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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.
171

Determination of the relationship between epiphytes and selected filamentous bacteria in activated sludge

Conco, Thobela January 2016 (has links)
Submitted in fulfillment for the Degree of Masters of Applied Sciences (Biotechnology), Durban University of Technology, Durban, South Africa, 2016. / Activated sludge (AS) flocs are paramount in biological treatment of wastewater, are comprised of microbial consortia with organic and inorganic material bound together by extra polymeric substances (EPS). The filamentous bacteria play a vital role in the floc formation process by providing the necessary structural support. Presence of epiphytic attachment on selected filamentous bacteria is a commonly occurring phenomenon in activated sludge samples. Different theories have been proposed to describe this phenomenon; however, not much research has been carried out to explore the profundity of the attachment. In this study, an attempt has been made to elucidate the intrinsic nature of the epiphytic attachment between the bacterial rods and filamentous bacteria based on microscopic (morphological and structural) analysis. Characterization of these epiphytes were performed using fluorescence in situ hybridization (FISH) at group level using Alpha, Beta and Gamma Proteo-bacterial probes. Morphological characteristics of filament hosts and the bacterial rods at the interface region was assessed using scanning electron microscopy (SEM). The SEM micrographs indicated that the attachment was facilitated by more than the EPS layer. Further ultrastructural examination using transmission electron microscopy (TEM) indicated a possible cell-to-cell interaction between epiphytes and the selected filaments. Fibrillar structures resembling amyloid-like proteins were observed within the filament cell targeted by the epiphytes. An interaction was apparent between the amyloid like proteins and the epiphytes as exhibited by the direction of fibrillar structures pointing towards the approaching epiphytes. Common bacterial appendages such as pili and fimbria were absent at the interface and further noted was the presence of cell membrane extensions on the epiphytic bacteria protruding towards the targeted filamentous cell. The sheath of host filaments however, remained intact and unpenetrated, during colonization. Amyloid-like fibrils at interface may potentially play the role of attachment sites for the attaching epiphytes, as attachment facilitating appendages were not visualized. / M
172

Estudo de degradação térmica e caracterização de lodos provenientes de diferentes sistemas de tratamento de esgotos /

Torquato, Lilian Danielle de Moura. January 2012 (has links)
Orientador: Marisa Spirandeli Crespi / Banca: Valdir Schalch / Banca: Wellington Cyro de Almeida Leite / Resumo: Neste trabalho foram caracterizadas as amostras de lodo dos sistemas de tratamento de efluentes sanitários de Araraquara-SP e São José do Rio Preto-SP com o intuito de: 1- investigar, por meio de técnicas termoanalíticas (TG/DTG, DTA e DSC), a ocorrência dos eventos que compreendem sua degradação térmica, além da obtenção de parâmetros que norteiam o entendimento da cinética dessa degradação; 2- avaliar os aspectos estruturais e morfológicos das partículas sólidas que os compõem, com o suporte de técnicas como: DRX, EDX, EAA, IV, EDL e MEV. A amostra de lodo LM (ETE Araraquara) apresentou apenas 7% de perda de massa atribuída à presença de matéria orgânica, com caráter predominantemente cristalino reafirmado por todas as técnicas utilizadas. Em relação às amostras LU e LF (ETE São José do Rio Preto), pôde-se observar o caráter predominantemente amorfo por DRX confirmado por perfis de decomposição térmica muito semelhantes com perda de massa de até 57% referente ao conteúdo orgânico. A aplicação do método isoconversional de Flynn-Wall-Ozawa revelou diferenças na cinética de degradação entre as amostras LU e LF atribuídas à presença da poliacrilamida aplicada no processo de desidratação do lodo. Observou-se ainda a ocorrência de efeito de compensação cinética, que indica um esquema de degradação similar em todo o intervalo estudado, apesar de sua composição complexa. Este efeito também foi relatado para resíduos de outras origens, sugerindo que estes apresentam conteúdo orgânico similar durante sua degradação térmica. No que diz respeito à caracterização morfológica, verificou-se congruência entre a distribuição dos tamanhos das partículas e as imagens obtidas por MEV para todas amostras e os metais Zn, Ni, Cu e Cr identificados por EDX, foram quantificados em... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work were employed sludge samples of wastewater treatment systems (WWTS) from Araraquara-SP and São José do Rio Preto-SP, whose characterization was performed in order: 1 - to investigate, by means of thermoanalytical techniques (TG / DTG, DTA and DSC), the occurrence of events which include thermal degradation, in addition to obtaining parameters that guide the understanding of the kinetics of this degradation; 2 - to evaluate the structural and morphological aspects of the solid particles that compose them, with the support of techniques such as: XRD, XDE, AAS, IR, SEM and DLS XRD. The sludge sample caled LM (WWTS Araraquara) showed only 7% mass loss attributed to the presence of organic matter, with a crystalline prevailing character reaffirmed by all techniques used. As regards the samples LU and LF (WWTS São José do Rio Preto), it was observed the amorphous predominantly character by XRD confirmed by very similar decomposition profiles which presented mass loss of up to 57% assigned to the organic content. The Flynn-Wall-Ozawa isoconversional method application revealed differences in kinetics degradation between samples LU and LF attributed to the presence of polyacrylamide applied in the sludge dewatering process. It was also noted the occurrence of kinetic compensation effect, indicating a similar degradation scheme in the whole range studied, although its complex composition. This effect was also reported for other sources of waste, suggesting a similar organic contents during their thermal degradation. In the morphological characterization it was possible to verify agreement between the particle sizes distribution and the SEM images obtained for all samples. Furthermore, metals Zn, Ni, Cu and Cr identified by XDE have been quantified in concentrations less than these recommended by national... (Complete abstract click electronic access below) / Mestre
173

