Purification and optimization of salt solution-extracted coagulation-active components from Moringa oleifera seeds for enhanced drinking water treatment

Moringa oleifera seeds contain components that can coagulate and flocculate turbid substances during water treatment. Their extract is called a natural nature-based coagulant. However, the extract also contains some impurities that are unrelated to coagulation and can potentially cause problems in treated water, such as color and odor. Furthermore, disinfection by-products can be formed after chlorination due to the presence of residual organic material. The balance between coagulation efficiency and treated water quality is key to the successful development of Nb coagulants. This study aimed to establish a simple method for purifying coagulation-active components from a crude extract of Moringa oleifera seeds using a salt solution, either by solidification or dilution. The insoluble gel formed from the salt extracts by dilution with ions in tap water considerably improved the quality of treated water. Although dissolved organic carbon and salt concentrations generally increase after coagulation due to the salt-extracted solution, the deterioration of treated water quality did not occur when this purification method was adopted. In addition, its coagulation-sedimentation efficiency was maintained at approximately 90% turbidity removal for water with a turbidity of 40 NTU. The high potential of the purified coagulation components in Moringa seeds and the possible application of this sustainable and natural coagulant were demonstrated in this study.