Question

The primary treatment of sewage water involves

• A. Sludge digestion.
• B. Aerobic bacterial activity.
• C. Anaerobic bacterial activity.
• D. Filtration and sedimentation.

Answer 1

Answer: (D)

Filtration and sedimentation.

There are three levels of the sewage water treatment namely primary, secondary and tertiary treatment. The primary treatment of sewage water involves filtration and sedimentation of solid waste within the water. The secondary treatment of sewage water involves biofiltration, oxidation and aeration. Tertiary treatment of sewage water involves removal of inorganic compounds such as the nitrogen and phosphorus.

Thus, the correct answer is option D.