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Áreas contaminadas em São Paulo: Uma análise crítica das propostas da operação urbana consorciada bairros do Tamanduateí, Setor Henry Ford / Contaminated areas in São Paulo: A critical analysis of the proposals of the urban operation consortium Tamanduateí neighborhoods, Sector Henry FordFlores Salinas, Vania Cristiane 06 April 2017 (has links)
A expansão desordenada das cidades contemporâneas, além de causar problemas de mobilidade, déficit habitacional devido ao seu rápido crescimento, levou também à ocupação de áreas protegidas ambientalmente bem como de territórios dos quais não se tinha conhecimento sobre seus riscos e restrições, como é o caso das áreas contaminadas. Estas áreas, na sua maioria derivadas de antigos terrenos industriais ou locais de depósito de resíduos, são abundantes na cidade de São Paulo, dado o seu histórico fortemente ligado à expansão industrial.Diante disto, o pressente trabalho reúne algumas das principais políticas públicas utilizadas em diversos países para tratar as áreas contaminadas, a partir de então, procura-se neste trabalho entender quais medidas podem ser aplicadas na cidade de São Paulo de forma a viabilizar a remediação do território com uma ocupação compatível com a demanda local. / The disordered growth of contemporary cities, besides problems with mobility, housing deficit and occupation of protected areas, also led to the occupation of territories with few information about their restrictions and risks, such as contaminated areas. These areas, mostly derived from old industrial lands or waste disposal sites, are abundant in the city of São Paulo, due their history strongly linked to the industrial expansion. Therefore, the present work brings together some of the main public policies used in several countries to treat the contaminated areas. From then on, it seeks to understand what measures can be applied in the city of São Paulo in order to make feasible the remediation of the territory with an occupation compatible with the demands of the city and the local population.
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Incômodo em relação ao ruído urbano entre trabalhadores de estabelecimentos comerciais no município de São Paulo / Annoyance related about urban noise among workers of commercial establishments in the city of Sao Paulo, BrazilPetian, Andréa 10 October 2008 (has links)
Objetivos: 1) Estimar a prevalência do incômodo causado pelo ruído em trabalhadores de estabelecimentos comerciais no município de São Paulo. 2) Identificar o conhecimento e a opinião dos trabalhadores de estabelecimentos comerciais em relação ao ruído urbano 3) Identificar fatores sócio-demográficos associados ao incômodo, ao conhecimento e a opinião em relação ao ruído urbano. Métodos: Estudo transversal com 400 trabalhadores de estabelecimentos comerciais situados na zona central do município de São Paulo. O instrumento utilizado foi um questionário que contemplava questões sobre dados sócio-ambientais, ruído e aspectos relacionados aos incômodos por ele causados. As entrevistas foram realizadas no próprio estabelecimento onde o trabalhador atuava, em horário comercial. Mediu-se também o nível de pressão sonora no posto de trabalho, em um estabelecimento de cada rua visitada. Resultados: Dos 400 participantes, 59% eram do sexo feminino. A idade dos indivíduos variou entre 18 e 89 anos, com a mediana de 31 anos. 60% tinham nível escolar médio completo ou incompleto, 46% eram do setor de moda e 44% exerciam a função de balconista. Espontaneamente o ruído aparece em quarto colocado em incômodos no município e em primeiro em incômodo no local de trabalho e na residência. Do total, 65,75% achavam o local de trabalho ruidoso e 62,5% se mostraram incomodados com ruído neste local. O ruído interferia na atividade laboral de 43% dos trabalhadores sendo que a principal falar ao telefone (54%). Os principais problemas causados ou agravados pelo ruído, na opinião dos trabalhadores foram: perda auditiva, (72%), estresse (29%), irritabilidade (9%), dor de cabeça (7%), nervosismo (3%) e alterações do sono (1%). A maioria dos entrevistados referiu ter boa audição (96%). O sexo masculino e o maior nível de escolaridade se mostraram associados ao fato do trabalhador referir que o local de trabalho era ruidoso. Conclusões: A prevalência de trabalhadores que trabalhavam em estabelecimentos comerciais no município de São Paulo que referiram incômodo relacionado ao ruído no local de trabalho foi estimada em 62,5%. Referiram que o local de trabalho era ruidoso 65,75% trabalhadores e, o ruído do tráfego no local de trabalho incomodou 62% trabalhadores. Com os resultados deste estudo pode-se inferir que os trabalhadores conheciam tanto o risco físico do ruído, quanto o incômodo que ele pode causar. Os trabalhadores relataram que o ruído poderia causar ou agravar alguns problemas de saúde, principalmente a perda auditiva, estresse e irritabilidade / Objectives: 1) To evaluate the annoyance caused by noise among workers of commercial establishments of the city o Sao Paulo. 