What is the difference between coagulant and flocculant?
Those who do sewage treatment should know that there are coagulants and flocculants in water treatment chemicals. So what exactly are coagulants and flocculants, and what are the differences between them? As a polyacrylamide manufacturer, Yunhai Water Purification will tell you in detail what coagulants and flocculants are.
What is coagulation and flocculation?
Flocculation is a process in which polymer chains of polymers form bridges between suspended particles. “Bridging” means that different segments of polymer molecules are adsorbed on different particles, promoting the aggregation of particles.
The coagulation process is to add positively charged coagulants to neutralize the negative charges on the surface of the particles and “destabilize” the particles. As a result, the particles combine with each other and become larger through collision, surface adsorption, van der Waals attraction, etc., to facilitate separation from water.
What are coagulants and flocculants used for?
Flocculants are used to improve the speed and efficiency of sedimentation, clarification, filtration, flotation, centrifugation and other processes. The flocculation process is the process in which many individual particles in a suspension form aggregates (flocs or alum flowers).
Coagulants are water-soluble polymers with low molecular weight and high positive charge density, most of which are liquid. They are divided into two categories: inorganic and organic. Inorganic coagulants are mainly aluminum, iron salts and their polymers.
The difference between coagulation and flocculation
However, it is not difficult to find from the above definition of difference that the difference between the two is not clearly defined. It’s the kind that’s a little different but not clearly defined. Therefore, in fact, there is a high degree of overlap between the two in use. For example, inorganic coagulants and inorganic flocculants are basically aluminum salts and iron salts, but there are certain differences between organic coagulants and organic flocculants, which depend on the properties of the water being treated.
Since coagulants/flocculants are all polymer substances, and there are molecules of both large and small sizes in the same product, the so-called “molecular weight” is just an average concept. Therefore, when using a certain coagulant or flocculant to treat sewage, the “electrical neutralization” and “bridging” effects will be intertwined and occur simultaneously. The flocculation process is the result of a combination of multiple factors, and there are still some problems that have not been recognized and solved.
