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Coagulation and flocculation are used to separate the suspended solids portion from the water. Suspended particles vary in source, charge, particle size, shape, and density. Correct application of coagulation and flocculation depends upon these factors.
What is the ultimate goal of coagulation and flocculation?
Terms in this set (50) What is the purpose of coagulation and flocculation? The purpose of coagulation and flocculation is to remove particulate impurities and color from the water being treated.
What is the purpose of coagulation?
Coagulation is a process used to neutralise charges and form a gelatinous mass to trap (or bridge) particles thus forming a mass large enough to settle or be trapped in the filter.
What is the difference between flocculant and coagulant?
Flocculants differ from coagulants in that they are often polymers, whereas coagulants are typically salts. Generally speaking, anionic flocculants are used to catch mineral particles while cationic flocculants can capture organic particles.
Is alum positive or negative?
For example, the colloidal particles are negatively charged and alum is added as a coagulant to create positively charged ions. Once the repulsive charges have been neutralized (since opposite charges attract), van der Waals force will cause the particles to cling together (agglomerate) and form micro floc.
What are the similarities and differences between flocculation and coagulation?
Coagulation is a chemical process and flocculation is a physical process, In coagulation, the process involves the utilization of a coagulant that has the ability to destabilize the charged particles which are not settleable whilst flocculation involves a similar destabilization process that is achieved through Dec 10, 2017
What is the purpose of flocculation in water treatment?
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.
Why is coagulation flocculation necessary?
Coagulation and flocculation are used to separate the suspended solids portion from the water. Suspended particles vary in source, charge, particle size, shape, and density. Coagulation and flocculation occurs in successive steps, allowing particle collision and growth of floc.
Is coagulation reversible?
Coagulation is irreversible, the proteins cannot be turned back into their liquid form.
What is difference between flocculation and Deflocculation?
The key difference between flocculation and deflocculation is that flocculation is the formation of flocs by the clumping of fine particles, whereas deflocculation is the dispersion of flocs to form a stable colloid. Flocculation refers to the formation of clumps from fine particles in a colloid.
Is FeCl3 a coagulant?
Ferric chloride (FeCl3) is the most common iron salt used to achieve coagulation. Its reactions in the coagulation process are similar to those of alum, but its relative solubility and pH range differ significantly from those of alum. Both alum and ferric chloride can be used to generate inorganic polymeric coagulants.
How does a flocculant work?
A flocculant is a chemical that can be added to the water to help colloids and any other suspended solids bind together and form heavier particles. The heavier particles then settle to the bottom of the container/tank and the water on the top is drained off.
Is alum a coagulant or flocculant?
To accomplish this, the water is treated with aluminum sulfate, commonly called alum, which serves as a flocculant. Raw water often holds tiny suspended particles that are very difficult for a filter to catch. Alum causes them to clump together so that they can settle out of the water or be easily trapped by a filter.
What is the relationship between flocculation and coagulation?
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 two chemicals are commonly used as water coagulants?
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 happens during coagulation?
Blood clots and coagulation Blood vessels shrink so that less blood will leak out. Tiny cells in the blood called platelets stick together around the wound to patch the leak. Blood proteins and platelets come together and form what is known as a fibrin clot. The clot acts like a mesh to stop the bleeding.
What is the best coagulant?
Chemical Coagulants Used In Water Treatment Aluminum Sulfate (Alum) – One of the most commonly used water treatment chemicals in the world. Aluminum Chloride – A second choice to Alum as it is more expensive, hazardous and corrosive. Polyaluminum Chloride (PAC) & Aluminum Chlorohydrate (ACH).
Does alum increase pH?
Ionic species present in alum solutions are highly dependent on the degree of reaction with hydroxyl ions. It is tempting to say that “the composition is pH-dependent.” However, in the vicinity of pH=4.3 the composition of alum solutions changes a great deal with very little change in pH.
Why is alum added to the water?
In a typical water treatment process: Alum is used to coagulate suspended particles, algae, protozoa, viruses, bacteria, and some metal ions (such as iron and manganese) into larger particles. Chlorine is added to kill bacteria that may have entered the water during the filtration process.
What is the coagulation process?
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 the side effects of alum?
If experienced, these tend to have a Severe expression i fluid accumulation around the eye. throat swelling. a feeling of throat tightness. a skin ulcer. hives. a shallow ulcer on the skin. fainting. puffy face from water retention.
What is the purpose of flocculant?
Flocculants are substances that promote the agglomeration of fine particles present in a solution, creating a floc, which then floats to the surface (flotation) or settles to the bottom (sedimentation). This can then be more easily removed from the liquid.
