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Flocculation: Particles that aggregate by the use of polymers that binds them together. They are typically used for treatment of wastewater containing colloids (suspended particles) and metal ions. But the phenomena are also well-known from everyday life – especially coagulation. A good example is sour milk.
What is flocculation with example?
Flocculation is the collection of cells into aggregates by the addition of multivalent cations, metal salts or polymers (for example, polyaluminum chloride).
What are examples of flocculants?
The iron-based flocculants include ferric chloride, ferric sulfate, ferrous sulfate, and ferric chloride sulfate [15, 69]. Aluminum sulfate or alum (Al2(SO4)3), ferric chloride (FeCl3) and ferric sulfate (Fe(SO4)3) are the most widely used flocculants [1, 70].
Why is flocculation important?
Applying flocculation ensures a high flux over filtration units as well as efficient and cost effective separation of cell material from supernatant. Used water can contain significant amounts of suspended particulate matter, which often takes long to sediment.
Is flocculation good for soil?
In all but the sandiest soils, dispersed clays plug soil pores and impede water infiltration and soil drainage. Flocculation is important because water and oxygen moves mostly in large pores between aggregates moves mostly in large pores between aggregates. Also, plant roots grow mainly between aggregates.
What affects flocculation?
Several factors can affect flocculation, primarily poly- mer type, ionic strength, water pH, slurry solids, flocculant dilution, shear, molecular weight, and pro- cess conditions.
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 flocculation mention some of its applications?
Flocculation and sedimentation are widely employed in the purification of drinking water as well as in sewage treatment, storm-water treatment and treatment of industrial wastewater streams.
What is the principle of flocculation?
Flocculation refers to the process used to bring the coagulated particles together so that they can combine to form larger, settleable, and filterable masses of particles called floc. Zeta potential is defined and its role in coagulation described.
What makes a good flocculant?
Polymers are useful as flocculants because they are robust molecules and sometimes carry charges. Because they are so large, small particles can get trapped in the curves of the polymer causing them to accumulate a mass heavy enough to prevent their retention in solution.
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.
Why is flocculation important for treating water?
Coagulation and flocculation are both critical processes to separate and remove suspended solids in water and wastewater treatment. These processes improve the clarity of the water to reduce turbidity.
Is gypsum a flocculant?
Gypsum can coagulate or bridge clay particles, which accelerates settling. Flocculants should be used to prevent damage to sensitive water resources such as ponds, lakes and trout streams or whenever turbidity control is required. The best thing to do is a jar or bucket test using slightly varying rates of gypsum.
What is flocculating ion?
Coagulation or precipitation:-it is a process of aggregating together the colloidal particle so as to change them into large sized particles which ultimately settles as a precipitate. The ion which is responsible for neutralization of charge on the colloidal particles is called the coagulating ion or Flocculating ion.
What is flocculant made of?
The aluminum-based flocculants include aluminum sulfate, aluminum chloride, sodium aluminate, aluminum chlorohydrate, and polyaluminum chloride. The iron-based flocculants include ferric chloride, ferric sulfate, ferrous sulfate, and ferric chloride sulfate [15, 69].
What chemical is used for flocculation?
Coagulants such as alum (Al2(SO4)3-14H2O), iron salts (ferric chloride (FeCl36H2O), ferric sulfate (Fe2(SO4)3) and ferrous sulfate (FeSO47H2O)), lime (Ca(OH)2) and organic polyelectrolytes are used as flocculation aids during wastewater treatment.
What is the meaning of a flocculant?
flocculant. / (ˈflɒkjʊlənt) / noun. a substance added to a suspension to enhance aggregation of the suspended particles.
How can flocculation be prevented?
When particles of a suspension come close together they can form aggregates called flocculates which will settle more rapidly. To prevent that we often coat the particle with a charged surfactant. The charge (Zeta potential) acts to keep the particles separate and prevent flocculation.
What is an example of flocculation test?
A Flocculation Test Procedure is used to determine how much Flocculants need be added to solids in suspension (slurry or pulp) to cause the individual particles to collect in the form of flocs. Flocculation, i.e. aggregation through the use of long-chain organic polymers that bridge between adjoining particles.
What is flocculation simple?
Flocculation, in physical chemistry, separation of solid particles from a liquid to form loose aggregations or soft flakes. These flocculates are easily disrupted, being held together only by a force analogous to the surface tension of a liquid.
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 is a 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 does flocculation not remove?
Suspended particles cannot be removed completely by plain settling. Large, heavy particles settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Aluminum sulfate (alum) is the most common coagulant used for water purification.
Can you use too much flocculant?
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. These flocculant clumps will not drop to the pool floor and can clog up your filter.
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.
