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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.
1

Microplásticos têxteis : emissão de fibras sintéticas na lavagem doméstica / Textile microplastics: synthetic fibers\' emission during domestic washings

Cesa, Flavia Salvador 23 August 2017 (has links)
Há tempos a ubiquidade dos materiais plásticos no meio ambiente é assunto de discussão, com destaque para as partículas menores, ditas microplásticos (< 5 milímetros). Fibras provenientes de materiais têxteis são um subgrupo dos microplásticos e têm origem em diversas fontes, incluindo lavagens domesticas, uma vez que filtros de lavadoras e sistemas de tratamento de esgoto não são desenhados especificamente para retê-las. Quando no meio ambiente, estes materiais podem alcançar concentrações até milhares de unidades por metro cúbico, ficando disponíveis a uma gama de espécies. Neste cenário, o presente estudo teve como objetivo avaliar parâmetros de lavagem, e características têxteis que pudessem influenciar no desprendimento de fibras em efluentes de lavadoras domesticas. Foram realizados experimentos com dez sucessivas lavagens individuais, com e sem detergente, para quatro tipos de artigo: algodão (como padrão de comparação), acrílico, poliéster e poliamida. Os efluentes foram então filtrados (< 1 milímetro, 500 mícrons, 63 mícrons, 8 mícrons) e pesados. Resultados demonstram que todos os artigos têxteis liberaram fibras na lavagem. Dez sucessivas lavagens representaram queda na massa desprendida, bem como o uso de detergentes em comparação a lavagens sem detergente. Diferenças entre artigos sugeriram variação conforme características têxteis, onde algodão liberou mais fibras, seguido de acrílico, poliamida e poliéster. Em relação ao tamanho das fibras, a maioria ficou retida no filtro da lavadora (< 1 milímetro) e na peneira de 63 mícrons, mostrando o potencial de diminuição de porosidade do filtro. A visualização de fibras em papel-filtro de 8 mícrons sugere a existência de fibras micro e nano. Convertendo massa para numero de unidades, a lavagem individual de um artigo têxtil mostrou desprender entre milhares e centenas de milhares de fibras. Para uma extrapolação mundial, cerca de 40,4 mil toneladas de algodão e 21,5 mil toneladas de fibras sintéticas seriam liberadas em efluentes de esgoto. No Brasil estes valores corresponderiam, respectivamente, a 1,6 mil e 860 toneladas ano. Caso fossem tratadas em estações de tratamento de esgoto em condições ideais, seriam liberadas, em um ano, cerca de 737 toneladas de fibras sintéticas em escala mundial e 29 toneladas em escala nacional. Uma vez em cursos d\'água, estas fibras atingiriam, em ultima instância, o ambiente marinho, indicando a necessidade por soluções que combatam este tipo de poluição, sem antes deixar de explorar as lacunas do conhecimento, relacionadas, no âmbito têxtil, especialmente às diferenças metodológicas entre os estudos. / Since decades, the ubiquity of plastic materials in the environment has been a matter of discussion. Smaller pieces, named microplastic (< 5 millimeters) gained more attention recently and are now the focus of several studies. Textile fibers are a subgroup of microplastics and can be originated from several sources, including domestic washings, once filters and sewage treatment plants are not specifically designed to retain them. In the environment, these materials can reach concentrations up to millions of units per cubic meter, being available to many species. The objective of the present study was to evaluate washing parameters and also textile characteristics, which could influence in fibers emission from domestic washing machines. Experiments were done in ten successive times, with and without detergent, for four types of articles: cotton (as a pattern for comparison), acrylic, polyester and polyamide. Resulting effluents were then filtered in different porosities (< 1 millimeter, 500 microns, 63 microns, 8 microns), weighted, related to mass of textile articles and simulated regarding number of fibers. Results demonstrated that all textile articles emitted fibers during domestic washings. Ten successive washings represented a decrease in the emitted mass, as well as the use of detergent in relation to washings without the product. Differences between articles suggested variation of results according to textile characteristics, where the ranking of emission was: cotton, acrylic, polyamide and polyester. When considering the size of fibers, the majority was retained in the filter of the washing machine (porosity < 1 millimiter) and in 63 microns sieve, when compared to 500 microns sieve, showing the importance of the filter of the washing machine and the potential to decrease its porosity. Fibers retained in the filter- paper of 8 microns, couldnt be weighted because of its low mass, but their visualization suggests the existence of fibers in micro and nano scales. Converting mass to number of fibers, one individual washing was responsible for something between thousands and hundred of thousands of units. When extrapolating values to a global perspective, it reaches something around 40.4 thousand tonnes of cotton per year and 21.5 thousand tonnes of synthetic fibers per year. In a Brazilian perspective, these values correspond, respectively, to 1.6 thousand tonnes year and 860 tonnes year. If this effluents were all treated in sewage treatment plants, in ideal conditions, still they would release something like 737 tonnes of synthetic fibers per year in a global scale and 29 tonnes of synthetic fibers per year in a national scale. Once in water bodies, those fibers would reach the marine environment, indicating the necessity of solutions that could impair this kind of pollution, not before solving knowledge gaps, specially related, in the textile area, to methodology differences between studies
2

