Eduprobe
Question:
The domestic sewage in large cities is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
has a high BOD as it contains both aerobic and bacteria
when treated in STPs does not really require the aeration step as the sewage contains adequate oxygen
has very high amounts of suspended solids and dissolved salts
Solution:
Correct option is A. is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.
Activated sludge is a suspended-growth aerobic bacteria which remove the pollutants from wastewater in an aerobic environment during the secondary treatment. The aerobic stage is followed by the anaerobic stage in which anaerobic bacteria are used in the secondary treatment in Sewage Treatment Plants (STPs).
Hence The domestic sewage in large cities is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs).
So, the correct answer is 'is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs)'.