1. Precipitation Processes
III. Water Treatment Topic III.3. Water Precipitation: Processes and Facilities
Precipitation Processes
Precipitation of spherical mineral particles in batch settler
(Stockes)
Precipitation of natural particles (with arbitrary shapes and dimensions) in batch settler
Relationship between percentage of the settled particles -  and time of settling - t
Relationship between percentage of the settled particles -  and settling velocity - u0
Precipitation of natural particles in continuous flow settling tanks with mean horizontal flow velocity - v and real settling velocity - u
; ;

2. Precipitation Processes  = f(t)  = f(u0)

3. Precipitation Processes
Scheme of Horizontal Continuous Settling Tank
v - mean horizontal flow velocity; u0 - vertical precipitation velocity at batch conditions; w - vertical component of pulse (arbitrary flow) velocity;
u - real settling velocity
, where F is the water mirror area, m2
, where k = 7,5 with L/H = 10; k = 10 with L/H = 15; k = 12 with L/H = 20
,where W is volume the setter, m3

4. Kinds of Settling Tanks
Scheme of Horizontal Settling Tank
1 - coarse water; 2 - sediments cleaning device; channel for floating particles removal;
5 - sludge removal pipe

5. Kinds of Settling Tanks
Vertical Settling Tank
a - without flocculation chamber
б - with built-in flocculation chamber
1 - coarse water
2 - settled water
3 - sludge removal

6. Kinds of Settling Tanks
Radial Settling Tank
1 - coarse water; 2 - sludge circulation; 3 - stilling chamber; 4 - settling zone; 5 - sludge cleaner; 6 - sludge; 7 - settled water; 8 - mixer; 9 - reagents inlet pipe

7. Kinds of Settling Tanks
Scheme of Lamella Settling Tank

8. Kinds of Settling Tanks Lamella Settling Tank Prefabricated lamella settler Lamella modules