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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.
101

Estudo do comportamento dinâmico e do fenômeno de deslocamento em lavadoras de roupas de eixo vertical / Study of the dynamic behavior and walking phenomenon of a vertical axis washing machine

Wladimir Alex Magalhães Barcha 28 September 2004 (has links)
Este trabalho apresenta e compara alguns meios para o estudo do comportamento dinâmico de uma lavadora de roupas de eixo vertical durante o processo de extração de água das roupas, também conhecido como centrifugação. Os três métodos utilizados para estudar o comportamento dinâmico de uma lavadora de roupas de eixo vertical foram: analítico, experimental e simulação através de multicorpos. O interesse nesta etapa é devido ao fato dos problemas de vibração de uma lavadora ocorrerem principalmente durante a centrifugação. A modelagem de uma lavadora de roupas durante a etapa de centrifugação permite a obtenção de seu comportamento dinâmico bem como de suas principais características. Um outro tópico estudado neste trabalho foi o fenômeno de deslocamento da lavadora, um dos principais motivos de reclamação dos usuários de lavadoras de roupa automáticas. / This work presents and compares some ways to study the dynamic behavior of a vertical axis washing machine during the water extraction process, also called spinning stage. The three methodologies used to study the dynamic behavior of a vertical axis washing machine area: analytical, experimental and simulation using Multi Body System. The interest in this stage is due to the fact that the main vibration problems of an automatic washing machine occur in the spinning cycle. Since the unbalance force that causes the vibration problems is centrifugal in nature, this makes intuitive sense as the rotational speed of the basket is the largest during the spin extraction cycle. Thus, modeling the washing machine during the spinning cycle allow us to get its dynamic behavior as well as the main characteristics of this behavior. Another topic studied in this work was the walking phenomenon, the main complaint of the users.
102

Avaliação da toxicidade e genotoxixidade dos corantes azo reativos remazol preto B e remazol alaranjado 3R e da eficácia da radiação com feixe de elétrons na redução da cor e efeitos tóxico / Assessment of toxicity and genotoxicity of the reactive azo dyes remazol black B and remazol orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects

PINHEIRO, ALESSANDRO de S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:29Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:12Z (GMT). No. of bitstreams: 0 / As indústrias têxteis desempenham um importante papel na economia nacional e mundial. Entretanto, do ponto de vista ambiental, suas atividades são consideradas como potencialmente poluidoras e utilizadoras de recursos naturais. Os corantes azo reativos são os principais corantes utilizados no setor para o tingimento do algodão no Brasil e no mundo. Devido à sua baixa fixação à fibra e a variações no processo de produção, cerca de 30 % da concentração inicial utilizada nos banhos de tingimento são perdidos e vão compor o efluente final. Esses compostos apresentam uma baixa biodegradabilidade e elevada solubilidade em água e, por isso, não são completamente removidos pelos processos biológicos convencionais. Os corantes quando descartados sem tratamento adequado no corpo dágua receptor podem causar modificações estéticas, alterar a fotossíntese e a solubilidade dos gases, além de serem tóxicos e genotóxicos para a biota. Os principais objetivos do trabalho foram avaliar a toxicidade e genotoxicidade de dois diferentes corantes azo reativos (Remazol Preto B RPB e Remazol Alaranjado 3R R3AR) e a eficiência de redução da cor e toxicidade após o uso da radiação com feixe de elétrons. Também foi analisada a toxicidade dos corantes em diferentes formas químicas, que podem ser encontradas nos efluentes. Os ensaios de toxicidade aguda realizados com Vibrio fischeri, Daphnia similis e Biomphalaria glabrata evidenciaram diferentes padrões de resposta para os corantes. Os dois corantes em suas formas químicas foram levemente tóxicos para Vibrio fischeri, com exceção da forma vinilsulfona do corante RPB que foi tóxico (CE(I)5015min = 6,23 mg L-1). Nos ensaios com Daphnia similis, o corante RPB foi levemente tóxico na sua forma original, sulfatoetilsulfona (CE(I)5048h = 91,25 mg L-1) e não apresentou toxicidade nas demais formas químicas. Entretanto, o corante RA3R foi tóxico para o dafnídeo, sendo muito tóxico na forma vinilsulfona (CE(I)5048h = 0,54 mg L-1). Não foi observada toxicidade nos ensaios com o organismo Biomphalaria glabrata. A toxicidade crônica foi avaliada com o organismo Ceriodaphnia dubia e o corante RPB apresentou valores de CENO e CEO iguais a 12,5 e 25 mg L-1, respectivamente, para a forma sulfatoetilsulfona. Após a hidrólise do corante (vinilsulfona e hidroxietilsulfona) foi observado um aumento os valores obtidos de CENO e CEO. Não foi verificado efeito crônico para o corante R3AR e suas formas químicas. O teste do cometa adaptado para o caramujo Biomphalaria glabrata foi utilizado para avaliar a genotoxicidade dos corantes. O corante RPB apresentou genotoxicidade nas concentrações mais elevadas (1 e 2 g L-1), com valores de dano quantitativo de 117 e 112 e o R3AR não foi genotóxico. O uso da radiação com feixes de elétrons demonstrou eficácia na remoção da cor dos corantes. Com a dose de 10 kGy foi possível uma redução de 97,64 % para RPB e de 96,8 % para R3AR. Após irradiação do corante RPB com a dose de 10 kGy foi evidenciada uma redução de 59,52 % da toxicidade aguda avaliada com Vibrio fischeri. Nas demais doses não houve redução significativa, assim como na avaliação com Daphnia similis, onde os valores de CE(I)5048h obtidos foram menores que o corante não irradiado. O corante R3AR apresentou diminuição da toxicidade mais acentuada após a radiação quando comparado com o RPB, com reduções de 82,95 % (V. fischeri) e 71,26 % (D. similis) com 10 kGy. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
103

