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O sulfato de aluminio e o policloreto de aluminio sao coagulantes quimicos eficientes para formacao de flocos em unidades de tratamento de agua. No entanto, estes coagulantes podem contribuir para o desenvolvimento da doenca de Alzheimer pelo aluminio residual na agua pos-tratamento. Em razao disso, esta pesquisa teve como objetivo verificar a aplicacao de extrato salino (CaCl 2 ) de sementes de Moringa oleifera no tratamento de aguas com baixa turbidez, usando flotacao por ar dissolvido (FAD). A eficiencia do processo foi determinada mediante os parâmetros cor, turbidez, pH e condutividade, os quais foram discriminados por Analise de Componentes Principais. Duas condicoes de turbidez (10 e 20 uT) foram utilizadas neste estudo, enquanto os ensaios de coagulacao, floculacao e FAD foram realizados com extratos salinos da semente nas dosagens de 10, 20, 30, 40 e 50 mg L -1 . Os resultados indicaram que houve remocao de turbidez (64,2 e 78,2%) e cor (77,6 e 72,4%) em aguas com turbidez de 10 e 20 uT, respectivamente. A condutividade aumentou em funcao do maior acrescimo de coagulante, enquanto o pH nao foi alterado de forma significativa. Concluiu-se, desta forma, que o uso do coagulante Moringa oleifera favoreceu a remocao dos parâmetros cor e turbidez, melhorando a qualidade da agua. A B S T R A C T Aluminum sulphate and aluminum polychloride are efficient chemical coagulants for flake formation in water treatment plants. However, these coagulants can provide the development of Alzheimer's disease by residual aluminum in the post-treatment water. The objective of this research was to verify the application of saline extract (CaCl 2 ) from Moringa oleifera seeds in the treatment of water with low turbidity using dissolved air flotation (DAF). The efficiency of the process was determined by the parameters color, turbidity, pH and conductivity, which were discriminated by Principal Component Analysis. Two turbidity conditions (10 and 20 NTU) were used in this study, while coagulation, flocculation and DAF assays were performed with saline extracts at the doses of 10, 20, 30, 40 and 50 mg L -1 . The results indicated that turbidity (64.2 and 78.2%) and color (77.6 and 72.4) were removed in waters with turbidity of 10 and 20 NTU, respectively. The conductivity increased as a function of the higher coagulant addition, while the pH was not significantly altered. It was concluded, therefore, that the use of the Moringa oleifera coagulant favored the removal of the color and turbidity parameters, improving the quality of the water. Keywords: Water quality. Natural coagulant. Dissolved air flotation. Chemometrics Analysis. |
