Removal of Bioaerosols by Air Ionizer of Carbon Nanotubes

The purpose of this study was to evaluate control efficiency on bioaerosols, including E.coli、B.subtilis、C.famata(Yeast)、P.citrinum, by using negative air ion (NAI) which was produced on carbon nanotubes (CNTs). The effects of relative humidity were investigated in this study. Also, it compared the generation of NAI at a concentration of 7×105-1.2×106 ions cm-3 in experimental chamber (9.32×10-2 m3) by negative electric discharge with different discharge voltage on CNTs needle and conventional stainless steel needle.he results showed that the higher concentration of NAI was produced under lower discharging voltage on CNTs needle, but unstable and the NAI concentration decreased with time compared with stainless steel needle. The control efficiency of bioaerosols increased with discharge voltage of stainless steel needle,but it is not significant on CNTs needle. In general, the order of control efficiency on bioaerosols by NAI is ηB.Subtilis ≒ ηE.Coli > ηYeast ≒ ηP.Citrinum. When NAI generated by stainless steel needle, the best control efficiency of E.coli and B.subtilis were found at RH=50%, and the control efficiency under RH=30% is better than that at RH=70%. The best control efficiency of C.famata(Yeast) and P.citrinum were obtained at RH=70%. However, when the NAI produced by carbon nanotubes needle to control bioaerosols, the effect of RH was not significant. The control efficiency of the bioaerosols on stainless steel needle was stable with time, but decreased for CNTs needle.