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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.
21

Origem, distribuição e mobilidade potencial de metais pesados em ambiente fluvial impactado por curtumes

Rodrigues, Maria Lucia Kolowski January 2007 (has links)
Neste estudo, avaliou-se a ocorrência de metais pesados em ambiente fluvial sob influência de curtumes - a bacia hidrográfica dos rios Cadeia e Feitoria (RS, Brasil), focalizando sua origem, distribuição e mobilidade potencial. Trimestralmente, entre julho/1999 e abril/2000, analisaram-se metais e parâmetros complementares em amostras de água e sedimento coletadas em dez locais. Após identificar os contaminantes e locais críticos (cromo e mercúrio, no trecho inferior do rio Feitoria), avaliaram-se também perfis sedimentares verticais e tecido muscular de peixes de fundo (Rineloricaria). As análises de água seguiram recomendações do Standard Methods, enquanto as demais basearam-se principalmente em métodos da agência de proteção ambiental dos Estados Unidos (USEPA) ou Comunidade Européia, buscando prever a disponibilidade potencial dos metais. Utilizou-se estatística descritiva e multivariada na análise dos dados, visando sintetizar informações e subsidiar a futura elaboração de um atlas ambiental. Rastreou-se o risco potencial de danos crônicos não carcinogênicos à saúde humana por ingestão de água e peixes contaminados, conforme metodologia recomendada pela USEPA.A ocorrência de metais vinculou-se a contribuições naturais e antropogênicas, representadas principalmente pela intemperização de basaltos e atividades de curtumes. Influenciada pela proximidade dos curtumes e flutuações na vazão, a qualidade das águas diminuiu ao longo dos rios e no período de menor disponibilidade hídrica (janeiro). Os teores de metais nas águas obedeceram aos padrões da legislação brasileira, exceto para alumínio, ferro e eventualmente manganês. Considerando a ingestão de água em cenário hipotético de alta exposição aos metais estudados (água bruta, picos de contaminação, cromo na forma hexavalente), verificouse uma potencial ausência do risco de efeitos adversos à saúde humana. Entretanto, a área sob maior influência de curtumes demonstrou considerável aumento desse risco, em comparação aos locais de referência. Nos sedimentos, as concentrações de alumínio, cobre, ferro, níquel, manganês, titânio e zinco pareceram refletir níveis basais, ao contrário de cromo e mercúrio, enriquecidos no trecho inferior da bacia. Além de condições de avançado intemperismo, os perfis sedimentares indicaram que as descargas de metais antropogênicos poderiam não estar restritas a atividades pretéritas. A partição dos metais nas fases geoquímicas dos sedimentos revelou maior mobilidade potencial do manganês em toda a bacia, seguido por cromo, na área de concentração de curtumes (predominantemente vinculado à fração oxidável). Ainda que em teores abaixo do recomendado pela Organização Mundial da Saúde (0,5 μg/g), observou-seacúmulo de mercúrio nos peixes, indicando condições ambientais favoráveis à sua metilação. Para reduzir efeitos tóxicos crônicos não carcinogênicos à saúde humana por exposição ao mercúrio, um eventual consumo do peixe estudado deveria ser restrito a 32 g/dia no trecho contaminado. Mesmo não sendo detectado nos peixes, o considerável aumento do teor de cromo nos sedimentos do trecho inferior da bacia sugeriu possibilidade de ocorrerem localmente outros efeitos prejudiciais à biota aquática. Uma potencial mobilização do cromo retido nos sedimentos estaria vinculada às condições redox do meio, enquanto o enxofre poderia condicionar a biodisponibilidade do mercúrio. Estudos posteriores são necessários para melhor entendimento dos processos de mobilização e bioacumulação de metais na área de estudo, envolvendo organismos de diferentes níveis tróficos. / This study evaluated the occurrence of heavy metals in a