2) To find out the knowledge and opinion of these workers about the urban noise. 3) To identify socio-demographic factors associated to the annoyance, the knowledge and the opinion of the workers of commercial establishments in the city of Sao Paulo about the urban noise. Methods: This is a cross sectional study with 400 workers of commercial establishments located at the central area of the city of Sao Paulo. It was used a questionnaire that included questions about socio-environmental, noise and aspects related to the annoyances caused by them. The interviews were carried on at the workers workplace, during working hours. It was also measured the noise level at the workstation in one establishment of every street visited. Results: Of the 400 participants, 59% were female. The age ranged from 18 and 89 years old, with a median of 31 years. 60% of them had complete or incomplete high school educational level, 46% worked with clothes, and 44% were clerks. Noise appears spontaneously in fourth place among the annoyances at the workplace and at home. Of the participants 65.75% considered the workplace noisy, and 62.5% declared the felt annoyed by the noise at this place. Noise interfered with the professional activities of 43% of the workers, being talking to the phone the main activity disrupted (54%). Main problems caused or worsened by noise, for the workers, were: hearing loss (72%), stress (29%), irritability (9%), headache (7%), nervousness (3%), and sleep disturbances (1%). Most of the interviewed workers consider themselves as having a good hearing (96%). Male gender and higher schooling level were associated to the fact the worker mentions the workplace is noisy. Conclusions: The prevalence of people working at commercial establishments in the city of Sao Paulo who mentioned annoyance related to noise at the workplace was estimated to be 62.5%. 65.75% of the workers mentioned that the workplace was noisy, and the traffic noise was disturbing for 62% of the workers. From the results of this study it can inferred that the workers knew the physical risks associated to noise and the annoyances it can cause. The workers mentioned that noise could cause or worsen some health problems, especially hearing loss, stress and irritability
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Assessment of diffuse pollution originating from estuarine historical landfillsO'Shea, Francis Timothy January 2016 (has links)
The UK contains 5000 unlined historical landfills in the coastal zone currently at risk of erosion within the next 50 years. These rely on natural attenuation in surrounding sediment to reduce the contaminant load to the environment. This thesis investigates the extent and magnitude of sediment metal contamination from historical estuarine landfills. An intensive investigation of Newlands historical landfill, Essex, indicated elevated metal concentrations in surface and sub-surface sediments. Surface sediment concentrations were similar to other industrially impacted estuaries, whilst peak metal concentrations at c. 50 cm depth were indicative of industrial activity in the mid-20th Century. Below this depth, sediments were enriched with Pb (EF > 2) and Zn (EF = 1.5) indicative of an historic leachate plume that extends c. 15 m from the landfill site boundary. These sediments present a secondary source of diffuse pollution and a site contamination load of c. 1200 kg Pb. In-situ XRF was demonstrated as a rapid contamination screening tool for Fe, Pb, Sr and Zn enabling a broad-scale investigation of historical landfills across SE England. Sediment cores from eight sites containing both hazardous and inert waste were screened. Concentrations and EFs of Pb and Zn at depth were significantly higher in hazardous sites compared to inert sites. Spatial distributions of Pb and Zn were comparable to Newlands historical landfill. This indicates that diffuse pollution from historical landfill sites with similar chemical and physical attributes to Newlands is likely to present a regional, if not national problem, with UK historical landfills presenting contaminated sediments, comprising a significant, previously unidentified and unquantified diffuse pollution source in the coastal zone.
