Question
Biology Question on Microbes in human welfare
The primary treatment of waste water involves the removal of
A
Dissolved impurities
B
Stable particles
C
Toxic substances
D
Harmful bacteria
Answer
Dissolved impurities
Explanation
Solution
The primary treatment involves physical removal of particles from the sewage through filtration and sedimentation. These are removed initially by sequential filtration which removes the floating debris and then grit is removed by sedimentation.