Coagulation of low turbidity surface waters with Moringa oleifera seeds

The use of Moringa oleifera seed extracts both as primary coagulant coagulant aid and its conjunctive use with alum in treating low turbidity waters was studied. The laboratory based studies used the natural polyelectrolyte to treat waters with turbidities between 23 and 90 ntu, obtained from three surface water sources in Kano, Nigeria. On the average, 50% turbidity removal was achieved when Moringa oleifera was used as primary coagulant. In combination with alum, the rates at which floes were formed were the same or often faster than with alum alone. In this study, between 40 and 80% savings in alum was observed. When used as a coagulant aid, the optimum dose was found to be 10 mg/1 while that of alum was 20 mg/1. Finally, it was observed that the time Moringa oleifera is applied (after slow mixing), is critical in determining the efficiency of coagulation. The optimum time for this was found to be 50 seconds after slow mixing.