Natural coagulants in water clarification

Powdered seed suspensions of the Moringa oleifera tree have proved effective as a primary coagulant to clarify a stable kao­linite suspension. Acting as a cationic polyelectrolyte optimum minimum dosage to achieve maximum turbidity removal have been determined over a range of initial turbidity values (50-550NTU). The weight ratio of seed dosage to clay concentration appears in­dependent of initial clay concentration. A field usable dissolved air flotation system has been developed. This technique, when applied to a kaolinite/bentonite model sus­pension, produced clear water in minutes as opposed to hours for conventional sedimenta­tion. Topics for further investigation are outlined.