Calculate the detention time in hours for a circular tank with a flow of 1.42 MGD. The tank is 45 feet in diameter and 10 feet deep.

To calculate the detention time for the circular tank, it is essential to determine both the volume of the tank and the flow rate in a consistent unit, then use the formula for detention time.

First, calculate the volume of the circular tank. The formula for the volume ( V ) of a cylindrical tank is given by:

[

V = \pi r^2 h

]

where ( r ) is the radius of the tank and ( h ) is the height (or depth) of the tank. In this case, the diameter of the tank is 45 feet, which means the radius ( r ) is half of that:

[

r = \frac{45 \text{ ft}}{2} = 22.5 \text{ ft}

]

The depth ( h ) is given as 10 feet. Now substituting these values into the volume formula:

[

V = \pi (22.5 \text{ ft})^2 (10 \text{ ft}) = \pi (506.25 \text{ ft}^2) (10 \text{ ft}) = 5062.5 \pi \text{ ft}^3

]

Next, calculating