In activated sludge treatment, sometimes there may be fluctuations in sewage treatment due to the presence of toxic substances in the influent. So, how do toxic substances affect microorganisms to reduce or even lose their activity? The loss of activity here specifically refers to the loss of nitrogen treatment ability by nitrifying bacteria. We first need to understand the general mechanism of microorganisms (mainly nitrifying bacteria) in treating organic matter. The surface of microorganisms is covered with receptors, which have specificity. Some structures of organic matter perfectly match the receptor, and the matched receptor allows bacteria to open surface channels and enter the body for processing. The mechanism of action is similar to that of keys and locks. After toxic substances enter the water body, they either directly puncture microorganisms and cause their death, or toxic substance molecules enter the receptor but cannot enter the microbial body, and the channel is temporarily used. The more toxic substances there are, the more temporary channels are used, and the fewer receptor channels on the surface of bacteria, the weaker their processing ability will be.
