In wastewater treatment, which statement best describes the purpose of screens?

• A. Remove large objects
• B. Remove dissolved salts
• C. Add nutrients
• D. Sterilize water

Answer: (A)

Screens at the wastewater plant act as a first line of defense by physically removing large objects from the incoming flow. This keeps pumps, grinders, and downstream equipment from clogging or getting damaged and helps the rest of the treatment process run smoothly. Dissolved salts stay in solution and aren’t affected by screening, so they’re not removed by this step. Adding nutrients isn’t a function of screens, and sterilization happens later in treatment, not at the screening stage. So removing large objects is the best description of the purpose.