Civil Engineering - GATE Exam Questions - Discussion

47. 

For a flow of 5.7 MLD (million litres per day) and a detention time of 2 hours, the surface area of a rectangular sedimentation tank to remove all particles having settling velocity of 0.33 mm/s is

[A]. 20 m2
[B]. 100 m2
[C]. 200 m2
[D]. 400 m2

Answer: Option C

Explanation:

No answer description available for this question.

Arnab Bhattacharyya said: (Jan 3, 2018)  
Settling velocity = .00033 m/sec.

Settlement within detention period = .00033 *2 hrs = .00033*2*60*60 = 2.376 m.
Flow = 5.7 MLD = 5.7 * 10^6 LD = 5.7*10^3 M3 per Day = (5.7*10^3)/24 m3 per hour = 237.5 m3 per hour.
Flow within detention period = 237.5 *2 m3 = 475 m3.
Area = Flow/settlement = 475/2.376 = 199.91 m2 = 200 m2.

Post your comments here:

Name *:

Email   : (optional)

» Your comments will be displayed only after manual approval.