Welcome back to TPO magazine's Exam Study Guide Series, which offers a pair of water/wastewater study questions with in-depth explanations of the answers. Last time, we covered a set of wastewater and drinking water treatment questions on the topics of Rising Sludge Causes and Right-to-Know Programs. This time you can test your knowledge about activated sludge treatment parameters and chlorine dioxide.
Wastewater Treatment Sample Question
What operational parameters are able to be controlled by the operator in an activated sludge treatment process?
A. BOD load, hydraulic load and detention times
B. Influent solids, flow and sludge retention times
C. DO, return rate and wasting rate
D. Weather, flow and demand
Water Treatment Sample Question
What is the maximum residual disinfectant level for chlorine dioxide?
A. 4.0 mg/L as chlorine dioxide
B. 1.0 mg/L as chlorine dioxide
C. 0.8 mg/L as chlorine dioxide
D. 0.5 mg/L as chlorine dioxide
To see answers for both of the above questions, click this link.
About the authors: Rick Lallish is the Water Pollution Control program director at the Environmental Resources Training Center (ERTC) of Southern Illinois University-Edwardsville. He provides training for entry-level operators in the wastewater field and operators throughout the state looking to further their education. Lallish was also named the 2017 Illinois Operator of the Year and 2018 president of the Illinois Association of Water Pollution Control Operators.
Drew Hoelscher is the program director of drinking water operations at the Environmental Resources Training Center in Edwardsville, Illinois.