fluvial environment under the influence of tanneries – the Cadeia and Feitoria rivers watershed (RS, Brazil), phocusing their origin, distribution, and potential mobility. Every three months, between July 1999 and April 2000, selected heavy metals and ancillary parameters were analyzed in water and sediment samples taken at ten sites. After identifying the contaminants and sites of concern (chromium and mercury at the lower reach of Feitoria River), vertical sediment profiles and bottom-fish tissue (Rineloricaria) were also evaluated. Water analyses followed recommendations of the Standard Methods, while the remaining analyses were based mainly on methods from the Environmental Protection Agency of the United States (USEPA) and European Community, searching for estimating the potential availability of metals. Descriptive and multivariate statistics were applied to water and sediment data sets, in order to obtain a synthesis of the environmental diagnosis, and to support the elaboration of an environmental atlas. A risk assessment methodology recommended by USEPA was conducted at a screening level, in order to estimate the potential non-carcinogenic toxic effects to the human health arising from life-time consumption of contaminated water and fish.The results revealed that the heavy metals originate from natural and anthropogenic contributions, mainly resultant from the weathering of basalt rocks and tannery activities. The water quality decreased along both rivers, and during the dry period (January), showing the influence of tannery plants vicinity and flow variations. Except for iron, aluminum, and eventually manganese, heavy metal contents in water were generally in agreement with Brazilian standards. Despite considering the ingestion of water in a hypothetical scenario of high human exposure to the selected metals (untreated water, peaks of contamination, chromium in the hexavalent form), the risk screening indicated a potential absence of adverse toxicological health effects. However, in comparison to the reference sites, this risk considerably increased at the lower reach of Feitoria River, the most affected by tanneries. Concerning sediments, aluminum, copper, iron, nickel, manganese, titanium, and zinc concentrations appeared to reflect the base levels, in opposition to chromium and mercury, which were enriched in the lower part of the basin. The sediment profiles revealed an advanced weathering-stage, and also indicated that the anthropogenic discharges of heavy metals might not be strictly resultant from past activities. The partition of heavy metals among the sediment geochemical phases showed higher mobility of manganese along the basin, followed by chromium in thearea most affected by tanneries (predominantly associated to the oxidizable fraction). Although occurring in levels below the World Health Organization threshold for human consumption (0.5 μg/g), the accumulation of mercury in fish indicated that the prevailing environmental conditions could favor its methylation. Considering the methodology of risk assessment, an eventual consumption of the investigated fish should be restricted to 32 g/day at the lower reach of Feitoria River, in order to reduce the occurrence of non-carcinogenic toxic effects to the human health, arising from oral exposure to mercury. Although chromium was not detected in fish tissue, its considerable enrichment in sediments from the lower part of the basin indicated a potential occurrence of other hazardous effects on aquatic organisms. A potential mobilization of chromium from the contaminated sediments would be associated to the prevailing redox conditions, while the sulfur cycling could influence the bioavailability of mercury. Further research with organisms from distinct trophic levels is needed, in order to better understand the metal bioaccumulation processes that are taking place in the study area.
22

