Basic Wastewater Operator Practice Exam

What is the pounds per day of chemical dosage with a flow of 5 MGD at a rate of 218 ppm?

1. 1090 lbs/day

2. 9090 lbs/day

3. 8153.2 lbs/day

4. 1818 lbs/day

The correct answer is: 9090 lbs/day

To determine the pounds per day of chemical dosage, we can use the formula: \[ \text{Chemical Dosage (lbs/day)} = \text{Flow (MGD)} \times \text{Concentration (ppm)} \times 8.34 \] In this context: - **Flow** is given as 5 million gallons per day (MGD). - **Concentration** is given as 218 parts per million (ppm). - The factor 8.34 is used to convert the concentration in ppm to pounds per million gallons. Now, substituting the values into the formula: \[ \text{Chemical Dosage} = 5 \, \text{MGD} \times 218 \, \text{ppm} \times 8.34 \] Calculating this step-by-step: 1. Multiply the flow by the concentration: \[ 5 \, \text{MGD} \times 218 \, \text{ppm} = 1090 \] 2. Then multiply by the conversion factor: \[ 1090 \times 8.34 = 9087.6 \] Rounding this value gives