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Aplicação do rejeito do beneficiamento do carvão de Moatize (Moçambique) como sólido sorvente na remoção de cromo (VI)Barbosa, Dafne Lanfermann January 2017 (has links)
Uma das principais consequências dos processos de mineração e beneficiamento do carvão é a elevada produção de rejeitos. Esses materiais retornam às cavas de mineração ocasionando efeitos negativos ao meio ambiente, como a drenagem ácida de mina. Uma alternativa em potencial para esses rejeitos é aplica-los no tratamento de efluentes líquidos como sólidos sorventes. Dentre os principais poluentes aquosos destacam-se os metais pesados e, entre eles, o cromo hexavalente, devido aos seus efeitos carcinogênicos e mutagênicos, sendo altamente prejudicial aos organismos vivos. Neste contexto, o presente trabalho tem como objetivo utilizar o rejeito do beneficiamento do carvão de Moatize (Moçambique) como sólido sorvente para a remoção de cromo hexavalente de águas contaminadas. O sólido foi utilizado em duas granulometrias diferentes: no intervalo entre 0,7 e 1,5 mm (R1) e menor que 0,074 mm (R2). As amostras foram caracterizadas segundo sua massa específica, densidade aparente, área superficial (BET), volume de poros e diâmetro de poros (BJH), ponto de carga zero, composição química (FRX) e mineralógica (DRX). Ensaios experimentais foram realizados a fim de determinar as melhores condições de sorção, onde foram avaliados o efeito do pH, do tempo de residência e da concentração de sorvente As melhores condições encontradas para o sólido R1 foram: pH 2, 10 h de ensaio e concentração de sorvente de 8 g L-1, onde foi obtido 98,6% de remoção de Cr(VI). A maior remoção para o sólido R2 foi de 98,8%, obtida utilizando-se: pH 2, 50 min de ensaio e concentração de sorvente de 10 g L-1. Comparando com o limite previsto pela legislação brasileira CONAMA 430 para despejos industriais as concentrações finais de cromo hexavalente em solução ficaram abaixo do valor máximo estabelecido (0,1 mg L-1). A partir destas condições encontradas, foram construídas isotermas de equilíbrio e os modelos de Langmuir, Freundlich e Sips foram ajustados aos dados experimentais. Para o sólido R1, os modelos de Langmuir e Sips demostraram um bom ajuste, apresentando valores de R2 de 0,897 e 0,907 respectivamente. Já para o sólido R2, o modelo de Sips foi o que melhor representou os dados experimentais, com um R2 de 0,954. Os resultados encontrados indicam que o rejeito de carvão de Moatize pode ser utilizado para o tratamento de águas contaminadas com cromo hexavalente. / One of the main consequences of coal mining and beneficiation process is the large production of waste and by-products. These materials return to the mines generating significant negative impacts to the environment. One of the possible applications for the coal wastes is in the wastewater treatments, where it can be used as a sorbent. Amongst the main water pollutants, heavy metals stand out, especially hexavalent chromium, due to its carcinogenic and mutagenic effects, being highly prejudicial to the living organisms. In this context, the objective of this study is to use coal beneficiation waste from Moatize (Mozambique) as a sorbent to remove hexavalent chromium from aqueous solution. Coal waste was utilized in two different particle sizes: between 0.7 and 1.5 mm and smaller than 0.074 mm. These solids were characterized for their specific weight, bulk density, superficial area (BET), pore volume and diameter (BJH), point of zero charge, chemical composition (XRF) and mineral composition (XRD). Experiments were conducted to determinate the best sorption conditions, were the operating parameters investigated were: solution pH, contact time and sorbent concentration The best conditions for Cr(VI) sorption onto R1 were: pH 2, 10 h and 8 g L-1 of sorbent concentration, were 98.6% removal was obtained. Cr(VI) maximum removal onto R2 of 98.8% was achieved at pH 2, 50 min and 10 g L-1 of sorbent concentration. Comparing with the limit permitted by Brazilian legislation, CONAMA 430, for industrial wastewaters, the final Cr(VI) concentration in water were below the maximum established by law (0.1 mg L-1). From these results, equilibrium isotherms were build and the mathematical models of Langmuir, Freundlich and Sips were fitted to the experimental data. For the R1 sorbent, Langmuir and Sips models fitted better the experiments, with R2 values of 0.897 and 0.907, respectively. Sips model described better the experimental data when the R2 sorbent was used, with a R2 of 0.954. Results showed that Moatize’s coal waste can be utilized for hexavalent chromium wastewater treatment.
