The commonly used treatment process varies greatly due to different regions and climatic conditions. For example, the average temperature, humidity, and air pressure vary greatly, and the methods and techniques used are also different. There are also factors such as different technological process conditions, different waste heat resources, different investment requirements, and different whitening methods adopted by various enterprises. There are great differences in the ever-changing technological schemes, but meeting user requirements is the fundamental requirement of technical schemes. According to the mechanism of wet plume formation and dissipation, the commonly used methods are summarized as: flue gas heating technology, flue gas condensation technology, flue gas condensation and reheating technology, and combination technology of various methods. Generally speaking, the combination of the above technologies achieves the purpose of whitening, energy saving, and low investment, that is, high "cost performance".