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
104

Isolamento e identificação de substâncias provenientes da laranjeira ´Valência` (Citrus sinensis) envolvidas no estímulo e/ou quebra da dormência de estruturas quiescentes de Colletotrichum acutatum, agente causal da podridão floral dos citros / Isolation and identification of substances from sweet orange Valencia (Citrus sinensis) involved in the stimulation and/or dormancy-breaking of quiescent structures of Colletotrichum acutatum, causal agent of citrus postbloom fruit drop

Simone Cristiane Brand 01 February 2012 (has links)
A podridão floral dos citros (PFC), causada por Colletotrichum acutatum, induz a abscisão de frutos jovens, podendo causar perdas de até 100%. A presença de inóculo viável na forma de conídios e/ou apressórios quiescentes na planta justifica a ocorrência generalizada da doença. Em períodos de chuva a PFC é agravada, possivelmente, em função de substâncias lavadas das diferentes partes da planta, as quais contêm metabólitos que estimulam o desenvolvimento do fungo. Diante do exposto, objetivou-se verificar o efeito das águas de lavagem brutas (ALBs) de flores, botões, folhas velhas (FV) e folhas novas (FN) e mistura destas sobre conídios, apressórios e hifas quiescentes de C. acutatum (isolados 61A e 142) in vitro e in vivo e sobre a severidade da PFC, bem como identificar substâncias presentes nas ALBs, exibindo a atividade biológica de interesse. Além disso, buscou-se verificar variações na composição das ALBs. O efeito de compostos voláteis brutos (CVBs) e os identificados a partir de laranjeira Valência (linalol, limoneno, mirceno, nonanal e a mistura destes) sobre o desenvolvimento do patógeno também foi avaliado. Todas as frações das ALBs estimularam a germinação dos conídios do fungo, sendo que a ALB de flores apresentou o maior estímulo para ambos os isolados. Para apressórios quiescentes (isolado 61A), o maior estímulo foi verificado nos tratamentos com ALBs de botões e da mistura e para conídios no tratamento mistura. Os maiores valores para comprimento do tubo germinativo foram observados nos tratamentos mistura, FN e botões. Para as estruturas quiescentes, o efeito das ALBs foi mais significativo para o isolado 142. Não foi observado efeito das ALBs sobre o micélio quiescente. Houve estímulo da germinação de conídios e ramificação de hifas in vivo, principalmente, em resposta ao tratamento com ALB de botões. A aplicação da ALB da mistura em flores resultou em maior severidade da PFC. Por sua vez, os CVBs apresentaram efeito inibitório. A exposição do isolado 61A aos voláteis (CVs) linalol, nonanal e mistura, resultou em germinação apenas na menor dose. O mirceno manteve a germinação semelhante a testemunha em todas as doses testadas, assim como limoneno nas doses de 0,005 a 0,25 µL mL-1. Todos os voláteis reduziram o comprimento do tubo germinativo. Para o isolado 142, houve redução em todas as variáveis para todas as doses dos CVs. Houve variações na composição das ALBs nas diferentes coletas, o que explica em parte a variação na capacidade de estímulo em alguns testes. Na ALB de flores, identificou-se a presença de cafeína, dos flavonóides glicosilados hesperidina e naringina, além de compostos glicosilados e peptídeos. Nas partes vegetais de laranjeira Valência foram identificados 54 CVs. As ALBs apresentam efeito estimulatório sobre conídios e apressórios quiescentes de C. acutatum in