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Retenção e degradação de 14C-glifosato e remobilização dos seus resíduos ligados em diferentes classes de solos / Retention and degradation of 14C-glyphosate and remobilization of its bound residues in two tropical soilsArantes, Sayonara Andrade do Couto Moreno 19 December 2007 (has links)
O glifosato é um dos herbicidas mais consumidos no Brasil e com perspectivas de aumento deste consumo, diante da expansão do plantio direto e do plantio de culturas geneticamente modificadas com resistência a esse herbicida. Porém, pesquisas com esta molécula são ainda incipientes em solos de clima tropical. Nesse contexto, esta pesquisa objetivou gerar dados para uma melhor compreensão do comportamento ambiental desta molécula. Com este intuito, foram realizados ensaios laboratoriais com um Latossolo Vermelho (LE) e um Neossolo Quartzarênico (RQ) que permitiram o desenvolvimento dos capítulos descritos. Os ensaios foram realizados no laboratório de Ecotoxicologia do Centro de Energia Nuclear na Agricultura (CENA/USP), com glifosato radiomarcado no carbono fosfonometil. Na parte inicial da tese, foi realizada uma breve revisão do comportamento ambiental do glifosato. No segundo capítulo, procurou-se determinar os principais constituintes dos solos responsáveis pela sorção do herbicida. Para isso, foram realizadas extrações seqüenciais dos principais componentes dos solos, com métodos adequados, e em seguida, realizados os ensaios de sorção e dessorção nas amostras. No terceiro capítulo, foi estudado o efeito da calagem, prática comum na agricultura brasileira, nos processos de retenção e mineralização do glifosato, além de avaliar o efeito da calagem e do glifosato na atividade microbiana dos solos estudados. No quarto capítulo foi avaliado a remobilização dos resíduos ligados de 14C-glifosato nos solos, na presença ou não de calagem. Os dados obtidos permitiram verificar que, dentre as frações avaliadas no segundo capítulo, os óxidos de ferro foram os principais responsáveis pela sorção do glifosato nos dois solos estudados e a dessorção do herbicida foi baixa em todas as condições. Nos resultados obtidos com os ensaios do terceiro capítulo, foi possível observar que a calagem não influenciou significativamente a sorção e a dessorção do glifosato, tanto no LE quanto no RQ. A atividade da microbiota de ambos os solos foi afetada pela calagem e pelo glifosato. Com relação ao ensaio de mineralização, a calagem aumentou significativamente a mineralização do glifosato no LE e no RQ. Este mesmo efeito da calagem foi observado na remobilização dos resíduos ligados deste herbicida nos solos. Em todos os ensaios foi possível observar a elevada capacidade que o glifosato possui em formar resíduo ligado nos solos, sendo a principal fração formada deste herbicida. Diante dos resultados obtidos foi possível notar a necessidade de mais pesquisas sobre o comportamento do glifosato em solos de clima tropical, sob diferentes condições. / Nowadays, glyphosate is one of the most used herbicides in the Brazilian agriculture being expected an increase in its employment due to both the expansion of no-tillage cropped areas and the cultivation of transgenic plants resistant to this molecule. Considering that research related to glyphosate behaviour in tropical soils remains incipient, the present study aimed at to get more detailed information on the dynamics of this molecule in two different Brazilian soils. Laboratory experiments were carried out with both a Red Latosol (LE) and a Quartzarenic Neosol (RQ) at the Ecotoxicology Laboratory from Nuclear Energy in Agriculture Center (CENA/USP) by using 14C-glyphosate (C labelled at phosphonomethyl group). In the first part of the thesis, it is presented a brief review of the environmental behaviour of glyphosate. The second chapter describes an experiment carried out to identify the main soil component responsible for the glyphosate sorption. To attend this, the sequential removals of organic matter, iron oxides and gibbsite was done being each one followed by glyphosate sorption and desorption batch experiments. In the third chapter it was studied the soil liming effects on both retention and mineralization of glyphosate and also the mutual effect of liming and glyphosate on the soil microbial activity. In the fourth chapter it was evaluated the remobilization of glyphosate bound residues in soil with or without liming. The results presented in the second chapter indicated that the iron oxides are the main components responsible for the glyphosate sorption in both studied soils and that the desorption was low in all studied conditions. The results of the third chapter showed that liming influences neither glyphosate sorption nor its desorption in the two soils and that its mineralization increased in both of them due to the lime application. Similar effects were observed in the fourth chapter, where, for all experiments, liming increased the remobilization of bound residues of glyphosate.
