For a total design flow of 67 MGD and an overflow rate of 1300 gal ft2 · day, what is the minimum area of each of 11 sedimentation basins (n - 1 = 10) in parallel? Answer in units of ft2
For a depth of 13 ft, what is the volume of each basin? Answer in units of ft3
What is the design detention time of each basin? Answer in units of hr.
For a L/D ratio of 25, what is the length of each sedimentation basin?
1 US gallon = 0.1336 ft3
Total Design flow = Q = 67 MGD
= 67 x 106 x 0.1336 ft3/d
= 8.95 x 106 ft3/d
Surface overflow rate = vs = 1300 gal/ft2/day
= 1300 x .1336 ft3/ft2/day
= 173.7 ft/day
Surface area = At = Q/vs
= (8.95 x 106)/173.7
= 51525.6 ft2
Area of one basin = A = 51525.6/11
= 4684.14 ft2
= 4684 ft2
Volume of basin = V = Axd = 4684x13
= 60892 ft3
Total Volume of all basins = Vt = 11 x 60892 = 669812 ft3
Detention time = t = Vt/Q
= 669812/(8.95x106)
= 0.0748 day
= 0.0748 x24 hr
= 1.8 hrs
L/D = 25
L = 25D = 25x13 = 325 ft
Get Answers For Free
Most questions answered within 1 hours.