Maintaining your education is important, especially in a career that demands licensing exams. Prove you’re an expert operator by answering this question and others from our Exam Study Guide Series. Take a look at this question on Public Water Systems along with an explanation of the correct answer.
Sample question:
What is the primary cause of odors in activated sludge processes?
A) Poor housekeeping
B) Inadequate DO
C) Poor primary treatment
D) Inadequate MCRT process control
The answer is B. Inadequate DO is the primary cause of odors. To correct odor problems, first increase the DO concentration by additional aeration. Second, reduce the organic loading. If these measures fail, the recommended measure is to add oxidizer chemicals.
About the author
Ricky Lallish is the water pollution control program director at the Environmental Resources Training Center 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.











