dominancy of water fern or water lettuce in the 4 reservoirs, respectively. A triple ratio, where the three species were equally disposed at proportion of 33,33%, was used as check. Dye solutions of FD&C Yellow n. 5 at 3,500 ppm and FD&C Blue n. 1 at 1,000 ppm were used as spraying tracers for TXVK-8 and DG 11002 VS nozzles, respectively. Both solutions were sprayed at same plot within at 30 minutes interval each one through a CO2 pressured backpack knapsack calibrated to delivery a spray volume around 200 L/ha. Samples of reservoirs water were taken before and after sprays in order to evaluate the carrier quantity that not reaches the target. After that, the plants present at reservoirs were washed with distillated water until totally dyes removal deposited on the leaves. Plastic dishes containing 20 mL of distillated water were disposed in each experimental plot in order to check the spray efficacy and possible drift losses. Absorbance measures at 427 and 630 nm of wavelength were procedures... (Complete abstract, click electronic access below)
42

Alometria foliar, biomassa e fitoacumulação de cromo em Eichhornia crassipes (Mart.) Solms

Gonçalves, Cátia Viviane January 2006 (has links)
Nos ambientes aquáticos tropicais, o crescimento das macrófitas aquáticas é favorecido pelas altas temperaturas e elevada intensidade de radiação solar. Nestas condições, tal crescimento pode subsidiar efetivamente a manutenção das cadeias tróficas e os fluxos de energia dos ambientes aquáticos naturais ou até mesmo construídos. Considerando que as alterações ao longo do tempo na diversidade das macrófitas aquáticas ocorrem pelas variações na biomassa e na abundância relativa das espécies, o presente trabalho limitou sua pesquisa a espécie Eichhornia crassipes (Mart.) Solms. Deste modo, são apresentados dois artigos científicos desenvolvidos sobre o tema: um enfocando o ambiente natural e as relações alométricas foliares da espécie com sua biomassa e outro desenvolvido em ambiente construído (estação de tratamento de efluentes) onde foram introduzidos exemplares da espécie com o objetivo de avaliar a capacidade depuradora em um sistema aquático contendo cromo e sua reação ao elemento químico. A conexão dos dois artigos desenvolvidos está no fato de que o primeiro faz uma definição e avaliação detalhada da metodologia a ser utilizada (não destrutiva) e o segundo aplica o método, já devidamente aferido, em plantas desenvolvidas em ambiente construído e com acentuada concentração de contaminantes. Desta forma, o presente trabalho, além de estabelecer uma nova metodologia de determinação de biomassa vegetal com base em dados alométricos, utiliza o mesmo para definir a eficiência de Eichhornia crassipes no processo de depuração de efluentes da indústria de couro. / In tropical aquatic environments, the growth of the aquatic macrophytes is favored had to the high temperatures and the raised intensities of solar radiation. In these conditions, such growth can effectively subsidize the maintenance of the trophic chains and the flows of energy of natural aquatic environments or even though constructed. Considering that the alterations in the diversity of aquatic macrophytes throughout the time occur for the substitution and variations in the biomass and relative abundance of the species, the present work limited its research the species Eichhornia crassipes (Mart.) Solms and presents two developed scientific articles on the subject: one focusing the natural environment and the allometry leaf relations of the species with its biomass and developed other in constructed environment (station of treatment of effluent) where had been introduced exemplary of the specimen with the objective to evaluate the depurant capacity in aquatic system contends chromium and its reaction to the chemical element. The connect of two produced articles is in the fact of that the first one makes a definition and detailed evaluation of the methodology to be used (not destructive) and as it applies the method, already duly surveyed, in plants developed in environment constructed and with accented concentration of contaminantes. In such a way, the present work, beyond establishing a new methodology of determination of vegetal biomass on the basis of given allometric, uses the same to define the efficiency of Eichhornia crassipes in the process of purification of effluent of the leather industry.
43