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Potencial de fitorremediação de diferentes plantas em solo contaminado por 14C-tebuthiuron / Phytoremediation potential of different plants in soil contaminated by 14C-tebuthiuronConciani, Paulo Alberto 30 September 2015 (has links)
Este trabalho teve como objetivo avaliar a tolerância e a capacidade de fitorremediação de crotalária (Crotalaria spectabilis), sorgo (Sorghum bicolor), nabo forrageiro (Raphanus sativus), amendoim (Arachis hypogaea) e alfafa (Mendicago sativa) a solos contaminados por tebuthiuron. Para determinar a tolerância das plantas ao herbicida estas foram submetidas a 5 diferentes doses (300, 600, 1200, 2400 e 4800 gramas de ingrediente ativo por hectare gi.a. ha-1) e comparadas com uma testemunha que não recebeu aplicação do herbicida. Crotalária, Nabo forrageiro e alfafa se mostraram sensíveis ao herbicida, mesmo na menor dose de aplicação, enquanto sorgo se mostrou tolerante ao herbicida até a dose de 600 gi.a. ha-1 tendo apresentado fitointoxicação de 80% na dose de 1200 gi.a. ha-1 e amendoim foi tolerante até a dose de 4800 gi.a. ha-1 para a qual apresentou apenas 40% de fitointoxicação. Plantas de amendoim e sorgo foram submetidas a dose de contaminação de 600 gi.a. ha-1 aplicada por meio de uma solução de trabalho contendo 17,47kBq (Quilobecquerels) de 14C-tebuthiuron. As duas plantas foram capazes de remediar o solo, no entanto amendoim se mostrou mais eficiente reduzindo a contaminação em 75,8% enquanto sorgo retirou do solo 44,49% do herbicida contaminante / This study aimed to evaluate the tolerance and phytoremediation capacity of sunn hemp (Crotalaria spectabilis), sorghum (Sorghum bicolor), turnip (Raphanus sativus), peanuts (Arachis hypogaea) and alfalfa (Mendicago sativa) in tebuthiuron contaminated soil. To determine the tolerance to the herbicide, plants were subjected to five different doses (300, 600, 1200, 2400 and 4800 grams of active ingredient per hectare gi.a. ha-1) and compared with a control that had no herbicide application. Sunn hemp, turnip forage and alfalfa were sensitive to the herbicide, even at the lowest application dose, while sorghum showed tolerance to the herbicide at 600 gi.a. ha-1 dose, having 80% phytointoxication presented at dose 1200 gi.a. ha-1 and peanut was tolerant at dose 4800 gi.a. ha-1 for which it showed only 40% of phytointoxication. Peanut and sorghum plants were subjected to a contamination dose 600 gi.a. ha-1 applied in a work solution containing 17.47kBq (Kilobecquerels) of 14C-tebuthiuron. The two plants were able to remediate the soil, however peanut was more efficient reducing contamination by 75.8% while sorghum removed 44.49% of the soil contaminant herbicide
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Investigação hidrogeoquímica do cromo no aquífero Adamantina no município de Urânia - SP / Hydrogeochemical investigation of chromium in the Adamantina aquifer, in the municipality of Urânia - SP, BrazilMarcolan, Leonardo Nobuo Oshima 16 December 2009 (has links)
Teores anômalos de cromo hexavalente vêm sendo detectados na água subterrânea de vários municípios da região noroeste do Estado de São Paulo, sendo que em Urânia foram observadas as maiores concentrações do elemento, afetando as condições do consumo e uso humano. Estudos prévios realizados indicaram que a origem do cromo na água subterrânea é natural e proveniente de minerais com cromo no aqüífero profundo. Este projeto teve como principais objetivos: (1) a caracterização química e mineralógica da fase sólida do aqüífero profundo, realizada em testemunhos de duas sondagens profundas; (2) a caracterização da estratificação das concentrações de cromo na água subterrânea, com base na coleta e análise de amostras de água provenientes de poços de monitoramento instalados em diferentes profundidades do aqüífero; (3) a identificação dos processos hidrogeoquímicos que justificam a passagem do cromo da fase sólida para a água. Para tanto, foram realizadas análises químicas e mineralógicas por WDS, microssonda eletrônica e CTC, diversos métodos de análise química da água subterrânea, utilizados programas como o AquaChem e PHREEQc para trabalhamento do banco de dados e modelagens, além de uma grande variedade de experimentos de laboratório. As análises químicas por WDS e microssonda eletrônica indicaram concentrações de cromo de até 12.600 ppm em cristais de diopsídio, e de 650 ppm em capas de argilomineral. O material sólido apresenta uma capacidade de troca de cátions da ordem de 30 meq/100g, com ordem de abundância dos cátions Ca>>Mg>>K>Na. Na porção profunda do aqüífero, foi observada uma anomalia de sódio adsorvido, influenciando na composição química da água. As características hidroquímicas do aqüífero indicaram a ocorrência de estratificações de águas com diferentes perfis hidroquímicos. As águas são, no geral, do tipo bicarbonatadas cálcicas, porém com uma elevação do conteúdo de sódio na base do aqüífero. O cromo foi identificado na água predominantemente