1. Large emissions, wide pollution range, and complex emission methods;

There are many types of pollutants, and the concentration fluctuates greatly.

3. The toxicity of toxins is very strong.

4. There are significant differences in the variation patterns of transferred substances after emissions.

5. Recovery is quite difficult. Once the water body is polluted, even if the discharge of pollutants is reduced or stopped, it still takes a considerable amount of time to recover to its original state.