The process of flocculation is applicable to water purification, compaction and dewatering of sludge, in which the result is an aggregation of particles formed during the coagulation step and the formation of the so-called flocs. Such treatment can be applied only after coagulation since the reduction of repulsive forces between the particles favours their formation in aggregates, and flocculation, in turn, promotes growth and accelerates the separation of these phases from particles. The process takes place under the influence of a polymer - a substance composed of high molecular weight molecules formed from a large number of identical molecules called monomers linked by covalent bonds. The electric charge (+ or -) of the flocculant is chosen depending on the nature of the particles dissolved in the water, usually, an anionic flocculant (-) is applied to mineral particles and a cationic flocculant (+) to organic particles.
Flocculants (+ or -) are sold in solid and liquid form: