Evaluation of Coagulation/ Floculation Process for Water Treatment using Defatted Cake from Moringa Oleifera

Abstract

The Moringa oleifera Lam belongs to Moringaceae family and is native to India and widely cultivated in the tropics all over the world.Their seeds are a good source of oil with an excellent quality and protein that present potential coagulant for water treatment. Studies reported that even after the removal of the oil from the seed, the defatted cake keeps its coagulant properties. The aim of this study was to evaluate the Moringa seed as coagulant in the treatment of surface water, after the removal of its oil. Saline coagulants were prepared in concentrations range of 3.45 - 75.8 mg / L, using seed (unprocessed) and defatted cake using mechanical and chemical extraction process with the solvents hexane and ethanol. The different coagulants were evaluated in the Jar test to verify their power to treat water with low turbidity. The results showed that both the defatted coagulants and the integral coagulant (unprocessed seeds) obtained similar results in the removal of approximately 83%, 90% and 69% for color, turbidity and UV_254nm, respectively. However, the defatted coagulants (hexane and mechanical) that presented the low lipids content showed better results in the removal of dissolved organic carbon present in the raw water. The high efficiency in water treatment and decreased concentration in organic matter in the water, open new perspectives in the use of defatted coagulant of Moringa oleifera as a natural coagulant for the treatment of supply water. In addition, it is possible to extract oil from Moringa oleifera seeds that have several applications and use the defatted cake in the water treatment process without losing its ability to coagulate.