Treatment Plant Operator Exam Study Guide Answers

An oxidation ditch has a volume of 1,560,000 gallons. If the flow to the oxidation ditch is 980,000 gallons per day, what is the detention time in hours? The answer to this question is B, 38.2 hours. This can be solved using the detention time formula below. In many plants, the detention time of the aeration basin is not normally calculated — it is for oxidation ditches. The easiest method to find this answer is to divide the flow by 24 (hours) and find out how many gallons flowed in one hour. Then take the volume of the oxidation ditch by