Florida Wastewater Practice Test

If the chlorinator is feeding 120 lbs/day and the average daily flow is 3.5 MGD, what is the chlorine dosage?

1. 2.5 mg/L

2. 3.8 mg/L

3. 4.1 mg/L

4. 5.0 mg/L

The correct answer is: 4.1 mg/L

To determine the chlorine dosage in milligrams per liter (mg/L), you can use the formula: Dosage (mg/L) = (Chlorine Feed Rate in lbs/day × 8.34) / Average Daily Flow in MG In this scenario, the chlorinator is feeding 120 lbs/day of chlorine, and the average daily flow is 3.5 million gallons per day (MGD). First, convert the chlorine feed rate from pounds to mg/L using the conversion factor where 1 pound per day equals 8.34 mg/L per million gallons. Therefore: Dosage = (120 lbs/day × 8.34 mg/L per MG) / 3.5 MGD Calculating the numerator: 120 lbs/day × 8.34 mg/L = 1000.8 mg/L Now divide this by the average daily flow: Dosage = 1000.8 mg/L / 3.5 MGD ≈ 286.5 mg/L To convert this into the dosage per million gallons, you take: 286.5 mg/L / 1000 = 0.2865 mg/L However, in this case, since we need the dosage in mg/L and keeping the