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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.
81

[pt] AVALIAÇÃO TECNOLÓGICA E ECONÔMICA DE UMA ROTA DE PROCESSAMENTO PARA RECICLAGEM DE SUCATAS ELETRÔNICAS / [en] TECHNOLOGICAL AND ECONOMIC ASSESSMENT OF A PROCESSING ROUTE FOR ELECTRONIC WASTE RECYCLING

FELIPE SEABRA D ALMEIDA 07 June 2022 (has links)
[pt] O Brasil é o segundo maior produtor de lixo eletrônico das Américas, com uma produção que cresce a cada ano e apenas 10 por cento dela sendo tratada de forma apropriada. Adicionalmente, o Brasil não possui tecnologia própria para tratamento de placas de circuito impresso, componente chave presente neste tipo de resíduo. Atualmente, o Brasil não possui uma planta industrial voltada para essa atividade extrativista a partir de resíduos eletrônicos, sendo a maior parte do seu tratamento realizado no exterior. A hipótese de pesquisa deste manuscrito é que as universidades e suas comunidades poderiam desenvolver fontes de matéria-prima para tais processos de extração e, portanto, merecem atenção para a criação de pontos de coleta e parcerias. Nesse contexto, é necessário entender o comportamento dessa comunidade em relação à aquisição, armazenamento e descarte de equipamentos eletrônicos, bem como informações sobre temas relacionados ao gerenciamento e reciclagem de resíduos eletrônicos. Adicionalmente, criou-se uma rota conceitual de tratamento, a partir da integração de tecnologias descritas na literatura. Após a criação do design da rota, foi realizado um balanço de massa e energia, considerando dois casos base de fonte de placas de circuito impresso como matéria prima matéria prima: A) Lixo eletrônico em geral; B) utilizando somente celulares. Para ambos os casos, foi considerado o tratamento de 2 t/h. Determinou-se que o grupo estudado possui mais de 16,96 milhões de telefones celulares em hibernação, além de outros equipamentos, com valor de estoque estimado em 67,45 milhões de dólares para o grupo estudado na região metropolitana do Rio de Janeiro. Se extrapolado para todo o Brasil, pode chegar a 797,50 milhões de dólares para o grupo estudado. uma taxa interna de retorno de 141,6 por cento e 3990,7 por cento para o caso A e B, respectivamente e valor presente líquido de USD 44,834,616 e USD 3,215,300,083 para o caso A e B, respectivamente. Adicionalmente, foi determinado que o caso A possui uma grande sensibilidade a variação da taxa de ocupação. Neste contexto, a presente pesquisa tem o potencial de ajudar na criação da primeira planta industrial brasileira voltada para a reciclagem de placas de circuito impresso, assim como entender quais são as variáveis chaves para o processamento destes componentes. Adicionalmente, o projeto apresenta o investimento necessário para a criação da planta, sendo uma informação crucial para potenciais investidores. / [en] Brazil is the second largest producer of electronic waste in the Americas, with a production that grows each year and only 10 percent of it is properly treated. Additionally, Brazil does not have its own technology for treating printed circuit boards, a key component present in this type of waste. Currently, Brazil does not have an industrial plant dedicated to this extractive activity from electronic waste, with most of its treatment carried out abroad. The research hypothesis of this manuscript is that universities and their communities could develop raw material sources for such extraction processes and, therefore, deserve attention for the creation of collection points and partnerships. In this context, it is necessary to understand the behavior of this community in relation to the acquisition, storage and disposal of electronic equipment, as well as information on issues related to the management and recycling of electronic waste. Additionally, a conceptual treatment route was created based on the integration of technologies described in the literature. After creating the route design, a mass and energy balance was carried out, considering two base cases of printed circuit boards as raw material: A) Electronic waste in general; B) using cell phones only. For both cases, the treatment of 2 t/h was considered. It was determined that the studied group has more than 16.96 million cell phones in hibernation, in addition to other equipment, with an estimated inventory value of 67.45 million dollars for the studied group in the metropolitan region of Rio de Janeiro. If extrapolated to all of Brazil, it could reach 797.50 million dollars for the studied group. an internal rate of return of 141.6 percent and 3990.7 percent for case A and B, respectively, and net present value of USD 44,834,616 and USD 3,215,300,083 for case A and B, respectively. Additionally, it was determined that case A is highly sensitive to occupancy rate variation. In this context, this research has the potential to help in the creation of the first Brazilian industrial plant dedicated to the recycling of printed circuit boards, as well as to understand the key variables for the processing of these components. Additionally, the project presents the investment necessary for the creation of the plant, being crucial information for potential investors.
82

