What is the BOD loading rate for a trickling filter with a diameter of 75 feet and a depth of 5 feet, given a BOD to the filter of 270 mg/L and a flow of 0.790 MGD?

To determine the BOD loading rate for the trickling filter, you first need to calculate the volume of the filter and then use this information to calculate the BOD load.

1. Calculate the volume of the trickling filter:

The volume can be calculated using the formula for the volume of a cylinder:

[ \text{Volume} = \pi \times r^2 \times h ]

Where:

• (r) is the radius (half the diameter),

• (h) is the height (or depth in this case).

For a trickling filter with a diameter of 75 feet:

• Radius ( r = 75 / 2 = 37.5) feet,

• Depth ( h = 5) feet.

Calculating the volume:

[

\text{Volume} = \pi \times (37.5)^2 \times 5 \approx 3.1416 \times 1406.25 \times 5 \approx 22096 \text{ cubic feet} (rounded)

]

2. Convert the flow rate from MGD to cubic feet per day:

Since 1 MGD is approximately 693,000 gallons per