Aerobic and anaerobic microorganism die and are degraded continuously through a variable anaerobic-aerobic process.

The article describes the inhibitory experiment which the aerobic microorganism breathing responds to one kind of chlorophenol compounds named 2, 4-double chlorophenol (2, 4-dcp).

And it also studies the dynamics process between 2, 4-dcp concentration and aerobic microorganism breathing rate, which is proved to be the bio-chemical first class dynamics reaction.