Bioodpad: školní projekt pro 2. stupeň základní školy / Biodegradable Waste: School Project for Lower Secondary School

Dvořáková, Kateřina January 2021 (has links)
The proper way to manage biological waste has only recently become a topic of discussion and the public still does not have enough information about it and does not have a comprehensive opinion. In order for bio-waste to be properly managed, knowledge of this topic and positive attitude towards it is necessary, in class this could be achieved by activating pupils through project based education. Teaching in projects is a great way to understand the issue, which can influence pupils' attitudes towards bio-waste management. The aim of this diploma thesis is to create a project on the topic of biodegradable waste, and then to find out how the knowledge and opinions of students about bio-waste have changed. The created project was verified at the lower secondary school, for which it is primarily intended. A total of 54 6th-year pupils was involved in this project. They were given a pretest before the start of the project, finding out the initial knowledge about bio-waste and their opinion on the classification of bio-waste. After the project, the pupils completed a posttest and by comparing the individual answers, it was determined whether and how the knowledge of the tested pupils and their attitude towards the topic changed. The answers of individual pupils in the pretest and posttest were evaluated...
83

[en] A PROPOSAL FOR RECYCLING WASTE LOGISTICS CONSTRUCTION OF THE CITY OF RIO DE JANEIRO / [pt] UMA PROPOSTA PARA LOGÍSTICA DE RECICLAGEM DOS RESÍDUOS DA CONSTRUÇÃO CIVIL NA CIDADE DO RIO DE JANEIRO

