Study on the Sterilization Mechanism of Negative Corona Discharge

To investigate the sterilization mechanism of corona discharge in air, a needle-to-ring configuration was employed to produce atmospheric pressure negative corona plasma. The active species from the corona discharge were obtained. The sterilization efficiency of different active substances (i.e., UV, charged particles and neutral active species) were tested experimentally. The results show that, UV and ozone can alone achieve sterilization with high bactericidal efficiency, but they can not complete a simple synergy. In negative corona discharge, neutral active substances act as the key bactericidal agents and the charged particles also play an auxiliary role in sterilization. But individual charged particles have little or no bactericidal effect. It is suggested that improving the neutral active species of corona discharge is beneficial to the plasma sterilization.