Answer:
Detention time will be 9 days
Explanation:
We have given diameter of setting tank d = 50 feet
Radius of setting tank [tex]r=\frac{d}{2}=\frac{9}{2}=25 feet[/tex]
SWD = 9 FEET
Area [tex]A=\pi r^2=3.14\times 25^2=1962.5ft^2[/tex]
So volume [tex]V = area\times SWD=1962.5\times 9=17671.5ft^3[/tex]
We have given flow Q = 15000 gpd
So Q= 15000×0.13368 =2005.22 [tex]ft^3[/tex] per day
Detention time is given by [tex]=\frac{volume}{Q}=\frac{17671.5}{2005.22}=9days[/tex]
So detention time will be 9 days