JOEL VIEIRA BAPTISTA JUNIOR 23 November 2021 (has links)
[pt] Existem milhares de técnicas e metodologias construtivas sustentáveis, e para o tratamento e reaproveitamento do resíduo da construção civil nos centros urbanos. Esse trabalho procura ordenar, de forma sintetizada, esses procedimentos para redução da geração e reaproveitamento do resíduo da construção civil no Rio de Janeiro, apresentando sugestões para as fases de idealização, projeto e execução do empreendimento e uma logística reversa para a reinserção do resíduo à cadeia produtiva. A pesquisa sugere no capitulo dois a utilização da ferramenta de Avaliação do Ciclo de Vida (ACV) na fase de idealização dos empreendimentos para uma visão ampla do impacto ambiental durante a execução da obra e na utilização do empreendimento até o descarte final, mostrando que a manutenção na fase de utilização representa mais de oitenta por cento do custo de toda a sua vida útil. O capitulo três apresenta uma analise do resíduo, sua composição, as classificações de acordo com o CONAMA e NBR 10.004, e seu potencial de impacto nas regiões urbanas, as principais fontes geradoras, um resumo das principais leis e resoluções brasileiras que regulamenta a sua gestão. Trás ainda uma comparação entre tipos de desconstruções com apresentação de um exemplo de uma demolição certificada no centro do Rio de Janeiro. O capitulo quatro apresenta um panorama geral da gestão dos resíduos da construção civil nas grandes cidades, evidenciando no Rio de Janeiro a existência de dois tipos distintos de geradores de resíduos na construção civil, o gerador das obras com canteiros instalados, licenciados, que segue as normas e exigências técnicas para seletividade do resíduo e os geradores das pequenas obras e reformas, responsável pela contribuição acima de 50 porcento do total de resíduo gerado e pela quase totalidade da poluição. O capitulo cinco trabalha sobre a formula: (Sustentabilidade = Projetos eficientes + Reaproveitamento dos detritos). Projetos eficientes, obras com baixa geração de resíduos e erradicação dos desperdícios é o caminho para a sustentabilidade no setor. Apresenta métodos construtivos para esse objetivo e sustenta que a segregação do resíduo na fonte é pré condição para um processo eficiente de reciclagem. Apresenta o Social como o principal legado da logística para reciclagem dos resíduos nas grandes cidades nos países em desenvolvimento. O capitulo seis propõe um caminho para a logística de reciclagem do resíduo da construção civil no Rio de Janeiro, transformando o processo linear em um processo circular para a indústria da construção civil. O fim do despejo de resíduo da construção civil in natura é uma meta a ser continuamente perseguida por toda a sociedade no compromisso com as gerações futuras. Esse trabalha apresenta sugestões para esse fim. / [en] The historical importance of the construction industry in the constant improvement of society s quality of life is undeniable. A major source of employment, it accounts for twenty percent of all U.S. economic activity, and in Brazil, in 2008, it represented 8.9 percent of the GDP; in 2000 it consumed 210 million tons of natural aggregates. These figures express the sector s strategic need justifying investments in research for its sustainability, which is currently less than 1 percent from the U.S. government and 6 percent in Europe. There are thousands of sustainable building techniques and methodologies, as well as those for the treatment and reuse of construction waste in urban centers. This article aims to organize, in a summarized way, these procedures to reduce generation and treat construction waste in Rio de Janeiro, making suggestions for sustainable processes in the idealization, design and implementation phases of a new development and the reverse logistics for treating waste and reintegrating it into the production chain. In chapter two the study suggests the use of the Life Cycle Assessment (ACV) tool during new developments idealization phases for a broad overview of the environmental impact of their execution, during the use of the developments until their final disposal. Research shows that maintenance costs in a development s utilization phase represent more than eighty percent of its entire life span. The ACV study qualifies knowledge of sizing, materials specifications and construction techniques, as well as routines for use of developments. It adjusts its viability guiding developments toward sustainable principles, for example, low power consumption settings, minimizing the use of natural resources, parameters for diversity of materials being used, the impact of the use of assembly and/or mounting adhesives that hinder selective disassembly for reuse, and the importance of planning deconstruction ahead of time in order to reuse materials; these factors are crucial in the quest for sustainability in the sector. Chapter three brings an analysis of this waste, its impact potential in urban areas, major generating sources, and a summary of the main Brazilian laws and resolutions regulating its management. By listing the main sources generating waste and scrap in construction, attention is drawn to the selective deconstructions of yesteryear that reused materials. Made viable by the construction techniques used at that time in these buildings that allowed the selective removal of material. Also in chapter three, an example of a current certified demolition in downtown Rio de Janeiro is presented. Finally, it shows the general composition of waste and its classifications according to CONAMA (the National Environment Council) and NBR (Brazilian Technical Standards Association) 10,004. Chapter four provides an overview of construction waste management in large cities, in Rio de Janeiro it is evident that two distinct types of waste generators exist in constructions: the first is the generator in construction works with installed and licensed construction sites, which follow the standards and technical requirements for waste selection from generation to transportation under joint liability during the whole process until the final destination, in accordance with CONAMA s resolutions; these generators are monitored throughout the process. Yet the second, the generator in small construction works and renovation without installed construction sites, they do not comply with waste management standards and requirements, they use the same bucket to carry all classes of mixed waste, with no responsibility for the segregation and final disposal. Most often these wastes are dumped in illegal transshipment areas, mostly in protected areas. This widespread practice under the pretext of lack of segregation space in the civil work is endorsed by the lack of an urban policy to empower and require waste segregation at source and its reprocessing. The segment of small generators is responsible for contributing over 50 percent of waste generated in the city, and for almost all of the total pollution generated by construction waste, due to their crude mixtures that cannot be recycled and untreated transshipments into nature. Thus this study focuses on studying a suggestion for waste segregation logistics and recycling for this second group of generators. Chapter five dissects the formula: (Sustainability = Effective projects + Waste reutilization). Efficient projects, civil works with low waste generation and waste elimination is the way toward sustainability in the sector. In some regions of Brazil, the loss reaches 33 percent as opposed to the world average of 10 percent. Several factors rooted in the country s culture of raw material abundance are mentioned. There is still a lack of sustainable efficiency concern in national projects, of doing more using fewer natural resources, using construction methods to lower the impact on the use and disposal of materials in the process.
84

Preservation and nutritional value of caged layer waste treated with different preservatives

