Question

True or False.

If the SRT of the activated sludge system is greater than the minimum SRT, the solids will be washed out of the system and the treatment process will ultimately fail because the biomass concentration in the aeration basin will not be maintained at a high enough concentration to sustain continued BOD removal.

Answer 1

SRT is CELL RESIDENCE TIME....

If the cell residence time is less than a critical value, SRTmin, then the sewage flow is too fast at steady state for bacteria to grow, existing cells are flushed out faster than they can multiply, and the result is the absence of cells. When this happens, the sewage is not consumed and the exiting sewage shows no reduction in BOD...

When SRT > SRTmin, the cells will have more time to reduce BOD...

Hence, the above statement is FALSE...