Microbes in Sewage Treatment - Unsolved Practice Set
Chapter: Microbes in Human Welfare | Topic: Microbes in Sewage Treatment
MICROBES IN SEWAGE TREATMENT - UNSOLVED PRACTICE SET
Topic: Microbes in Sewage Treatment
Multiple Choice Questions
Q1. Sewage or municipal wastewater primarily contains large amounts of:
- Only clean drinking water
- Human excreta and other organic waste materials
- Only industrial chemicals
- Only rainwater
Q2. In sewage treatment, the initial step that removes large solid particles through physical processes like filtration and sedimentation is called:
- Secondary treatment
- Primary treatment
- Anaerobic digestion
- Biogas production
Q3. Secondary (biological) treatment of sewage primarily relies on:
- Chemical bleaching only
- Microorganisms breaking down organic matter present in the sewage
- Filtering out only large plastic waste
- Adding salt to the water
Q4. Biochemical Oxygen Demand (BOD) is a measure of:
- The amount of oxygen dissolved in completely pure water
- The amount of oxygen required by microorganisms to break down the organic matter present in a water sample
- The temperature of wastewater
- The pH level of sewage
Q5. The sludge left after secondary treatment is often further processed in anaerobic digesters, which primarily produce:
- Oxygen gas
- Biogas (a mixture including methane)
- Pure drinking water directly
- Table salt
Short Answer Questions
Q6. What is sewage, and why does it need to be treated before being released into water bodies?
Q7. Briefly describe what happens during the primary treatment stage of sewage treatment.
Q8. Define Biochemical Oxygen Demand (BOD), and explain why a lower BOD value indicates cleaner water.
Q9. What happens to the activated sludge produced during secondary sewage treatment?
Long Answer Questions
Q10. Describe the process of sewage treatment, explaining both primary and secondary (biological) treatment stages and the role microorganisms play in each.
Q11. Explain the significance of measuring BOD in assessing the effectiveness of sewage treatment and the quality of treated water released into the environment.
APPLICATION / ANALYSIS
Q12. A water testing lab finds that a sample taken from a river near a large city has a significantly higher BOD than a sample taken from a relatively unpolluted river further upstream. Explain what this difference in BOD suggests about the level of organic pollution in each water sample.
Q13. A municipal sewage treatment plant decides to install anaerobic sludge digesters as part of its treatment process, in addition to its existing aeration tanks. Explain the additional benefit this step could provide, considering both waste management and potential energy generation.