Wakeham, Andres I. January 1987 (has links)
Two experiments were conducted with caged layer waste. In the first experiment fresh waste was treated with: no additive, 2% formaldehyde, 3% sodium metabisulfite, 1% formaldehyde and 2% propionic acid, 3% formic and 2% propionic acids and stored in polyethylene lined 208 liter metal drums. In experiment II waste treated with 2% formaldehyde, 1 % formaldehyde and 2% prop ionic, 3 % formic and 2% propionic (w/w), stored for at least 42 d, used in a metabolism trial as N supplements to a basal diet fed to sheep. The formaldehyde, formaldehyde/propionic and formic/propionic treatments eliminated the bacterial decomposition of the waste and no undesirable fermentation was observed on the stored material. Waste treated with no additive or sodium metabisulfite underwent putrefaction. Nitrogen supplementation of a basal diet with treated caged layer wastes improved apparent digestibility of crude protein and N retention in sheep fed these diets. Supplementation of a basal diet with chemically treated caged layer waste improves the nutritional value of the diet which suggests that caged layer waste is efficiently utilized as a N source by ruminants when used as a protein supplement. / Master of Science
85

Modélisation des flux de biomasse et de nutriments dans les territoires agricoles : simulation et évaluation de scénarios appliqués à un cas d’étude en France / Modelling biomass and nutrient flows in agro-food systems at the local scale : scenario simulation and assessment in a French case-study

Fernandez mena, Hugo 19 December 2017 (has links)
Nourrir une population mondiale croissante dans un contexte de changements globaux pose de nouveaux défis à l’agriculture en termes d’efficience de production et d’impacts environnementaux. Rendre les systèmes agro-alimentaires plus soutenables nécessite de mieux recycler la biomasse et les nutriments, c’est-à-dire de tendre vers des flux de fertilisants, de produits végétaux, d’aliments du bétail, de coproduits et de déchets plus circulaires. À ce titre, il est nécessaire de développer de nouveaux outils pour mieux explorer et évaluer les échanges de matières entre les fermes et leurs partenaires économiques amont et aval dans les territoires. Dans le travail présent, l’état de l’art concernant les méthodes d’analyse, de modélisation et d’évaluation environnementale des flux de biomasse et d’éléments minéraux à différentes échelles est réalisé. Le modèle multi-agents FAN (« Flows in Agricultural Network») qui simule les flux des matières entre les fermes et leurs partenaires économiques dans les territoires agricoles a été développé. Les processus de FAN sont expliqués en détail et une analyse de sensibilité des variables clefs est présentée. Par ailleurs, le modèle FAN a été appliqué à un cas d’études en France pour évaluer la performance des scénarios contrastés visant à améliorer l’efficience d’utilisation des éléments minéraux, développer le recyclage de la matière, favoriser la production du biogaz ou reconcevoir les systèmes de production. Les sorties de simulations des scénarios sont analysées en termes de production alimentaire et énergétique, de flux de matières et de logistique, de cycle des nutriments et d’émissions de gaz à effet de serre. Ce travail montre l’utilité des outils de prospective et modèles multi-agents pour améliorer la durabilité des systèmes agricoles et des chaines alimentaires, pour créer et évaluer des solutions collectives tendant vers l’économie circulaire et pour prendre en charge les interactions entre acteurs économiques au sein des chaines et filières alimentaires complexes. / Feeding the growing global population in a context of global change raises new challenges for agriculture regarding its production efficiency and impacts on natural resources. Solutions for towards farming sustainability require to improve nutrient and biomass recycling in agro-food systems, i.e. to move from linear to more circular flows of fertilizers, crop products, feedstuff, by-products and organic wastes. Innovative tools exploring material exchanges between farms and their upstream and downstream partners in agro-food systems at the local scale are needed. In the present work, the state of the art about analysis methods, models and environmental tools addressing nutrient and biomass flows at different scales is reviewed. The FAN (“Flows in Agricultural Network”) model, an agent-based model that simulates a range of material flows among farms and their partners within agricultural districts is developed. FAN processes are explained in details and a sensitivity analysis to some key variables is performed. In addition, the FAN model is applied to a French case-study to assess the performances of contrasted scenarios aiming to enhance nutrient use efficiency, recycling strategies, biogas production and system redesign. The outcomes from the scenario simulation are analyzed are assessed in terms of food provisioning, nutrient cycling and greenhouse gas emissions. This work shows the usefulness of prospective, agent-based tools for greater farming and food-chain sustainability, to design and evaluate collective solutions for circular economy and to account for interactions among economic actors within complex agro-food systems.
86

