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Abstract(s)
Os metais como cálcio, potássio e sódio, contribuem significativamente para
a qualidade das águas e manutenção dos meios abíoticos. As concentrações desses
iões em águas podem ser atribuídas devido ao acontecimento de lixiviação destes e
outros elementos no solo, bem como de atividades antrópicas (resíduos industriais
e/ou agrícolas). A diferença nas concentrações dadas por cada um dos processos,
está relacionada com o quantitativo do impacto e a duração.
Os iões cálcio, potássio e sódio devem estar presentes em água em
concentrações ideais para suprir as necessidades do ser humano, porém águas
contendo elevadas concentrações desses e outros metais podem causar danos à
saúde humana. O cálcio bem como outros elementos são importantes para a
manutenção da saúde humana, entretanto, a ingestão não controlada desses
compostos podem afetar a saúde humana. Após o cálcio e fósforo, o potássio é o
elemento encontrado em maiores concentrações no corpo humano, estando presente
nos tecidos e orgãos, porém, se em altas concentrações pode causar
problemas/falhas nos rins. DeZuane (1997) refere que o efeito do potássio em águas
potáveis é insignificante para chegar a causar problemas na saúde humana. Já o sódio
é considerado um elemento que deve ser controlado pois o consumo de elevadas
quantidades pode desencadear falhas renais, circulatórias e problemas cardíacos.
Os ambientes aquáticos são altamente heterogêneos e dinâmicos e, por isso,
o desenvolvimento de ferramentas analíticas para a monitorização in-situ de
ecossistemas aquáticos é importante para substituir as análises laboratoriais
tradicionais baseadas em amostragens periódicas. Neste âmbito, o principal objetivo
deste trabalho foi estudar a aplicação de um sistema potenciométrico de multisensores,
construído em laboratório, na análise simultânea de 3 iões metálicos (cálcio,
potássio e sódio) em amostras de água naturais de diferentes origens (águas de rio,
mar e potável da rede pública e comerciais). Para validar os resultados do sistema
potenciométrico, as águas naturais foram também analisadas por técnicas analíticas
de referência, a espectrofotometria de absorção atómica e de emissão atómica.
Metals such as calcium, potassium and sodium contribute significantly to water quality and maintenance of abiotic environment. The concentrations of these ions in waters is due to the leaching event of these and other elements in the soil, as well as of anthropic activities (industrial and/or agricultural waste). The difference in the concentrations given by each of the processes, is related to their quantitative impact and duration. Calcium, potassium and sodium ions should be present in water at concentrations that are optimal to meet human needs, but water containing high concentrations of these and other metals can cause harm to human health. Calcium, as well as other elements, is important for the maintenance of human health, however, uncontrolled ingestion of these compounds can affect human health. After calcium and phosphorus, potassium is the element found in higher concentrations in the human body, being present in tissues and organs, but if in high concentrations it can cause and/or make kidney problems/failures. DeZuane (1997) states that the effect of potassium on drinking water is insignificant to cause problems in human health. Sodium is considered an element that must be controlled since if consumed in high concentrations because can lead to renal failure, circulatory and heart problems. Aquatic environments are highly heterogeneous and dynamic, thus, the development of analytical tools for on-site monitoring of aquatic ecosystems is important to replace traditional laboratory analyses based on periodic sampling. In this context, the main objective of this work is to study the application of a potentiometric system of multi-sensors, built in the laboratory, in the simultaneous analysis of 3 metal ions (calcium, potassium and sodium) in natural water samples from different sources (river, sea and drinking water from the public and commercial network). In order to validate the potentiometric system results, the natural waters were also analysed by reference analytical techniques, as atomic absorption and flame emission spectrophotometry.
Metals such as calcium, potassium and sodium contribute significantly to water quality and maintenance of abiotic environment. The concentrations of these ions in waters is due to the leaching event of these and other elements in the soil, as well as of anthropic activities (industrial and/or agricultural waste). The difference in the concentrations given by each of the processes, is related to their quantitative impact and duration. Calcium, potassium and sodium ions should be present in water at concentrations that are optimal to meet human needs, but water containing high concentrations of these and other metals can cause harm to human health. Calcium, as well as other elements, is important for the maintenance of human health, however, uncontrolled ingestion of these compounds can affect human health. After calcium and phosphorus, potassium is the element found in higher concentrations in the human body, being present in tissues and organs, but if in high concentrations it can cause and/or make kidney problems/failures. DeZuane (1997) states that the effect of potassium on drinking water is insignificant to cause problems in human health. Sodium is considered an element that must be controlled since if consumed in high concentrations because can lead to renal failure, circulatory and heart problems. Aquatic environments are highly heterogeneous and dynamic, thus, the development of analytical tools for on-site monitoring of aquatic ecosystems is important to replace traditional laboratory analyses based on periodic sampling. In this context, the main objective of this work is to study the application of a potentiometric system of multi-sensors, built in the laboratory, in the simultaneous analysis of 3 metal ions (calcium, potassium and sodium) in natural water samples from different sources (river, sea and drinking water from the public and commercial network). In order to validate the potentiometric system results, the natural waters were also analysed by reference analytical techniques, as atomic absorption and flame emission spectrophotometry.
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Keywords
Águas naturais Análise de cálcio Análise de potássio Análise de sódio