La métagénomique, un outil pertinent pour évaluer l'impact de différentes pratiques agricoles sur les communautés microbiennes du sol / Metagenomics, a relevant tool for assessing the impact of different agricultural practices on soil microbial communities

Alahmad, Abdelrahman 12 December 2017 (has links)
Selon les projections démographiques de la FAO, la population mondiale atteindra 9 milliards de personnes d'ici 2050. Cette augmentation sera associée à une demande accrue de produits agricoles et à une augmentation de la production de déchets. Par conséquent, des approches alternatives dans les pratiques agricoles, tels que l'utilisation permanente de la couverture végétale et/ou l'application de boues d'épuration, sont envisagées pour répondre aux exigences mondiales et préserver l'environnement. Ces nouvelles pratiques pourraient influencer le fonctionnement et les propriétés du sol et des organismes microbiens présents dans cet environnement. Par conséquent, passer de l'agriculture intensive à une agriculture écologiquement intensive pourrait entraîner des modifications de la biodiversité des sols. En utilisant différents systèmes expérimentaux permettant une comparaison entre différentes pratiques agricoles, des études de la diversité microbienne taxonomique et fonctionnelle du sol (bactéries et champignons) ont été entreprises. La diversité taxonomique des organismes microbiens a été obtenue par séquençage à haut débit des régions hypervariables des gènes codant l'ARN16S et l'ITS1. Nous avons évalué les rôles écologiques des microorganismes du sol en utilisant des identifications taxonomiques, puis des études permettant d'examiner leur physiologie et leurs fonctions par rapport à différentes propriétés physicochimiques du sol. Nous avons constaté que la fertilisation azotée avait une incidence négative sur la diversité microbienne du sol et modifié leur fonctionnalité. Ces effets peuvent être modulés par l'utilisation de PPC ou l'application de boues. Ces travaux indiquent que les pratiques agricoles conventionnelles ont un impact sur la biodiversité microbienne du sol et peuvent être remplacées par des pratiques agricoles plus respectueuses de l'environnement afin de préserver l'écosystème et ses services / According to demographic projections, world population will reach 9 billion people by 2050. This increase will be associated with higher demand of agricultural products and an increase in wastes production. Therefore, alternative approaches in agricultural practices; such as permanent plant cover usage and/or sewage sludge application, are envisaged to meet global demands and preserve the environment. These new practices could therefore influence the properties of the soil and its functioning. Therefore moving from intensive to ecologically intensive agriculture could lead to modifications in soil biodiversity. Using different experimental systems allowing comparison between different agricultural practices, studies of the taxonomic and functional soil microbial diversity (bacteria and fungi) had been undertaken. This was achieved by next generation high-throughput sequencing of the hypervariable regions of the genes encoding RNA16S and ITS1. Sequencing was performed using an Illumina platform and the sequences obtained were analyzed using various bioinformatic tools. We inferred the ecological roles of soil micro-organisms by using taxonomic identifications, moving on to the examination of their physiology and functions in comparison with different soil physiochemical properties. We found that nitrogen fertilization negatively impacted the soil microbial diversity and altered their functionality. These negative effects have been modulated by the PPC usage or SS application. Proving that conventional agricultural practices effects the soil biodiversity and can be replaced by ecofriendly farming applications in order to preserve the ecosystem and its services
174

Detecção e quantificação de ovos viáveis de Ascaris sp e outros ovos de helmintos em lodo de esgoto / Detection and quantification of Ascaris sp and other helminth eggs in sewage sludge.

