Industry perspectives

Mixing steps in Water Waste Treatment

Mixing steps in Water Waste Treatment

1 – Coagulation :

agitator for coagulation tank


The coagulation process consists in adding products to the water to remove all the charges between the particles. Ferric chloride, aluminum sulfate for example. Polymers are also added which will then allow flocculation. During this step, rapid mixing is necessary.

2 – Floculation or Maturation :

Flocuation step un waste water treatment plant
Here comes the polymers to allow the particles agglomeration together. We try to create the biggest flocs as possible. Medium to slight agitation is required to promote the formation of these flocs while avoiding shear destruction.

3 – Neutralization :

Neutralization step in waste water treatment process


The aim of neutralization is to neutralize the water to allow coagulation or flocculation operations adding lime, soda or sodium carbonate. The water pH must be 7. The Number of Agitation is 4.

4 – Sludges :

Sludges in waste water treatment process


The coagulation, flocculation and neutralization stages produce a lot
of sludge which containing a high proportion of organic products, in a more or less liquid state, which must be treated. The aim is to reduce the volume to limit the quantities to store

5 – Digester :

Agitator for deigester in waste water treatment process


Organic products fermented produce gas and sludge concentration, thereby lowering the sludge volume up to 20%. Digestion tanks from 2000 to 6000m3 operate on a residence time of 10 to 15 days.