AGUAPÉ (Eichhornia crassipes) COMO BIOADSORVENTE DO CORANTE TURQUESA REMAZOL / WATERY WINE (Eichhornia crassipes) AS BIOADSORVENTE OF THE CORANTE TURQUOISE REMAZOL

Holanda, Carlos Alexandre 16 December 2010 (has links)
Made available in DSpace on 2016-08-19T12:56:35Z (GMT). No. of bitstreams: 1 CARLOS ALEXANDRE HOLANDA.pdf: 2182022 bytes, checksum: c22abe4de00a3629f5ab00248eca87e4 (MD5) Previous issue date: 2010-12-16 / FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTIFICO E TECNOLÓGICO DO MARANHÃO / In this work, the root, stem and leaf of Eichhornia crassipes were used in preparing bioadsorbent for removal of the textile dye Remazol Turquoise, from its aqueous solution. The biomass of water hyacinth was crushed isolated and treated with a solution of nitric acid at 50°C, followed by five washes for extraction of soluble matter. After filtration, the samples were dried and sieved to a particle size between 44 to 210 μm. The pHzpc values of bioadsorbent (pH at zero point of charge) were estimated at 3.3, 3.1 and 3.4 for the root, stem and leaf, respectively. Kinetic studies were performed at pH 2, due in this value the efficiency of the dye removal was the best. The kinetic models of pseudo-first and second orders were applied at temperatures 10, 25 and 40°C, and the second order model (R2 > 0.98) was that best modeled the experimental data. The intraparticle diffusion model showed three linear segments, indicating the three stages of the adsorptive process. The adsorption isotherms were obtained by varying the dye concentration from 50 to 50 mg.L-1 in the range from 50 to 1000 mg.L-1. The Freundlich, Langmuir, Sips and multilayers adsorption isotherms models have been applied to fit the experimental data, and the Sips model was the best one. The thermodynamic parameters confirmed the spontaneity of all studied adsorptive processes, which are endothermics, but with increasing entropies. The low desorption of the dye at pH's 8 and 11 showed the high affinity between matrices and dye, and the relative difficulty of the dye recovery and consequently, the reuse of these bioadsorbents, by this route. / Neste trabalho, a raiz, o caule e a folha da Eichhornia crassipes foram utilizados na preparação de bioadsorventes para remoção do corante têxtil Turquesa Remazol, em meio aquoso. A biomassa do aguapé (raiz, caule e folha) foi triturada separadamente e tratada com uma solução de ácido nítrico, a 50ºC, seguida de cinco lavagens para a melhor extração da matéria solúvel. Após filtração, o material foi seco e peneirado a uma granulometria entre 44 e 210 μm. Os valores dos pHzpc (pH no ponto de carga zero) dos bioadsorventes foram estimados em 3,3; 3,1 e 3,4 para a raiz, caule e folha, respectivamente. Os estudos cinéticos foram realizados em pH 2, devido a maior eficiência de remoção do corante. Os modelos cinéticos de pseudo-primeira e segunda ordem foram aplicados nas temperaturas 10, 25 e 40ºC, sendo o modelo de segunda ordem (R2 > 0,98) o que melhor representou os dados experimentais. O modelo de difusão intrapartícula apresentou as três etapas que indicam a difusão e o equilíbrio do corante com os bioadsorventes. As isotermas de adsorções foram obtidas variando-se a concentração do corante de 50 em 50 mg.L-1 na faixa de 50 a 1000 mg.L-1. Os modelos isotérmicos de Freundlich, Langmuir, Sips e multicamadas foram aplicados na avaliação dos resultados experimentais, sendo o modelo proposto por Sips o que mais se aproximou dos resultados experimentais. Os parâmetros termodinâmicos confirmaram a espontaneidade dos processos de adsorção, os quais apresentaram-se endotérmicos, mas com aumento de entropia. Os baixos valores de dessorção do corante em pH´s 8 e 11 demonstram a alta afinidade das matrizes pelo corante, e a relativa dificuldade de recuperação do corante, e consequente reuso de ambos, por esta via.
44

