Table of Contents
The dose of the coagulant to be used can be determined via the jar test. The jar test involves exposing same volume samples of the water to be treated to different doses of the coagulant and then simultaneously mixing the samples at a constant rapid mixing time.
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 Jar test?
Jar testing is a pilot-scale test of the treatment chemicals used in a particular water plant.It simulates the coagulation/flocculation process in a water treatment plant and helps operators determine if they are using the right amount of treatment chemicals, and, thus, improves the plant’s performance.
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.
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.
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 is the difference between flocculant and coagulant?
Depending on the charge and chemical composition of your wastewater, flocculants can either be used on their own or in combination with coagulants. Flocculants differ from coagulants in that they are often polymers, whereas coagulants are typically salts.
What are the common coagulants?
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 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.
Is coagulation reversible?
Coagulation is irreversible, the proteins cannot be turned back into their liquid form.
How the coagulant works in jar test?
The jar test involves exposing same volume samples of the water to be treated to different doses of the coagulant and then simultaneously mixing the samples at a constant rapid mixing time. The microfloc formed after coagulation further undergoes flocculation and is allowed to settle.
Why is coagulant added to water?
Coagulant aid Chemicals (typically synthentic polymers) added to water to enhance the coagulation process. if an excess of alum is added so that the dosed water pH is less than 5.0, then the metal ions (Al3+) will directly ˜eutralize the negatively charged organic compounds and colloids in the raw water. 1.
What is the principle of coagulation?
Coagulation and flocculation are related terms describing the process of preparing colloidal materials for removing by sedimentation. Coagulation is the process used to reduce the energy forces present around particles that tend to keep them from joining together to form a larger mass.
What are the 4 steps 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.
How do you run a jar test?
- The jar test procedures involves the following steps:
- Add the coagulant to each container and stir at approximately 100 rpm for 1 minute.
- Turn off the mixers and allow the containers to settle for 30 to 45 minutes.
- Reduce the stirring speed to 25 to 35 rpm and continue mixing for 15 to 20 minutes.
How is the process of coagulation done?
The coagulation process involves adding iron or aluminum salts, such as aluminum sulphate, ferric sulphate, ferric chloride or polymers, to the water. The positive charge of the coagulant neutralizes the negative charge of dissolved and suspended particles in the water.
What is the most common used coagulant?
1. Alum (aluminum sulfate), Al2(SO4)3. Still, the most common coagulant in the United States, it is often used in conjunction with cationic polymers.
What are the factors affecting coagulation?
Many factors effect of colloidal matter such as, nature of coagulant, retention time, concentration of coagulant and the physical properties such as temperature, pH and others.
What is coagulation with example?
In haematology, the term coagulation refers to clotting or the process of clot formation. A blood clot is a thrombus that forms inside of a blood vessel. The process of blood coagulation involves activation, adhesion, and aggregation of platelets followed by the deposition of fibrin. Mar 1, 2021
What are the similarities and differences between flocculation and coagulation?
Flocculation is synonymous with agglomeration and coagulation / coalescence. Basically, coagulation is a process of addition of coagulant to destabilize a stabilized charged particle. Meanwhile, flocculation is a mixing technique that promotes agglomeration and assists in the settling of particles.
What does coagulation mean?
Coagulation: In medicine, the clotting of blood. The process by which the blood clots to form solid masses, or clots. More than 30 types of cells and substances in blood affect clotting. The process is initiated by blood platelets. The blood cells and plasma are enmeshed in the network of fibrils to form the clot.
How is Jar test calculated?
- Jar Testing of Chemical Dosages. Prepared By.
- Jar Testing. Equipment Needed:
- 1 Graduated Cylinder, 1000 ml. Scale for weighing chemicals.
- For alum, lime, other dry materials: Use a 1 % solution.
- Use a 1 % solution.
- 45 % X 1.49 X V1 = 1 % X 1000 ml.
- Have 45 % Ferric Chloride Solution.
- 1 % X 1000 ml.
