water treatment clarification

Clarification Treatment

Clarification TreatmentClarification Treatment is widely used in many industries including:

  • Paper Industry
  • Sand and Gravel
  • Vegetable Washing and Processing

The clean water from the clarifier is often recycled back to be used as a primary wash water in many applications.




The clarification process is used when there is a large number of Suspended Solids in the wastewater or when solids must be separated from liquids. The clarification process is very effective at reducing and removing colour, solids and colloidal material from wastewater when combined with a chemical treatment regime.

Chemical Treatment

Before an effluent can be settled in a clarifier it must first be treated using pH adjustment, coagulation and flocculation chemicals.  

Coagulants neutralize the negative electrical charge on particles, which destabilizes the forces keeping colloids apart. Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization. Inorganic coagulants, organic coagulants or a combination of both are typically used to treat water for suspended solids removal.

During the mixing process, the pH of the effluent can be adjusted to enable the treatment chemicals to work more efficiently as well as making sure that the discharge water is within pH consent levels.

Flocculants are then introduced to collect the coagulated solids resulting in larger flocs of suspended solids content in the wastewater. The larger flocs separate resulting in clear water. The majority of these chemicals added to the process do not stay in the aqueous phase. They are attached to the solids that are further processed and removed from the treatment area.

Once the effluent has been sufficiently treated, it is then moved forward for Clarification. Clarifiers consist of tanks which hold wastewater for a period of time sufficient to allow the floc and other suspended materials to settle to the bottom. The clarification process removes all kinds of floc, particles, suspended solids, sediments, oil, natural organic matter and colour.

Clarification Treatment New Developments [1]

Improvements and modifications have been made to enhance clarifier performance dependent on the constraints of the substance undergoing the separation.

Addition of flocculants is common to aid separation in clarifiers, but density difference of flocculant concentrate may cause treated water to have an excessive flocculant concentration. Uniform flocculent concentration can be improved and flocculant dosage reduced by installation of an intermediate diffused wall perpendicular to the flow in the clarifier. [2]

The two dominant forces acting upon the solid particles in clarifiers are gravity and particle interactions. Disproportional flow can lead to turbulent and hydraulic instability and potential flow short-circuiting. Installation of perforated baffle walls in modern clarifiers promotes uniform flow across the basin. Rectangular clarifiers are commonly used for high efficiency and low running cost. Improvements of these clarifiers were made to stabilize flow by elongation and narrowing of the tank.

GPC Clear Solutions Limited products are used to increase the settlement of the solids helping the effluent plant keep up with the manufacturing process and to give a clear supernatant.


1 – https://en.wikipedia.org/wiki/Clarifier

2 – http://www.soe.uoguelph.ca/webfiles/rzytner/WQ/Settling_DW.pdf

For more information about how Clarification Treatment works or you want to improve the performance of an existing plant, please fill in our enquiry form.