Multiple choice

Waste water containing solid waste material like faeces is called _________.

  1. biogas

  2. clarified water

  3. sludge

  4. potable water

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sludge is the semi-solid material that accumulates during wastewater treatment, consisting of settled solids, organic matter, and microorganisms. It contains the heavy solid waste materials removed from the wastewater and is often further processed for disposal or beneficial use.