Question
Biology Question on Microbes in human welfare
______is the first step of sewage treatment.
A
Precipitation
B
Chlorination
C
Sedimentation
D
Aeration
Answer
Sedimentation
Explanation
Solution
Primary treatment in sewage treatment involves physical removal of particles (large and small) from the sewage through filtration and sedimentation. Initially floating debris is removed by sequential filtration. Then the grit (soil and small pebbles) are removed by sedimentation.