Moringa oleifera seeds for softening hardwater

In this paper, preliminary investigations into the possible use of Moringa oleifera seed suspension for the softening of hardwater are presented. Four water sources: synthetic water (distilled water spiked with calcium chloride), naturally hard surface water and groundwater from two tube wells at different locations were used for the study. Modified laboratory jar test procedures for coagulation studies were used for the experimental runs. Water hardness from the sources varied from 300 up to 1000 mg/l as CaCO3. The mechanism for softening was found to be due to adsorption with the adsorption isotherm approximating to the Langmuir type, and conversion of soluble hardness-causing ions to insoluble products by precipitation reactions. Removal efficiency was found to increase with increasing dosage of Moringa oleifera. Higher dosages were required to achieve equivalent residual hardness for water samples with the same initial hardness but higher number of hardness-causing species in the water. Hardness removal was found to be independent of pH of the raw water.