What is flocculation in water treatment?
Flocculation is the separation of a solution, commonly the removal of sediment from a fluid. The term is derived from floc, which means flakes of material; and when a solution has been flocculated, the sediment has formed into larger aggregated flakes, making them easier to see and remove.
What is flocculation and why is it used in water treatment?
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 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.
How many types of flocculation are there?
The flocculation process can be broadly classified into two types, perikinetic and orthokinetic. Perikinetic flocculation refers to flocculation (contact or collisions of colloidal particles) due to Brownian motion of colloidal particles.
What is the importance of flocculation?
Flocculants improve filtration, leading to an improved cleaning and disinfection of the water. This treatment method is recommended when the filtration system struggles to remove all the floating particles (murky/troubled water). The chemical process which follows is called flocculation.
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.
What is flocculation value?
The minimum concentration of an electrolyte which is required to cause the coagulation or flocculation of a sol is known as flocculation value. According to Hardy Schulze rule, greater the valency of the active ion or flocculating ion, greater will be its coagulating power.
Why does flocculation happen?
In dispersed clay slurries, flocculation occurs after mechanical agitation ceases and the dispersed clay platelets spontaneously form flocs because of attractions between negative face charges and positive edge charges.
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.
How is flocculation value calculated?
“The minimum concentration of an electrolyte that is required to cause the coagulation or flocculation of a sol is known as flocculation value.” It is expressed in terms of millimoles per litre. 2 mL of 1 M NaCl contains 2 / 1000 mol = 2 millimole.
What is difference between coagulation and flocculation?
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.
What do flocculants do in water treatment?
Flocculants are used in water treatment processes to improve the sedimentation or filterability of small particles. For example, a flocculant may be used in swimming pool or drinking water filtration to aid removal of microscopic particles which would otherwise cause the water to be turbid…
What is added to water to cause flocculation?
In the first stage of flocculation, a coagulant like aluminium sulphate is added to the wastewater. The positively charged coagulant molecules neutralize the negatively charged solid particles suspended in the water. Neutralising these particles paves the way for them to flocculate together into a larger mass.
What are examples of flocculation?
For example, the Microscale Flocculation Test developed by LaRue et al. reduces the scale of conventional jar tests down to the size of a standard multi-well microplate, which yields benefits stemming from the reduced sample volume and increased parallelization; this technique is also amenable to quantitative dewatering metrics, such as
What is filtration process in water treatment?
Water filtration is a physical process of separating suspended and colloidal particles from waste by passing the water through a granular material. The process of filtration involves straining, settling, and adsorption. As floc passes into the filter, the spaces between the filter grains become clogged, reducing this opening and increasing removal.