Plant-based release system of negative air ions and its application on particulate matter removal

Particulate matter (PM, especially PM2.5 with diameter 2.5 microns) has been regarded as the major air pollutant. Negative air ions (NAIs) could electrically charge PM and remove it much more efficiently. In this study, a bio-generator of NAIs has been developed, which helps plants to generate NAIs at around 100 x 10(6) ions/cm(3) under pulsed electrical field (PEF) treatment. By using the bio-generator, PM2.5 concentration in a growth chamber could be reduced from around 500 to near 0 mu g/m(3) within 5 minutes. It could also be used to remove continuously generated PM. Upon PEF treatment, genes encoding oxidoreductases and other enzymes were up-regulated, some of which might contribute to the generation of superoxide anions (one of NAIs). On the other hand, the emission of large numbers of electrons from the surface/edge of plant leaves has been detected upon PEF treatment and these electrons might be captured by surrounding air molecules to generate high concentration of NAIs.

Automated summary

A bio-generator of negative air ions (NAIs) has been developed in this study to help plants generate NAIs for more efficient removal of particulate matter. The use of this bio-generator can significantly reduce PM2.5 concentration in a growth chamber within a short period of time.