Srovnání ekonomických a ekologických aspektů zpracování odpadů ve vybraných obcích různých velikostí / Comparison of economic and environmental aspects of waste management in selected municipalities of different sizes

HAVLOVÁ, Marie January 2016 (has links)
The industrial development of our society pushes waste management into becoming an important part of both the economy as well as the environmental protection. It is essential to reduce the amount of waste which is being deposited in landfills without any further use. In the next 10 years it is necessary to completely eliminate waste disposal of the reusable waste and especially of the mixed municipal waste. This thesis focuses on the waste management of various types of municipalities. It aims to provide optimization of waste management, in the connection with economical and technical possibilities of various types of municipalities. This thesis is divided into two parts. The theoretical part describes the issue of waste management in the course of history. It shows the various methods of waste disposal and describes the economic and environmental aspects and impacts in general. It briefly summarizes the development of waste management legislation. The second part of this thesis is focused on the analysis of waste management in selected municipalities. Twelve towns in three groups of different sizes were chosen. A survey of waste disposal and the influence of the size of the town and its technical options on the waste management was conducted. The results showed that municipalities have substantial reserves in reducing the amount of waste going to landfill and also in the practical use of waste sorting. In the conclusion of this thesis suggestions to optimization of waste disposal are being presented.
87

A study on working conditions and health status of waste pickers working at landfill sites in the City of Tshwane Metropolitan Municipality

Mothiba, Mathema Phozisa 01 March 2017 (has links)
Waste management is a global phenomenon and a challenge to all nations. There is a need to ensure that waste is handled in an environmental friendly and healthy manner. The high rate of unemployment in South Africa leads to elevated poverty, which is one of the most serious socio-economic problems in developing countries. This leads to people opting to work anywhere, particularly in the informal sector for survival. Waste picking is classified as a type of informal employment. In South Africa, the last stage in the life cycle of waste disposal is at the landfill sites. Landfill sites are normally located on the outskirts of towns and away from communities for safety and health reasons. This study researched the working conditions and health status of waste pickers working at some landfill sites in the City of Tshwane Metropolitan Municipality, namely Ga-Rankuwa, Onderstepoort and Hatherly. The study used a multi method approach, where both qualitative and quantitative factors of research were utilized. Data was gathered through survey questionnaire with a sample of 176 waste pickers at three landfill sites, together with unstructured interviews with municipal workers. The researcher also observed how waste pickers work at the landfill sites. Some of the findings of this study are that: • About 66 % of waste pickers at the landfill sites were females with an average age of 45 years. • A majority (93 %) of waste pickers did not reach matric and were not employable in the formal sector • Most waste pickers (53%) work 5 days and a few (41%) work 6 days per week. • Only 22% of participants reported injury at work and 41% consulted the clinic or hospital due to injury or illness. Descriptive statistical results of the study revealed that waste pickers view their health to be fair as compared to their peers but were not satisfied with their working conditions. Waste pickers are aware of stigma including health challenges associated with working at a landfill site and the need of acting appropriately in protecting themselves / Department of Environmental Sciences / M. Sc. (Environmental Management)
88

Resíduos da construção civil na cidade do Recife : percepção de trabalhadores envolvidos

