Question

Sedimentation

1. Describe the difference between Type I, II, III, and IV settling and give an example of where they are applied in water or wastewater treatment.

Answer 1

to usage pathogene (Disease causing dya plain sedimentation, a of watean have plain sedimentation " the first unit operation employed to remove suspended particles from weter. All particles whoose specific gravity greater than specific gravity of wa tendency to settle down but resisted by turbulence of the plain sedimentation is the method of removing deed pended particle from water by controlling the turbu turbulence of f low velocity by virtue of gravitational forre. Plain se di mentation follows Type I sette linge Type -I Settling Type I sette ling deals with disere te particle pettlement in dilute Lespension. I Discrete is the one which doe not alter its fize, shope, mass & specific gravity with time and spare. Water is treated as dilute suspension] Rastiden (VS); the by controlling the particle removal lower

= 2381 Sedimentation tank follows Sedimentation tenk employed to capture locaulent particles Settling Type II settling deals with flocculent particle settlement in dilute suspendion. Flocculent particle the one which change its size, maps, specific gravity, with time and space] linear (parabolicy path it non - → Trajectory trajectory of particle of pa

DT: 3 to 5 min. Primary clarifies : ' primary sedimentation tanks settleable organic so from poimory clan leable organic solids present in waste water are removed pormory clarifier. Primary clarifies removed 60% to 70% settleeble organic matter ( Biodegradable). and 20 °% +0 30% of Bob Removal primary clarifier follore Type II settling is known ad Hindered settling

TUU 715 Howowers "40904418 Viel Secondary clarifieri ( secondary sedimente tion Tank) Secondary clarifier settle ifier settle biological biological of flocs (micro-organisms). from ulaste water flow. Secondary dove clarifies clarifier follow follows Type IV e settling Type - IV settling also known as compression settling or zone setting. Design op secondary clarifier Oy is based on "Solids flex yeter. 41 yazaxd Qout layer of microorganisms