Treatment Plant Operator Exam Study Guide Answers

What is the Mean Cell Residence Time (MCRT) of the following activated sludge process, given the following data: Aeration tank volume 2.5 mgdInfluent flow (Q) 2.25 mgdInfluent TSS 300 mg/LEffluent TSS 5 mg/LInfluent BOD 280mg/LEffluent BOD 10 mg/LAeration MLSS 2,800 mg/L RAS MLSS 4,400 mg/LSolids in Clarifiers (2) 836 pounds each Wasted Act. Sludge 124,000 gallonsSettleometer reading after 30 minutes: 380 The answer to this question is B, 13 days. This may be solved using the MCRT formula below. To solve this problem, you need to determine the pounds of solids in the plant (MLSS 2,800 mg/L * tank volume 2.5 mg *