This set of Environmental Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Oxidation and Stabilization Ponds”.
1. Which of the following is an anaerobic process for treating sewage?
a) Oxidation pond
b) Imhoff tank
c) Oxidation ditch
d) Rotating Biological Contactors
Explanation: Oxidation pond, Oxidation ditch and Rotating Biological Contactors are an aerobic process of treating sewage whereas Imhoff tank is an anaerobic process of treating sewage.
2. The minimum design depth of oxidation pond is
Explanation: The minimum design depth of oxidation pond is 1m while its maximum design depth is 1.5m.
3. State whether the following statement is true or false.
Oxidation pond is ineffective in removing pathogenic bacteria.
Explanation: Oxidation pond is highly efficient in removing pathogenic bacteria with an efficiency of 99.9%.
4. The detention period of oxidation pond is
a) 12-36 hours
b) 4 hours
c) 10-20 days
d) 30-60 seconds
Explanation: Oxidation ponds have a long detention period between 10 to 20 days.
5. The maximum BOD removal efficiency of an oxidation pond is
Explanation: The BOD removal efficiency of an oxidation pond lies between 80% and 90%, so the maximum BOD removal efficiency is 90%.
6. What is the minimum depth of water to be kept in oxidation pond?
Explanation: The minimum depth of water to be kept in oxidation pond is 0.3m and the depth of sludge deposited in the pond is 0.02m per year.
7. Which chemical is added to the oxidation pond to avoid bad odor?
a) Calcium chloride
b) Sodium nitrate
c) Potassium chloride
d) Silver nitrate
Explanation: Sodium nitrate is added to the oxidation pond to avoid bad odor. It acts as an oxidizing agent and also as the food of the plant.
Sanfoundry Global Education & Learning Series – Environmental Engineering.
To practice all areas of Environmental Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.