Pré-tratamento de efluente de curtume por bactérias e enzima lipolíticas

Lima, Vivian de Oliveira 07 July 2015 (has links)
As águas residuárias industriais possuem propriedades físico-químicas distintas, sendo necessários estudos específicos para a escolha do tratamento de cada efluente visando garantir maior eficiência e atendimento aos requisitos ambientais. Diversas indústrias, dentre elas o Curtume, potencialmente, geram efluentes com elevado teor de óleos e gorduras (O&G). Tais compostos podem causar problemas operacionais e interferir no desempenho dos sistemas biológicos de tratamento. Por esse motivo, a remoção preliminar de O&G, em geral, é recomendada. A hidrólise enzimática de lipídios tem se mostrado promissora no pré-tratamento de águas residuárias como alternativa ao uso de métodos físico-químicos. O objetivo deste trabalho foi isolar bactérias lipolíticas do efluente da graxaria de curtume, aplicá-las no pré-tratamento deste efluente em escala laboratorial e comparar seus efeitos com o uso do produto comercial Enzilimp® e com enzima LPP (lipase de pâncreas de porco - Sigma Aldrich®). Foram isoladas 14 cepas produtoras de lipase. A cepa MOV7 (estafilococo positivo), que apresentou maior índice enzimático, foi utilizada nos ensaios. Foram realizados três ensaios preliminares com o intuito de avaliar o perfil temporal e a influência da concentração dos inóculos, dos efeitos da diluição do efluente e da aeração. Posteriormente realizou-se o DCCR avaliando a influência da temperatura, da concentração do inóculo, da concentração do efluente e do pH para as variáveis respostas DQOt, DQOs, O&G e Índice de Acidez ao longo de 48 horas em sistema fermentativo e posteriormente 24 horas em sistema aerado. Ao final do experimento concluiu-se que o efluente da graxaria do curtume é fonte potencial de bactérias lipolíticas e que tais cepas isoladas apresentam comportamento semelhante ao Enzilimp®. Após 72 horas de experimento (48 horas em período fermentativo e 24 horas em sistema aerado) foram alcançadas remoções de 75% de O&G e 47% de DQOt com MOV7 e 52% de O&G e 30% DQOt com a enzima LPP. A enzima LPP provocou aumento de 1,1g de DQOt por g de enzima adicionada. Quando in natura, o aumento da concentração dos inóculos não resultou em melhoria do tratamento. Porém, a diluição do efluente favoreceu a redução dos parâmetros DQO, O&G e IA para os diferentes inóculos. A aeração favoreceu a redução da matéria orgânica nas diluições entre 12,5 e 62,5 mL.L-1. Observou-se que a temperatura e pH influenciaram significativamente o desempenho do sistema com melhores resultados a 30°C e 8,0, respectivamente. / Industrial wastewaters present different physiochemical characteristics, requiring specific studies for choose the correct treatment for each effluent, ensuring more efficiency, taking into account environmental requirements. Many kinds of industries, including tannery, potentially produce effluents with high content of oil and grease (O&G). Those compounds can cause operational problems and interfere on the performance of biological treatment systems. For these reasons, in general, is recommended the preliminary removal of O&G. The enzymatic hydrolysis of lipids has proven promising in pretreatment of wastewaters like an alternative for physiochemical methods. The aim of this study was isolate microorganisms from tannery effluent able to produce extracellular lipase, apply them in the pretreatment in laboratorial scale of this effluent and compare their effects with the commercial product Enzilimp® and with PPL enzyme (porcine pancreas lipase Sigma Aldrich®). Were isolate 14 strains from tannery's effluent. The strain MOV7 (positive staphylococci), that presented the greatest enzymatic index, was used on the tests. Were done three preliminary tests with the objective to evaluate the time and the influence from inoculum concentration, from effluent dilution and aeration. After, were made the DCCR to evaluating the influence from temperature, inoculum and effluent concentration, and pH on the variables responses CODt, CODs, O&G e Acid Index during 48 hours in fermentation system and 24 hours after in aerobic system. In the end of the tests were concluded that the tannery effluent is a potential source of lipolytic bacteria and those strains have similar behavior to Enzilimp®. During 72 hours (48 hours in fermentative conditions and 24 in aerated conditions) the pretreatment reached the reduction of 75% of O&G and 47% of CODt with MOV7 and 52% of O&G and 30% with PPL enzyme. The PPL enzyme caused the increasing of 1,1g CODt on each gram from added enzyme. When in natura, the increasing of inoculum concentration gave no better results on treatment. However, the effluent dilution promoted the decreasing of parameters COD, O&G and AI for the different inoculums. The aeration was effective on reduction from organic matter in dilutions between 12,5 and 62,5 mL.L-1. Was observed that the temperature and pH influenced significatively the system's work with better results on 30°C and 8,0, respectively.
23

