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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.
261

Abordagem teórica do processo de geração de biometano a partir de resíduos agroindustriais / Theoretical approach to the process of generating biomethane from agroindustrial waste

Silva, Cristine Brandt da 30 March 2017 (has links)
Capes; CNPq / A geração de energia renovável desafia as empresas a envolver um processo em cadeia, no qual, todos os elos são corresponsáveis pela geração de novos produtos, processos, e pelo consumo e produção responsável, protegendo o meio ambiente e melhorando a vida das pessoas com que mantém interações. A presente pesquisa objetivou propor uma abordagem teórica do processo de geração de biometano a partir de resíduos agroindustriais. Para a realização da abordagem teórica, foi construído um Portfólio Bibliográfico e adotadas técnicas de revisões sistemáticas de literatura, para assegurar que estudos recentes e relevantes sobre o tema da pesquisa fossem capturados. A abordagem teórica foi dividida em três principais fases, sendo que a primeira fase do processo de geração de biometano incluiu a escolha, o pré-tratamento e o transporte do material orgânico até o biodigestor. A segunda fase do processo incluiu decisões como, a escolha do modelo do biodigestor e a utilização final do biofertilizante e do biogás gerado. Por fim, a terceira fase do processo de geração de biometano incluiu decisões como, a escolha da tecnologia a ser utilizada para o processo de purificação, e o uso final do biometano. O processo de geração de biometano a partir de resíduos agroindustriais, é um tema de poucas publicações no Brasil. O uso do biometano em países como Alemanha, Reino Unido e Suécia, está em um estágio consideravelmente avançado em relação a legislação e tecnologias, comparado ao Brasil. Desta forma, a proposta formulada neste estudo, auxilia acadêmicos, pesquisadores e gestores na área, na compreensão do processo como um todo e na tomada de decisões sustentáveis. / Renewable energy generation challenges companies to engage in a chain process in which all links are co-responsible for the generation of new products, processes and responsible consumption and production, protecting the environment and improving the lives of people with whom Interactions. The present research aimed to propose a theoretical approach of the biomethane generation process from agroindustrial waste. For the accomplishment of the theoretical approach, a Bibliographic Portfolio was constructed and techniques of systematic literature reviews were adopted to ensure that recent and relevant studies on the research topic were captured. The theoretical approach was divided into three main phases, and the first phase of the biomethane generation process included the selection, pretreatment and transport of the organic material to the biodigester. The second phase of the process included decisions such as the choice of biodigester model and the final use of biofertilizer and biogas generated. Finally, the third phase of the biomethane generation process included decisions such as the choice of technology to be used for the purification process and the final use of biomethane. The process of generating biomethane from agro-industrial waste is a subject of few publications in Brazil. The use of biomethane in countries such as Germany, the United Kingdom and Sweden is at a considerably advanced stage compared to legislation and technologies compared to Brazil. Thus, the proposal of this study assists academics, researchers and managers, in understanding the process as a whole and in making sustainable decisions.
262

Logística reserva aplicada aos resíduos de informática : uma investigação nas IFES de Sergipe

