Question

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Consider the following:

1. Softening
2. Aeration
3. Reverse Osmosis

Which of the above are measures for secondary treatment of waste water?

• A.
  1 and 3 only
• B.
  1 and 2 only
• C.
  2 and 3 only
• D.
  1, 2 and 3

Answer 1

The correct option is B

1 and 2 only
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Secondary Treatment: The water after primary treatment is not fit for drinking purposes and has to undergo secondary treatment. A commonly used method is to allow polluted water to spread over a large bed of stones and gravel so that the growth of different microorganisms needing nutrients and oxygen is encouraged.
Softening
Aeration
Reverse Osmosis is a tertiary treatment of wastewater