Hello,I agree with Ademar & ...

Hello,

I agree with Ademar & Andre. 

Further information. When the water/wastewater contains slowly settleable particles (e.g. like clay whose settling time could be close to 2hrs or tiny particles like colloids -whose diameter is smaller than 1 micron) or non settleable particles, coagulation & flocculation processes are used by adding chemicals.  

So during coagulation, the objective is to destabilise ("detach") the particles from the water/wastewater while the flocculation process denotes the process of “floc” formation (i.e. consisting of bridging particles/creating an enmeshment of coagulated particles into "flocs") that will settle better/faster given their size & weight in the sedimentation process.

Common coagulant chemicals are aluminum sulfate (Alum), ferric chloride, ferric sulfate, ferrous sulfate (copperas), sodium aluminate, polyaluminum chloride (PACI) and polymers. Selection of the most suitable coagulant depends on many things. Jar test would be right way along with into discussion/interaction with chemical providers.

About flocculant chemicals, there are essentially polymer.

Regards,