Vesícula de polidiacetileno para detecção de triclorometano em água potabilizada

• Ano de defesa: 2011
• Autor(a) principal: Medeiros, Hiasmyne Silva de
• Orientador(a): Andrade, Nélio José de
• Banca de defesa: Pires, Ana Clarissa dos Santos , Cruz, Renato Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Qualidade de água; Trihalometanos; Sensor colorimetrico
• Palavras-chave em Inglês: Water quality; Trihalomethanes; Colorimetric sensor
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/2902

By-products of the water disinfection with chorine compounds are considered harmful to human health. Among them is trichloromethane (TCM) caused by the reaction of chlorine with humic and fulvic acid present in the water. The detection of TCM in water is made by the using chromatographic methods, generally expensive and nedd weel-trained staff. This research aimed to develop an alternative to evaluate the presence of TCM in the water using a simple and rapid procedure using poli diacetileno vesicle. Initially, we tried to know the physical and chemical quality, including the concentration of TCM, and microbiological of the samples collected in four water treatment plants, 15 distribution network points and five wells. Of 28 samples tested, only two samples, about 2.5% had values above 100 μg·L-1, maximun allowed value by Brazilian standard legislation according to the Ordinance 518/MS 2004. The results of physical-chemical, microbiological samples were analyzed within the limits required by Brazilian legislation for drinking water. Low concentrations of turbidity and color, showing a good quality control in water treatment plants, probably contributed to the low concentrations found in TCM water samples. There was a trend of increasing concentration value of TCM from the tratments plants, due to the amount of free residual chlorine in the network, organic matter from the supply source and because of the THM formation reaction is slow. For the development of colorimetric sensor was evaluated different vesicles containing acid pentacosadiinócio 10.12, with and without the addition of different phospholipids and cholesterol (CO), esfigomielina (ES) and dimiristoifosfatidilcolina (DMPC) and also was varied the ultrasonic power for production of vesicular suspension. The vesicle suspension that had the biggest colorimetric response (CR) and the smaller diameter, with the addition of TCM, was the PCDA + 1mM 1mM CO.ES subjected to 400W of power. This vesicle suspension was chosen to be conditioned with different values of pH, temperature and concentration and evaluated in relation to RC and size before and after the addition of solutions containing 100 μg·L-1, 1000 μg·L-1 and 10000 μg.L-1 of TCM diluted in deionized water. Observing the values of RC for the treatments, it was noted that the treatment - pH 5.00, temperature 35° C without dilution of the vesicle- was what got the biggest difference between the values of RC in relation to the control treatment and the 100 μg·L-1.