Pré-tratamento de efluente de curtume por bactérias e enzima lipolíticas

Lima, Vivian de Oliveira 07 July 2015 (has links)
As águas residuárias industriais possuem propriedades físico-químicas distintas, sendo necessários estudos específicos para a escolha do tratamento de cada efluente visando garantir maior eficiência e atendimento aos requisitos ambientais. Diversas indústrias, dentre elas o Curtume, potencialmente, geram efluentes com elevado teor de óleos e gorduras (O&G). Tais compostos podem causar problemas operacionais e interferir no desempenho dos sistemas biológicos de tratamento. Por esse motivo, a remoção preliminar de O&G, em geral, é recomendada. A hidrólise enzimática de lipídios tem se mostrado promissora no pré-tratamento de águas residuárias como alternativa ao uso de métodos físico-químicos. O objetivo deste trabalho foi isolar bactérias lipolíticas do efluente da graxaria de curtume, aplicá-las no pré-tratamento deste efluente em escala laboratorial e comparar seus efeitos com o uso do produto comercial Enzilimp® e com enzima LPP (lipase de pâncreas de porco - Sigma Aldrich®). Foram isoladas 14 cepas produtoras de lipase. A cepa MOV7 (estafilococo positivo), que apresentou maior índice enzimático, foi utilizada nos ensaios. Foram realizados três ensaios preliminares com o intuito de avaliar o perfil temporal e a influência da concentração dos inóculos, dos efeitos da diluição do efluente e da aeração. Posteriormente realizou-se o DCCR avaliando a influência da temperatura, da concentração do inóculo, da concentração do efluente e do pH para as variáveis respostas DQOt, DQOs, O&G e Índice de Acidez ao longo de 48 horas em sistema fermentativo e posteriormente 24 horas em sistema aerado. Ao final do experimento concluiu-se que o efluente da graxaria do curtume é fonte potencial de bactérias lipolíticas e que tais cepas isoladas apresentam comportamento semelhante ao Enzilimp®. Após 72 horas de experimento (48 horas em período fermentativo e 24 horas em sistema aerado) foram alcançadas remoções de 75% de O&G e 47% de DQOt com MOV7 e 52% de O&G e 30% DQOt com a enzima LPP. A enzima LPP provocou aumento de 1,1g de DQOt por g de enzima adicionada. Quando in natura, o aumento da concentração dos inóculos não resultou em melhoria do tratamento. Porém, a diluição do efluente favoreceu a redução dos parâmetros DQO, O&G e IA para os diferentes inóculos. A aeração favoreceu a redução da matéria orgânica nas diluições entre 12,5 e 62,5 mL.L-1. Observou-se que a temperatura e pH influenciaram significativamente o desempenho do sistema com melhores resultados a 30°C e 8,0, respectivamente. / Industrial wastewaters present different physiochemical characteristics, requiring specific studies for choose the correct treatment for each effluent, ensuring more efficiency, taking into account environmental requirements. Many kinds of industries, including tannery, potentially produce effluents with high content of oil and grease (O&G). Those compounds can cause operational problems and interfere on the performance of biological treatment systems. For these reasons, in general, is recommended the preliminary removal of O&G. The enzymatic hydrolysis of lipids has proven promising in pretreatment of wastewaters like an alternative for physiochemical methods. The aim of this study was isolate microorganisms from tannery effluent able to produce extracellular lipase, apply them in the pretreatment in laboratorial scale of this effluent and compare their effects with the commercial product Enzilimp® and with PPL enzyme (porcine pancreas lipase Sigma Aldrich®). Were isolate 14 strains from tannery's effluent. The strain MOV7 (positive staphylococci), that presented the greatest enzymatic index, was used on the tests. Were done three preliminary tests with the objective to evaluate the time and the influence from inoculum concentration, from effluent dilution and aeration. After, were made the DCCR to evaluating the influence from temperature, inoculum and effluent concentration, and pH on the variables responses CODt, CODs, O&G e Acid Index during 48 hours in fermentation system and 24 hours after in aerobic system. In the end of the tests were concluded that the tannery effluent is a potential source of lipolytic bacteria and those strains have similar behavior to Enzilimp®. During 72 hours (48 hours in fermentative conditions and 24 in aerated conditions) the pretreatment reached the reduction of 75% of O&G and 47% of CODt with MOV7 and 52% of O&G and 30% with PPL enzyme. The PPL enzyme caused the increasing of 1,1g CODt on each gram from added enzyme. When in natura, the increasing of inoculum concentration gave no better results on treatment. However, the effluent dilution promoted the decreasing of parameters COD, O&G and AI for the different inoculums. The aeration was effective on reduction from organic matter in dilutions between 12,5 and 62,5 mL.L-1. Was observed that the temperature and pH influenced significatively the system's work with better results on 30°C and 8,0, respectively.
24

Origem, distribuição e mobilidade potencial de metais pesados em ambiente fluvial impactado por curtumes

