Flocculation process comes after the coagulation. It is the chemical polyelectrolyte used for flocculation and the polyelectrolyte is mixed with the wastewater by means of slow mixer.

Dimensions of flocculation tanks is important for system of chemical treatment. Parameters such as rpm of mixer and tank volume directly affect the purification efficiency.

Slow mixers consist of shaft, impeller pallets and low rpm reductors. It is important the number of pedals and width.

Slow mixer equipment is designed separately for both chemical and biological treatment. While the slow mixer pedal type is made for chemical treatment plants, the slow mixers used in the sludge condensation units of the biological treatment plants are manufactured as pedal.

Both types from AISI 304 stainless steel for slow mixer; shaft and propeller elements are produced.