vitro e in vivo, bem como sobre a severidade da PFC. Os CVs linalol, limoneno, mirceno, nonanal e a mistura destes são, de forma geral, inibitórios ao desenvolvimento de C. acutatum. / The postbloom fruit drop of citrus (PFDC), caused by Colletotrichum acutatum, induces abscission of young fruits, and it may cause losses up to 100%. The presence of viable inoculum in the form of conidia and/or quiescent appressoria on the plant justifies the widespread occurrence of the disease. Under rain, the PFDC is increased, possibly due to substances washed from different parts of the plant, which contain metabolites that stimulate the development of the fungus. Therefore, we aimed to determine the effect of watery washing (WWs) of flowers, flower buds, old leaves (OL) and young leaves (YL) and the mixture of them on quiescent conidia and hyphae of C. acutatum (isolates 61A and 142) in vitro and in vivo and on the severity of the PFDC, and to identify substances in the WWs, exhibiting the biological activity of interest. In addition, variations in the composition of WWs were determinated. The effect of crude volatile compounds (CVCs) and those identified from Valencia sweet orange (linalool, limonene, myrcene, nonanal and the mixture of them) on the development of the pathogen was also evaluated. All fractions of WWs stimulated spore germination, and the flower WW exhibited the highest effect for both isolates. For quiescent appressoria (isolate 61A), the highest stimulus was observed in treatments with WWs from flower buds and the mixture and for quiescent conidia in the treatment mixture. The highest values for germ tube length were observed on the treatments mixture, YL and flower buds. For the quiescent structures, the effect of WWs was more significant for isolate 142. There was no effect of WWs on the quiescent mycelium. There was stimulation of conidia germination and hyphal branching in vivo in response mainly to treatment with WW from flower buds. The application of the mixture of WW in flowers resulted in higher severity of the PFDC. On the other hand, the CVCs showed inhibitory effect. Exposure of the isolate 61A to the volatiles (VCs) linalool, nonanal and the mixture of them, resulted in germination only at the lowest concentration. The germination on myrcene was similar to control at all doses tested as well as on limonene at doses from 0.005 to 0.25 mL mL-1. All volatiles reduced the length of the germ tube. In the case of isolate 142, a reduction in all variables for all concentration of VCs was observed. There were changes in the composition of WWs based upon times of harvesting, which partly explains the variations observed in the ability to stimulate the structures in some experiments. In flower WWs, we identified the presence of caffeine, the flavonol glycosides hesperidin and naringin, glycosylated compounds and peptides. In the plant parts of sweet orange \'Valencia\' were identified 54 VCs. The WWs have stimulatory effect on quiescent conidia and appressoria of C. acutatum in vitro and in vivo as well as in the severity of the PFDC. The VCs linalool, limonene, myrcene, nonanal and the mixture of them are, in general, inhibitory to the development of C. acutatum.
105

RESÍDUOS POLIMÉRICOS: QUANTIFICAÇÃO, CARACTERIZAÇÃO, LAVAGEM E TRATAMENTO DO EFLUENTE GERADO NO PROCESSO / POLYMERIC WASTE: QUANTIFICATION, CHARACTERIZATION, WASHING AND WASTEWATER TREATMENT GENERATED IN PROCESS

