Anionic polyacrylamide (APAM) is a water-soluble linear macromolecule flocculant formed by the copolymerization of acrylamide and acrylate. It promotes the flocculation of particles by neutralizing the charge of suspended particles, thus destabilizing the particles in water. The destabilized particles adsorb each other under the bridge action of the active gene of macromolecule polymers. Finally, larger flocs are formed.