There is worldwide concern over the possible estrogenic effects of organic chemicals on a variety of wildlife and indeed on humankind. In the U.K., estrogenic compounds in sewage treatment works (STW) effluents have been implicated in causing the increases in egg yolk protein production observed in caged male trout and other fish species. At the initiation of the present study, few of the estrogenic compounds in STW effiuents had been recognised, although circumstantial evidence suggested that steroidal hormones were primary candidates. Cholesterol is abundant in STW effluents and is the precursor of all steroidal hormones biosynthesised in mammalian systems. Thus, the aim of the present study was to examine the hypothesis that cholesterol might undergo A-ring aromatisation, during sewage treatment, producing estrone and 17β-estradiol via, intermediates such as l9-norcholest-l,3,5(10)-trien-3-ol (NCT). To study this hypothesis NCT was first synthesised via a known route and several of its chromatographic and mass spectral properties established for the first time. NCT itself was found to possess some estrogenic potential determined using an established assay but this was rather weak compared to 17β-estradiol - about 200,000 times less active at the minimum concentration needed to invoke a response. NCT also proved to be a much more hydrophobic compound than, for example, 17β-estradiol with a computed log octanol-water partition coefficient (Kow) of over 9 compared with a log Kow of about 4 for l7β-estradiol. The established analytical properties of NCT were then used to investigate possible NCT formation in sewage. Radiolabelled 14C-cholesterol was incubated aerobically and anaerobically in Semi-Continuous Aaivated Sludge (SCAS), Die Away (DA) or simple stand alone STW simulation vessels. The products of incubation in both aqueous and solid fractions were examined by radio-high performance liquid chromatography (r-HPLC), radio-thin layer chromatography (r-TLC) and radio-gas chromatography (r-GC). Aerobic studies showed that side chain cleavage and A-ring rupture of cholesterol occurred rapidly (~25 % of added activity within 24 hrs) as measured by 14C02 evolution. Gaseous evolution was not monitored from the anaerobic experiments. Most remaining activity was associated with the solids fractions in all experiments. In the aqueous experiments both SCAS and DA systems, r-HPLC revealed rapid production of polar products which were not identified further. r-HPLC also revealed non-polar components of which choIest-3,5-diene, an unknown cholestadiene, a cholestadienol (other than 5,7-dienol), cholest-4-en-3-one and possibly NCT were identified by r-GC in the products of DA experiments. Whilst r-HPLC and r-TLC also revealed several products of anaerobic digestion of cholesterol, no compounds were detected by r-GC. STW effluents from two wastewater plants in the North London area were monitored over 7 months for A-ring steroids and other suspected estrogenic chemicals. Both effluents had previously proved estrogenic to caged fish. Liquid and SPM samples were taken, extracted and analysed by GC-MS. The two main estrogens, l7β-estradiol and estrone were identified from all liquid samples but not in SPM extracts. Generally the concentration of estrone (maximum ca 3 ng Lˉ¹) was significantly higher than that for 17β-estradiol (maximum 1 ng fˉ¹). The third natural estrogen, l6a,l7β-estriol, was identified in all Harpenden effluent samples analysed up to a concentration ca 0.5 ng Lˉ¹. However, estriol was not found in Deephams effluent extracts. The phytoestrogen, daidzein, found in soya based products was intermittently found in aqueous effluents samples from both sites >1 ng Lˉ¹. SPM made up <0.001 % of the effluent. Extracts showed that there was a high percentage of steroidal based material with coprostanol>cholesterol=β-sitosterol>>stigmasterol. NCT was twice identified from SPM taken from Deephams with a concentration of 39 and 136 ng 1ˉ¹ but <LOD in Harpenden SPM extracts. In conclusion this study showed that formation of NCT from cholesterol in STW treatment under conditions monitored herein is not a major process. However, estrone, 17β-estradiol and 16a, 17β-estriol are relatively abundant and widespread components of the STW effluents tested. The origins of the components undoubtedly include direct inputs from female urine and faeces but other metabolic sources should not be entirely ruled out.

Master's thesis. / Format: PDF. Bibl.

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

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Thesis (M. Soc. Sc.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 88-92).

Thesis (M.Soc.Sc.)--University of Hong Kong, 1994. / Includes bibliographical references (leaves 88-92) Also available in print.

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

Orientador: Lucia Regina Durrant / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T21:40:43Z (GMT). No. of bitstreams: 1 Migliorelli_SuelmaAparecidaFeijo_M.pdf: 3942895 bytes, checksum: 065a0ec4b7b2c209bfea1bf136a46b13 (MD5) Previous issue date: 2003 / Resumo: No atual cenário mundial, o uso de corantes sintéticos tem se tomado um recurso cada vez mais utilizado pelas indústrias, com o intuito de tomar seus produtos comercialmente mais aceitáveis para o público. Por outro lado, uma grande parte desses corantes acaba sendo depositada no meio ambiente, principalmente através de efluentes despejados em rios ou cursos de águas, causando problemas de poluição cada vez maiores. Não se pode afirmar que exista um método ideal usado para tratar efluentes contendo corantes sintéticos, mas alguns métodos biológicos têm sido propostos com freqüência, devido aos benefícios que apresentam em relação aos métodos tradicionais, como baixo custo. Biosurfactantes são substâncias com caráter anfótero, que são produzidas por microrganismos cultivados em diversas fontes de carbono. Pouco ainda se conhece sobre os motivos que levam microrganismos a produzirem tais substâncias, mas um deles refere-se à necessidade de solubilização de substratos insolúveis. o presente trabalho mostra a atividade de emulsificação apresentada por cepas bacterianas, os tipos de atividade de biosurfactantes produzidos pelas mesmas e avalia a capacidade de descoloração de corantes, artificiais e hidrossolúveis, pelas cepas bacterianas em estudo. Dentre as linhagens destacaram-se C 50 (identificada como Bacillus subtilis) e A 50 (não identificada), produzindo biosurfactante (nível de compactação de bolhas +4) quando crescem em meio contendo corantes, artificiais e hidrossolúveis. Apresentaram também capacidade superior às demais cepas, na descoloração dos corantes contidos nos meios. Na segunda etapa do trabalho, a atividade de emulsificação frente ao tolueno, após dez dias de crescimento das linhagens A 50 e C 50 foram, respectivamente, 0,53 U em meio de cultura contendo tartrazina (oitavo dia) e 0,27 U em meio contendo erioglaucine (quinto dia). Frente ao xileno, a atividade de emulsificação após dez dias de crescimento das linhagens A 50 e C 50 foram, respectivamente, 0,39 U, no quinto dia (meio contendo orange G) e 0,45 U no quarto dia (meio contendo erioglaucine ) / Abstract: Worldwide at the present time synthetic dyes have been frequently employed by the industry to provide commercial products more acceptable to people. On the other hand, a great part of these dyes have been deposited in the environment, mainly through eff1uent discharges into water courses, resulting in growing pollution problems. There does not exist an ideal method that can be used to treat eff1uents containing synthetic dyes, but biological methods have been frequently proposed, probably due to their advantages in relation to the traditional methods, such as low costs. Biosurfactants are substances with both hydrophylic and lipophylic character, produced by microrganisms growing on different carbon sources. There is not sufficient information about the reason why microrganisms synthetise biosurfactants, but one of them relates to the solubilization of insoluble substracts. The present work shows bacterial emulsification activities and the different types of biosurfactant activities that these microrganisms can produce. The ability of some strains to remove the dyes color was evaluated. The C 50 (that was identified as Bacillus subtilis) and A 50 (not identified) cepas can produce biosurfactant (+4 compactation leveI) in artificial and U (for tartrazin-containing medium) and 0,27 U (for erioglaucine-containing medium). ln presence of xileno, the emulsification activity during the growth of the A 50 and C 50 strains was 0,39 U (for orange G-containing medium) and 0,45 U (for erioglaucine-containing medium) / Mestrado / Mestre em Ciência de Alimentos

Please read the abstract in the section 00front of this document / Thesis (PhD (Applied Science: Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

O controle de emissões em veículos pesados está em foco desde a década de 90, com a criação de regulamentações nacionais e internacionais que impõe limites cada vez mais rígidos para as concentrações de poluentes emitidos por estes veículos. O desenvolvimento de novas tecnologias possui papel fundamental neste processo, buscando redução nos níveis de emissões com mínimo impacto negativo no desempenho e no consumo do veículo. Para tanto, o presente trabalho visa avaliar a influência da posição dos dutos de admissão de ar de cabeçotes de motores a combustão interna, especificamente em motores de ignição por compressão (MIC) de 4 válvulas, no escoamento de ar dentro do cilindro. O escoamento do ar e o movimento de swirl são fatores importantes para a mistura e distribuição do combustível injetado, e quando otimizados para uma queima melhor distribuída, contribuem para redução nos níveis de emissões. Procura-se investigar quais direções características dos dutos são determinantes para o escoamento e para o comportamento de swirl do motor através de simulações em fluidodinâmica computacional (Computational Fluid Dynamics - CFD) utilizando o programa CD-adapco STAR-CCM+®. Os resultados de alguns dos cenários simulados são comparados a resultados de testes experimentais realizados em bancada de medição de swirl, no âmbito de outro trabalho sendo desenvolvido no mesmo grupo de projeto. / The emissions control in heavy-duty vehicles has been in focus since the 1990\'s, with the creation of national and international regulations which impose strict limits for pollutant concentrations released by these vehicles. The development of new technologies has a fundamental role in this process, aiming the reduction of emission levels with minimum impact on the performance and fuel consumption of the vehicle. Therefore, the present study aims to evaluate the influence of the position of intake ports in cylinder heads from internal combustion engines, specifically 4-valves compression-ignition (CI) engines, in the in-cylinder air flow. The air flow and swirl motion are important factors for the mixture and distribution of injected fuel, and when optimized for a better distributed combustion, contribute for the reduction of emission levels. This study investigates the characteristic directions of ports which are determinant for the air flow and swirl behaviour of the engine through Computational Fluid Dynamics (CFD) simulations using CD-adapco software STAR-CCM+®. The results from a group of simulated cases are compared to experimental test results from another project, developed on the same project group, performed in a swirl meter test rig.