Tunes, Elisiane Carra 08 August 2014 (has links)
This study examines how the reverse logistics is being used in the final destination of informatics equipment and supplies post-consumer at the central campi of federal institutions of higher education in Sergipe: Universidade Federal de Sergipe (UFS) and Instituto Federal de Sergipe (IFS). Specifically, it was sought to: a) measure the degree of knowledge of managers responsible for the management of waste electronic equipment on the legal instruments and programs of the Federal Government aimed at managing these wastes; b) describe the process of managing and disposing of waste equipment and computer supplies in federal institutions of higher education of Sergipe; c) determine the similarities and differences in the disposal process of waste equipment and computer supplies between UFS and IFS; d) identify alternatives to improve the management and disposal process of these wastes in the federal institutions of higher education of Sergipe. As methodological aspects, the study is classified as exploratory, descriptive and qualitative, whose research strategy adopted was the study of multiple cases. Regarding the time dimension, the research is cross-sectional. In data collection were applied semi-structured interviews with the managers of the institutions surveyed. Document analysis and direct non-participant observation were used as other sources of evidence. The results revealed that public managers have low degree of knowledge regarding the concepts, legal instruments and federal government programs aimed at disposal of these wastes. Waste management equipment at both institutions have similar procedures. However, the management of post-consumer supplies is distinct, and the final disposition offered to equipment and computer supplies. It was concluded that reverse logistics is still not used at IFES in Sergipe due to the following factors: i) the inapplicability of sectoral agreements between public and private power (they exist but are not yet in force); ii) the refusal by the specific program of the Federal Government to receive donations of equipment and supplies of the institutions surveyed. Among the possible improvements in this process, it can be listed the elaboration of normative instructions, the integrated action of all responsible sectors and the elaboration of an agreement for the Brazilian federal agencies having as a guiding model the Computers Inclusion Programme. / Este estudo analisa a forma como a Logística Reversa (LR) está sendo utilizada na destinação final dos equipamentos e suprimentos de informática pós-consumo dos campi sede nas Instituições Federais de Ensino Superior (IFES) de Sergipe: a Universidade Federal de Sergipe (UFS) e o Instituto Federal de Sergipe (IFS). Especificamente, buscou: a) mensurar o grau de conhecimento dos gestores responsáveis pelo gerenciamento dos resíduos de equipamentos eletrônicos sobre os instrumentos jurídicos e os programas do Governo Federal voltados à gestão desses resíduos; b) descrever o gerenciamento e o processo de disposição final dos resíduos de equipamentos e suprimentos de informática nas Instituições Federais de Ensino Superior de Sergipe; c) verificar as semelhanças e diferenças no processo de disposição final dos resíduos de equipamentos e suprimentos de informática entre a UFS e o IFS; e d) identificar alternativas para melhora no processo de gerenciamento e disposição final destes resíduos nas IFES de Sergipe. Quanto aos aspectos metodológicos, o estudo é classificado como exploratório, descritivo e qualitativo, cuja estratégia de pesquisa adotada foi o estudo de casos múltiplos. Em relação à dimensão tempo, a pesquisa é de corte transversal. Na coleta de dados aplicaram-se entrevistas com roteiros semiestruturados aos gestores das Instituições pesquisadas. Foram utilizadas análise de documentos e observação direta não participante como outras fontes de evidências. Os resultados revelaram que os gestores públicos possuem reduzido grau de conhecimento no que se refere a conceitos, instrumentos jurídicos e programas do Governo Federal voltados ao descarte de resíduos de equipamentos eletroeletrônicos (REEE). O gerenciamento dos resíduos de equipamentos nas duas instituições possuem trâmites semelhantes. Entretanto, a gestão dos suprimentos pós-consumo é distinta, bem como a disposição final oferecida aos equipamentos e suprimentos de informática. Concluiu-se que a logística reversa ainda não é utilizada nas IFES de Sergipe em função dos seguintes fatores: i) a inaplicabilidade dos acordos setoriais entre poder público e privado (eles existem, mas ainda não estão vigorando); ii) a recusa por parte do programa específico do Governo Federal em receber doações de equipamentos e suprimentos das instituições pesquisadas. Dentre as possíveis melhorias neste processo, pode-se elencar a elaboração de instruções normativas, a ação integrada de todos os setores responsáveis e a elaboração de um convênio para os órgãos federais brasileiros tendo como modelo norteador o Programa Computadores para Inclusão.
263

Estudos sobre misturas de agregados reciclados de resíduos da construção civil com solos para utilização em pavimentos

Santana, Fagner Ismael Teixeira de 10 April 2014 (has links)
The growth of the construction industry in Brazil has resulted in increasing of construction and demolition wastes generation (CDW). Given this fact, various studies and researches have been conducted in order to mitigate or even extinguish the undesirable impacts caused by improper disposal of these wastes on the environment. On the other hand, the road infrastructure constructions, in general, consume large amounts of natural resources, that have become scarce in many regions of the country. But fortunately, it is worth noting that this construction area has a favorable history about incorporation of wastes in your construction process, and CDW is the most prominent. Against this background, with this research sought to evaluate the geotechnical properties of CDW recycled aggregates produced by a recycling plant in the Aracaju metropolitan region (AMR), preparing mixtures of these materials with two typically soils of Sergipe state. Therefore, tests were conducted to evaluate the composition and percentage of impurities, gradation, Atterberg limits, absorption, abrasion resistance, bulk density, grain form, compaction, degradation, califórnia bearing ratio and resiliente modulus. Based on results, obtained using the intermediate compaction energy, it was found that the CDW recycled aggregates provided significant improvements in the soils properties, expressed by satisfactory mechanical performance observed in the CBR and RM parameters of mixtures. The results presented in this research indicate and ratify the technical feasibility of using the CDW in base and sub-base pavements layers, which can contribute to sustainable development, increasing the materials supply and a application methodology in AMR and Sergipe urban roads constructions, in addition to resulting in decreased extraction of natural materials and areas of final disposal of such wastes. / O crescimento da indústria da construção civil no Brasil tem resultado no aumento crescente da geração de resíduos de construção e demolição (RCD). Diante desse fato, diversos estudos e pesquisas têm sido realizados com a finalidade de amenizar ou até mesmo extinguir os impactos indesejáveis causados pela deposição inadequada desses resíduos no meio ambiente. Por outro lado, as obras de infraestrutura rodoviária, em geral, consomem grandes quantidades de recursos naturais, que já se tornam escassos em diversas regiões do país. Mas, felizmente, cabe destacar que essa área da construção já possui um favorável histórico de incorporação de resíduos no seu processo construtivo, sendo o RCD o de maior destaque. Diante deste cenário, com esta pesquisa procurou-se avaliar as propriedades geotécnicas de agregados reciclados de RCD produzidos em uma usina recicladora da região metropolitana de Aracaju (RMA), preparando-se misturas desses materiais com dois solos tipicamente encontrados no Estado de Sergipe. Dessa forma, foram realizados ensaios para se avaliar a composição e porcentagem de materiais indesejáveis, granulometria, limites de Atterberg, absorção, desgaste por abrasão, massa específica, índice de forma, compactação, degradação, índice de suporte califórnia e módulo de resiliência. Com base nos resultados obtidos, utilizando-se a energia intermediária de compactação, verificou-se que os agregados reciclados de RCD proporcionaram significativas melhorias nas propriedades dos solos, expressa pelo desempenho mecânico satisfatório observado nos parâmetros ISC e MR das misturas. Os resultados apresentados nesta pesquisa indicam e ratificam a viabilidade técnica do uso do RCD em camadas de base e sub-base de pavimentos, o que pode contribuir para o desenvolvimento sustentável, o aumento da oferta de materiais e uma metodologia de aplicação na construção de vias urbanas da RMA e do Estado de Sergipe, além de resultar na diminuição da extração de materiais naturais de jazidas e das áreas de disposição final desses resíduos.
264

Resíduos sólidos : risco ambiental e políticas públicas de proteção do meio ambiente no município de Passo Fundo

Schneider, Vanderlei 23 April 2014 (has links)
Nesta pesquisa trata-se sobre os resíduos sólidos, produzidos pelo homem, que lançados no ambiente, prejudicam o ecossistema. Conceitualmente delimita-se entre a ação decisiva das políticas públicas, a consideração do risco ambiental e a efetiva destinação de resíduos sólidos em análise geral e, na sequência, no município de Passo Fundo (RS). Deste modo, mesmo considerando-se o risco ambiental, é possível diminuir o impacto negativo dos resíduos sólidos produzidos pelo homem e lançados à natureza, através de políticas públicas efetivas que congreguem o desenvolvimento sustentável? Especialmente, o impacto ambiental dos resíduos sólidos gerados é negativo ou positivo no município de Passo Fundo (RS)? Elencaram-se duas hipóteses de resolução: a primeira, de que o risco ambiental é previsível e, por isso, é possível, com base nele, efetivar o desenvolvimento sustentável; a segunda, de que a eficácia de políticas públicas ambientais está atrelada diretamente ao poder local e, por isso, é possível se minimizar os efeitos negativos da produção dos resíduos sólidos através de ações públicas, inclusive, no município de Passo Fundo (RS). Os objetivos são comprovar que a eficácia de políticas públicas ambientais depende de ações efetivas locais para gerar melhores resultados e, secundariamente, exacerbar a necessidade de desenvolvimento da consciência das pessoas no sentido de preservar e conservar o meio ambiente como forma única de sobrevivência da espécie humana e como procedimento metodológico, utilizou-se o caminho da pesquisa bibliográfica e documental concernente ao tema. O método de abordagem eleito foi o dialético, partindo-se da análise do risco ambiental, perpassando o desenvolvimento sustentável até as políticas públicas de resíduos sólidos e a efetivação delas no município de Passo Fundo (RS). Como marco teórico foi eleito o desenvolvimento sustentável. O texto se estrutura em três capítulos: o risco ambiental; desenvolvimento sustentável; e políticas públicas aplicáveis aos resíduos sólidos. Conclui-se que, diante da intensa produção dos resíduos sólidos, na cidade de Passo Fundo, é imperativo o equacionamento do índice de risco ambiental, originado pela emissão de tais resíduos para o estabelecimento de ações, permeadas por políticas públicas educacionais, para melhoria da qualidade de vida dos cidadãos. / This research is about the solid waste produced by humans that enter the environment, harming the ecosystem. Conceptually it is delimited between the decisive action of public policies, the consideration of environmental risk and the effective disposal of solid waste in general analysis and , following, in Passo Fundo (RS). Thus, even considering the environmental risk, it is possible to reduce the negative impact of solid waste produced by humans and released to nature through effective public policies that bring together sustainable development? Especially, the environmental impact of solid waste generated is negative or positive in Passo Fundo (RS)? Two hypotheses are showed for the resolution of those problems: the first, that the environmental risk is predictable and therefore it is possible, based on it, accomplish sustainable development, and second, that the effectiveness of environmental policies is linked directly to local government and therefore it is possible to minimize the negative effects of the production of solid waste through public shares in Passo Fundo (RS). The objectives are to demonstrate the effectiveness of environmental policies depends on local effective actions to generate better results and secondarily exacerbate the need to develop awareness of the people to preserve and conserve the environment as the only way of survival of the human species. As methodological procedure, we used the path of literature and documents related to the theme. The method chosen was the dialectical approach, starting from the analysis of environmental risk, and then analyzing the sustainable development policies of solid waste and committing them in Passo Fundo (RS). Was elected as the theoretical framework the sustainable development. The text is divided into three chapters: environmental risk, sustainable development, and public policy applicable to solid waste. We conclude that, given the intense production of solid waste in the city of Passo Fundo, it is imperative to equate the index of environmental risk, originated by the issuance of such waste for establishing actions permeated by public educational policies, to improve the quality of life of citizens.
265

Extração de carotenóides totais e ß-caroteno por ultrassom no resíduo de indústria de polpa de goiaba (Psidium guajava L)

Santos, Thatiana Santana 30 July 2013 (has links)
This work reports the extraction ß-carotene and total carotenoids in the residue of the guava pulp industry by Soxhlet and ultrasound. The Soxhlet technique was evaluated from the solvent: dichloromethane, methanol and hexane, and drying process: freeze-drying and convective drying. The solvents dichloromethane showed the best yield ß-carotene and total carotenoids and the drying by freeze was most favorable. Ultrasound extraction was evaluated: relation mass/solvent, temperature, time and power extraction device. The better extraction condition for maximum yield of ß-carotene by ultrasound was 20 minutes, at a sample to solvent radio 1:70 (g mL-1), power 154 W and temperature 30°C. The results showed that ultrasound obtained it highest ß-carotene yield (693,16 µg 100 g-1) in 20 minutes only, while Soxhlet obtained low yield (494, 9 µg 100g-1) in 8h. For total carotenoids the Soxhlet extraction obtained a yield of 6693,4 µg 100 g-1, in the ultrasound obtained the better yield (9912,28 µg 100 g-1) in the power 92,4W. / Este trabalho reporta a extração de ß-caroteno e carotenoides totais em resíduo agroindustrial de polpa de goiaba por Soxhlet e ultrassom. Na técnica de Soxhlet foram avaliados os solventes: hexano, diclorometano e metano e os processos de secagem: liofilização e secagem convectiva. O solvente diclorometano apresentou melhor rendimento para a extração de ß-caroteno e carotenoides totais e a liofilização foi o processo de secagem mais favorável. A extração por ultrassom foi avaliada quanto a relação massa/solvente, temperatura, tempo e potência de extração. A melhor condição de extração de ß-caroteno em ultrassom foi 20 minutos, razão massa/solvente 1:70 (g mL-1), potência 123,2 W e temperatura 30°C. Os resultados mostraram que o ultrassom gerou o melhor rendimento (693,16 µg 100g-1) em 20 minutos, enquanto que a extração por Soxhlet alcançou um rendimento inferior (494,97 µg 100g-1) em 8 h. Para carotenoides totais a extração por Soxhlet apresentou um rendimento de 6693,4 µg 100g-1 e no ultrassom foi obtido um melhor rendimento (9912,28 µg 100g-1) com uma potência de 92,4 W.
266

