When the gas is under outside conditions (microscopic particles, the electric field), it can ionize, producing electronics, all kinds of ions, atoms and free radicals. Although the temperature is very high in the process of discharging, the heavy particles (ions, atoms and molecules) temperature is low; the system presents the low temperature state, so we call cold plasma. Cold plasma is produced by high energy electron bombardment with pollutant molecules, causing the effect of ionization, dissociation and excitation, and then it lead to a further chemical reaction, making simple complex pollutants into small molecules and the toxic & harmful substances into harmless non-toxic or low toxic less harmful substances such as carbon dioxide and water, hence promoting the degradation of pollutants removal. The degradation process is as follows:

Process 1: high energy electron bombardment directly

Process 2: the formation of oxygen, ozone, hydroxyl radicals and small molecular fragments

O₂+2e→2O·

O₂+O·→O₃ +e

H₂O+2e→H·+HO·

H₂O+O·+e→2HO·

H·+O₂→HO·+O

C_(a+b)H_(m+n)O_(x+y)+2e→C_aH_mO_x·+C_bH_nO_y

Process 3: Molecular fragment oxidation

C_aH_mO_x+HO·→CO₂+ H₂O

C_aH_mO_x+O·→CO₂+ H₂O

C_aH_mO_x+O₂→CO₂+ H₂O

C_aH_mO_x+O₃→CO₂+ H₂O