Rodrigues, Maria Lucia Kolowski January 2007 (has links)
Neste estudo, avaliou-se a ocorrência de metais pesados em ambiente fluvial sob influência de curtumes - a bacia hidrográfica dos rios Cadeia e Feitoria (RS, Brasil), focalizando sua origem, distribuição e mobilidade potencial. Trimestralmente, entre julho/1999 e abril/2000, analisaram-se metais e parâmetros complementares em amostras de água e sedimento coletadas em dez locais. Após identificar os contaminantes e locais críticos (cromo e mercúrio, no trecho inferior do rio Feitoria), avaliaram-se também perfis sedimentares verticais e tecido muscular de peixes de fundo (Rineloricaria). As análises de água seguiram recomendações do Standard Methods, enquanto as demais basearam-se principalmente em métodos da agência de proteção ambiental dos Estados Unidos (USEPA) ou Comunidade Européia, buscando prever a disponibilidade potencial dos metais. Utilizou-se estatística descritiva e multivariada na análise dos dados, visando sintetizar informações e subsidiar a futura elaboração de um atlas ambiental. Rastreou-se o risco potencial de danos crônicos não carcinogênicos à saúde humana por ingestão de água e peixes contaminados, conforme metodologia recomendada pela USEPA.A ocorrência de metais vinculou-se a contribuições naturais e antropogênicas, representadas principalmente pela intemperização de basaltos e atividades de curtumes. Influenciada pela proximidade dos curtumes e flutuações na vazão, a qualidade das águas diminuiu ao longo dos rios e no período de menor disponibilidade hídrica (janeiro). Os teores de metais nas águas obedeceram aos padrões da legislação brasileira, exceto para alumínio, ferro e eventualmente manganês. Considerando a ingestão de água em cenário hipotético de alta exposição aos metais estudados (água bruta, picos de contaminação, cromo na forma hexavalente), verificouse uma potencial ausência do risco de efeitos adversos à saúde humana. Entretanto, a área sob maior influência de curtumes demonstrou considerável aumento desse risco, em comparação aos locais de referência. Nos sedimentos, as concentrações de alumínio, cobre, ferro, níquel, manganês, titânio e zinco pareceram refletir níveis basais, ao contrário de cromo e mercúrio, enriquecidos no trecho inferior da bacia. Além de condições de avançado intemperismo, os perfis sedimentares indicaram que as descargas de metais antropogênicos poderiam não estar restritas a atividades pretéritas. A partição dos metais nas fases geoquímicas dos sedimentos revelou maior mobilidade potencial do manganês em toda a bacia, seguido por cromo, na área de concentração de curtumes (predominantemente vinculado à fração oxidável). Ainda que em teores abaixo do recomendado pela Organização Mundial da Saúde (0,5 μg/g), observou-seacúmulo de mercúrio nos peixes, indicando condições ambientais favoráveis à sua metilação. Para reduzir efeitos tóxicos crônicos não carcinogênicos à saúde humana por exposição ao mercúrio, um eventual consumo do peixe estudado deveria ser restrito a 32 g/dia no trecho contaminado. Mesmo não sendo detectado nos peixes, o considerável aumento do teor de cromo nos sedimentos do trecho inferior da bacia sugeriu possibilidade de ocorrerem localmente outros efeitos prejudiciais à biota aquática. Uma potencial mobilização do cromo retido nos sedimentos estaria vinculada às condições redox do meio, enquanto o enxofre poderia condicionar a biodisponibilidade do mercúrio. Estudos posteriores são necessários para melhor entendimento dos processos de mobilização e bioacumulação de metais na área de estudo, envolvendo organismos de diferentes níveis tróficos. / This study evaluated the occurrence of heavy metals in a fluvial environment under the influence of tanneries – the Cadeia and Feitoria rivers watershed (RS, Brazil), phocusing their origin, distribution, and potential mobility. Every three months, between July 1999 and April 2000, selected heavy metals and ancillary parameters were analyzed in water and sediment samples taken at ten sites. After identifying the contaminants and sites of concern (chromium and mercury at the lower reach of Feitoria River), vertical sediment profiles and bottom-fish tissue (Rineloricaria) were also evaluated. Water analyses followed recommendations of the Standard Methods, while the remaining analyses were based mainly on methods from the Environmental Protection Agency of the United States (USEPA) and European Community, searching for estimating the potential availability of metals. Descriptive and multivariate statistics were applied to water and sediment data sets, in order to obtain a synthesis of the environmental diagnosis, and to support the elaboration of an environmental atlas. A risk assessment methodology recommended by USEPA was conducted at a screening level, in order to estimate the potential non-carcinogenic toxic effects to the human health arising from life-time consumption of contaminated water and fish.The results revealed that the heavy metals originate from natural and anthropogenic contributions, mainly resultant from the weathering of basalt rocks and tannery activities. The water quality decreased along both rivers, and during the dry period (January), showing the influence of tannery plants vicinity and flow variations. Except for iron, aluminum, and eventually manganese, heavy metal contents in water were generally in agreement with Brazilian standards. Despite considering the ingestion of water in a hypothetical scenario of high human exposure to the selected metals (untreated water, peaks of contamination, chromium in the hexavalent form), the risk screening indicated a potential absence of adverse toxicological health effects. However, in comparison to the reference sites, this risk considerably increased at the lower reach of Feitoria River, the most affected by tanneries. Concerning sediments, aluminum, copper, iron, nickel, manganese, titanium, and zinc concentrations appeared to reflect the base levels, in opposition to chromium and mercury, which were enriched in the lower part of the basin. The sediment profiles revealed an advanced weathering-stage, and also indicated that the anthropogenic discharges of heavy metals might not be strictly resultant from past activities. The partition of heavy metals among the sediment geochemical phases showed higher mobility of manganese along the basin, followed by chromium in thearea most affected by tanneries (predominantly associated to the oxidizable fraction). Although occurring in levels below the World Health Organization threshold for human consumption (0.5 μg/g), the accumulation of mercury in fish indicated that the prevailing environmental conditions could favor its methylation. Considering the methodology of risk assessment, an eventual consumption of the investigated fish should be restricted to 32 g/day at the lower reach of Feitoria River, in order to reduce the occurrence of non-carcinogenic toxic effects to the human health, arising from oral exposure to mercury. Although chromium was not detected in fish tissue, its considerable enrichment in sediments from the lower part of the basin indicated a potential occurrence of other hazardous effects on aquatic organisms. A potential mobilization of chromium from the contaminated sediments would be associated to the prevailing redox conditions, while the sulfur cycling could influence the bioavailability of mercury. Further research with organisms from distinct trophic levels is needed, in order to better understand the metal bioaccumulation processes that are taking place in the study area.
25

