What is the chemical feed rate to obtain a 12 mg/L dose in a 4 MGD wastewater flow?

To determine the chemical feed rate needed to achieve a specific concentration in a given flow rate, one can use the following formula:

[ \text{Feed Rate (lbs/hr)} = \left(\text{Concentration (mg/L)} \times \text{Flow (MGD)} \times 8.34\right) ]

In this situation, the desired concentration is 12 mg/L, and the flow rate of wastewater is 4 MGD.

First, we can convert the flow rate into the appropriate units for the calculation. The factor 8.34 is used to convert million gallons per day to pounds per hour. Plugging in the values:

[ \text{Feed Rate} = 12 , \text{mg/L} \times 4 , \text{MGD} \times 8.34 ]

Calculating this step-by-step:

1. Calculate the product of the concentration and the flow rate:

[ 12 , \text{mg/L} \times 4 , \text{MGD} = 48 , \text{mg/MGD} ]

2. Now multiply by the conversion factor:

[ 48 , \