Table of Contents
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 is coagulation process?
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.
How is the process in stage coagulation done?
Coagulation and flocculation occurs in successive steps, allowing particle collision and growth of floc. This is then followed by sedimentation (see Sedimentation Chapter). If coagulation is incomplete, flocculation step will be unsuccessful, and if flocculation is incomplete, sedimentation will be unsuccessful.
What is egg coagulation?
Coagulation indicates a change from a fluid to a solid or semisolid (gel) state. The success of many cooked foods depends on the coagulative properties of proteins, particularly the irreversible coagulative properties of egg proteins. Egg proteins denature and coagulate over a wide temperature range.
What is difference 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 is the function of coagulant?
What are coagulants used for? In water treatment, coagulants are used to remove a wide variety of hazardous materials from water, ranging from organic matter and pathogens, to inorganics and toxic materials, like arsenic, chemical phosphorous and fluoride.
Why is coagulation?
Coagulation factors are proteins in the blood that help control bleeding. You have several different coagulation factors in your blood. When you get a cut or other injury that causes bleeding, your coagulation factors work together to form a blood clot. The clot stops you from losing too much blood.
How do I reduce NTU?
Settling and decanting is a method to reduce turbidity by letting the water sit for 2-24 hours so that the particulates settle to the bottom of the container. The clear water is then decanted off the top into a second container.
Which is not example of coagulation?
Alum acts as a coagulant for water purification processes. A coagulant binds small particles suspended in raw impure water into larger particles which can be removed by filtration and settling. Creaming of milk is not an example of coagulation.
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 are the 5 stages of water treatment?
These include: (1) Collection ; (2) Screening and Straining ; (3) Chemical Addition ; (4) Coagulation and Flocculation ; (5) Sedimentation and Clarification ; (6) Filtration ; (7) Disinfection ; (8) Storage ; (9) and finally Distribution. Let’s examine these steps in more detail.
What are the three phases of coagulation?
The three phases of coagulation occur on different cell surfaces: Initiation on the tissue factor-bearing cell; Amplification on the platelet as it becomes activated; and Propagation on the activated platelet surface. Based on our work and that of many other workers, we have developed a model of coagulation in vivo.
What are the factors affecting coagulation?
Factors. Coagulation is affected by the type of coagulant used, its dose and mass; pH and initial turbidity of the water that is being treated; and properties of the pollutants present. The effectiveness of the coagulation process is also affected by pretreatments like oxidation.
What does coagulation remove?
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.
How do coagulants remove turbidity?
Coagulation-flocculation, a treatment process where colloids in water are destabilized so they can aggregate and be physically removed, can effectively reduce turbidity when combined with sedimentation and/or filtration.
How effective is coagulation?
Several studies have reported the effectiveness of dual coagulants application when dealing with various types of wastewater where it can reduce up to 90% of COD, total suspended solids (TSS), turbidity, and colour.
What does coagulation test for?
Coagulation tests measure your blood’s ability to clot, and how long it takes to clot. Testing can help your doctor assess your risk of excessive bleeding or developing clots (thrombosis) somewhere in your blood vessels. Coagulation tests are similar to most blood tests.
How is turbidity treated?
There are three ways to reduce this turbidity: Store the runoff long enough for the sediment to settle (weeks to years in many cases). Store the runoff and filter it (high maintenance and expensive). Treat it with chemical flocculants.
What are the five phases of coagulation?
Terms in this set (5) phase one- vascular phase. vasoconstriction, vessels respond by trying to reduce blood flow to the area. phase two- platelet phase. phase three- coagulation phase. phase four- clot retraction. phase five- fibrinolysis.
What are the common coagulants used?
The commonly used metal coagulants fall into two general categories: those based on aluminum and those based on iron. The aluminum coagulants include aluminum sulfate, aluminum chloride and sodium aluminate. The iron coagulants include ferric sulfate, ferrous sulfate, ferric chloride and ferric chloride sulfate.
Is coagulation reversible?
Coagulation is irreversible, the proteins cannot be turned back into their liquid form.
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 first step in blood coagulation?
Hemostasis includes three steps that occur in a rapid sequence: (1) vascular spasm, or vasoconstriction, a brief and intense contraction of blood vessels; (2) formation of a platelet plug; and (3) blood clotting or coagulation, which reinforces the platelet plug with fibrin mesh that acts as a glue to hold the clot
What are natural coagulants?
They are mainly composed of polymers of natural origin extracted from plants, algae or animals. Among these are polysaccharides and water soluble substances that act as coagulation and / or flocculation agents.
How coagulants are help in treatment of water?
Coagulation treatment neutralizes the negative electrical charge on particles, which destabilizes the forces keeping colloids apart. Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization.