À l'ombre de la montagne : le paysage archéologique du versant nord du mont Royal, Montréal, 1698-1900

Janssen, Valérie 02 1900 (has links)
Ce mémoire s’inscrit dans un projet de recherche plus global sur l’évaluation du potentiel archéologique du mont Royal réalisé par l’Université de Montréal en partenariat avec la Ville de Montréal et le ministère de la Culture et des Communications du Québec. Plus précisément, il a pour objectif de mettre en œuvre et d’apporter une réflexion sur l’outil dans la gestion du patrimoine archéologique. Au Québec, malgré l’importance de cet outil à l’étape du diagnostic en archéologie préventive, il existe peu de connaissances empiriques sur son efficacité et sur la validité des différentes méthodologies employées. Nous avons donc voulu mieux comprendre la démarche de l’évaluation du potentiel à partir de l’approche du paysage culturel et de celle de l’écologie historique, et ce, afin de voir comment cela pouvait apporter une nouvelle façon d’envisager le potentiel archéologique. L’élaboration de notre cadre théorique s’est appuyée, notamment, sur une trentaine d’études de potentiel archéologique produite au Québec. À l’aide de ce cadre théorique, le potentiel archéologique du versant nord du Mont-Royal a été documenté sur une période allant de la fin du XVIIe siècle jusqu’au XXe siècle. La recherche théorique a été complétée par des inspections visuelles des zones, permettant ainsi de documenter plus finement certains éléments environnementaux, tels la topographie, le couvert végétal, l’hydrographie, etc. Dans la construction du paysage culturel, c’est l’aspect mythique et symbolique de la montagne qui nous intéresse. Nous en avons retenu trois thèmes principaux qui s’échelonnent dans le temps, c’est-à-dire la montagne pittoresque et le paysage forestier, la montagne agricole et l’industrie des tanneries et, enfin, l’arrivée des cimetières et des établissements religieux. Pour chacun de ces thèmes, des orientations de recherche sont énoncées en guise de réflexion sur les éléments d’intérêt archéologique présentés. Ces thèmes, nous le suggérons, pourront être pris en compte dans un contexte d’archéologie préventive. / This thesis is part of a broader research project on the archaeological potential of Mount Royal carried out by Université de Montreal in partnership with the City of Montreal and the Ministry of Culture and Communications of Quebec. More specifically, it aims to assess the utility and efficiency of archaeological potential studies as a tool in cultural resource management. In Quebec, despite the importance of this tool in preventive archaeology at the diagnostic stage, there has been very little empirical study of its effectiveness and the validity of the different methodologies used. We therefore wish to bring a better understanding to the assessment of archaeological heritage potential by using a cultural landscape and historical ecology approach, in order to see how this can bring about a new way of considering archaeological potential. The development of the theoretical framework for this paper was based on some thirty archaeological assessments produced in Quebec. It is through this theoretical framework that the archaeological potential of the territory under study, namely the northern slopes of Mount Royal, was documented for a period starting at the end of the 17th century up to the 20th century. The theoretical research was complemented by visual inspections of the geographical zones, thereby permitting a more precise documentation of certain environmental features such as the topography, the ground vegetation and tree cover, the hydrography, etc. In the construction of the cultural landscape, the mythical and symbolic aspects of the mountain retain our interest. We have chosen three main themes, namely the picturesque mountain and the forest landscape, the agricultural mountain and the tanning industries and, lastly, the arrival of cemeteries and religious institutions. For each theme, research orientations are formulated in order to reflect the elements of archaeological interest that we present. These themes may be taken into account for archaeological resource management.
26