Bastos, Veridiana Karmann 08 February 2012 (has links)
Introdução O lodo gerado em estações de tratamento de esgotos é um resíduo de composição variável e com potencial poluidor dependendo de sua origem, tipo de tratamento e sazonalidade; pode conter patógenos dentre os quais os parasitas. Porém, quando tratado adequadamente, o lodo de esgoto pode ser aplicado na agricultura como fertilizante ou condicionador de solo. Em países em desenvolvimento, estudos têm demonstrado que a incidência de enteroparasitoses é elevada, sendo Ascaris sp um dos mais prevalentes. Portanto, o uso agrícola do lodo de esgoto pode oferecer riscos à saúde humana. Com intuito de salvaguardar a saúde da população entrou em vigor a Resolução CONAMA nº375/06, que estabelece critérios e procedimentos para o uso do lodo em áreas agrícolas. Objetivo - Determinar e quantificar ovos de helmintos e de Ascaris sp em lodos provenientes de três ETEs de uma região metropolitana, verificando o atendimento ao padrão parasitológico estabelecido pela CONAMA nº375/06. Método Utilizou-se o método descrito no apêndice I da norma CFR 503 USEPA de 2003. Resultados Os lodos analisados no período do estudo apresentaram rica fauna parasitária onde foram observados ovos de Ancylostoma sp, Ascaris sp, Capillaria sp, Enterobius vermicularis, Fasciola hepatica, Hymenolepis sp, Taenia sp, Toxocara sp e Trichuris sp. Observou-se que ovos de Ascaris sp foram os mais prevalentes com 67,71 por cento , seguido por Toxocara sp (13,62 por cento ). Ovos viáveis de Ascaris sp estavam presentes em 10,16 por cento das amostras. Conclusão Pode-se concluir que o lodo gerado nas ETEs estudadas apresentaram amplo espectro de ovos de helmintos, sendo Ascaris sp o mais prevalente. Das três ETEs analisadas, nenhuma atendia os parâmetros parasitológicos para lodo classe A, segundo a Resolução CONAMA nº375/06 / Introduction: Sewage sludge from wastewater treatment plants (WWTP) presents a diverse composition and is a source of pollution depending on its origin, type of treatment and seasonality; moreover it can contain a large variety of pathogens including parasites. However, if this residue is submitted to an efficient treatment, it can be used as a fertilizer and soil conditioner. Some epidemiologic studies conducted in developed countries demonstrated a high incidence of enteroparasitosis, being Ascaris sp the most prevalent. Therefore, the use of sewage sludge in the agriculture can bring risks to the human health. In order to protect the population health, a recent Brazilian regulation, Rule CONAMA 375/2006, has established standards regarding its use in agricultural areas. Objective To detect and quantify Ascaris sp and other helminth eggs in sewage sludge from three wastewater treatment plants from a metropolitan region and also to verify the compliance with CONAMA standards. Method The analysis were carried out according to appendix F of CRF 503 USEPA 2003. Results All samples presented a rich parasitological fauna such as eggs of Ancylostoma sp, Ascaris sp, Capillaria sp, Enterobius vermicularis, Fasciola hepatica, Hymenolepis sp, Taenia sp, Toxocara sp and Trichuris sp. Non-viable Ascaris sp eggs were prevalent with 67.71 per cent , followed by Toxocara sp (13.62 per cent ).Viable Ascaris sp eggs were present in 10.16 per cent of the samples. Conclusion It was concluded that the sludge samples analyzed presented a large variety of helminth eggs, being Ascaris sp the most prevalent. None of the three WWTPs met CONAMA parasitological standards for class A sewage sludge
175

Utilisation of animal wastes and sewage sludges and their subsequent effects on higher trophic levels in food chains.