na forma hexavalente, com concentrações que atingiram 0,139 mg/L, acima, portanto do limite de potabilidade (0,05 mg/L). A ocorrência de valores mais elevados de cromo na água parece estar associada a ambientes de elevados pH e Eh, como observado no aqüífero profundo, enquanto que nas zonas rasas, que apresentam valores de pH e Eh neutros, apresentaram baixo conteúdo de cromo. Os principais resultados dos ensaios de laboratório indicaram que há passagem de cromo para água subterrânea, através do ataque aos minerais pesados com pH ácido; os ensaios de batch test realizados apontaram que o material sólido do aqüífero apresenta alguma capacidade de adsorção de Cr6+, chegando a um máximo de 0,12 ppm; o experimento de solubilização indicou a passagem de pequenas concentrações de cromo para a água e que a composição química da água do ensaio é semelhante à água do aqüífero. O modelo mais provável das reações geoquímicas que explicam a passagem do cromo da fase sólida para a água é apresentado a seguir, divido por etapas: (1) o intemperismo dos diopsídios cromíferos deve ser o processo inicial de disponibilização de cromo para a água, resultando na precipitação do cromo como hidróxidos ou sendo adsorvido por hidróxidos de ferro e manganês; (2) ocorrência de uma reação de oxi-redução a partir do cromo trivalente que ocorre nos minerais secundários, disponibilizando o cromo para a água subterrânea, sendo que esta oxidação ocorre a partir da redução de óxidos de manganês presentes como minerais em aqüíferos, liberando Mn2+; (3) O Cr3+ é rapidamente e fortemente imobilizado por adsorção em argilominerais de baixo valor de pHpzc, enquanto que o Cr6+, devido à sua natureza aniônica, é preferencialmente retido em superfícies carregadas positivamente, como os óxidos e hidróxidos de ferro e alumínio (minerais com elevados valores de pHpzc), principalmente em condições hidroquímicas neutras a ácidas; (4) altas concentrações de OH-, de HCO3- e de CO3 2- provavelmente elevam a competição pelos sítios de adsorção de ânions e causam a dessorção dos ânions de Cr6+ para a água do aqüífero. / Anomalous hexavalent chromium contents have been detected in groundwater in many municipalities of the northwestern region of São Paulo state. In the city of Urânia, the highest concentrations of this element have been observed, affecting the conditions for human consumption. Previous studies indicated that the origin of chromium in groundwater is from natural sources and derived from chromium minerals in the deep aquifer. The main objectives of this research are to: (1) characterize chemically and mineralogically the solid phase from the deep aquifer; (2) characterize the stratification of chromium concentrations in groundwater, based on sampling and analysis of groundwater from wells installed in different depths of the aquifer; (3) identify hydrogeochemical processes that justify the passage of chromium from solid phase to groundwater. To achieve these objectives, chemical and mineralogical analysis by WDS, microprobe and CEC were made, diverse chemical analytical methods were used for groundwater, database and modeling were used through AquaChem and PHREEQc programs, besides a great variety of laboratory experiments. Chemical analysis from WDS and microprobe indicated chromium concentrations of up to 12.600 ppm in diopside crystals, and up to 650 ppm in clay mineral coats. The solid material has a Cation Exchange Capacity (CEC) of about 30 meq/100g, with cation abundance order of Ca>>Mg>>K>Na. In the aquifer deep zone, it was observed an adsorbed sodium anomaly, that influences groundwater chemical composition. The aquifer hydrochemical characteristics indicated the occurrence of water stratifications with different hydrochemical profiles. The groundwaters are, in general, calcium bicarbonated, with a elevation of sodium contents in the base of the aquifer. Chromium was identified predominatly in hexavalent state of oxidation, with concentrations of up to 0,139 mg/L, thus above potability standards (0,05 mg/L). The occurrence of higher chromium concentrations in groundwater seems to be related to high pH and Eh environments, whereas shallow zones, that have neutral values of pH and Eh, presented low chromium contents. The main results of laboratory experiments have indicated that there is passage of chromium to groundwater through acid etching in heavy minerals; batch tests have shown that solid phase has some sorption capacity, reaching a maximum of 0,12 ppm; solubilization experiment indicated the passage of low concentrations of chromium to water and that chemical composition from the experiment water is similar to groundwater. The probable model that explain the passage of chromium from solid phase to groundwater is presented hereafter, divided in steps: (1) it is indicated that weathering of chromium diopsides must be the initial process of availability of chromium to water; (2) hexavalent chromium can only occur in groundwater after the occurrence of an oxi-reduction