Eficiência de sistemas de leitos cultivados com Eichhornia crassipes na retenção de poluentes convencionais e o emergente 17-alfa-etinilestradiol / Retention efficiency of conventional pollutants and 17-alpha-ethinylestradiol using constructed wetlands cultivated with Eichhornia crassipes

Campos, Julyenne Meneghetti, 1985- 25 August 2018 (has links)
Orientador: José Teixeira Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-25T00:46:54Z (GMT). No. of bitstreams: 1 Campos_JulyenneMeneghetti_M.pdf: 7123166 bytes, checksum: da20e59802401636508451e97ba79194 (MD5) Previous issue date: 2014 / Resumo: Leitos cultivados tem sido citados como um método alternativo de redução da concentração de alguns agrotóxicos e hormônios levemente hidrofóbicos, como o 17-?-etinilestradiol, que é um dos principais responsáveis pela causa da alteração no sistema endócrino de humanos e animais. Neste contexto, o presente projeto visou avaliar a eficiência da redução de pH, 17-?-etinilestradiol, oxigênio dissolvido (OD), cor aparente, turbidez, nitrogênio total Kjeldahl (NTK), nitrogênio amoniacal (NH3), nitrito (NO2-), nitrato (NO3-), demanda química de oxigênio (DQO) e fósforo total (PT), utilizando-se três leitos tendo brita como meio suporte ¿ dois deles cultivados com a macrófita Eichhornia crassipes (aguapé), com 43 dias de diferença de cultivo entre eles, e outro leito sem cultivo apenas com a brita para controle e comparação dos resultados. A vazão de entrada nos leitos cultivados variou entre 312 e 1.059 L.dia-1, o TDH médio permaneceu entre 2 e 3 dias, as médias máximas de retenção da concentração de DQO, cor, turbidez, NTK, NH3 e PT pelos leitos foram 94,2%, 76,7%, 90,0%, 42,7%, 39,6% e 51,0%, respectivamente. A biomassa dos dois leitos cultivados com aguapé absorveram juntos, 163 g.kg-1 de nitrogênio e 47,2 g.kg-1 de fósforo, durante o período monitorado. Dentre os parâmetros de eficiência analisados o leito cultivado com Eichhornia crassipes com maior grau de desenvolvimento foi o mais eficiente na retenção da maioria dos parâmetros avaliados com nível 5% de significância. A metodologia adaptada para análise do hormônio 17-?-etinilestradiol por Cromatografia Líquida de Alta Eficiência acoplada à Detector de Arranjo de Diodos obteve limite de detecção de 1,26 µg.L-1, e limite de quantificação de 2,52 µg.L-1, porém as amostras analisadas ficaram abaixo do nível de detecção, não sendo possível a determinação das concentrações das amostras. Conclui-se que a macrófita Eichhornia crassipes fixada em meio suporte obteve retenções de nutrientes consideradas satisfatórias em tratamento de esgoto doméstico, e as informações obtidas por este trabalho poderão contribuir com a melhoria e desenvolvimento de novas tecnologias para retenção e métodos analíticos para quantificação de 17-?-etinilestradiol em águas residuárias, diminuindo o lançamento destes interferentes endócrinos nos corpos hídricos / Abstract: Constructed wetlands have been quoted as an alternative method for the removal of slightly hydrophobic pesticides and hormones, such as 17-?-ethinylestradiol, which is one of the main hormones responsible for humans and animals endocrine systems changes. In this context, this project tried to evaluate the reduction efficiency with regards to pH, 17-?-ethinylestradiol, dissolved oxygen (DO), apparent color, total Kjeldahl nitrogen (NTK), ammonia nitrogen (NH3), nitrite (NO2-), nitrate (NO3-), chemical oxygen demand (COD) total phosphorus (PT), using three constructed wetlands having gravel as support media ¿ two of them cultivated with Eichhornia crassipes (water hyacinth), with 43 growth days gap between, and another with gravel only for control and results comparison. The entrance flow rate in the constructed wetlands ranged between 312 to 1,059 L.dia-1, the average HRT stayed between 2 and 3 days, the maximum chemical oxygen demand retention averages, color, turbidity, NTK, ammonia nitrogen and total phosphorus by the constructed wetlands were 94,2%, 76,7%, 90,0%, 42,7%, 39,6% and 51,0%, respectively. The biomass of both water hyacinth constructed wetlands absorbed together 163 g.kg-1 of nitrogen and 47,2 g.kg-1 of phosphorous during the monitored period. Among the analyzed efficiency parameters, the constructed wetland cultivated with Eichhornia crassipes, also 43 days older, was the most efficient in the majority of the parameters evaluated at a 5%significance level. The suitable methodology for analyzing 17-?-ethinylestradiol by high efficiency liquid chromatography attached to a Diode Arrange Detector, had a detection limit of 1.26µg.L-1, and a quantification limit of 2.53 µg.L-1, but the analyzed samples stayed below the detection level, becoming impossible determine the samples¿ concentrations. The conclusion is that the macrophyte Eichhornia crassipes fixed in a support media had satisfactory nutrients retention from domestic sewage, and the obtained information by this work can contribute for an improvement and development of new technologies for retention and analytical methods for 17-?-ethinylestradiol wastewater quantification, decreasing the discharge of these endocrine disruptors in water bodies / Mestrado / Agua e Solo / Mestra em Engenharia
45