Environmental policy processes surrounding South Africa's plastic bags regulations : tensions, debates and responses in waste product regulation

Nhamo, Godwell 07 June 2013 (has links)
This study was conducted in South Africa. South Africa is the first country within the Southern African Development Community to have regulated plastic shopping bags waste through the imposition of both a standard on thickness and a levy. Given this scenario, the Plastic Bags Regulations present an illustrative case for researching complexity, uncertainty and controversies surrounding a new trend in environmental policy making, namely waste product regulation. The thesis focuses on understanding and investigating tensions, debates and responses emerging from the policy process as actors and actor-networks put not only the Plastic Bags Regulations asfocal actant (token) but also other actants and actant-networks as well. To this end, a research question that addressed environmental policies, tensions, debates and responses that informed the development of South Africa's Plastic Bags Regulations was spelt out. The research objectives included the need to: (I) analyse selected international environmental policy processes surrounding plastic shopping bags litter and waste regulation and how these influenced developments in South Africa; (2) identify actors, actants and actor/actant-networks that shaped and were being transformed by South Africa's Plastic Bags Regulations and explain the tensions, debates and responses arising in the policy processes; (3) identify environmental policy outputs and assess outcomes emerging from the formulation and implementation of South Africa's Plastic Bags Regulations; and (4) establish patterns in environmental policy process reforms around South Africa's Plastic Bags Regulations. The language of actors (human), actants (non-human) and actor/actant-networks brings to the fore the aspects of processes and relationships that exist around them. As such, insights from the actor/actant-network theory (AANT) were drawn upon to inform the research. AANT enquiry framework collapses binaries such as nature/society, art/science, structure/agency and global/local historically associated with a particular type of social theory. AANT also denies that purely technical, scientific or social relations are possible (the notion of quaSi-objects or token). Data sets were generated following' the Plastic Bags Regulations as token actant with time frames ranging from prior to, during and after the formulation of the regulations. Similarly, data analysis drew insights from AANT's four moments of translation namely problematisation, interessement, enrolment and mobilisation, with the intervention theory providing an evaluative perspective that complemented AANT. The findings were that after the promulgation of the first draft of the Plastic Bags Regulations in May 2000, tensions emerged around the nature of regulation (whether command and control - preferred by government or self regulation - preferred by industry and labour). In this regard the latter group raised concerns about jobs, income and equipment loss as well as the need to have a holistic approach to waste management rather than targeting a single product at a time whilst the former maintained that this would not be so. As such, education, awareness and stringent antilitter penalties were proposed by industry and labour as sustainable responses to the problem of plastic shopping bags waste rather than regulation. These debates continued and resulted in minor amendments to the original regulations as finalised by Government in May 2002. However, industry and labour continued lobbying government resulting in the conclusion of the Plastic Bags Agreement in September 2002 and the ultimate repulsion of the May 2002 regulations in May 2003. As revealed by this research, these responses led to broader social responses and further tensions as demand for plastic shopping bags went down by about 80% although an estimated 1000 jobs were lost and a number of companies lost equipment and business (with some closing down) following the implementation of the regulations. During implementation, debates emerged around the need to promote locally made carry facilities with two alternatives in sight namely: the Green Bag and the Biodegradable Plastic Bag. Debates also took place regarding enforcement of the new law resulting in the amendments of various pieces of legislation including the Environmental Conservation Act, Environmental Management Act and the Revenue Laws Act. Overall, a 15-year policy reform cycle and sub-cycles was determined. The research also established that the government considered the regulations a success and was already implementing simi lar initiatives to regulate other waste products, among them, used tyres, used oil and glass, confirming the trend towards waste product regulation in South Africa. From these research findings, a series of conceptual frameworks were drawn up to clarify the nature of tensions, debates and responses surrounding certain lead actors, actants and actorlactant-networks. Some of the conceptual frameworks that emerged around the actors and actor-networks include Organised Government, Organised Industry and Organised Labour. Conceptual frameworks that emerged around key actants and actant-networks include the Integrated Pollution and Waste Management, Plastic Bags Regulations as well as the discourses surrounding the Green bag and biodegradable plastic bags. The thesis concludes by reflecting on how the above and the grand actor/actant-network conceptual frameworks emerging from this research might be adopted with varying degrees of flexibility to research environmental and waste management policy processes in different waste product regulation set-ups. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in
267

