GATE CE 2018 Set 2 — Question 62
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Environmental Engineering → Wastewater Treatment Processes → ASP Design (F/M, MLSS, SVI)
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Question
A schematic flow diagram of a completely mixed biological reactor with provision for recycling of solids is shown in the figure.
The mean cell residence time (in days, up to one decimal place) is ______.
The mean cell residence time (in days, up to one decimal place) is ______.
Correct answer
7.5 to 7.5
Solution
The mean cell residence time () is given by the formula:Where:
- is the volume of the aeration tank.
- is the MLVSS in the aeration tank.
- is the influent flow rate.
- is the waste sludge flow rate.
- is the effluent microorganism concentration.
- is the underflow microorganism concentration.
- Detention time
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