Rapidly eliminating pathogenic microorganisms in large air space using spraying •OH radicals

A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying •OH radicals is presented in this paper. With a physical method of strong electric-field discharge, large numbers of •OH radicals were produced by the oxygen activated particles of O2 +, O( 1D), O( 3P), etc., and the introducing reagent HO2 −. The gram-positive bacteria Bacillus subtilis, the gram-negative bacteria Serratia marcescens, and Bacillus spores were used for the eliminating experiments. Results show that the different microorganisms were rapidly killed by •OH radicals with a concentration of 0.8 mg/L and spraying density of 21 μL/m2 within 4 sec. Cell morphological changes were also observed under microscope. The cells of B. subtilis and Bacillus spores in their cellular wall, cellular membrane, or cell protoplasm were greatly destroyed when being exposed to a killing dosage of •OH radicals. Implications: Increasing air spread of pathogenic microorganisms has prompted serious concerns for their threat to environmental safety. However, there is no an effective method to rapidly eliminate these harmful microorganisms in large air space. In comparison with conventional disinfectants, advanced oxidation technology (AOT) based on hydroxyl radicals (•OH) has excellent advantages. The main problem of how to produce the •OH radicals with high concentration and large production is solved by a physical method of strong electric-field discharge. A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying •OH radicals is described in this paper.