Aplicação de sementes de Moringa oleífera como agente coagulante no tratamento de águas de reservatórios do Agreste e Sertão da Paraíba

Abstract

Water scarcity is a phenomenon which causes many socio environmental issues in Brazil and in the world. Accessibility to safe and efficient water resources through the development of technologies such as alternative water treatment methods is needed. Studies show that Moringa oleífera seeds (MO) have coagulation properties and that the usage of standard chemical coagulants such as aluminum sulfate, could be linked to the development of neurological diseases. In order to turn water treatment methodologies safer and more sustainable, done with local inputs and with lower financial costs, the performance of Moringa oleífera seeds as a natural coagulant has been studied. Therefore, this present study aims to analyze the efficiency of MO seeds as a natural coagulant in the treatment of water samples from a small reservoir in the city of Queimadas and Açude Grande reservoir, in Cajazeiras, state of Paraíba. MO seeds were shelled, oven dried, powdered and applied in raw water, which was then submitted to 2 and 48 hours of settling time. In order to make this methodology easier to apply by rural producers during field activities, the natural coagulant was used in a range of 20 to 100 seeds per 500 mL of water sample. Water quality analysis was done using the following physical-chemical parameters: turbidity, apparent color (AC), pH, electrical conductivity (EC), total dissolved solids (TDS) and total hardness, so that the coagulant’s performance and the most efficient treatment arrangement could be verified. This methodology resulted in a 88,25% and 70% removal of turbidity and apparent color, respectively, from Queimadas’ water sample. Nonetheless, it was inefficient on treatment of Açude Grande’s water sample by increasing initial turbidity and apparent color according to the number of seeds and settling time.