reaction from the trivalent chromium that occurs in minerals. Many authors recognize that this oxidation occurs from the reduction of manganese oxide presented as minerals in the aquifer, releasing Mn2+, that later will be oxidated again; (3) the trivalent chromium is rapidly and strongly immobilized by sorption in clay minerals of low values of pHzpc, whereas the hexavalent chromium, due to its anionic nature, is preferably retained in positively charged surfaces, like iron and aluminium hydroxides (minerals with high values of pHzpc), mainly in neutral to acid hydrochemical conditions; (4) high OH-, HCO3 - and CO3 2- concentrations probably elevate the competition for anion sorption sites and cause the desorption of hexavalent chromium anions to groundwater.
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An investigation and examination of the levels and types of bacterial contamination on the surface of clean room operators' garmentsSmith, Laurie McKenzie January 2018 (has links)
The contamination of sterile pharmaceutical products is a serious event which has in the worst case scenario led to patient death. Operators are the primary source of clean room contamination, with the majority of their detritus being identified as skin squames and their related microorganisms. The ability of operator associated bacterial contamination to disseminate through specialist garments worn in the clean room environment is apparent in the literature. However, despite the fibres of such garments being identified as a suitable substrate for bacteria to adhere to and grow upon, the bacterial bioburden of the surface of clean room operators’ garments is an area which severely lacks in published research. Reported here is the recovery, enumeration and comparison of the levels of bacteria on the surface of reusable antistatic carbon filament polyester clean room garments, using the direct agar contact method, following their laundering with and without terminal gamma sterilisation, immediately following their donning with operators dressing wearing either no gloves, non – sterile gloves or sterile clean room gloves, and following their wear within the clean room environment, with respect to gender. The aforementioned method, with its recovery efficiency shown to be unaffected by agar composition (NA or TSA), recovered bacteria from the surface of garments laundered with and without gamma sterilisation. Such terminal decontamination was shown to reduce the surface bacterial bioburden of the garments, especially at the chest and umbilicus regions, which were shown to harbour higher levels of bacteria than the other sites tested. The direct agar contact method, showing an increase in recovery efficiency following a 48 hour agar incubation period as opposed to a 24 hour period, also recovered bacteria from the surface of clean room garments donned by operators dressing wearing either no gloves, non – sterile gloves and sterile clean room gloves. Bacteria were transferred onto the surface of these garments via the hand borne route, with the chest and oral cavity regions being found to harbour more bacteria than the other sites tested. Overall, glove type was shown to have no effect upon the resultant bacterial bioburden of the surface of the garments, suggesting expensive clean room gloves could be substituted for their cheaper non – sterile equivalents or no gloves during the donning process without subsequently increasing the surface bacterial bioburden of the garment. The direct agar contact method also recovered bacteria from the surface of clean room garments worn by male and female operators, following their working period within a clean room environment. Gender was found to significantly affect the surface bacterial bioburden of the garments, with the surface of those garments worn by male operators being more contaminated than the surface of those worn by their female counterparts. In addition, the donning of a clean room hood was shown to reduce the levels of bacteria at the chest and posterior cervicis regions of suits worn by both genders. Overall, the direct agar contact method was identified as a successful tool to recover, enumerate and estimate the surface bacterial bioburden of reusable antistatic polyester carbon filament clean room garments. Finally, using 16S rRNA gene sequencing, found to be more reliable and accurate at identifying unknown isolates than traditional phenotypic first - stage tests, which were subsequently found to misidentify > 85 % of the isolates tested, a self - selected representative number of isolates recovered from the surface of garments during the laundering and gender comparison studies were predominantly identified as skin commensal species of Staphylococcus and Micrococcus, as well as environmental species of Bacillus. The knowledge contained within this thesis, with respect to clean room operators and their specialist garments, contributes towards improving contamination control standards within clean room facilities.
