Inactivation of E. coli with plasma generated by bipolar pulsed discharge in a three-phase discharge plasma reactor

The inactivation of Escherichia coli (E. coli) with non-thermal plasma generated by bipolar pulsed dielectric barrier discharge in three-phase discharge plasma reactor with glass pellets included was investigated in this paper. The effects of the addition of glass pellets on the productions of ozone and hydrogen peroxide, various parameters on the inactivation efficiency of E. coli and the change in the temperature of E. coli solution were clarified. Experimental results show that the addition of glass pellets enhanced the productions of ozone and hydrogen peroxide. At the optimum airflow rate of 0.75 m3/h, the addition of ferrous sulfate in aqueous solution and the increase of pulse repetitive rate increased the inactivation efficiency of E. coli, but the presence of sodium carbonate in aqueous solution decreased the inactivation efficiency. The temperature of the solution in which E. coli cells were suspended before and after treatment displayed no marked change, which proved that the temperature of solution could not inactivate E. coli at room temperature, whereas the complicated physical, chemical and biological effects inactivated E. coli.