What is the formula for calculating loading rate in pounds per day?

The formula for calculating the loading rate in pounds per day is based on the relationship between flow rate, concentration of the waste being measured, and a conversion factor that translates the units into pounds.

When using the flow rate in million gallons per day (MGD) and the concentration in milligrams per liter (mg/L), the conversion factor of 8.34 pounds per gallon is crucial because it provides the necessary conversion from the volume of water (gallons) to mass (pounds). Specifically, this conversion factor indicates how many pounds of a substance are present in a gallon of water, allowing for the accurate computation of the loading rate.

This approach ensures that the loading rate reflects the total mass of contaminants being processed by the wastewater treatment facility, which is essential for monitoring and regulating treatment efficiency. The other formulas, while they involve similar concepts, either use inappropriate units or incorrect conversion factors, which would not yield the correct loading rate in pounds per day.