Types of sedimentation tanks:
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- Ballasted sedimentation: There is an extremely small difference between the densities of water the solid particles (flocs) present in water treatment that is produced during the process of coagulation. Therefore they slowly settle down. The two methods of plain sedimentation (i.e. radial, horizontal and inclined sedimentation) and preceded by the flocculation, the slow mixing process. The flocculation process helps in supporting the coagulated particles to collide and combine so that the large particles are formed that get settled down faster. Flocculation can be assisted by using polyelectrolytes which are high molecular weight polymers. At first, the flocculation does not increase the density of particles. Flocs particles have a property that as the size of particles increases the density of flocs decreases. One can increase the density of flocs particles by using a ballasting agent such as fine sand or Bentonite. The treatment of this tank and grease trap denver required denver septic tank services and drain cleaning denver co. The used fine sand can be recovered for the recycling purpose bypassing the sludge that is collected from the sedimentation tank through a hydrocyclone. The speed of settling down of floc that is ballasted with fine sand is three times or sometimes even more than that of the floc that is not ballasted.
- Floc blanket sedimentation: Earlier the Floc blanket tanks used to have an inverted pyramidal shape and at the top there used to be a short vertical section. The use of a floc blanket is prior to the sludge banket because it is assumed that the floc in suspension is still acting as the floc i.e., it helps to remove the solid particles present in the untreated water. Once the floc becomes an integral part of the sediment and it becomes a surplus to process, the sediment is sludge.
- Sirofloc process: Sirofloc process is an alternate process that can be used instead of using a clarification process based on flocculation and coagulation for treating the water that contains little mineral turbidity. Firstly, finely divided magnetite is prepared by washing it with a sodium hydroxide solution at high pH, and then this solution is applied to the raw water along with a small concentration of cationic polyelectrolyte. These magnetite particles absorb the color-producing dissolved organic substances and attract the fine colloidal particles. Just like fine sand, the used magnetite can also be recovered for recycling purpose by passing it through the hydrocyclone before it being repaired with sodium hydroxide solution.
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