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Flocculation is a water treatment process where solids form larger clusters, or flocs, to be removed from water. This process can happen spontaneously, or with the help of chemical agents. It is a common method of stormwater treatment, wastewater treatment, and in the purification of drinking water.
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 flocculation reaction?
Flocculation is a two-step particle aggregation process in which a large number of small particles form a small number large flocs. Step 1: Coagulation. Small particles usually carry negative surface charges that hinder aggregation and settling (1a).
What is meant by coagulation and flocculation?
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.
Can you drink flocculant?
In addition, coagulants and flocculants are expensive, which is why you want to avoid adding more than are necessary to the water; drinking water treatment plants use “jar tests” to identify the optimal coagulant and flocculant concentrations. Do not drink any of your water samples—even if they appear clear.
What are the side effects of alum?
Side effects of Alum The excessive amount of alum intake may cause breathing difficulty, facial puffiness, pricking sensation & small ulcers on the skin, chest/throat tightness, and burns rarely seen in some cases.
Why alum is used in wastewater treatment?
Iron free Aluminum Sulfate (Alum) is most widely used in municipal drinking water and wastewater treatment systems. In potable water applications, alum functions as an excellent primary coagulant. Through charge neutralization and flocculation in raw water, alum removes: Turbidity.
What is flocculation test?
Medical Definition of flocculation test : any of various serological tests (as the Mazzini test for syphilis) in which a positive result depends on the combination of an antigen and antibody to produce a flocculent precipitate.
What is difference between alum and iron floc?
Coagulation process is important in water treatment. It is a common understanding that alum is more efficient and cheaper as compared to ferric chloride. I have used these two coagulants for the treatment of Flour Mill Wastewater. Ferric Chloride is way more superior than alum.
What is flocculant for?
Used in a wide range of industries and applications, flocculants help to remove suspended solids from wastewater by aggregating contaminants into flakes or “flocs” that float to the surface of the water or settle at the bottom. They can also be used for lime softening, sludge thickening, and solids dehydration.
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 Lime a coagulant?
Lime (Ca(OH)2 or CaO): Lime, or calcium hydroxide, is predominantly used to adjust pH, but as a softener, it can also be used as a coagulant aid. The lime bonds with the other particles and increases the size/weight of the flocs which then increases the speed with which they settle out of the water.
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.
How fast does flocculant work?
How Long Does It Take to Work? The beauty of flocculants is that they work fast. Your pool can be cleaned in 24 hours, whereas with a clarifier, it takes a few days for the filter to do its job.
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 is the pH of alum?
Alum is most commonly delivered as a liquid concentration, having a solids level of 8.3% as Al2O3 or about 50% as hydrate. Alum solutions are acidic. For instance, a 1% solution has a pH of around 3. Ionic species present in alum solutions are highly dependent on the degree of reaction with hydroxyl ions.
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 an example of flocculation?
Flocculation and coagulation treatment chemicals are used in effluent wastewater water treatment processes for solids removal, water clarification, lime softening, sludge thickening, and solids dewatering. Examples of ChemTreat coagulation products include aluminum salts, iron salts, and polyelectrolytes.
Does flocculant affect pH?
Because flocculants can affect the pH level, you’ll want to start out with it at about 7.0 so you can make sure your sanitizer keeps working at maximum efficiency.
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 is difference 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.
Can you add too much flocculant?
Adding too much flocculant can cause its own issues. Flocculant is aluminum sulfate, which is designed to clump with the particles you’re trying to remove. But if you add too much, the flocculant will start to agglomerate with itself instead of those particles.
