A polymeric electrolyte (natural or synthetic) with a long chain-like structure and a high molecular weight which may be used as a cationic, anionic, or nonionic flocculent (or coagulant aid) in the treatment of potable water.

Polyelectrolytes are polymers whose repeating units bear an electrolyte group. These groups will dissociate in aqueous solutions (water), making the polymers charged. Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers (high molecular weight compounds), and are sometimes called polysalts.