Luiz Leopoldino Tavares da Silva 30 July 2012 (has links)
Esta pesquisa teve como objetivo geral avaliar a percepção de alguns trabalhadores envolvidos com o descarte dos resíduos da construção atual na cidade do Recife. Desse modo, a investigação da composição dos resíduos de construção civil na cidade do Recife é importante haja vista muitos serem recicláveis, o que pode proporcionar a redução dos custos nas obras e melhor a qualidade de vida da população a medida que busca encontrar mecanismos de reutilização de tais resíduos. A metodologia adotada para alcançar os objetivos propostos, constou de uma revisão da literatura que aborda o tema proposto, um levantamento de áreas de construção licenciadas no ano de 2011 na cidade do Recife; aplicação de questionário com os trabalhadores da construção civil nos canteiros de obras; e identificação com registro fotográfico de áreas de disposição irregular de resíduos da construção civil. Dentre os locais de deposição irregular dos resíduos da construção civil pode-se destacar: encostas (que provocam sobrecarga, condenando a vegetação provocando a instabilidade dos taludes); cursos dágua (o que prejudica a drenagem urbana e contamina as águas); logradouros (o que permite a proliferação de vetores); e, ainda, próximos a hospitais (tornando o ambiente ainda mais insalubre). A reciclagem é hoje uma atividade em constante ascensão e de grande importância para o desenvolvimento do país. Constatou-se no Recife que nos bairros próximos ao centro, as construções possuem depósitos coletores de resíduos da construção civil, que são despejados sem qualquer separação e ficam aguardando a coleta. Entretanto em bairros marginais é comum visualizar deposição irregular as margens de rodovias municipais, estaduais e federais, evidenciando a necessidade de uma fiscalização mais rigorosa e abrangente a todo o município e maior investimento em informação e projetos de reutilização de resíduos da construção civil na própria construção. / This research aimed to evaluate the perception of some workers involved with the disposal of construction wastes present in the city of Recife. Thus, the investigation of waste from construction in the city of Recife is important considering many are recyclable, which can provide lower costs in the works and the better the quality of life measure that seeks to find ways to reuse of such waste. The methodology adopted to achieve the proposed objectives, consisted of a literature review that addresses the theme, a survey of construction areas licensed in 2011 in Recife, a questionnaire with the construction workers at construction sites; identification and photographing of areas of irregular disposal of waste from construction. Among the local deposition of irregular construction waste can be highlighted: the slopes (which cause overload, condemning the vegetation causing the instability of slopes), watercourses (which undermines the urban drainage and contaminates the water), parks (which allows the proliferation of vectors), and also near hospitals (making the environment more unhealthy). Recycling is now a steady rise in activity and of great importance for the development of the country. It was found that in Recife in the neighborhoods near the center, the buildings have deposits collectors construction waste that are dumped without any separation and are awaiting collection. However in marginal neighborhoods is common view deposition irregular margins county roads, state and federal, highlighting the need for stricter monitoring and comprehensive to the entire municipality and increased investment in information and reuse projects of construction waste in the construction.
89

Compósitos à base de resíduos da recuperação química da produção Kraft de celulose

Cusma, Daniel Fernandes 07 May 2015 (has links)
Cada vez mais, os resíduos industriais são vistos como uma fonte alternativa de materiais a serem utilizados na construção civil. Dessa maneira, realizou-se a pesquisa com o objetivo de analisar a utilização de resíduos da Caustificação: dregs, grits e lama de cal, originados de uma fábrica de celulose Kraft do Espírito Santo, utilizando cal residual como ligante. Os teores de dregs variaram entre 0 e 45 %, os de grits de 0 à 45 %, os de lama de cal de 0 à 30 % e a cal residual variou entre 10 e 25 %. Os corpos de prova cilíndricos de 20 x 20 mm apresentaram valores máximos de resistência à compressão uniaxial, no 3° dia de cura de 5,9 MPa, no 7° dia de 7,9 MPa, no 14° dia de 9,3 MPa, no 60° dia de 18,5 MPa e no 180° dia de 19,3 MPa. Através dos métodos de Fluorescência de Raio-X, Difração de Raio-X, Microscopia Eletrônica de Varredura e Espectroscopia de Energia Dispersiva foram determinadas as interações físico-química dos componentes das misturas iniciais e os processos de formação das estruturas dos novos materiais. O aumento dos valores das propriedades mecânicas observadas durante a cura ocorre em função da dissolução das superfícies das partículas sólidas dos componentes em ambiente alcalino, ocasionando à síntese das novas formações amorfas e cristalinas, especialmente da calcita. Os resultados da pesquisa permitiram concluir que os resíduos da Caustificação associados ao Resíduo da Produção de Cal podem ser utilizados como matéria prima em compósitos destinados à construção civil. / Increasingly the industrial wastes are used with alternative source of raw material in the civil construction. Thus, the study was conducted with the objective to analyze the use of wastes from chemical recovery of Kraft pulp production: dregs, grits and cal mud, generated for one Kraft pulp industry of Espírito Santo, Brazil, and waste from the lime production using as a binding agent. The concentration of dregs varied between 0 and 45 %, grits - between 0 and 45%, cal mud – between 0 and 30 % and waste of lime production ranged between 10 and 25%. The maximum values of materials for uniaxial compressive strength on the 3-rd day of curing was 5.89 MPa, on the 7-th day – 7.95 MPa, on the 14-th day – 9.35 MPa, on the 60-th day – 18.52 MPa and on the 180-th day it reached the value of 19.34 MPa. Through the methods X-Ray Fluorescence Spectrometry, X-Ray Diffraction, Scanning Electron Microscopy and Energy Dispersive Spectroscopy were determined physical-chemical interaction of the components to initial mixtures and the processes for structures formation of new materials, which can explain the values of mechanical properties during curing. They occurred due to dissolving of the solid particles surfaces of the components in an alkaline environment and to synthesis of new formations, amorphous and crystalline, especially of calcite. The results of the study indicate that the waste from chemical recovery can be used in the production of composites for civil construction.
90

