Study Guide Answer Key

Here are the answers to the Oct. 22, 2020 edition of TPO's Exam Study Guide:1. If you notice excessive ashing on the secondary clarifier in an activated sludge plant, what action might you try to correct the issue?The answer to this question is B. Ashing is a common occurrence on secondary clarifiers. Ashing may be caused by poor flocculation of the mixed liquor or excess grease in the system. Slowly increasing the waste activated sludge (WAS) to reduce the mean cell residence time (MCRT) is generally accepted as a method of ashing control. Troubleshooting and recognizing problems in the clarifiers or activated sludge