Question

The domestic sewage in large cities

• A. Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plant (STPs)
• B. When treated in STPs does not really require the aeration step as the sewage contains adequate oxygen
• C. Has very high amounts of suspended solids and dissolved salts
• D. Has a high BOD as it contains both aerobic and anaerobic bacteria

Answer 1

The correct option is A Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plant (STPs)

The municipal wastewater is called as Sewage. It contains a large amount of organic matter and microbes. Before disposal, sewage is treated in Sewage Treatment Plants(STPs) to make it less polluted. The treatment is done in two stages:

1) Primary treatment

2) Secondary treatment or Biological treatment

It is processed by aerobic and then anaerobic bacteria in the secondary treatment in STPs.

The BOD is a measure of the rate of uptake of oxygen by microorganisms in a sample of water thus, Indirectly, BOD is a measure of organic matter present in the water.

So, the correct answer is 'Option A'.