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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analysis of the bio-physicochemical quality of surface and ground water in the Tubatse Municipality

Mathipa, Morongwa Mary January 2016 (has links)
Thesis (M. Sc. (Microbiology)) -- University of limpopo, 2016 / Human activities are known to be the major contributors to contamination of natural water sources. This becomes a serious health risk when the communities rely on the same water sources for their household water needs. The current study investigated the bio-physicochemical quality of surface and ground waters found in a mining area in the Tubatse locality, for their suitability for drinking and other household use. The bacteriological analyses of surface waters showed dominance by genera of the phylum Proteobacteria, followed by Actinobacteria and Firmicutes. The isolates included the genera Aeromonas, Pseudomonas, Cronobacter, Acinetobacter, Enterobacter, Pantoea, Serratia, Bordetella, Kocuria and Streptococcus. This dominance pattern is proportionately similar to the pattern reported on human skin and of gut biota. Enterobacter spp. were the predominant species in the surface waters, followed by Bordetella spp. With regard to ground water, one sample was laden with coliforms whereas the other sample was free of coliforms. Physical quality parameters such as turbidity, colour and (total suspended solids) TSS of the surface and ground water samples were compliant with the set standards for drinking water according to South African water quality guidelines (2005). The concentrations of Zn, [SCN-], Cr, Co, Fe, Ni, Cu, H2O2, Cl2 were determined in the surface and ground waters in dry and wet seasons as well. A non-significant decrease in the levels of Cl2 and [SCN-] and an increase in TDS and Cr were observed in the wet season. All metal and chemical levels in surface and ground water, except Cr, were lower than permitted concentration for drinking water. However the concentrations of Zn, Fe and Co exceeded the normal expected concentrations of < 3.5 μg/L, 0.5 mg/L, < 0.01 mg/L and < 5 μg/L respectively. The sediments and soil samples were digested with aqua regia for Cu, Cr, Fe, Co and Zn analyses. An increase in the levels of Zn, Cr and Co in the wet season was observed. The concentrations of the heavy metals such as Co, Cu and Cr were higher in sediments at the sampling points closer to the mining sites. Cytotoxicity assay was performed with different concentrations, as detected in the water and sediment samples, of Zn, [SCN-], Cr, Co, and Fe on C2C12 (mammalian) cells. An increase in viable cells was observed after treatment with Cr (0.2, 0.45 and 0.9 mg/L), Zn and Fe (1.0 and 2 mg/L), Co (2, 5 and 10 mg/L). Only cells treated with SCN- (3.3, 5.4 and 7.2 mg/L) exhibited a significant decrease in viability. These results demonstrate that the water in the Tubatse municipality is not suitable for drinking and other household purposes without prior treatment which will remove contaminating microorganisms and chemicals and heavy metals.
2

Etude du comportement hydraulique, physico-chimique et microbiologique d'un système de récupération d'eaux de toiture. Evaluation de l'empreinte environnementale / Hydraulic, physicochemical and microbiological study of a roof runoff harvesting system and environmental assessment

