Emprego de filtro de fibras flexíveis constituído de fibras de algodão mercerizado e poliéster na clarificação de água para abastecimento
Data
2017-11-15
Autores
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Biblioteca Digital de Teses e Dissertações da USP
Universidade de São Paulo
Escola de Engenharia de São Carlos
Universidade de São Paulo
Escola de Engenharia de São Carlos
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Descrição
Os filtros de fibras flexíveis são módulos de filtração direta cujo leito filtrante é formado por micro fibras de poliamida, permitindo altas eficiências de remoção de sólidos suspensos, e aplicação de altas taxas de filtração. O presente estudo avaliou tal configuração de filtro utilizando fibras de algodão mercerizado e poliéster na forma de fios. Foram realizados testes de resistência dos fios a meios com características químicas distintas - alcalino, ácido e com cloro residual. Foi realizada caracterização das fibras estudadas através de Microscopia Óptica e Microscopia Eletrônica de Varredura. Foram construídos 4 filtros com diâmetro interno de 28 mm, e porosidade 67% (algodão), e 75% (poliéster), sendo 2 filtros constituídos de fibras de algodão mercerizado - comprimento de leito 60 e 100 cm; e 2 filtros constituídos de fibras de poliéster - comprimento de leito 60 e 100 cm. Foi utilizada para alimentação dos filtros água sintética de turbidez 7,7 ± 0,3 uT, e cor aparente 97 ± 5,0 uC, e realizada coagulação in-line com 22,5mg/L e 15 mg/L (este último valor somente para os filtros de 100 cm) de sulfato de alumínio. Foram avaliadas taxas de filtração de 40, 60, 80, 100 e 120 m/h. Os limites de turbidez estabelecidos para o filtrado foram de 1 e 2 uT. Os filtros de fibras flexíveis de algodão mercerizado e poliéster de leito 60 cm só conseguiram atingir os limites de turbidez até taxa de 80 m/h. Os filtros de leito 100 cm atingiram os limites satisfatoriamente em todas as taxas de filtração. Os filtros de poliéster obtiveram carreiras de filtração mais longas do que as obtidas pelos filtros de algodão, além de apresentarem perdas de carga menores. Exceto para taxa 40 e 60 m/h para o filtro de algodão mercerizado, todas as outras taxas em ambos os filtros obtiveram desempenhos melhores (carreiras de filtração longas, e filtrado de melhor qualidade) com dosagem menor de coagulante. Esse estudo mostrou potencial no uso das fibras de algodão mercerizado e poliéster nos filtros de fibras flexíveis aplicados em tratamento de água para abastecimento. Sugere-se estudos avançados para aplicação no Brasil de tal tecnologia.
The flexible fiber filters are direct filtration modules which filter media is made of polyamide micro fibers, obtaining high solids removal efficiency, and high filtration rates. This study evaluated the performance of the filter using mercerized cotton and polyester fibers. Tests of fibers resistance due to alkaline, acid and chlorinated environments were realized at the present research. The fibers were also analyzed by means of Optic and Scanning Electronic Microscopy. Four field-scale filters with an internal diameter of 28mm, porosity of 67% (cotton), and 75% (polyester) were installed; two of them made of mercerized cotton fiber- high of 60 and 100 cm; and two made of polyester fiber - high of 60 and 100 cm. A synthetic water was used as influent - turbidity 7,7 ± 0,3 uT, and color 97 ± 5,0 uC. In-line coagulation was used with 22,5 mg/L and 15 mg/L (this last value was only applied on 100cm length filters) of aluminium sulfate. The filtration rates studied were 40, 60, 80, 100 e 120 m/h. The turbidity limits were 1 e 2 uT. The 60 cm high flexible fiber filter made of mercerized cotton and polyester only could work under the established turbidity limits until 80 m/h. The 100 cm high flexible fiber filter could work well in all the filtration rates. The flexible fiber filter made of polyester obtained longer filtration times, and lower pressure drop comparing to the flexible fiber filter made of mercerized cotton. Except for filtration rates of 40 e 60 m/h which mercerized cotton filter, in all the rates for both fiber filters, the lower coagulant dosage demonstrated better results - longer filtration times, and better quality in the effluent. This study indicated the potential of using flexible fiber filter made of mercerized cotton and polyester in water treatment. It is suggested advanced studies for this technology application in Brazil.
The flexible fiber filters are direct filtration modules which filter media is made of polyamide micro fibers, obtaining high solids removal efficiency, and high filtration rates. This study evaluated the performance of the filter using mercerized cotton and polyester fibers. Tests of fibers resistance due to alkaline, acid and chlorinated environments were realized at the present research. The fibers were also analyzed by means of Optic and Scanning Electronic Microscopy. Four field-scale filters with an internal diameter of 28mm, porosity of 67% (cotton), and 75% (polyester) were installed; two of them made of mercerized cotton fiber- high of 60 and 100 cm; and two made of polyester fiber - high of 60 and 100 cm. A synthetic water was used as influent - turbidity 7,7 ± 0,3 uT, and color 97 ± 5,0 uC. In-line coagulation was used with 22,5 mg/L and 15 mg/L (this last value was only applied on 100cm length filters) of aluminium sulfate. The filtration rates studied were 40, 60, 80, 100 e 120 m/h. The turbidity limits were 1 e 2 uT. The 60 cm high flexible fiber filter made of mercerized cotton and polyester only could work under the established turbidity limits until 80 m/h. The 100 cm high flexible fiber filter could work well in all the filtration rates. The flexible fiber filter made of polyester obtained longer filtration times, and lower pressure drop comparing to the flexible fiber filter made of mercerized cotton. Except for filtration rates of 40 e 60 m/h which mercerized cotton filter, in all the rates for both fiber filters, the lower coagulant dosage demonstrated better results - longer filtration times, and better quality in the effluent. This study indicated the potential of using flexible fiber filter made of mercerized cotton and polyester in water treatment. It is suggested advanced studies for this technology application in Brazil.
Palavras-chave
Algodão mercerizado, Poliéster, Tratamento de água, Filtro de fibras flexíveis, Filtração, Filtration, Mercerized cotton, Drinking water treatment, Polyester, Flexible fiber filter