Compósitos à base de resíduos da recuperação química da produção Kraft de celulose

Cusma, Daniel Fernandes 07 May 2015 (has links)
Cada vez mais, os resíduos industriais são vistos como uma fonte alternativa de materiais a serem utilizados na construção civil. Dessa maneira, realizou-se a pesquisa com o objetivo de analisar a utilização de resíduos da Caustificação: dregs, grits e lama de cal, originados de uma fábrica de celulose Kraft do Espírito Santo, utilizando cal residual como ligante. Os teores de dregs variaram entre 0 e 45 %, os de grits de 0 à 45 %, os de lama de cal de 0 à 30 % e a cal residual variou entre 10 e 25 %. Os corpos de prova cilíndricos de 20 x 20 mm apresentaram valores máximos de resistência à compressão uniaxial, no 3° dia de cura de 5,9 MPa, no 7° dia de 7,9 MPa, no 14° dia de 9,3 MPa, no 60° dia de 18,5 MPa e no 180° dia de 19,3 MPa. Através dos métodos de Fluorescência de Raio-X, Difração de Raio-X, Microscopia Eletrônica de Varredura e Espectroscopia de Energia Dispersiva foram determinadas as interações físico-química dos componentes das misturas iniciais e os processos de formação das estruturas dos novos materiais. O aumento dos valores das propriedades mecânicas observadas durante a cura ocorre em função da dissolução das superfícies das partículas sólidas dos componentes em ambiente alcalino, ocasionando à síntese das novas formações amorfas e cristalinas, especialmente da calcita. Os resultados da pesquisa permitiram concluir que os resíduos da Caustificação associados ao Resíduo da Produção de Cal podem ser utilizados como matéria prima em compósitos destinados à construção civil. / Increasingly the industrial wastes are used with alternative source of raw material in the civil construction. Thus, the study was conducted with the objective to analyze the use of wastes from chemical recovery of Kraft pulp production: dregs, grits and cal mud, generated for one Kraft pulp industry of Espírito Santo, Brazil, and waste from the lime production using as a binding agent. The concentration of dregs varied between 0 and 45 %, grits - between 0 and 45%, cal mud – between 0 and 30 % and waste of lime production ranged between 10 and 25%. The maximum values of materials for uniaxial compressive strength on the 3-rd day of curing was 5.89 MPa, on the 7-th day – 7.95 MPa, on the 14-th day – 9.35 MPa, on the 60-th day – 18.52 MPa and on the 180-th day it reached the value of 19.34 MPa. Through the methods X-Ray Fluorescence Spectrometry, X-Ray Diffraction, Scanning Electron Microscopy and Energy Dispersive Spectroscopy were determined physical-chemical interaction of the components to initial mixtures and the processes for structures formation of new materials, which can explain the values of mechanical properties during curing. They occurred due to dissolving of the solid particles surfaces of the components in an alkaline environment and to synthesis of new formations, amorphous and crystalline, especially of calcite. The results of the study indicate that the waste from chemical recovery can be used in the production of composites for civil construction.

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