Coagulation and flocculation processes are used in order to remove suspended solids and/ or impurities from the water. They are usually used in drinking water and wastewater treatment.

In coagulation process, a certain chemical is dosed to the water so the electrical charge of the suspended solids becomes neutralized, causing the particles to bind together to larger forms.

When flocculation takes place subsequent to coagulation, another type of chemical is dosed. The forms from the coagulation process bond together to create larger flocs, which are visible to the naked eye.

Since their weight is much larger now, they:

 At Clarifiers: settle at the bottom, where they can easily be removed.

At filters: are easily trapped (as they are much bigger), so eventually they are filtered away