Microplásticos têxteis : emissão de fibras sintéticas na lavagem doméstica / Textile microplastics: synthetic fibers\' emission during domestic washings

Flavia Salvador Cesa 23 August 2017 (has links)
Há tempos a ubiquidade dos materiais plásticos no meio ambiente é assunto de discussão, com destaque para as partículas menores, ditas microplásticos (< 5 milímetros). Fibras provenientes de materiais têxteis são um subgrupo dos microplásticos e têm origem em diversas fontes, incluindo lavagens domesticas, uma vez que filtros de lavadoras e sistemas de tratamento de esgoto não são desenhados especificamente para retê-las. Quando no meio ambiente, estes materiais podem alcançar concentrações até milhares de unidades por metro cúbico, ficando disponíveis a uma gama de espécies. Neste cenário, o presente estudo teve como objetivo avaliar parâmetros de lavagem, e características têxteis que pudessem influenciar no desprendimento de fibras em efluentes de lavadoras domesticas. Foram realizados experimentos com dez sucessivas lavagens individuais, com e sem detergente, para quatro tipos de artigo: algodão (como padrão de comparação), acrílico, poliéster e poliamida. Os efluentes foram então filtrados (< 1 milímetro, 500 mícrons, 63 mícrons, 8 mícrons) e pesados. Resultados demonstram que todos os artigos têxteis liberaram fibras na lavagem. Dez sucessivas lavagens representaram queda na massa desprendida, bem como o uso de detergentes em comparação a lavagens sem detergente. Diferenças entre artigos sugeriram variação conforme características têxteis, onde algodão liberou mais fibras, seguido de acrílico, poliamida e poliéster. Em relação ao tamanho das fibras, a maioria ficou retida no filtro da lavadora (< 1 milímetro) e na peneira de 63 mícrons, mostrando o potencial de diminuição de porosidade do filtro. A visualização de fibras em papel-filtro de 8 mícrons sugere a existência de fibras micro e nano. Convertendo massa para numero de unidades, a lavagem individual de um artigo têxtil mostrou desprender entre milhares e centenas de milhares de fibras. Para uma extrapolação mundial, cerca de 40,4 mil toneladas de algodão e 21,5 mil toneladas de fibras sintéticas seriam liberadas em efluentes de esgoto. No Brasil estes valores corresponderiam, respectivamente, a 1,6 mil e 860 toneladas ano. Caso fossem tratadas em estações de tratamento de esgoto em condições ideais, seriam liberadas, em um ano, cerca de 737 toneladas de fibras sintéticas em escala mundial e 29 toneladas em escala nacional. Uma vez em cursos d\'água, estas fibras atingiriam, em ultima instância, o ambiente marinho, indicando a necessidade por soluções que combatam este tipo de poluição, sem antes deixar de explorar as lacunas do conhecimento, relacionadas, no âmbito têxtil, especialmente às diferenças metodológicas entre os estudos. / Since decades, the ubiquity of plastic materials in the environment has been a matter of discussion. Smaller pieces, named microplastic (< 5 millimeters) gained more attention recently and are now the focus of several studies. Textile fibers are a subgroup of microplastics and can be originated from several sources, including domestic washings, once filters and sewage treatment plants are not specifically designed to retain them. In the environment, these materials can reach concentrations up to millions of units per cubic meter, being available to many species. The objective of the present study was to evaluate washing parameters and also textile characteristics, which could influence in fibers emission from domestic washing machines. Experiments were done in ten successive times, with and without detergent, for four types of articles: cotton (as a pattern for comparison), acrylic, polyester and polyamide. Resulting effluents were then filtered in different porosities (< 1 millimeter, 500 microns, 63 microns, 8 microns), weighted, related to mass of textile articles and simulated regarding number of fibers. Results demonstrated that all textile articles emitted fibers during domestic washings. Ten successive washings represented a decrease in the emitted mass, as well as the use of detergent in relation to washings without the product. Differences between articles suggested variation of results according to textile characteristics, where the ranking of emission was: cotton, acrylic, polyamide and polyester. When considering the size of fibers, the majority was retained in the filter of the washing machine (porosity < 1 millimiter) and in 63 microns sieve, when compared to 500 microns sieve, showing the importance of the filter of the washing machine and the potential to decrease its porosity. Fibers retained in the filter- paper of 8 microns, couldnt be weighted because of its low mass, but their visualization suggests the existence of fibers in micro and nano scales. Converting mass to number of fibers, one individual washing was responsible for something between thousands and hundred of thousands of units. When extrapolating values to a global perspective, it reaches something around 40.4 thousand tonnes of cotton per year and 21.5 thousand tonnes of synthetic fibers per year. In a Brazilian perspective, these values correspond, respectively, to 1.6 thousand tonnes year and 860 tonnes year. If this effluents were all treated in sewage treatment plants, in ideal conditions, still they would release something like 737 tonnes of synthetic fibers per year in a global scale and 29 tonnes of synthetic fibers per year in a national scale. Once in water bodies, those fibers would reach the marine environment, indicating the necessity of solutions that could impair this kind of pollution, not before solving knowledge gaps, specially related, in the textile area, to methodology differences between studies
3