Impacto ambiental do uso do Glyphosate no controle de aguapé (Eichhornia crassipes) / Environmental impact resulting from the use glyphosate to control water hyacinth (Eichhornia crassipes)

Souza, Evandro Luiz Corrêa de, 1977- 22 August 2018 (has links)
Orientador: Luiz Lonardoni Foloni / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-22T22:50:44Z (GMT). No. of bitstreams: 1 Souza_EvandroLuizCorreade_D.pdf: 1935989 bytes, checksum: 8ed1c5f0a8eca62f3c6607c8f4bdf0b6 (MD5) Previous issue date: 2013 / Resumo: Visando avaliar o impacto ambiental do herbicida glifosato em ambiente aquático, escolheu-se estudar, em campo experimental controlado e fechado, o manejo do aguapé (Eichhornia crassipes), analisando parâmetros de qualidade de água e de resíduos de glifosato. Os experimentos foram conduzidos na área experimental do Núcleo de Pesquisas Avançadas em Matologia (NUPAM), pertencente à Faculdade de Ciências Agronômicas da UNESP, campus de Botucatu (SP). No experimento utilizaram-se 20 reservatórios de fibra de cimento, sendo quatro para cada tratamento, com capacidade de armazenamento de 250 L, sem reposição da água evapotranspirada. Os tratamentos utilizados foram: T1 - Reservatórios sem a presença de plantas de aguapé e sem aplicação de glifosato; T2 - Reservatórios sem a presença de plantas de aguapé e com aplicação de glifosato (Dose 7,0 L ha-1); T3 - Reservatórios com a presença de plantas de aguapé e com aplicação de glifosato (Dose 7,0 L ha-1); T4 - Reservatórios com a presença de plantas de aguapé e sem aplicação de glifosato e T5 - Reservatórios com a presença de plantas de aguapé e com controle por congelamento (nitrogênio líquido). Para aplicação nos reservatórios, empregou-se equipamento de precisão a gás carbônico (CO2), proporcionando vazão a 200 L ha-1. As coletas das amostras de água e de plantas foram realizadas antes da aplicação, logo após a aplicação e nos 2º, 4º, 8º, 16º, 32º e 64º dias após a aplicação. As amostras de água foram submetidas às análises de qualidade (pH, turbidez, condutividade elétrica e oxigênio dissolvido) e de resíduos (glifosato, AMPA e ácido chiquímico). Os resultados mostraram que o glifosato foi eficiente no controle do aguapé; que o uso do glifosato, aplicado diretamente na superfície da água ou sobre as plantas ou no controle do aguapé, não alterou significativamente os parâmetros de qualidade da água analisados; que os teores de resíduos de glifosato encontrados nas análises de água, nos reservatórios com ou sem a presença do aguapé, foram rapidamente degradadas ao longo do tempo. O modelo matemático de decaimento foi aplicado para descrever o decréscimo das concentrações e das cargas do glifosato. Esse modelo permitiu a estimativa da meia-vida do glifosato nos reservatórios entre 6 a 16 dias. Os resultados finais confirmam a hipótese de que o uso do herbicida glifosato no controle do aguapé (Eichhornia crassipes) em ambientes aquáticos fechados não apresenta impacto negativo na qualidade da água e/ou resíduos que impossibilitem o seu uso / Abstract: Seeking to evaluate the environmental impact of glyphosate in the aquatic environment, it was chosen to study in controlled and closed experimental field, the management of water hyacinth (Eichhornia crassipes), and analyzing parameters of water quality and residues of glyphosate. The experiments were conducted in the testing area of NUPAM at the UNESP Faculty of Agronomic Sciences, Botucatu (SP). In the experiment, 20 fiber cement tanks were used, four for each treatment, with storage capacity of 250 L, without replacement of the evapotranspirated water. The procedures for the experiment were: T1 - Tanks without water hyacinth and without glifosato application; T2 - Tanks without water hyacinth and with glyphosate application (dose - 7,0 L ha-1); T3 - Tanks with water hyacinth and with glyphosate application (dose - 7,0 L ha-1); T4 - Tanks with water hyacinth and without glyphosate application; T5 - Tanks with water hyacinth controlled by a freezing process. For application in the tanks, it was used carbon dioxide (CO2) precision equipment, providing an output of 200 L ha-1. Sample collections of water and plants were performed before the application, soon after application and on the 2nd, 4th, 8th, 16th, 32nd and 64th days after application. The samples were subjected to analyses of quality (pH, turbidity, electrical conductivity and dissolved oxygen) and residues (glyphosate, AMPA and shikimic acid). The results have shown the following: glyphosate was efficient to control the water hyacinth; the use of glyphosate, applied directly to the surface of the water or on plants or on water hyacinth control, did not significantly alter water quality parameters analyzed; the residues of glyphosate, AMPA and shikimic acid found in the analysis of water in the tanks, with or without the presence of water hyacinth, quickly degraded over time. The mathematical model of decay was applied to describe the decrease of the concentrations and loads of glyphosate. This model allowed the estimated half-life of glyphosate in the tanks between 6 to 16 days. The final results confirm the hypothesis that the use of glyphosate in the control of water hyacinth (Eichhornia crassipes) in closed aquatic environments has no negative impact on the quality of water and/or residues that prevent its use / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola
46

The Ability of an Aquatic Invader to Uptake Nutrients in an Upstream Estuarine Environment: Implications for Reducing the Intensity and Frequency of Massive Fish Kills in Florida

Kerr, Melissa L. 25 May 2017 (has links)
The purpose of this study was to assess whether nutrient absorption rates by water hyacinths are affected by low-salinity levels. In a controlled experiment, water hyacinths demonstrated the ability to absorb a significant amount of nutrients in low-saline waters while maintaining a slowed growth rate and shortened life span. Nutrient rates were reduced by an average of 36% in ammonia nitrogen and 48% in reactive phosphorus in the tanks of 4.45 parts per thousand (ppt) salinity. Growth rate in the experimental tanks of 4.45 ppt was observed at 33% slower than that of the control. The high salinity comparison tank of 7.0 ppt experienced complete mortality after three days. Phytoremediation practices through the use of an aquatic invader, water hyacinths, can be used to reduce large-scale fish kills along the eastern U.S.’s major estuarine systems, focusing on Florida’s waters. Toxic dinoflagellates and other harmful algal blooms have been plaguing the contributing waterways of North Carolina and the Chesapeake Bay and are the main causes of these massive fish kills. The characteristics and trends that these upstream estuarine systems are following could serve as a warning for Florida. An analysis of Florida’s fish kill database, as well as patterns and trends of the fish kills in North Carolina and the Chesapeake Bay, were used to determine areas at an increased risk for toxic dinoflagellates and harmful algal blooms to occur. Areas are proposed for water hyacinths to be implemented in a controlled method to reduce massive fish kills in Florida’s waters.
47

