Flocculants

Flocculants have the ability to interact and form chemical bonds on the surface of the dispersed phase particles. As a result of adsorption, so-called flocs are formed on the particles of a solid body, which initiates the coagulation of emulsions. The next step is to create large aggregates, which drop out of the solution in the form of sludge or turbid suspension. They can be separated from the water by sieves, filtration or decantation. Flocculation can be accelerated through gentle mixing of the system. The flocculants then reach the particles faster and bond with the particle, creating larger aggregates that can be removed more quickly.

Polymeric compounds such as polyacrylamides, polyacrylic acids and their derivatives are used as flocculants. They are characterized by high solubility in water and high biodegradability.

There are three types of flocculants which are distinguished due to their chemical nature:

• anionic flocculants – used in alkaline and neutral environments; they are mainly used for clarification and dewatering of mineral suspensions,
• cationic flocculants – which are used in acidic environments; most often used to clarify suspensions of organic substances,
• inert flocculants – have a wide range of applications in various industries, e.g. in the processing of coal and metal ores.

Flocculants are used in sewage treatment plants, water treatment plants and in many industrial processes where colloidal separation of suspended products is necessary.