Biotic-abiotic transformations of chromium in long-term tannery waste contaminated soils : implications to remediation

Kamaludeen, Sara Parwin Banu. January 2002 (has links) (PDF)
Bibliography: leaves 166-180. Determines the effect of chromium on the soil microbial community and its activity, the biotic-abiotic mechanisms involved in chromium oxidation, and phytostabilization of chromium using plants and organic amendment in tannery-waste contaminated soil.
27

Biotic-abiotic transformations of chromium in long-term tannery waste contaminated soils : implications to remediation / by Sara Parwin Banu Kamaludeen.

Kamaludeen, Sara Parwin Banu January 2002 (has links)
Bibliography: leaves 166-180. / 180, [4] leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Determines the effect of chromium on the soil microbial community and its activity, the biotic-abiotic mechanisms involved in chromium oxidation, and phytostabilization of chromium using plants and organic amendment in tannery-waste contaminated soil. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002
28

Long-term tannery waste contamination: effect on chromium chemistry / by Avudainayagam Subramanian.

Avudainayagam Subramanian January 2002 (has links)
Corrigenda inside front cover. / Includes bibliographical references (leaves 205-232) / xii, 232, [27] leaves : ill., plates ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Soil and Water, 2002
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Clarificação química com coagulante PGα21Ca e fotocatálise heterogênea aplicada ao tratamento de efluente de curtume / Chemical clarification with PGα21Ca coagullant and heterogeneous photocatalysis applied to the treatment of tannery wastewater

