What is coagulation and flocculation process?

Coagulation and flocculation are two separate processes, used in succession, to overcome the forces stabilising the suspended particles. While coagulation neutralises the charges on the particles, flocculation enables them to bind together, making them bigger, so that they can be more easily separated from the liquid.

What happens at the coagulation-flocculation step?

Coagulation-flocculation: The use of chemical reagents to destabilise and increase the size of the particles; mixing; increasing of flog size, A physical separation of the solids from the liquid phase. This separation is usually achieved by sedimentation (decantation), flotation or filtration.

What is flocculant and coagulant?

Coagulation: Particles that aggregate with themselves e.g. by the influence of a change in pH. Flocculation: Particles that aggregate by the use of polymers that binds them together. Coagulation and flocculation are well-known techniques within wastewater treatment.

What is the process of flocculation?

Flocculation is a process by which a chemical coagulant added to the water acts to facilitate bonding between particles, creating larger aggregates which are easier to separate. The method is widely used in water treatment plants and can also be applied to sample processing for monitoring applications.

What is the difference between Floculant and coagulant?

Coagulation is a chemical process. Flocculation is a physical process. Coagulants such as inorganic salts of aluminum or iron that neutralize the suspended particles are added during coagulation. Flocculant such as an organic polymer that involves in bridging and strengthening the flocs is added.

What is an example of coagulation?

Examples of Coagulation Milk proteins coagulate to thicken the mixture that forms yogurt. Blood platelets coagulate blood to seal a wound. Pectin gels (coagulates) a jam. Gravy coagulates as it cools.

What happens during coagulation?

Coagulation is the chemical water treatment process used to remove solids from water, by manipulating electrostatic charges of particles suspended in water. This process introduces small, highly charged molecules into water to destabilize the charges on particles, colloids, or oily materials in suspension.

What are coagulants?

Coagulants are a substance which cause particles in a liquid to curdle and clot together. Particles stay suspended in water rather than settling because they carry surface electrical charges that mutually repel each other.

Which is example of coagulant?

Examples of primary coagulants are metallic salts, such as aluminum sulfate (referred to as alum), ferric sulfate, and ferric chloride. Cationic polymers may also be used as primary coagulants.

What is coagulation process in chemistry?

Coagulation is a process of aggregation or accumulation of colloidal particles to settle down as a precipitate. Substances like metals, their sulfides etc. cannot be simply mixed with the dispersion medium to form a colloidal solution. Some special methods are used to make their colloidal solutions.

What is the function of coagulant?

Coagulants and flocculation processes are used to remove colloidal impurities: suspended particles such as bacteria, clay, silts, and organic matter from the contaminated water. This produces large flock aggregates that can be removed from the water in subsequent clarification/filtration processes.

What chemicals are used in coagulation?

Traditional chemical coagulation uses aluminum and iron coagulants. The most common aluminum coagulants are aluminum sulfate, aluminum chloride, and sodium aluminate. Iron coagulants include ferric sulfate, ferrous sulfate, ferric chloride, and ferric chloride sulfate [4].

What is coagulation method?

What means of coagulation?

Definition of coagulation : the process of becoming viscous or thickened into a coherent mass : the forming of clots (as in blood or cream) : the process of coagulating … an incision is made on the skin of the forearm with a spring-loaded device, and the time to coagulation is measured.—

What causes flocculation?

In dispersed clay slurries, flocculation occurs after mechanical agitation ceases and the dispersed clay platelets spontaneously form flocs because of attractions between negative face charges and positive edge charges.

What are the types of coagulation?

Types of coagulation tests

• Complete blood count (CBC) Your doctor may order a complete blood count (CBC) as part of your routine physical.
• Factor V assay. This test measures Factor V, a substance involved in clotting.
• Fibrinogen level.
• Prothrombin time (PT or PT-INR)
• Platelet count.
• Thrombin time.
• Bleeding time.

What chemical is used for flocculation?

Chemicals (coagulants) are added to the water to bring the nonsettling particles together into larger, heavier masses of solids called floc. Aluminum sulfate (alum) is the most common coagulant used for water purification. Other chemicals, such as ferric sulfate or sodium aluminate, may also be used.

What is coagulation with example?

Coagulation is the breakdown of a colloid by changing the pH or charges in the solution. Making yogurt is an example of coagulation wherein particles in the milk colloid fall out of solution as the result of a change in pH, clumping into a large coagulate.

What is the best pH for coagulation?

between 6 and 8
However, optimum coagulation occurs when negatively charged forms of alum predominate, which occurs when the pH is between 6 and 8.