1. The unit in which both sedimentation and sludge digestion processes take place simultaneously is
- Imhoff Tank
- Skimming Tank
- Digestion Tank
- Detritus Tank
2. In designing Imhoff tanks, the usual retention period is
- 8 hours
- 2 hours
- 20 hours
- 14 hours
3. Which process occurs in an imhoff tank?
- sedimentation alone
- sedimentation as well as sludge digestion
- sludge digestion alone
- sewage aeration
4. The working conditions in Imhoff tanks are
- Aerobic only
- Anaerobic only
- Aerobic in lower and anaerobic in upper compartment
- Anacerobic in lower and aerobic in upper compartment
5. Imhoff cone is employed to determine
- volatile solids
- suspended solids
- filterable solids
- settleable solids
6. The sewage treatment units in which biological decomposition of organic matter takes place are called
- Sludge sedimentation tanks
- Trickling filters
- Imhoff tanks
- None of the above