Estudo comparativo entre o uso do coagulante extraído das sementes de Moringa oleifera e os coagulantes químicos no tratamento de água
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Data
2021-06-14
Tipo de documento
Monografia
Título da Revista
ISSN da Revista
Título de Volume
Área do conhecimento
Engenharias
Modalidade de acesso
Acesso embargado
Editora
Autores
Silveira, Mirella Klausen da
Orientador
Moecke, Elisa Helena Siegel
Coorientador
Resumo
A disponibilidade e a gestão sustentável da água, assim como o saneamento para todos, são um dos Objetivos de Desenvolvimento Sustentável (ODS). No tratamento de água, coagulantes são utilizados para desestabilizar partículas presentes na água bruta, propiciando a geração de flocos capazes de serem removidos pelo processo de decantação. Além dos coagulantes químicos, como o sulfato de alumínio, há polímeros sintéticos e coagulantes naturais que podem ser utilizados para tal função. O presente trabalho objetivou avaliar a eficácia das sementes de Moringa oleifera, do cloreto de polialumínio (PAC) e do sulfato de alumínio, no processo de tratamento da água proveniente do rio localizado no Córrego dos Pombos. Os ensaios foram realizados em escala de bancada utilizando o equipamento Jar test para simular os processos de coagulação, floculação e decantação. Foram realizadas dosagens de 210 a 3200 mg/L do pó das sementes de Moringa oleifera (Método 1) e 1 a 1000 mg/L do extrato aquoso das sementes de Moringa oleifera (Método 2), para uma água de turbidez inicial de 21,30 NTU, e aplicadas dosagens de 7 a 8,58 mg/L de cloreto de polialumínio, 14 a 28 mg/L de sulfato de alumínio e 50 a 200 mg/L do extrato aquosos das sementes, para uma água com turbidez inicial de 73,98 NTU. A partir das análises dos parâmetros físico-químicos das amostras de água, antes e após os ensaios de coagulação, floculação e decantação, foi estabelecido a dosagem ótima para cada coagulante. Os resultados mostram que a dosagem ótima de 50 mg/L de extrato aquoso das sementes (Método 2) obteve uma melhor eficiência para uma água de turbidez inicial de 21,30 NTU, apresentando também uma geração de lodo inferior (0,8 mL/L) à do Método 1 (4,5 mL/L). Os coagulantes que obtiveram uma melhor eficiência na remoção da turbidez na água de 73,98 NTU foram o PAC e o extrato aquoso das sementes, com valores acima de 95% de remoção da turbidez, além de apresentarem uma estabilidade maior no pH quando comparados com o sulfato de alumínio. O extrato aquoso apresentou um menor volume de lodo em relação aos outros 2 coagulantes, mostrando ser uma opção eficiente, sustentável e viável para substituir os coagulantes químicos.
The availability and sustainable water management, as well as sanitation for all are part of the Sustainable Development Goals (SDGs). In water treatment, coagulants are used to destabilize particles that are in the raw water, generating flakes that can be removed by the decantation process. In addition to chemical coagulants, like aluminum sulfate, there are synthetic polymers and natural coagulants that can be used for this function. The present study aimed to evaluate the effectiveness of the Moringa oleifera seeds, polyaluminium chloride (PAC) and aluminum sulphate, in a river water treatment, located in Córrego dos Pombos. Bench scale tests were performed using the Jar test to simulate the coagulation, flocculation and decantation processes. Dosages of 210 to 3200 mg/L of Moringa oleifera seed powder (Method 1) and 1 to 1000 mg/L of Moringa oleifera seeds extract (Method 2) were used in a water with initial turbidity of 21.30 NTU. Dosages of 7 to 8.58 mg/L of polyaluminium chloride, 14 to 28 mg/L of aluminum sulphate and 50 to 200 mg/L of aqueous seed extract were used in a water with initial turbidity of 73.98 NTU. From the analysis of the physical-chemical parameters of the water samples, before and after the coagulation, flocculation and decantation tests, the optimum dosages for each coagulant were established. The results show that the optimal dosage of 50 mg/L of aqueous extract (Method 2) obtained a better efficiency in a water with an initial turbidity of 21.30 NTU, presenting a lower sludge generation (0.8 mL/L) than Method 1 (4.5 mL/L). The coagulants that had a better efficiency in removing turbidity in water of 73.98 NTU, were the polyaluminium chloride and the aqueous extract, with turbidity removal values above 95%, in addition to presenting better pH stability compared to aluminum sulphate. The aqueous extract had a smaller sludge volume when compared to the other 2 coagulants, proving to be an efficient, sustainable and viable option to replace chemical coagulants.
The availability and sustainable water management, as well as sanitation for all are part of the Sustainable Development Goals (SDGs). In water treatment, coagulants are used to destabilize particles that are in the raw water, generating flakes that can be removed by the decantation process. In addition to chemical coagulants, like aluminum sulfate, there are synthetic polymers and natural coagulants that can be used for this function. The present study aimed to evaluate the effectiveness of the Moringa oleifera seeds, polyaluminium chloride (PAC) and aluminum sulphate, in a river water treatment, located in Córrego dos Pombos. Bench scale tests were performed using the Jar test to simulate the coagulation, flocculation and decantation processes. Dosages of 210 to 3200 mg/L of Moringa oleifera seed powder (Method 1) and 1 to 1000 mg/L of Moringa oleifera seeds extract (Method 2) were used in a water with initial turbidity of 21.30 NTU. Dosages of 7 to 8.58 mg/L of polyaluminium chloride, 14 to 28 mg/L of aluminum sulphate and 50 to 200 mg/L of aqueous seed extract were used in a water with initial turbidity of 73.98 NTU. From the analysis of the physical-chemical parameters of the water samples, before and after the coagulation, flocculation and decantation tests, the optimum dosages for each coagulant were established. The results show that the optimal dosage of 50 mg/L of aqueous extract (Method 2) obtained a better efficiency in a water with an initial turbidity of 21.30 NTU, presenting a lower sludge generation (0.8 mL/L) than Method 1 (4.5 mL/L). The coagulants that had a better efficiency in removing turbidity in water of 73.98 NTU, were the polyaluminium chloride and the aqueous extract, with turbidity removal values above 95%, in addition to presenting better pH stability compared to aluminum sulphate. The aqueous extract had a smaller sludge volume when compared to the other 2 coagulants, proving to be an efficient, sustainable and viable option to replace chemical coagulants.
Palavras-chave
Coagulante natural, Lodo, Turbidez