The settling tanks are generally made of reinforced cement concrete and may be rectangular or circular in shape. The settling tanks can be classified in the following two ways: 1. Classification based on method of operation: (a) Fill and draw type settling tanks (b) Continuous flow type settling tanks 2. Classification based on location: (a) Preliminary settling tanks (grit chambers) [...]
In order to get a fairly high percentage of removal of the suspended material in a continuous flow type settling tank, it is desirable that the tank is properly designed. For this it is essential to study the various design considerations for these tanks which are as follows: (i) Velocity of flow (ii) Surface overflow rate and solids loading rate [...]
For the purpose of designing, the continuous flow basin may be divided into following four zones: (a) An inlet zone, (b) A settling zone, (c) Sludge zone, and (d) An outlet zone. Before starting design work the following simple assumptions could be made: (i) The water in the settling zone acts as quiescent without any disturbance and the sedimentation takes [...]