Co-utilisation of microalgae for wastewater treatment and the production of animal feed supplements

Johnson, Hailey E January 2011 (has links)
Microalgae have a variety of commercial applications, the oldest of which include utilisation as a food source and for use in wastewater treatment. These applications, however, are seldom combined due to toxicity concerns, for ethical reasons, and generally the requirement for cultivation of a single algae species for use as a feed supplement. These problems might be negated if a “safer” wastewater such as that from agricultural and/or commercial food production facilities were to be utilised and if a stable algae population can be maintained. In this investigation preliminary studies were carried out using an Integrated Algae Pond System (IAPS) for domestic wastewater treatment to determine the species composition in the associated High Rate Algae Ponds (HRAPs). The effect of different modes of operation, continuous versus batch, on nutrient removal, productivity and species composition was also investigated. Furthermore, indigenous species in the HRAP were isolated and molecularly identified as, Chlorella, Micractinium, Scenedesmus and Pediastrum. Additionally, the effect of the nor amino acid, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) and its Cu-chelated derivative, on the growth and biochemical composition of Chlorella, Micractinium, Scenedesmus, Pediastrum and Spirulina was investigated. Species composition in the HRAP was stable under continuous operation with Micractinium dominating > 90% of the algae population. Under batch operation the population dynamic shifted; Chlorella outcompeted Micractinium possibly due to nutrient depletion and selective grazing pressures caused by proliferation of Daphnia. Higher species diversity was observed during batch mode as slower growing algae were able to establish in the HRAP. Nutrient removal efficiency and biomass productivity was higher in continuous mode, however lower nutrient levels were obtained in batch operation. HMTBA did not significantly affect growth rate, however treatment with 10 mg.L-1 resulted in slightly increased growth rate in Micractinium and increased final biomass concentrations in Chlorella, Micractinium and Spirulina (although this was not statistically significant for Micractinium and Spirulina), which are known mixotrophic species. Algae treated with Cu-HMTBA, showed reduced final biomass concentration with 10 mg.L-1, caused by Cu toxicity. Biochemical composition of the algae was species-specific and differed through the growth cycle, with high protein observed during early growth and high carbohydrate during late growth/early stationary phase. Additionally, 0.1 mg.L-1 HMTBA and Cu-HMTBA significantly reduced protein content in Chlorella, Micractinium, Scenedesmus and Pediastrum. In conclusion, operation of the HRAP in continuous culture provided suitable wastewater treatment with high productivity of an ideal species, Micractinium, for use in animal feed supplementation. This species had 40% protein content during growth (higher than the other species tested) and dominated the HRAP at > 90% of the algae population during continuous mode. Addition of HMTBA (> 1 mg.L-1) to algae cultivation systems and those treating wastewater, has the potential to improve productivity and the value of the biomass by enhancing protein content. Overall, the co-utilisation of microalgae for wastewater treatment and the generation of a biomass rich in protein, for incorporation into formulated animal feed supplements, represents a closed ecosystem which conserves nutrients and regenerates a most valuable resource, water.
268