Streit, Angélica Fátima Mantelli 05 April 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the industrialization, the demographic growth and the consumption patterns of society there is an increase in the generation of solid waste, among which include polymeric waste. Thereby, the recycling emerges as a viable alternative, but for it to be effective is very important to carry out the cleaning of the waste, as well as the treatment of wastewater generated in the process. Thus, the main objective of this study was performed quantification, characterization and washing of polymer waste and treating the wastewater generated in the process. For the quantification of different polymeric waste was carried out a data collection in the Association of Selectors of Recyclable Materials (ASMAR). Where, also were collected the packages of HDPE, LDPE, PP, which were characterized by their degree of contamination and were subsequently used in the washing process. The washing process was carried out in three phases (pre-wash, washing and rinse), and using different cleaning products. Regarding the treatment of the effluent was adopted a physical-chemical process via the coagulation / flocculation, sedimentation, followed by filtration. The following coagulants were used: chitosan powder, chitosan diluted in acetic acid, tannin SG, tannin SL and aluminum sulfate. The results from the quantitation of different polymeric residues collected by ASRM demonstrated that the most representative resins in 2014 were the LDPE, with 33.87% and 21.74% with HDPE. Regarding the characterization of polymeric waste depending on their level of contaminants was possible to verify that packages of PP and HDPE, even though they come from selective collection still contained a high level of contaminants, unlike LDPE packaging. As the washing process, it was possible to ascertain that the three stages developed, consisting of an efficient sequence for obtaining clean polymeric residues and suitable for recycling. Furthermore, the combination of sulfonic acid with lauryl and sodium hydroxide showed be more efficient to the other conditions tested in the washing step. Regarding the treatment of the wastewater, the results indicated that the use of aluminum sulphate coagulating was the most efficient in the removal of turbidity. Also was noted the importance of completing the process of coagulation / flocculation before the filtration. From the results obtained in the characterization process of the raw and treated wastewater it was possible to verify that the chosen treatment is effective and appropriate, once the values removed for most of the analyzed parameters were higher than 90%, including turbidity, suspended solids, fixed and volatile amounted to nearly 100% removal. Therefore, the washing process applied was efficient for obtaining clean polymeric materials and favorable to recycling and the method employed for treatment of wastewater also played a great role, since it allows the obtention of a treated wastewater with appropriate quality standards, which gives safety and reliability for its reuse in the washing process of polymeric residues. / Com a industrialização, o crescimento demográfico e os padrões de consumo da sociedade há o aumento da geração de resíduos sólidos, entre os quais destacam-se os resíduos poliméricos. Assim, a reciclagem surge como uma alternativa viável, porém para que esta seja efetiva é de suma importância a realização da lavagem desses resíduos, assim como, do tratamento do efluente gerado nesse processo. Diante disso, o principal objetivo deste estudo foi realizar a quantificação, a caracterização e lavagem dos resíduos poliméricos, bem como, tratar o efluente gerado no processo. Para a quantificação dos diferentes resíduos poliméricos foi realizada uma coleta de dados na Associação de Selecionadores de Materiais Recicláveis (ASMAR). Onde, também foram coletadas as embalagens de PEAD, PEBD e PP, que foram caracterizadas quanto ao seu grau de contaminantes e posteriormente foram utilizadas no processo de lavagem. O processo de lavagem foi desenvolvido em três etapas (pré-lavagem, lavagem e enxague), sendo utilizados diferentes produtos de limpeza. Quanto ao tratamento do efluente foi adotado um processo físico-químico, via coagulação/floculação, sedimentação, seguida ainda por filtração. Os seguintes coagulantes foram utilizados: quitosana em pó, quitosana diluída em ácido acético, tanino SG, tanino SL e sulfato de alumínio. Os resultados obtidos a partir da quantificação dos diferentes resíduos poliméricos coletados pela ASMAR demonstraram que as resinas mais representativas no ano de 2014 foram a de PEBD, com 33,87% e a de PEAD com 21,74%. Referente à caracterização dos resíduos poliméricos em função do seu grau de contaminantes foi possível verificar que as embalagens de PP e PEAD, apesar de serem provenientes de coleta seletiva ainda continham um elevado grau de contaminantes, diferentemente das embalagens de PEBD. Quanto ao processo de lavagem, foi possível averiguar que as três etapas desenvolvidas, consistem em uma sequência eficiente para obtenção de resíduos poliméricos limpos e próprios para posterior reciclagem. Além disso, a combinação de ácido sulfônico com lauril e hidróxido de sódio se mostrou mais eficiente que as demais condições testadas na etapa de lavagem. Quanto ao tratamento do efluente, os resultados indicaram que o uso do coagulante a base de sulfato de alumínio foi o mais eficiente na remoção da turbidez. Também se observou a importância da realização do processo de coagulação/floculação anteriormente à filtração. A partir dos resultados obtidos no processo de caracterização dos efluentes bruto e tratado foi possível verificar que o tratamento adotado é eficiente e adequado, uma vez que os valores de remoção para a maior parte dos parâmetros analisados foram superiores a 90%, inclusive a turbidez, os sólidos suspensos, fixos e voláteis chegaram a quase 100% de remoção. Portanto, o processo de lavagem adotado foi eficiente para obtenção de materiais poliméricos limpos e propícios à reciclagem e o método empregue para o tratamento do efluente também desempenhou uma excelente função, visto que possibilitou a obtenção de um efluente tratado com padrões de qualidade adequados, o que lhe confere segurança e confiabilidade para o seu reúso no processo de lavagem dos resíduos poliméricos.
106