Ecological effects of water hyacinth (Eichhornia crassipes) on Lake Chapala, Mexico

Villamagna, Amy Marie 15 April 2009 (has links)
Water hyacinth (Eichhornia crassipes) is a floating non-native plant that has been reoccurring in Lake Chapala, Jalisco, Mexico for more than 100 years. In this research, I explore the effects of water hyacinth on freshwater ecosystems worldwide and specifically on Lake Chapala. In chapter 1, I reviewed studies conducted on water hyacinth worldwide and found that the effects of water hyacinth on water quality are similar but the magnitude of effects is dependent on the percent cover and potentially the spatial configuration of water hyacinth mats. Water hyacinth's effect on aquatic invertebrates, fish, and waterbirds is less predictable and dependent on conditions prior to invasion. In chapter 2, I tested for relationships between percent water hyacinth cover and waterbird abundance, species diversity, community composition, and habitat use. In general, I found a weak positive relationship or no relationship between these variables. In Chapter 3, I monitored habitat use by American Coots (Fulica americana) in a variety of habitats around Lake Chapala. I found that the time spent in water hyacinth positively corresponded to the percent water hyacinth cover and that the time foraging in water hyacinth was positively related to the time spent in water hyacinth. In Chapter 4, I compared invertebrate assemblages in open water to those within and at the edge of water hyacinth mats, emergent vegetation, and submerged trees. I also examined invertebrate assemblages within the roots of water hyacinth plants and compared assemblages between patch and shoreline water hyacinth plants. I found that density and taxonomic richness of water column invertebrates were generally higher in association with water hyacinth, but that mean percent cover of water hyacinth affected the magnitude of differences among habitats and vegetation types. I did not find significant differences in root invertebrate density and taxonomic richness between patch and shoreline water hyacinth plants. In chapter 5, I discuss how water hyacinth affected dissolved oxygen and water transparency on a small, localized scale, but was not the driving factor for seasonal differences. The overall results suggest that water hyacinth had a minimal ecological effect on Lake Chapala during this study. / Ph. D.
48

Evaluation of water hyacinth (Eichhornia crassipes) suitability as feedstock for biogas production

Makofane, Rosina 08 1900 (has links)
The suitability of water hyacinth in biogas production was evaluated as a means of waste management in the interests of sustainable energy production. Batch anaerobic digestion (AD) of water hyacinth was conducted to determine the optimal pre-treatment method for maximum methane production. Physical pre-treatment methods produced a highest cumulative methane of 2.3 L during batch AD. The selected pre-treatment method, hand-cutting, was further evaluated in a semi-continuous AD using both mono- and co-digestion. The emphasis was on identifying microbial communities involved and their response to organic loading rates (OLRs). The Illumina Miseq results proved that bacterial communities were more sensitive to disturbances caused by irregular OLRs as compared to archaeal communities. In addition, the variation in substrate nutrients as a result of mono- and co-digestion of water hyacinth, contributed to variations in the bacterial diversity. For example, Bacteroides and Petrimonas diversity varied between mono- and co-digestion. Overall, the study verified that water hyacinth is a suitable feedstock for biogas production and the simple pre-treatment methods are recommended. Furthermore, OLRs influenced the microbial community structure and associated biogas yield. / National Research Foundation (South Africa) / Environmental Science / M. Sc. (Environmental Science)
49

"Is more, less?" : insect-insect interactions in a biological control context using water hyacinth as a model