Vialle, Claire 21 October 2011 (has links)
L'objectif de ces travaux est de contribuer à augmenter la connaissance sur la réutilisation des eaux de ruissellement de toiture. Une maison individuelle située en zone rurale et équipée d'une toiture en tuiles, et un bâtiment collectif situé en zone périurbaine avec une toiture terrasse bitumée, ont été étudiés. Les eaux de pluie collectées sont réutilisées dans l'habitat pour l'alimentation des chasses d'eau. Un suivi analytique a permis l'étude de la qualité de l'eau en plusieurs points des systèmes. Les eaux stockées sont clairement non potables et révèlent une contamination microbiologique très variable. Des pathogènes ont été quantifiés à plusieurs reprises. La qualité de l'eau distribuée ne peut donc pas être garantie au cours de l'année, d'où la recommandation d'une désinfection de l'eau avant distribution. Un suivi hydraulique a permis de déterminer les volumes d'eau potable substitués et les taux de couverture de besoins en eau. Un modèle du comportement hydraulique a été développé puis utilisé pour discuter le dimensionnement des cuves. En présence d'une désinfection, les installations ne sont économiquement pas rentables. En l'absence de désinfection, le bilan économique est positif mais la période de retour sur investissement supérieure à la durée de vie de l'installation. Une première analyse de cycle de vie a été réalisée pour comparer les deux échelles étudiées. Dans les deux cas, les processus les plus impactants sont liés aux consommations électriques de l'éventuelle désinfection ultra-violet et des pompes. En présence d'une désinfection, l'échelle du bâtiment collectif présente des impacts plus faibles. Une deuxième analyse de cycle de vie a été réalisée pour étudier la pertinence de la substitution de l'eau du réseau d'eau public par de l'eau de pluie à l'échelle d'un particulier. Elle n'est pas probante d'un point de vue environnemental. / The aim of this work is to contribute to knowledge on roof runoff reuse. A private house located in rural area with a tiled sloping roof and a research building located in suburban zone with a bituminous flat roof were studied. The collected rainwater is reused for toilet flushing. An analytical monitoring allowed the study of water quality in several points of the systems. Stored rainwater is clearly non drinkable and reveals a very variable microbiological contamination. Pathogenic agents were quantified on several occasions. Distributed water quality cannot thus be guaranteed over the year and a disinfection before distribution is recommended. A hydraulic follow-up made it possible to determine substituted volumes of drinking water by collected rainwater and water saving efficiencies. A model of the hydraulic behaviour of systems was developed then used to discuss dimensioning of the tanks. In the presence of disinfection, the installations are economically not profitable. In the absence of disinfection, the economic assessment is positive but the payback period is longer than the lifespan of the installation. A first life cycle assessment was carried out to compare the two studied scales. In both cases, the more impacting processes are related to electricity consumptions of possible ultra-violet disinfection and the pumps. In the presence of disinfection, the scale of the building presents weaker impacts. A second life cycle assessment was carried out to study the relevance of the substitution of drinking water by rainwater on a private individual scale. It is not convincing of an environmental point of view.
3

Métodos alternativos para o manejo de anastrepha fraterculus (wied.) em pomares de maçã e sua influência sobre a qualidade dos frutos / Alternative methods to manage Anastrepha fratercukus (Wied) in apple orchards and its influence on fruit qualities