Remediation of materials with mixed contaminants : treatability, technology and final disposal

Elgh-Dalgren, Kristin January 2009 (has links)
Contaminated soils are a large issue worldwide and much effort has been made to find efficient remediation methods. At many contaminated sites, mixtures of dif­ferent contaminants with different properties are present, which may lead to addi­tional problems, and thus additional costs, during the remediation process. This thesis presents the results from soil remedia­tion of two mixed contaminated soils, containing explosives and heavy metals and polycyclic aromatic hydrocarbons (PAH) and arsenic, respectively. The re­sults demonstrate that bioremediation may be an efficient method for moderate explosives concentration, but that too high contaminant concentrations may prevent the biodegradation, measured by both chemical and ecotoxicological analyses. If the contaminant concentration is very high, soil washing with alkaline pH (~12, NaOH) may be a good alterna­tive, which was observed to remove both explosives and heavy metals. For a PAH and arsenic contaminated soil, little degradation of organics was ob­served during the bioremediation. However, the arsenic present was re-distributed in the soil, which could poten­tially lead to increased availability and thus in­creased risk for contaminant spreading. Soil washing at alkaline pH (~12-13; Ca(OH)2) with a combination of a biodegradable non-ionic sur­factant and a biodegradable chelating agent, executed at high temperature (50°C), reached treatment goals for both arsenic and PAH after 10 min treatment. Measurement of ecotoxicity using Microtox® demonstrated that remaining surfactant in the soil may lead to increased toxicity despite lower con­taminant concentrations. Soil is a basically non-renewable resource and thus re-cycling of remediated soil ought to be commonly occurring. Yet, the re-cycling of remediated masses has so far been limited in Sweden, mainly because of the risk of spreading of pollu­tant remains. However, a recent proposition from the Swedish EPA opens for re-cycl­ing, even though the thresholds are very con­servative. Risk assessment of the re­mediated soil includes the utilization of leach­ing tests to estimate the risk of spreading of remaining pollutants. A comparison of the leaching from four reme­diated soils using three different leaching solutions reveals that leaching of both heavy metals and PAH occurs. In addition, differ­ences between different legisla­tions were observed, which could imply that the same soil could be re-cycled in one country (the Netherlands) but not another (Sweden).
107

Optimal design and operation of HMs removal from soil by EDDS enhanced washing / Lavage de sols pollués par des métaux lourds : efficacité et optimisation du procédé

