Bibliographic review use of natural coagulants as an alternative for the treatment of wastewater

Abstract

In the flocculation-coagulation process, iron and aluminum salts are traditionally added as coagulants, which generate toxic residues in the sludge produced, alterations in pH and increase the concentration of salts. Therefore, the present bibliographic review aims to search for natural polymers as a non-toxic alternative, efficient in the destabilization of suspended particles. For this purpose, research articles published between 2010 - 2020 were consulted in various databases, where natural coagulants are added in real domestic and industrial wastewater samples. The consultation carried out indicates the use of 25 natural coagulants, including Moringa Oleifera Lam, Solanum tuberosum, Opuntia Ficus Indica, Pisum Sativum, Acacia Mearnsii, Oryza Sativa, Musa Acuminate, Strychnos Potatorum and Brachystegia Eurycoma, which have a turbidity removal efficiency of over 75 %. It is concluded that the use of natural polymers improves the coagulation processes, equals or increases the removal efficiency compared to conventional polymers, does not alter the pH and reduces the final toxicity.