Microesferas magnéticas de quitosana para remoção do corante violeta de metila 2B em meio aquoso

Toaldo, Luciane Torezan 09 March 2015 (has links)
A crescente utilização de corantes na indústria gera grande quantidade de resíduos.Estes, quando descartados inadequadamente, tornam-se uma fonte poluidora dos sistemas aquáticos, os quais são indispensáveis à vida e à manutenção do equilíbrio de ecossistemas naturais. Por este motivo, é importante que sejam desenvolvidos métodos de tratamento eficazes para a remoção de corantes. Dentro desse contexto, este trabalho teve por objetivo avaliar a capacidade de adsorção de microesferas magnéticas de quitosana na remoção do corante violeta de metila 2B (VM 2B) em meio aquoso. Inicialmente, preparou-se magnetita (Fe3O4) através da precipitação química dos sais de ferro (II) e (III), em meio alcalino. A etapa seguinte consistiu na preparação das microesferas de quitosana, por meio da técnica de reticulação em suspensão, utilizando glutaraldeído. Com o objetivo de conferir propriedades magnéticas à quitosana, adicionou-se a Fe3O4 anteriormente preparada. Estes materiais foram caracterizados quanto a sua morfologia e características químicas. Os parâmetros experimentais do processo de adsorção foram previamente otimizados, variando-se a massa de adsorvente, a velocidade de agitação do sistema e o pH inicial do meio. A capacidade adsorvente das microesferas magnéticas de quitosana foi avaliada em um sistema em batelada, sob temperatura controlada de 25 °C, sendo a concentração remanescente de VM 2B em solução determinada por espectroscopia de absorção molecular na região do visível. Os resultados revelaram que as microesferas magnéticas de quitosana apresentam potencial para a finalidade proposta, com elevada capacidade de remoção para o corante VM 2B (~86%). Os resultados experimentais mostraram que a cinética de adsorção foi melhor descrita pelo modelo de pseudossegunda ordem. No que se refere ao equilíbrio de adsorção, os resultados experimentais apresentaram um melhor ajuste à isoterma de Freundlich (R2 superior a 0,98). Os dados termodinâmicos revelaram um processo de adsorção espontâneo ( G°= -3,96 kJ mol-1), exotérmico ( H° = -1,70 kJ mol-1), e com S° = -3,73 J mol-1 K-1, o que sugere pequena mudança na aleatoriedade na interface sólido-soluto durante a adsorção. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. / The increasing use of dyes in the industry generates great quantities of waste. When disposed improperly, they become a source of pollution of aquatic systems which are essential to life and to maintain the equilibrium of natural ecosystems. For this reason, it is important to develop effective treatment methods for the removal of dyes. In this context, this work aimed to evaluate the adsorption capacity of magnetic chitosan microspheres for the removal of methyl violet 2B (MV 2B) dye in aqueous media. Initially, magnetite (Fe3O4) was prepared by chemical precipitation of iron salts (II) and (III). Then, chitosan microspheres were prepared by the suspension crosslinking technique. Finally, Fe3O4 was added to chitosan in order to achieve magnetic properties. These materials were characterized by their morphology and chemical characteristics. The experimental parameters of the adsorption process were optimized by varying the mass of adsorbent, the stirring rate, and the initial pH of the medium. The adsorbent capacity of magnetic chitosan microspheres was evaluated in a batch system at 25 °C. After the adsorption process in an aqueous medium, the remaining concentration of MV 2B solution was determined by molecular absorption spectroscopy in the visible region. The results showed that the magnetic chitosan microspheres present a high potential for the purpose, with a high capacity for removing MV 2B (~86%). The adsorption process followed pseudo-second-order rate kinetics, and the adsorption equilibrium was better described by the Freundlich isotherm (R2 higher than 0.98). The thermodynamic data revealed a spontaneous ( G° = -3.96 kJ mol-1), exothermic ( H° = -1.70 kJ mol-1), and S° = -3.73 J mol-1 K-1, which suggests a small variation in the randomness at the solidsolution interface.
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Interação composto de lodo de esgoto e cinzas de biomassa no desenvolvimento inicial de eucalipto /