Weyl, Philip Sebastian Richard January 2012 (has links)
Interactions between insects have been shown to be important regulators of population abundances and dynamics as well as drivers of spatial segregation and distribution. These are important aspects of the ecology of insects used in biological control and may have implications for the overall success of a particular programme. In the history of biological control there has been a tendency to release a suite of agents against a weed, which in some cases has increased the level of success, while in others little change has been observed. In most of these cases the implications of increasing the level of complexity of the system is not taken into account and there is little research on the effect of releasing another agent into the system. A brief meta-analysis was done on all the biological control programmes initiated in South Africa. Emphasis was placed on multi-species releases and the effects that overlapping niches were having on the number of agents responsible for the success of a programme. Where overlapping niches were present among agents released the number of agents responsible for success was lower than the number established. Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach in South Africa has more arthropod agents released against it than anywhere else in the world, yet control has been variable. If the biology and host utilisation of all the agents against water hyacinth is considered, a definite overlap of niches is apparent in at least one life stage of all the agents. Therefore the probability of these insects interacting is high, especially if they are established at the same site in the field. Three of the insects released in South Africa have been selected to investigate possible interactions. They are Neochetina eichhorniae Warner, Neochetina bruchi Hustache and Eccritotarsus catarinensis (Carvalho). Y-tube olfactometer bioassays were used to measure responses of these insects to water hyacinth with prior feeding damage by either conspecifics or heterospecifics. This was done to determine whether olfactory cues played a role in host acceptability and avoidance of conspecifics or heterospecifics. The insects were given a choice between damaged and undamaged plants in various combinations. There was a significant preference for the undamaged plants when given a choice between undamaged and damaged plants. However when the insects were given a choice between two damaged plants there was no discrimination between heterospecific or conspecific damaged plants. This may indicate that there is little or no ecological cost for the insect to share a plant with other insects utilising a similar resource. Insect – insect interactions were investigated in a common garden plot experiment to measure the impact that pairwise combinations of the insect may have on their performance. There was a significant interaction between the mirid E. catarinensis and the weevil N. eichhorniae, with the weevil not performing as well when in combination with the mirid than when alone. Interestingly there was a negative interaction between the two weevil species when in combination, however it was impossible to determine which species was being affected if not both. None of the insects performed significantly better when in combination with another insect. A field study on Wriggleswade Dam in the Eastern Cape, South Africa was initiated to determine whether the relationship between the mirid E. catarinensis and the weevil N. eichhorniae could be determined in the field. The performance of the insects at the different sites in the field suggests that there was an interaction between the agents. This interaction did not limit the establishment of either insect at a site, but it did result in one insect dominating at a site over another. Interactions between the three species of insect tested in this thesis suggest that there are both negative and neutral relationships between them. A basic comparison between the insect performances from 15 sites around the country was done to determine if the spatial segregation observed in the field could be extrapolated to the natural South African situation. The interaction observed between N. eichhorniae and E. catarinensis does seem to extrapolate to the general South African situation where there is definite spatial segregation on a landscape level. The co–occurrence of the two Neochetina weevils at these sites suggests that the negative relationship observed between them in the common garden experiment does not extrapolate to the field. The results from this thesis suggest that the interactions between the agents tested would not limit establishment or have significant ramifications on performance. However, there may be spatial and temporal segregation of these species in the introduced range.
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Uso de aguapé (Eichhornia crassipes) em sistema de tratamento de efluente de matadouro e frigorífico e avaliação de sua compostagem

