POLYAMPHOLYTES FOR WATER-TREATMENT WITH MAGNETIC PARTICLES

Amphoteric polymers which have cationic properties at acidic pH, but a re neutral or anionic at alkaline pH, have been prepared and tested fo r water clarification and decolourization. The polymer is an adjunct t o a magnetic iron oxide employed as the primary coagulant, which is re cycled after alkaline treatment. A range of structures has been invest igated, including copolymers of methacrylic acid with various quaterna ry ammonium monomers, terpolymers of these with methyl methacrylate as the third monomer, and polymers containing phenolic or amino acid moi eties as well as quaternary ammonium sites. The last two groups of pol ymers were the most effective in enhancing water treatment performance , with concomitant facile regeneration behaviour.