Rubilar, Cirdelene Sincoski 22 February 2017 (has links)
Os curtumes são indústrias que causam importante impacto ambiental, pois utilizam grande volume de água na produção do couro e o volume total de efluentes gerados normalmente é similar ao total de água captada. Além disso, há a utilização de vários compostos químicos no beneficiamento do couro, gerando, consequentemente, efluentes que possuem alta carga poluidora, com elevada DQO, matéria orgânica, sólidos em suspensão, sais dissolvidos e metais. Portanto, é indispensável o tratamento eficiente deste tipo de efluente, visando minimizar seus impactos ambientais e atender à legislação vigente. A clarificação química coagulação/floculação/decantação) é uma das etapas mais utilizadas no tratamento de efluente de curtume, ainda é utilizado coagulantes à base de sais de alumínio e ferro, porém estes são, comprovadamente, tóxicos ao ambiente. Com intuito de substituir os coagulantes inorgânicos, muitas pesquisas com polímeros naturais vêm sendo desenvolvidas. O PGα21Ca foi desenvolvido com esse propósito, sendo composto principalmente por sulfato de cálcio e ácido--poliglutâmico, possui alta biodegradabilidade e baixa toxicidade. O presente trabalho teve como objetivo o estudo do tratamento de efluente de curtume, por meio do processo de clarificação química com o coagulante PGα21Ca e degradação fotocatalítica utilizando o catalisador TiO2. As condições ideais de tratamento foram determinadas aplicando a metodologia de planejamento fatorial e pelo delineamento composto central rotacional (DCCR). Em condições otimizadas, a clarificação química apresentou remoção de 75% da cor real, 61% da DQO, 77% da turbidez, 94 % do cromo total, 95% de cromo trivalente e 92% do cromo hexavalente. Constatando assim, que o PGα21Ca foi eficiente, principalmente na remoção de cromo. O processo de tratamento completo com clarificação química e fotocatálise heterogênea resultou em remoção de 87% da cor real, 92% da DQO, 91% da turbidez, 97 % do cromo total, 98% de cromo trivalente e 94% do cromo hexavalente. O processo de fotocatálise heterogênea contribuiu principalmente com as remoções de turbidez. Por meio desta pesquisa, comprovou-se a viabilidade da utilização do coagulante PGα21Ca para tratamento de efluente de curtume, considerando-o uma boa opção de coagulante devido ao alto rendimento e capacidade para remoção de compostos orgânicos e inorgânicos. / Tanneries are industries that cause significant environmental impact, because they use a large volume of water in leather production and the total wastewater volume generated is normally similar to the total water caught. In addition, there is the use of several chemical compounds in leather processing, generating highly polluted wastewater with high COD, organic matter, suspended solids, dissolved salts and metals. Therefore, the efficient treatment of this type of wastewater is indispensable, in order to minimize its environmental impacts and to comply with the current legislation. Chemical clarification (coagulation / flocculation / decantation) is one of the most used steps in the treatment of tannery wastewater, it is still used coagulants based on aluminum and iron salts, but they have been proven to be toxic to the environment. In order to replace the inorganic coagullants, many researches with natural polymers have being developed. PGα21Ca was developed for this purpose. It is mainly composed of calcium sulphate and γ-polyglutamic acid, presenting high biodegradability and low toxicity. The present work had the objective of studying the treatment of tannery wastewater by chemical clarification with coagullant PGα21Ca and photocatalytic degradation using the TiO2. The ideal treatment conditions were determined using experimental design methodology and central rotational compound design (CCD). Under optimized conditions, chemical clarification presented removal of 75% of color, 61% of COD, 77% of turbidity, 94% of total chromium, 95% of trivalent chromium and 92% of hexavalent chromium. Thus, PGα21Ca was mainly efficient for chromium removal. Complete treatment process with chemical clarification and heterogeneous photocatalysis resulted in removal of 87% of color, 92% of COD, 91% of turbidity, 97% of total chromium, 98% of trivalent chromium and 94% of hexavalent chromium. Heterogeneous photocatalysis process contributed mainly to turbidity removal. This research proved the feasibility of usage of PGα21Ca for the treatment of tannery wastewater, considering it a good coagulant option due to the high yield and capacity for removal of organic and inorganic compounds.
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Studies on the completely mixed activated sludge treatment of fellmongery and tannery lime-sulphide effluents

Rawlings, Douglas Eric January 1977 (has links)
Industries producing highly polluted waste waters are having to purify their effluents to meet with ever increasing requirements laid down by water authorities. The South African Water Act of 1956 has prescribed a very high standard to which waste waters must conform before discharge into a South African water course. Enforcement of these standards falls under the jurisdiction of government authorities such as the Department of Water Affairs. Similarly, municipalities and other local authorities set standards with which trade effluents must comply before discharge into public sewers for treatment in a municipal sewage works. These local authorities are empowered to recover from the trader the additional costs incurred in treating trade effluents. Costs are usually levied in respect of volume, oxygen demand, settleable solids and the production of secondary sludge. In recent years, these standards have been enforced to an extent where the survival of several industries has become dependant on whether these industries are able to purify or dispose of their effluents in a manner acceptable to the water authorities. Chap. 1, p. 1.

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