Teixeira, Rosangela 18 September 2009 (has links)
Made available in DSpace on 2016-12-08T16:44:32Z (GMT). No. of bitstreams: 1 PGPV09MA025.pdf: 1332630 bytes, checksum: d4dcb0a524aaa8a52524e31392a208e0 (MD5) Previous issue date: 2009-09-18 / The cultivation of apple tree is the main activity from the mountain region of Santa Catarina, in Brazil. The fruit fly Anastrepha fraterculus (Wiedmann, 1830) (Diptera: Tephritidae) is the main pest from this culture being of difficult control, compromising the quality of fruits. Field and laboratory experiments were conducted with the objective of testing alternative methods to the management and control of the fruit fly. The tests involved the attractiveness efficiency of commercial food-based baits; the action of floristic localization and vegetation near the orchards, the efficiency of different material to bagging the fruits and also the action of phytotherapic and biotherapic preparations on adults of A. fraterculus. The efficiency of grape juice (25%), BioAnastrepha® hydrolyzed protein (5%), Isca Mosca® protein (5%) and Torula yeast (2.5%) was tested using McPhail traps placed on the external branches at 1.8 m high from soil and 50 m distant from each trap. In three orchards with different geographic localization it was realized the floristic survey from the surrounding area and monitoring of population fluctuation of the fruit fly by using traps containing grape juice at 25% placed at the orchards edges. Fuji suprema and Imperial gala had their fruits bagged with micro-perforated plastic bags made of non-textured fabric. At harvest time, the damage caused by the pest, disease incidence and the effect of bagging on the physicochemical quality of fruits were evaluated. In laboratory, the effect of phytotherapic and biotherapic preparations on the biology of the fruit fly was also tested. Healthy fruits treated with different preparations were offered to fruit fly adults for 48 hours. Seven days after infestation, the number of pupae and emerged adults was evaluated for 30 days. All the trials were carried out in randomized blocks during the crop seasons of 2007/08 and 2008/09. BioAnastrepha® hydrolyzed protein (5%) was the substance that attracted the highest number of A. fraterculus adults. Geographic position and floristic composition in the surrounding region affected population fluctuation of the fruit fly. The orchard located at 1,415 m of altitude and surrounded by commercial orchards constituted of host plants and the one located at 1,228 m of altitude surrounded by native forest were the ones the showed smaller population of flies. Bagging protected fruits from damage of A. fraterculus, Grapholita molesta, Bonagota salubricola, but did not protect against pathogens that cause apple scab and moldy core. Bagging of Imperial gala&#8223; fruits accelerated maturation process while for Fuji suprema&#8223; fruits it reduced the red color in fruits and calcium accumulation. The biotherapic preparation with Cinnamon at 6CH showed repellence effect on A. fraterculus adults. It was concluded that the management of A. fraterculus can be done by using ways alternative to pesticides, so that the contamination risk of the fruits and the environment, and even intoxication of the farmers can be reduced / O cultivo da macieira é a principal atividade da região serrana catarinense. A mosca-das-frutas Anastrepha fraterculus (Wiedmann, 1830) (Diptera: Tephritidae) é a principal praga desta cultura sendo de difícil controle e comprometendo a qualidade dos frutos. Com o objetivo de testar métodos alternativos para o manejo e controle da mosca-das-frutas, foram realizados experimentos a campo e em laboratório. Testou-se: a eficiência atrativa de substâncias alimentares comerciais; a ação da localização e da composição floristica do entorno dos pomares; a eficiência de diferentes materiais para o ensacamento de frutos e a influência destes materiais sobre a qualidade físico-quimica das frutas e a ação de preparados fitoterápicos e homeopáticos sobre adultos de A. fraterculus. Utilizando armadilhas, modelo McPhail, instaladas a 1, 80 m do solo e distribuídas nas linhas de plantas em intervalos de 50 m, foi testado a eficiência de suco de uva 25%, de proteína hidrolisada BioAnastrepha 5%, de proteína hidrolisada Isca Mosca 5% e da levedura torula 2,5%. Em três pomares com diferentes localizações geográficas foi realizado o levantamento florístico do entorno e o acompanhamento da flutuação populacional da mosca-das-frutas através de armadilhas contendo solução de suco de uva a 25%, instaladas nas plantas das bordas dos pomares. Frutos das cultivares Fuji Suprema&#8223; e Imperial Gala&#8223; foram ensacados com sacos plásticos micro-perfurados ede tecido não texturizado (TNT). Na época da colheita foi avaliado o dano causado por insetos praga, a incidência de doenças e o efeito do ensacamento sobre a qualidade físico-química dos frutos. No laboratório testou-se o efeito de preparados fitoterápicos e homeopáticos sobre a biologia da mosca-das-frutas. Frutos sadios e tratados com os diferentes preparados foram oferecidos aos adultos da mosca-das-frutas por um período de 48 horas. Aos sete dias após a infestação, durante 30 dias, avaliou-se o número de pupas e adultos emergidos. Todos os experimentos foram conduzidos em blocos ao acaso durante as safras de 2007-08 e 2008-09. A proteína hidrolisada BioAnastrepha 5% foi a substância que atraiu maior número de adultos de A. fraterculus. A posição geográfica do pomar e composição florística de seu entorno afetaram a flutuação populacional da mosca-das-frutas. O pomar localizado a 1.415 metros de altitude e circundado por pomares comerciais constituídos por plantas hospedeiras e aquele localizado a altitude de 1.228 circundado por mata nativa, foram os que apresentaram menor população de moscas. O ensacamento protegeu os frutos dos danos de A. fraterculus, Grapholita molesta, Bonagota salubricola, mas não protegeu contra patógenos causadores da sarna da macieira e podridão carpelar. O ensacamento de frutos de maçã Imperial Gala&#8223; acelerou o processo de maturação nos frutos, enquanto nos frutos de maçã Fuji Suprema&#8223; o ensacamento diminuiu a coloração vermelha dos frutos em ambas as safras e aumentou o acúmulo de cálcio na safra 2008/09. O preparado homeopático Cinamomo na potência 6CH mostrou efeito de repelência sobre adultos de A. fraterculus. Conclui-se que o manejo de A. fraterculus pode ser realizado com uso de medidas alternativas aos agrotóxicos reduzindo desta forma o risco de contaminação dos frutos e do meio ambiente e de intoxicação dos agricultores

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