Emission av mikroplast vid hushållstvätt : En kritiskt granskning av nuvarande forskning inom mikroplastemission vid tvätt

Vu, Jennifer, Ekberg, Julia January 2020 (has links)
Den här studien är under projektet MinShed som drivs av RISE. MinShed är ett 3årigt projekt som undersöker mikroplastemission från syntetiska textilier vid tvätt. Den här studien har som syfte att genomföra en Critical Review på tidigare studier inom ämnet: Olika syntetiska material som släpper mikroplaster via hushållstvätt. Samtliga studier har sammanfattats i en framtagen matris där information om studiernas materialdata presenteras. Den främsta anledningen till varför en sådan matris ska presenteras är för att finna textilteknologiska gap som existerar i nuvarande forskning. Vad som omfattar textilteknologi kommer förklaringar ges mer ingående under litteraturgenomgången. I dagsläget finns det inte tillräckligt spårbara material för existerande forskning, därav är det svårt att avgöra exakt vilka textilparametrar som orsakar mer eller mindre emission vid tvätt. Därför kan företag heller inte prioritera smartare designval för att reducera mikroplastemission. Av de18 undersökta studierna var det enbart 2 av dessa som hade full kontroll överprovmaterialet. Detta betyder att ytterligare forskning inom området är aktuellt. Vad som kan hindra forskningen att utvecklas är förnärvarande textilbranschen. Det finns ingen trovärdig uppsikt över textilmaterial och dess processer, vilket försvårarutförandet att spåra de textilparametrar som orsakar emission vid tvätt. För att dra slutsatser mellan emission och konstruktionsparametrar för textil så bör man i framtiden tänka på att enbart testa en parameter åt gången. Utifrån resultatet från denna studie rekommenderas en egen tillverkning av materialet för att få en spårbartextilproduktion, då det ger ett mer trovärdigt resultat på grund av mer kontroll över processerna som textiler genomgår. / This study is performed under the project MinShed run by RISE. MinShed is a 3-year project that investigates in Microplastics emissions from synthetic textiles during domestic washing. The aim of the study is to do a Critical Review on previous research in the subject: Various synthetic materials that release microplastics during domestic laundry. The previous research is presented in a matrix, where information about the presented by the investigated laundry parameters, as well as the textile parameters. The main reason why such matrix is needed is to find the gap that contains the textile parameters for the various researches. Some of the most important textile parameters will be described during the literature review. At present, there is not enough traceable material for existing research, hence it is difficult to determine exactly which textile parameters which cause during washing. Therefore, companies cannot prioritize smarter design choices in order to reduce microplastics emissions from the materials. Of the 18research studies which were analyzed, only 2 of them had full control over their sample material. This means that further research in this area is needed. What can prevent future research is currently the textile industry. There is no reliable oversight of textile materials and their processes, which makes it difficult to track textile parameters that cause emission when washing. In order to be able to draw conclusions between emission and textile design parameters, researchers should remember to test only one parameter at a time and have an inhouse or own production of the specimens, this will give a better control of the results.

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