This document discusses different types of sedimentation tanks used in water and wastewater treatment. It describes fill and draw tanks, which are filled and allowed to settle for 24 hours before the clear water is drawn off. Continuous flow tanks allow water to flow through continuously at a low velocity for particle settlement. Circular tanks can use radial, spiral or vertical flow. Hopper bottom tanks use a deflector box to reverse flow direction and cause particles to settle.

1. SARDAR PATEL COLLEGE OF
ENGINEERING
• SUB : WATER AND WASTE WATER ENGGINEERING
• SUB CODE : 2160604
• GUIDED BY : PROF. JINAL DALWADI

2. SR NO. NAME ENROLMENT NO.
1 PATEL AKSHAR K. 141240106040
2 PATEL BRIJESH R. 141240106041
3 PRAJAPATI BRIJEN V. 141240106060

3. TYPES OF
SEDIMENTATION TANK

4. TYPES OF SEDIMENTATION
TANK
 Depending upon the method of operation
1. Fill and draw type tank
2. Continuous flow type tank
 Depending upon the shape
1. Rectangular tanks
2. Circular tanks
3. Hopper bottom tanks

5. Fill And Draw Type Tanks

6. Fill And Draw Type Tanks
 In this types, the tank is first filed with incoming water, and is
allowed to rest for a certain time.
 During this period, the suspended particles settle down at the
bottom of the tank. Generally a detention period of 24 hours is
allowed.
 At the end of the period, the clear water is drawn off through the
outlet valve. The tank is cleaned of settled particles and filled again.
 The cleaning may take another 6 to 12 hours. thus the cycle of
operation takes 30 to 36 hours

7. Continuous Flow Type
Tanks

8. Continuous Flow Type
Tanks
 If the velocity is reduced, a large amount of suspended impurities
can be easily removed from water. This is the principle on which,
the continuous flow type sedimentation tank is working
 In this type of tank, water enters the tank from one end and as it
travels towards the outlet at the other end.
 The velocity of flow is so adjusted that the time taken by a particle
of water to move from one end to other is slightly more than that
required for the settlement of suspended impurities in water

9. Circular Tank With Radial Flow

10. Circular Tank With Radial Flow
 The water enters this tank through the central inlet pipe placed inside
the deflector box.
 The water flows radially from the deflector box towards the
circumference of the tank where an outlet is provided on the
periphery.
 All the suspended particles settle down on the sloppy floor and clear
water goes through the outlet.
 The sludge is removed by scrapper which continuously moves around
the floor at a very small velocity.
 It is mostly used in sedimentation with coagulation.

11. Circular Tank With Spiral
Flow

12. Circular Tank With Spiral
Flow
 In this case, the inlet is provided at the circumference and
directed at an angle between a radius and a tangent.
 The outlet, provided in the form of a submerged weir is also
provided at the outer circumference.
 Water while moving at very low velocity allows its suspended
impurities to settle in the tank, which can be removed from the
sludge outlet.
 The clear water is drawn over a small weir type outlet.

13. Hopper Bottom Settling Tank
With Vertical Flow

14. Hopper Bottom Settling Tank
With Vertical Flow
 In this type of tank, water enters in the tank from the top into
deflector box. After flowing downward inside the deflector box the
water reverses its direction and starts flowing upward around the
deflector box.
 The suspended particles having specific gravity more than one,
can’t follow the water at the time of reversing its direction, and settle
in the bottom, from where they are removed through sludge outlet
pipe under hydrostatic pressure.
 These tanks are mostly used in sedimentation with coagulation
process.