Mees, Juliana Bortoli Rodrigues 27 March 2006 (has links)
Made available in DSpace on 2017-07-10T19:24:44Z (GMT). No. of bitstreams: 1 Juliana Bortoli Rodrigues Mees.pdf: 2709034 bytes, checksum: 02264027f5193bac921eb872df0081a9 (MD5) Previous issue date: 2006-03-27 / The objective of the recent research was to evaluate the water hyacinth performance (E. crassipes), applied in situ in a slaughter house treatment system, located in the west of the Paraná state, observing the nutrients removal (nitrogen composts and total phosphorus), organic matter (COD and BOD), turbidity and suspended solids, obtaining as well data from the production, management and composting practices of the biomass generated in the system. The plants were introduced into the forth tank of the industry stabilization lagoons system, covering 35m2 of the total area delimitated for the experiment: 870m2. During a period of 11 months (47 weeks) of water hyacinth development, physic and chemical parameters were monitored monthly and meteorological parameters were monitored daily or weekly. In order to search information about the degradation of the water hyacinths removed from the treatment, another experiment was conduced in plant pilot. Eight composting piles were built measuring approximately 0.60m3, with four distinct treatments that were done twice. The treatments were T1 - Water hyacinth (E. crassipes), T2 - Water hyacinth and swine excrement (7:1), T3 - Water hyacinth, swine excrement and earth (7:1:0,67), T4 - Water hyacinth, swine excrement and cellulosic gut (7:1:0,67), for a period of 90 days. The temperature was monitored daily, and humidity, cinder, nitrogen and total organic carbon were monitored monthly. The result obtained, during 11 months, were promising and the efficient averages of 26.3% of COD and 32.5% of BOD removal were observed, with a maximum removal of 77.2% of COD and 77.87% of BOD. About the nutrient removal, a 21.2% average of nitrogen removal was observed, with a maximum removal of 87.9%, an 11.0% average for ammoniac nitrogen, with maximum of 47.5%, and an 11.1% average and maximum of 38.9% for total phosphorus, during an average of 5 days of retention. An increase in the water turbidity was noticed during the months of high pluviometric precipitation; however, the efficiency of the process was positive during all the monitoring period, with a maximum removal of 58.1%. Considering the C/N relation as a compost maturity indicator, the T4 treatment (water hyacinth, swine excrement and cellulosic gut) had the shorter period of stabilization: 60 days. / O presente trabalho teve por objetivo avaliar o desempenho da macrófita aquática (Eichhornia crassipes), aplicada in situ em sistema de tratamento de um matadouro e frigorífico, localizado no Oeste do Estado do Paraná, com relação à remoção de nutrientes (formas de nitrogênio e fósforo total), matéria orgânica (DBO e DQO), turbidez e sólidos sedimentáveis, bem como obter dados da produção, de práticas de manejo e compostagem da biomassa gerada no sistema. As plantas foram introduzidas na quarta célula do sistema de lagoas de estabilização da indústria, ocupando 35m2 da área total delimitada para o experimento: 870m2. Durante o período de 11 meses (47 semanas) de desenvolvimento das macrófitas na lagoa, realizou-se o monitoramento de parâmetros físico-químicos, analisados com freqüência mensal e parâmetros meteorológicos, coletados com freqüência diária e/ou semanal. Com intuito de buscar informações sobre a degradação das macrófitas retiradas do sistema de tratamento, foi conduzido um experimento em planta piloto, montando-se oito leiras de compostagem com aproximadamente 0,60m3, com quatro tratamentos distintos, sendo: T1 - Aguapé (E. crassipes), T2 - Aguapé e dejeto suíno (7:1), T3 - Aguapé, dejeto suíno e terra (7:1:0,67), T4 - Aguapé, dejeto suíno e tripa celulósica (7:1:0,67), por um período de 90 dias, monitorando-se semanalmente a temperatura, e mensalmente a umidade, cinzas, nitrogênio e carbono orgânico total. Os resultados obtidos, durante os 11 meses do experimento, foram promissores e observou-se uma eficiência media de remoção de DQO de 26,3% e de DBO de 32,5%, com remoção máxima de DQO de 77,2% e de DBO de 77,8%. Em relação aos nutrientes, observou-se uma remoção média de nitrogênio total de 21,2% com máxima de 87,9%, de nitrogênio amoniacal de 11,0% com máxima de 47,5% e de fósforo total de 11,1% com máxima de 38,9%, para um tempo médio de retenção de cinco dias. Com relação à turbidez, observou-se aumento da turbidez afluente nos meses com maior índice de precipitação pluviométrica, contudo a eficiência manteve-se positiva durante todo período de monitoramento, com remoção máxima de 58,1%. Considerando a relação C/N como um indicador da maturidade do composto, observou-se que o tratamento T4 (aguapé, dejeto e tripa celulósica) obteve o menor período de estabilização do composto orgânico: 60 dias.

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