January 1981 (has links)
by Cheung Yun Hing Richard. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1981. / Bibliography: leaves 182-206.
176

Nitrogen-cycle dynamics of a waste recycling oyster culture system.

Riker, Diane Holbert January 1978 (has links)
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1978. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 29-30. / B.S.
177

Níveis de lodo de esgoto no desenvolvimento, nutrição e produtividade da cultura do girassol

Lobo, Thomaz Figueiredo [UNESP] 08 December 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-08Bitstream added on 2014-06-13T19:07:32Z : No. of bitstreams: 1 lobo_tf_me_botfca.pdf: 211179 bytes, checksum: 0c0444539289f4a553456a621bf9f544 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O experimento foi conduzido na Fazenda São Manuel da Faculdade de Ciências Agronômicas da UNESP Campus de Botucatu, localizada no município de São Manuel. O objetivo foi avaliar a eficiência do lodo de esgoto como fonte de N à cultura do girassol. Adotou-se o delineamento experimental em blocos casualizado constituído por 6 tratamentos e 5 repetições. Os tratamentos foram: T0 - adubação mineral de acordo com o boletim 100, mas sem N; T1 - adubação química de acordo com o boletim técnico 100 do IAC; T2 - foi utilizado 50% do N proveniente do lodo de esgoto e o restante foi proveniente da adubação química; T3 - foi utilizado 100 % do N proveniente do lodo de esgoto; T4 - foi utilizado 150% do N proveniente do lodo de esgoto; T5 - foi utilizado 200% do N proveniente do lodo de esgoto. O cálculo do N proveniente do lodo de esgoto foi feito levado em consideração a sua taxa de mineralização do nitrogênio durante o ciclo da cultura. Utilizou-se o lodo de esgoto da Estação de Tratamento de Esgoto da cidade de Jundiaí/SP. A fonte de N químico adotado foi a uréia, a fonte de K foi cloreto de potássio, a fonte de P adotado foi o superfosfato simples, a fonte de B foi o ácido bórico. Cada parcela teve 100 m2 com um espaço de 3 m entre uma parcela e outra do mesmo bloco. O espaço entre blocos foi de 1,8 m. Foi utilizado o híbrido simples HELIO 251. Foi aplicado o lodo de esgoto nos tratamentos, 2 seguindo-se a incorporação com grade e posteriormente semeado o girassol. O girassol foi plantado em um espaçamento de 0,9 metros entre linha e 30 cm entre plantas, as adubações com P e K foram feitas no plantio de acordo com a análise de solo. O N foi feito logo após o plantio e no tratamento onde não foi efetuado a utilização do lodo de esgoto. Foi realizada uma cobertura nitrogenada... / The experiment was carried out at São Manuel Farm from Faculdade de Ciencias Agronomicas - UNESP, Botucatu, located in the city of São Manuel. The aim of the experiment was to evaluate the sewage sludge efficiency as a source of N for sunflower culture. An experimental outlining in radomized blocks was adopted, formed by 6 treatments and 5 repetitions. The treatments were as it follows: T0 - mineral fertilization according to bulletin 100 but without N; T1 - chemical fertilization according to IAC technical bulletin 100; T2 - 50% of Nitrogen from sewage sludge were used and the complementary part was obtained from chemical fertilization; T3 - 100% of Nitrogen from sewage sludge were used; 4 T4 - 150% of Nitrogen from sewage sludge were used; T5 - 200% of Nitrogen from sewage sludge were used. The calculation of nitrogen from sewage sludge was done considering its Nitrogen mineralization rate during the culture cycle. The sewage sludge was obtained from thre Sewage Treatment Station in the city of Jundiai - SP. The source of chemical N adopted was urea, the source of K was Potassium chloride, the source of P adopted was simple superphosphate, the source of B was Boric acid. Each part had 100 m2 with a space of 3 m between the parts in a same block. The space between blocks was 1,8 m. HELIO 251 simple hybrid was used. The sewage sludge was applied to the treatments, after that, an incorporation was made with a grid and the sunflower was sown. The sunflower was planted in a spacement of 0,9 meters betwen lines and 30 cm betwen plants, the fertilization with P and K was done at planting according to the soil analysis N was applied right after planting to the treatment where sewage sludge wasn t used. A nitrogenated coating was also done... (Complete abstract, click electronic access below)
178

Bioleaching of heavy metals from anaerobically digested sewage sludge using isolated indigenous iron- and sulphur-oxidizing bacteria

Chan, Lau Chi 01 January 2001 (has links)
No description available.
179

Detecção e quantificação de ovos viáveis de Ascaris sp e outros ovos de helmintos em lodo de esgoto / Detection and quantification of Ascaris sp and other helminth eggs in sewage sludge.

