Grating-like DBD plasma for air disinfection: Dose and dose-response characteristics

Atmospheric pressure dielectric barrier discharge (DBD) plasma is an emerging technique for effective bioaerosol decontamination and is promising to be used in indoor environments to reduce infections. However, fundamental knowledge of the dose and dose-response characteristics of plasma-based disinfection technology is very limited. By examining the single-pass removal efficiency of S. lentus aerosol by in-duct grating-like DBD plasma reactors with varied discharge setups (gap distance, electrode size, number of discharge layers, frequency, dielectric material), it was found that the specific input energy (SIE) could be served as the dose for disinfection, and the efficiency was exponentially dependent on SIE in most cases. The corresponding susceptibility constants (Z values) were obtained hereinafter. Humidity was a prominent factor boosting the efficiency with a Z value of 0.36 L/J at relative humidity (RH) of 20% and 1.68 L/J at RH of 60%. MS2 phage showed a much higher ef-ficiency of 2.66-3.08 log10 of reduction than those of S. lentus (38-85%) and E. coli (42%-95%) under the same condition. Using SIE as the dose, the performance of plasma reactors in the literature was compared and eval-uated. This work provides a theoretical and engineering basis for air disinfection by plasma-based technology.

Automated summary

Atmospheric pressure dielectric barrier discharge (DBD) plasma is effective for bioaerosol decontamination in indoor environments. However, there is limited understanding of the dose-response characteristics of plasma-based disinfection. This study investigated the removal efficiency of S. lentus aerosol using different DBD plasma setups and found that the specific input energy (SIE) can be used as the dose for disinfection, with efficiency exponentially dependent on SIE. The study also identified factors such as humidity and the higher efficiency of MS2 phage compared to S. lentus and E. coli.