Question

Sludge formation is a part of _______ process in the wastewater treatment plant.

• A. primary treatment
• B. secondary treatment
• C. screening
• D. aeration

Answer 1

The correct option is A primary treatment

• Sludge refers to solids like faeces, that settle at the bottom of large settlement tanks, during primary treatment of water.
• Screening removes large objects like plastic bottles before primary treatment is done.
• Aeration is a part of secondary treatment, in which, air is pumped so that aerobic bacteria can grow and consume remaining human waste, food.