Ferraro, Alberto 17 December 2015 (has links)
Ce travail de recherche porte sur l'optimisation des procédés de lavage de sol permettant le traitement des sites contaminés par des métaux lourds. Cette étude se concentre sur le cycle complet de ce type de traitement, incluant la possibilité de réutilisation et un traitement adapté de la solution de lavage de sol utilisée. La conception et l'exploitation d'un procédé de lavage de sol sont étudiées dans le but d'optimiser leur coût et leur efficacité. Dans ce but, les paramètres et la configuration du réacteur utilisé pour ce procédé sont étudiés en détail à travers des tests à l'échelle du laboratoire, et les cinétiques sont simulées par une modélisation mathématique. Les échantillons de sol utilisés au cours de cette étude proviennent de terres agricoles présentant une forte contamination en cuivre. Parmi plusieurs agents chélateurs de la famille des aminopolycarboxylates, il a été choisi d'utiliser l'acide éthylènediamine-N, N'-disuccinique (EDDS) pour sa biodégradabilité - largement rapportée dans la littérature – et son efficacité importante d'extraction des métaux lourds, y compris du cuivre. Le travail bibliographique a permis d'identifier les deux paramètres cruciaux pour l'optimisation du procédé de lavage de sol : le rapport molaire EDDS : Cu et le rapport liquide-solide (L/S). Des tests réalisés dans un réacteur à agitation continue (RAC) en fonctionnement discontinu ont permis d'étudier l'influence de ces deux paramètres sur le rendement et la cinétique d'extraction du cuivre. L’augmentation du rapport molaire EDDS : Cu a permis une meilleure amélioration de l'efficacité du procédé, comparée à l'augmentation du rapport L/S. Par ailleurs, les tests réalisés en discontinu ont clairement mis en évidence une première étape cinétique rapide au début du traitement, suivie d'une seconde étape d'extraction plus lente jusqu'à la fin du traitement. Il a donc été formulé un modèle empirique basé sur deux termes cinétiques. Les paramètres du modèle ont été calibrés puis validés grâce à deux séries de données expérimentales différentes. Ce modèle permet d'abord d'évaluer la validité de l'hypothèse d'un procédé reposant sur deux étapes cinétiques différentes. Cela représente aussi un nouvel outil pour prévoir l'efficacité du procédé en fonction de l'évolution du ratio molaire EDDS : Cu et du temps de traitement. Les coûts d'exploitation du procédé ont été minimisés en étudiant différentes configurations de traitement. En particulier, deux configurations en réacteur piston ont été analysées et comparées à celle en RAC. Les réacteurs pistons ont été simulés en utilisant plusieurs réacteurs en série et en variant les temps de rétention et le fractionnement de l'injection de la solution de lavage de sol. Comparés à la configuration en RAC, les résultats obtenus en réacteur piston ont montré une amélioration du rendement et de la cinétique d'extraction du cuivre, ainsi qu'une réduction de la quantité de solution de lavage utilisée. Pour finir, un procédé électrochimique a été mis en place pour le traitement et la récupération de la solution d'EDDS utilisée. Des tests en réacteur discontinu ont permis d'optimiser les paramètres de ce procédé (densité de courant, pH et conductivité de la solution de lavage de sol). La solution récupérée a ensuite été utilisée pour d'autres étapes de lavage de sol. Les résultats obtenus ont prouvé l'efficacité du traitement électrochimique pour la récupération de la solution d'EDDS, et permettent d'envisager l'application de cette technique pour réduire le coût des procédés de lavage de sol utilisant l'EDDS / The object of the present research work is the optimization of soil-washing processes applied to heavy metal contaminated soils. The work focuses on the whole cycle of these treatments, including the possible recovery and the proper disposal of the used washing solution. Both the design and the exploitation of a soil washing treatment are investigated, in order to maximize their efficacy, in terms of cost and process efficiency. At this aim process parameters and reactor configurations are studied in details through lab-scale tests, and the observed kinetics are simulated through mathematical modeling. Soil samples used for the experimental activity were collected from an agricultural field located in Southern Italy, mainly contaminated by copper. Among several Aminopolycarboxylate (APC) chelating agents, Ethylenediamine-N,N'-disuccinic acid (EDDS) was selected, for its recognized biodegradability, widely reported in literature works, and its efficiency as extracting agent towards several heavy metals, including Cu. Literature review allowed determining the two most important process parameters to be investigated for washing optimization. The two parameters were identified as EDDS : Cu molar ratio and liquid to soil ratio (L/S). In order to investigate the effect of these parameters on process kinetics and Cu extraction yield, batch washing tests in continuous-stirred tank reactor configuration (CSTR) were carried out. EDDS : Cu molar ratio increase was found to be able to enhance process efficiency more than L/S increase. Batch tests clearly displayed a first fast kinetic step at the beginning of the treatment, followed by a second slower kinetic extraction step, which lasted until the end of the treatment. According to this observation, an empirical mathematical model based on two-kinetic terms was formulated. Model parameters were firstly calibrated and then validated using two different sets of experimental data. The derived mathematical model was useful to assess the validity of the two-kinetic steps process hypothesis, and to provide a tool for process efficiency prediction depending on EDDS : Cu molar ratio and treatment time length. Exploitation costs of the process were minimized studying different treatment configurations. In details two Plug-Flow configurations were analyzed and compared to the CSTR one. The two Plug-Flow configurations were simulated using several reactors in series, varying the detention time of the reactors, and fractionating the injection of the washing solution. Achieved results displayed improvements in terms of Cu extraction yield and process kinetic for the tested Plug-Flow conditions compared to the CSTR one, and showed that the use of a Plug-Flow reactor allows to reduce the amount of required washing solution. Finally, an electrochemical process was tested for the treatment and the recovery of the spent EDDS solution. Batch tests were carried out to optimize electrochemical process parameters (e.g. current density, washing solution pH and conductivity). The recovered solution was also used for a multi-washing test. Results proved the effectiveness of the electrochemical treatment for EDDS solution recovery and its potential application as technique for EDDS-enhanced soil washing costs reduction
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Undersökning av parametrar som kan öka mobiliteten av arsenik i grundvatten efter jordtvätt i Gudarp. / Investigation of parameters that can increase the mobility of arsenic in groundwater after soil washing in Gudarp.

