Coagulation = coagulation + flocculation, usually the agents that play the role of coagulation and flocculation are collectively referred to as coagulants. So I think as long as you understand the two concepts of coagulation and flocculation, you can distinguish coagulation and flocculation.

So what is agglomeration?

There are a large number of suspended particles with particularly small particle size in the wastewater. These particles are affected by Brownian motion, and there is no way to carry out gravity sedimentation.

Here is a brief explanation of Brownian motion, because the liquid molecular population is in random motion all the time, and when the liquid molecules move, they will hit the solid particles in the solution, and these particles are squeezed by the surrounding liquid molecules. Random motion is Brownian motion.

When Brownian motion is greater than gravity, solid particles cannot sink, so external means must be used to make small particles in water aggregate into large particles, which can resist Brownian motion and cause gravitational sedimentation, but let small particles gather in It is not easy to work together, because these particles have the same charge on the surface, so they are all stable and keep a distance from each other.

So is there any way to get the small particles to clump together? We only need to add the oppositely charged agent to neutralize the charge of these particles, so that they can contact each other and aggregate, and the process of making these particles out of a stable state and forming tiny aggregates is agglomeration.

Commonly used coagulants are aluminum sulfate, ferrous sulfate, alum, ferric chloride, etc.

What is flocculation?

Although the process of agglomeration will cause the small particles in the water to aggregate, but after all, the combination formed is still too small, and it is necessary to find a way to aggregate into larger particles, so there is a flocculant.

Flocculant is a high molecular polymer, each segment on its molecule is equivalent to a bridge, which can connect tiny particles in water to form large flocs and accelerate the sedimentation of particles. Commonly used flocculants are polyacrylamide (PAM) and polydimethyldiallyl ammonium chloride (Polydadmac).