ABSTRACT

ABSTRACT: More than 1 billion people in the developing countries do not have access to safe drinking water and as a consequence more than 2 million people, most of them children, die every year from water borne diseases. One of the reasons is the high cost of treatment chemicals and hence there is a need for low cost and locally available materials. The natural coagulants that can be used as a substitute for synthetic chemicals is a seed extract of Moringa oleifera. It contains an active coagulating protein that can be extracted for use in water treatment. This paper describes the purification and immobilization of the coagulant protein from M. oleifera seed. The coagulant protein from M. oleifera seeds was extracted with ammonium acetate buffer and its coagulation property for synthetic clay solution was studied. The crude extract has the same coagulation activity as alum. The active component was purified to homogeneity by ion exchange chromatography method using fast flow carboxymethyl Sepharose and the properties of the purified protein were characterized. The coagulant protein has also been purified using magnetic beads. The purified component is a cationic protein with a molecular mass less than 6.5 kDa (kilo Dalton). The magnetic beads have six times higher adsorption capacity for the crude extract compared to that of ion exchange matrix. The proteins immobilized to magnetic beads have coagulation property in synthetic clay suspension. The coagulated particles can be removed from immobilized protein by washing without disturbing the protein. The possibilities of using immobilized protein to magnetic beads are discussed. The immobilized beads or purified protein can be used in water treatment in developed and developing countries.