Veridiana Karmann Bastos 08 February 2012 (has links)
Introdução O lodo gerado em estações de tratamento de esgotos é um resíduo de composição variável e com potencial poluidor dependendo de sua origem, tipo de tratamento e sazonalidade; pode conter patógenos dentre os quais os parasitas. Porém, quando tratado adequadamente, o lodo de esgoto pode ser aplicado na agricultura como fertilizante ou condicionador de solo. Em países em desenvolvimento, estudos têm demonstrado que a incidência de enteroparasitoses é elevada, sendo Ascaris sp um dos mais prevalentes. Portanto, o uso agrícola do lodo de esgoto pode oferecer riscos à saúde humana. Com intuito de salvaguardar a saúde da população entrou em vigor a Resolução CONAMA nº375/06, que estabelece critérios e procedimentos para o uso do lodo em áreas agrícolas. Objetivo - Determinar e quantificar ovos de helmintos e de Ascaris sp em lodos provenientes de três ETEs de uma região metropolitana, verificando o atendimento ao padrão parasitológico estabelecido pela CONAMA nº375/06. Método Utilizou-se o método descrito no apêndice I da norma CFR 503 USEPA de 2003. Resultados Os lodos analisados no período do estudo apresentaram rica fauna parasitária onde foram observados ovos de Ancylostoma sp, Ascaris sp, Capillaria sp, Enterobius vermicularis, Fasciola hepatica, Hymenolepis sp, Taenia sp, Toxocara sp e Trichuris sp. Observou-se que ovos de Ascaris sp foram os mais prevalentes com 67,71 por cento , seguido por Toxocara sp (13,62 por cento ). Ovos viáveis de Ascaris sp estavam presentes em 10,16 por cento das amostras. Conclusão Pode-se concluir que o lodo gerado nas ETEs estudadas apresentaram amplo espectro de ovos de helmintos, sendo Ascaris sp o mais prevalente. Das três ETEs analisadas, nenhuma atendia os parâmetros parasitológicos para lodo classe A, segundo a Resolução CONAMA nº375/06 / Introduction: Sewage sludge from wastewater treatment plants (WWTP) presents a diverse composition and is a source of pollution depending on its origin, type of treatment and seasonality; moreover it can contain a large variety of pathogens including parasites. However, if this residue is submitted to an efficient treatment, it can be used as a fertilizer and soil conditioner. Some epidemiologic studies conducted in developed countries demonstrated a high incidence of enteroparasitosis, being Ascaris sp the most prevalent. Therefore, the use of sewage sludge in the agriculture can bring risks to the human health. In order to protect the population health, a recent Brazilian regulation, Rule CONAMA 375/2006, has established standards regarding its use in agricultural areas. Objective To detect and quantify Ascaris sp and other helminth eggs in sewage sludge from three wastewater treatment plants from a metropolitan region and also to verify the compliance with CONAMA standards. Method The analysis were carried out according to appendix F of CRF 503 USEPA 2003. Results All samples presented a rich parasitological fauna such as eggs of Ancylostoma sp, Ascaris sp, Capillaria sp, Enterobius vermicularis, Fasciola hepatica, Hymenolepis sp, Taenia sp, Toxocara sp and Trichuris sp. Non-viable Ascaris sp eggs were prevalent with 67.71 per cent , followed by Toxocara sp (13.62 per cent ).Viable Ascaris sp eggs were present in 10.16 per cent of the samples. Conclusion It was concluded that the sludge samples analyzed presented a large variety of helminth eggs, being Ascaris sp the most prevalent. None of the three WWTPs met CONAMA parasitological standards for class A sewage sludge
180

Parameter uncertainty and modeling of sludge dewatering in one dimension

Plaskett, Joseph H. 01 January 1992 (has links)
Separation of liquid from solids is a necessary step in the ultimate disposal of wastewater sludges. Most commonly, sludges are dewatered by pressure-filtration methods. Mathematical models of the physics of the sludge dewatering process would provide the ability to predict dewatering performance and optimize the design and operation of dewatering facilities.

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