Question
Download Solution PDFThe most commonly adopted detention period for grit chambers may vary from
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFExplanation:
Detention time (td):
The time taken by water (or particle of water) from entering to exit, in the settling tank is known as detention time. In other words, detention time refers to the amount of time that water or wastewater remains in the tank for the purpose of settling and separating solids from the liquid.
Various units detention time are given below in table;
| S. No. | Units | Detention time (td) |
| 1. | Grit chamber | 40 - 90 sec |
| 2. | Primary sedimentation tank | 2 - 2.5 hr |
| 3. | secondary sedimentation tank | 1.5 - 2 hr |
| 4. | Oxidation pond | 20 - 30 days |
| 5. | Septic tank | 12 - 36 hr |
| 6. | Imhoff tank | 2 - 4 hr |
| 7. | Skimming tank | 3 to 5 minutes |
Hence option (2) is correct answer.
Last updated on Jul 2, 2025
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