2011 · Q75
What is the correct sequence for treatment of polluted surface water?
- 1Disinfection and fluoridation
- 2Screening and mixing
- 3Flocculation and sedimentation
- 4Filtration and sludge processing.
Select the correct answer using the codes given below.
general-sciencechemistry
- A1, 2, 3, 4
- B3, 4, 1, 2
- C2, 3, 4, 1
- D3, 2, 1, 4
Explanation
The standard sequence is screening and mixing, then flocculation and sedimentation, then filtration and sludge processing, and finally disinfection and fluoridation.