Which of the following is a secondary treatment for water pollution?

Category: QuestionsWhich of the following is a secondary treatment for water pollution?
Editor">Editor Staff asked 4 weeks ago

Which of the following is a secondary treatment for water pollution?
 
(a) Sedimentation
 
(b) By the action of microbes
 
(c) Removal of nitrates
 
(d) Filtration
 
The question was posed to me at a job interview.
 
This question is from Environmental Issues topic in chapter Environmental Issues of Biology – Class 12

1 Answers
Editor">Editor Staff answered 4 weeks ago

The correct choice is (b) By the action of microbes
 
The best explanation: Also known as the active sludge process, in this method, the seed sludge is added to the wastewater for its further breakdown. This happens with the help of microbes that consume the remaining organic matter.