Modification of Polymer Flocculants for the Removal of Phosphate From Water.

Phosphate is frequently found in agricultural wastewater containing suspended solids. Cationic polymer flocculants have shown some success at binding phosphate from the aqueous portion of wastewater while removing the phosphate sorbed to or incorporated into the solid material. We developed bifunctional block copolymer flocculants which contained quaternary ammonium ion monomers used as the positive charge to promote flocculation and thiourea monomers used to selectively bind phosphate. We expected that these new polymers would maintain their ability to flocculate suspended colloidal material while binding free phosphate from solution. The efficacies of these polymers were tested with clay suspensions containing phosphate in solution. Results from these sequestration studies will be discussed.