Question

environmental engineering

Please explain why

plug flow reactors are more “efficient” than complete mix flow reactors.

Answer 1

Plug flow reactors and complete mix flow reactor are the 2 main types of activated sludge process(ASP).

Where ASP is the suspended growth system of microorganisms.

## Reasons for plug flow reactors are more “efficient” than complete mix flow reactors.

a) complete mix flow reactor is used for the small plants having capacity less than 25 MLD while plug flow reactors are used for more than 300 MLD capacity.

b)in complete mix flow reactor (F/M) ratio & O2 demand ramains constant throughout the length of the tank where in plug flow reactors (F/M) ratio and O2 demand decreases along the length of tnak which will help in efficient operation of activated sludge.

c)in complete mix flow reactor process of complete mixing of incoming activated sludge with waste water is done mechanically while in plug flow there is no such provision while long operational channels are adopted in this case which will decreases the cost of operation.

d)oprational stability of plug flow reactor is more as compared to complete mix flow reactor due to decreased demand along the length of tank.