Evaluation of Moringa oleifera seeds as a natural solution in comparison to alum for combatting common aquatic pathogenic bacteria by coagulation and antibacterial action

Abstract Conventional water treatment methods typically involve chemicals and mechanical processes; there is growing interest in exploring natural and sustainable alternatives. This study assessed Moringa oleifera seed as a natural coagulant for water purification, comparing its effectiveness with alum. Water samples from various sources were treated with different concentrations of Moringa seed powder. The coagulation-flocculation activity indicated that increasing Moringa concentrations raised pH levels within the World Health Organization’s (WHO) recommended range. At 400 mg/l, Moringa reduced turbidity by up to 89.19% in river water, while alum achieved a higher reduction at the same concentration. Moringa seeds significantly reduced bacterial counts, achieving up to 98.65% in wastewater at 400 mg/l, compared to alum’s 97.29%. Total coliform decreased by 95.00% and fecal coliform by 100%. Moringa seeds also exhibited antibacterial and anti-oxidant properties, with an expected concentration needed to scavenge 50% of free radicals (EC50 value) of 3.926 mg/ml. Proximate analysis revealed high protein (33.67%) and fat (36.45%) content. Phytochemical analysis confirmed the presence of bioactive compounds such as alkaloids, tannins, saponins, phenols, and flavonoids. High-performance liquid chromatography (HPLC) identified 14 phenolic and flavonoid compounds, with the most abundant vanillic acid (74.95%). M. oleifera demonstrated adequate removal effectiveness, supporting its potential application in water treatment as a sustainable, eco-friendly, and cost-effective solution alternative to conventional coagulants in regions facing water pollution concerns.