A review of Moringa oleifera seeds in water treatment: Trends and future challenges

Abstract The use of Moringa oleifera (MO) for cleaner processes in water treatment has been proposed to treat raw water for low-income locations for its abundant availability, low cost, reduced by-product generation, biodegradability, non-toxicity and multifunctional behavior. This review analyzed studies that used MO seeds in coagulation-flocculation processes, identifying the main proteins that presented coagulant activity. It was concluded that its most viable application would be as flocculation aid, since it was possible to reduce the concentration of the chemical coagulant with good removal results. Regarding the use of MO as adsorbent, studies could verify its potential to remove several water contaminants, such as pesticides, dyes and pharmaceuticals. Moreover, hybrid treatments have been investigated, however, a research gap could be verified regarding studies on pilot scale, which are fundamental for verifying the viability in water treatment plants. In this sense, the main trends, challenges and recommendations for further studies were assessed regarding the sustainable application of MO seeds in water treatment.