When faced with a licensing exam, don't struggle with test anxiety! Use the question below and others from our Exam Study Guide series to properly study and prepare for exam questions. Take a look at this sample wastewater treatment licensing question along with an explanation of the correct answer.

Sample question:

What type of sludge is typically processed in a conventional aerobic digestion?

A) Primary clarifier sludge

B) Sludge taken from belt filter press operations

C) Lagoon sludge

D) Waste activated sludge (WAS)

Answer: 

Typically aerobic digesters are used to treat waste activated sludge (WAS) from treatment systems that do not contain a primary settling process. The answer is therefore, D.

Source: WEF MOP11 20-174

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.