Leite, Regina Marques 1981 January 2012 (has links)
Orientador: Iraê Amaral Guerrini / Banca: Roberto Lyra Villas Boas / Banca: Dirceu Maximino Fernandes / Banca: Fernando Carvalho Oliveira / Banca: Rodrigo de Menezes Trigueiro / Resumo: Apesar dos interesses econômicos ainda serem os norteadores na resolução das situações, questões como a geração e destinação de resíduos começam a ser discutidas de forma um pouco mais realista e baseadas também em aspectos ambientais e sociais. Paralelamente, os plantios florestais passaram a ser discutidos dentro de um contexto mais amplo que não apenas para produção de matéria prima, mas de conservação dos recursos naturais. Neste cenário, o tratamento e destinação de resíduos estão diretamente ligados a esses desafios. Desta forma, o objetivo deste trabalho foi de avaliar a utilização de lodo de esgoto compostado e cinzas de caldeira, provenientes de fábrica de papel e celulose, em plantios de eucalipto, uma vez que o lodo de esgoto constitui fonte de matéria orgânica e de nutrientes para as plantas, com exceção do potássio, que é encontrado nas cinzas, além de evitar sua deposição em aterros sanitários, poupando os recursos naturais e reduzindo custos com fertilização química. Com isso, a hipótese deste trabalho é que um complementaria o outro na fertilização do eucalipto, podendo substituir a adubação convencional. Foi realizado um experimento em casa de vegetação de cobertura plástica, utilizando-se mudas de eucalipto transplantadas em tambores plásticos devidamente identificados e preenchidos com 50 litros de solo e os seus respectivos tratamentos, definidos a fim de se avaliar o efeito de doses de lodo de esgoto compostado e cinzas de caldeira e a adubação convencional em um solo de textura média, por seis meses. Os tratamentos constituíram em um fatorial com 4 doses de cinza (0, 5, 10 e 15 Mg ha-1) e 3 doses de Lodo de Esgoto Compostado (0, 10 e 20 Mg ha-1), além de um tratamento testemunha absoluta e a adubação inorgânica convencional + calagem. 2 Os efeitos da adubação inorgânica convencional no crescimento inicial do eucalipto ... / Abstract: Despite the economic interests are still guiding the solution of situations, issues such as generation and disposal of waste are beginning to be discussed in a slightly more realistic way and also based on environmental and social aspects. At the same time, the forest plantations have been began to be discussed within a broader context that not only for raw materials production, but conservation of natural resources. In this scenario, the treatment and disposal of wastes are directly linked to these challenges. Thus, the aim of this study was to evaluate the use of composted sewage sludge and boiler ash from paper and pulp factory in Eucalyptus plantations, since the sewage sludge is a source of organic matter and nutrients for plants, exception to potassium, which is found in the boiler ash, to avoid their disposal in landfills, saving natural resources and reducing costs with chemical fertilization. Thus, the hypothesis is that each other can complement Eucalyptus fertilization and replace conventional fertilization. The experiment was conducted in plastic greenhouse, using Eucalyptus seedlings transplanted in plastic pots and filled with 50 liters of soil. The treatments were defined in order to evaluate the effect of rates than of composted sewage sludge and boiler ash and compare with a conventional fertilization in a soil with medium textured for six months. The design used was a factorial with 4 levels doses of boiler ash (0, 5, 10 and 15 Mg ha-1) and 3 doses of composted sewage sludge (0, 10 and 20 Mg ha-1), and an absolute control treatment and conventional inorganic fertilization liming. The effects of conventional inorganic fertilization on initial growth of Eucalyptus were higher than the composted sewage sludge with the boiler ash, indicating that these residues 4 don't substitute inorganic fertilizer, under the conditions of this experiment. The composted sewage sludge (20 mg ha-1) ... / Doutor
270

Knowledge, attitudes and practices regarding solids household waste management in Tshisahulu Community of Vhembe District, Limpopo Province

Tshivhase, Shonisani Elizabeth 23 July 2015 (has links)
MPH / Department of Public Health

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