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Characterisation of stainless steel contamination in acidic mediaKerry, Timothy January 2018 (has links)
There is great interest in understanding the contamination of stainless steel by radionuclides across the nuclear fuel cycle. Through study of uptake mechanisms, contaminant localisation and process conditions that affect uptake, decontamination strategies can be tailored to remove built-up radioactive species. This study focusses on understanding stainless steel contamination by inactive lanthanides and radioactive actinide species (U, Np, Pu and Am) in acidic media. Through depth profiling, contamination has been seen to localise on the interface of the oxide layer and the bulk metal (at depths of up to 100 nm) indicating a potentially tenacious contamination mechanism. Furthermore, contaminant was observed at greater depths within the material (up to ~300 nm), suggesting penetration beyond the passive layer in to the bulk of the material. Long term immersion studies (up to 9 months) in 12 M HNO3 have also been undertaken to investigate the effect of surface corrosion on contaminant uptake. After 3 months the surface had undergone intergranular corrosion and grain droppage was observed. Further surface analysis revealed localisation of contaminants within the steel grain boundaries and vacancies. Once again, this may necessitate a more aggressive decontamination strategy. Conditions have been identified that enhance uptake of transuranic contaminants. Highest levels of uptake were seen in polished steel samples immersed in 4 M HNO3. The Np-237, Pu-239 and Am-241 contaminated samples showed surface concentrations of up to 1.2x107, 9.4x105 and 1x109 Bq/m2, respectively. In the case of Np contamination of stainless steel, microfocus X-ray absorption spectroscopy has shown the surface-mediated reduction of Np(V) leading to Np(IV) adsorption.
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Mental contamination: a replication and extension of the "dirty kiss" experiment. / CUHK electronic theses & dissertations collectionJanuary 2010 (has links)
Discussion: This study aims at expanding the understanding of mental contamination. First, the dirty kiss experiment is independently replicated in a Chinese population. Second, contact contamination and mental contamination are found to be separable and do not interact with each other. This underscores the independence of the two forms of contamination. Third, betrayal is shown to evoke mental contamination. Discussion has been made on the potential link between psychological violation, morality and mental contamination. / Mental contamination, an important phenomenon in OCD, refers to a sense of dirtiness without any contact with objectively dirty contaminant. However, the concept of mental contamination has not been thoroughly researched and there is an impending need for a psychological model to explain the phenomenon. / Method: Participants were assessed on questionnaires after imagining a non-consensual kiss or betrayal. / Objectives: The overall goal of this study is to enhance our understanding about mental contamination. Based on an experimental paradigm developed by Fairbrother, Newth, and Rachman (2005), three experiments are designed. The first experiment aims at replicating the results of the original study in local Chinese women. The second experiment examines the relationship between contact and mental contamination. The third experiment investigates the presence of mental contamination in persons experiencing betrayal. / Results: In Experiment 1, with an imagined non-consensual kiss, feeling of dirtiness, urge to wash and negative emotions were reproduced. In Experiment 2, it illustrated that either kissing a physically dirty looking man or being kissed non-consensually would experience stronger feeling of dirtiness, urge to wash and negative emotions. The last experiment showed that an imagined betrayal, a form of psychological violation, also induced a feeling of dirtiness, washing urge and negative emotions as with an imagined non-consensual kiss. / Three different pools of adult female participants were recruited for each experiment. In Experiment 1, 72 participants were recruited and randomly assigned to either a consensual kiss or a non-consensual kiss condition. In Experiment 2, 122 participants were recruited and randomly assigned to one of the four conditions. In Experiment 3, a total of 64 participants were recruited and randomly assigned to either non-betrayal or betrayal condition. / Kwok, Pui Ling Amy. / Adviser: Patrick Leung. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 166-177). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract and appendixes 1-3, 5-8 also in Chinese.
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