Dahlqvist, Erica January 2017 (has links)
After soil washing in the former wood preservation industry, the concentration of As (arsenic) have increased in the groundwater. The purpose of this study was to investigate different parameters that could increase the mobility of As in the groundwater. The impact the soil wash has on the soil and it is effect on mobility will also be consider. This study will also show how As, Cu and Cr changes over time, however, the focus will be on As when the soil washing have been controlled by the As concentration. Soil and groundwater samples have been collected. Through filtration Fe (iron), Al (aluminium) and TOC (Total organic carbon) together with As have been analysed to determine a possible relation. Redox potential and As specification have also been analysed. As occur probably dissolved in the groundwater or together with DOC (Dissolved organic carbon). No link between colloids and complexes with Fe and Al together with As was found through filtration. Redox potential has no impact since the water was well oxygenated and As occurred as As(V). As and Cu follow the same time trend, while different for Cr. It is clear that the concentration of As increased in the groundwater after soil washing and that soil excavating have not the same problem with increased levels. The ground structure is changed and the clay mineral with adsorption surface is removed with soil washing. This could explain the increase of As in the groundwater.
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Segmentation of washing detergents in the Czech Republic / Segmentace trhu pracích prostředků v České republice

Pejlová, Gabriela January 2012 (has links)
The master thesis is devoted to the explanation of the theory of market segmentation and then its application on the washing detergents market in the Czech Republic. The goal is to describe trends in segmentation of washing detergents and suggest possible reasons for them. Thus, the thesis is a combination of three parts -- the first depicts the theory in question, the second part captures empirical data of the washing detergents market describing the aggregate market and its individual segments in detail, and the third and final part is devoted to an attitude of customers to washing detergents in the Czech Republic.
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Development of a Machine to Control the Level of Washing in Panca Chili Seeds

De La Cruz, Anthony, Cardenas, Jaime, Vinces, Leonardo 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The washing of Panca chili seeds requires innovative solutions that allow controlling this process. It is necessary to handle variables (conductivity, pH, colorimetry) in the face of the challenge of working with small seeds. At present, there are no machines that are dedicated to the washing of this type of seeds, since in many companies this work is done manually, which is not the one indicated because this technique cannot guarantee homogeneity in the seed washing. In addition, direct handling of this type of seeds can cause irritation to the eyes and skin of the person who maintains contact with the seeds. That is why, it is proposed to make a machine to scale by means of a motorized rotary agitator inside a tank, in order to guarantee the homogeneity of the mixture when washing seeds. The present work will allow to determine, among two different types of agitators (axial and radial), which type of agitator is the most efficient in the washing of seeds of Panca chili, to achieve this objective the measurement of pH and electrical conductivity to the water will be carried after the mixture, after stirring. Finally, the analysis of the tests performed on the mixture obtained and washed by each type of agitator allowed to identify the turbine-type radial agitator, like the one that obtained greater efficiency in the washing of seeds, with respect to the helical agitator and pallets, designed for development of this work, in turn, could also confirm that this type of palette with the conductivity control allows to guarantee the homogeneity of the mixture during washing. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG. / Revisión por pares

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