POLYAMPHOLYTES FOR WATER-TREATMENT WITH MAGNETIC PARTICLES

Amphoteric polymers which have cationic properties at acidic pH, but are neutral or anionic at alkaline pH, have been prepared and tested for water clarification and decolourization. The polymer is an adjunct to a magnetic iron oxide employed as the primary coagulant, which is recycled after alkaline treatment. A range of structures has been investigated, including copolymers of methacrylic acid with various quaternary ammonium monomers, terpolymers of these with methyl methacrylate as the third monomer, and polymers containing phenolic or amino acid moieties as well as quaternary ammonium sites. The last two groups of polymers were the most effective in enhancing water treatment performance, with concomitant facile regeneration behaviour.