Title : Surface Dielectric Barrier Discharge (DBD) Plasma Decontamination
Abstract:
Enhanced distribution of atmospheric surface DBD (Dielectric barrier discharge) plasma generated ozone in air for effective decontamination is examined. This is achieved through experimental investigation of (a) the effect of better ozone distribution on decontamination and (b) ozone distribution produced by surface DBD plasma reactors. This study provides an alternative technique for decontamination of cleanroom facilities and heat-sensitive equipment, which can overcome disadvantages of high processing temperatures, long exposure times, harsh chemicals, toxic residuals, and material incompatibility associated with conventional decontamination methods. The need for such an alternative technique is crucial with the advent of advanced materials and disinfectant resistant micro-organisms, along with the global challenge of environmental pollution. Examples of such need of alternative approaches include minimizing (a) damage of heat sensitive materials and material alteration with thermal and chemical treatments in the manufacturing industry and (b) deterioration in food nutrition with traditional processing methods. In this study, spore forming bacterial species, Bacillus subtilis, which is commonly used to test decontamination methods, is used as the test organism. Significant reduction (~78%) of bacterial concentrations in the inoculated volume of air is observed using the comb shaped DBD plasma reactor. Increased reduction (~98%) is observed when the same reactor was used in conjunction with an external fan for better ozone distribution. Considering this, new surface DBD configurations can be used instead of the external fan to obtain better ozone distribution leading to lower ozone requirements and energy consumption. For this purpose, ozone distribution in conjunction with the flow generated by surface DBD reactors is studied using contrasting DBD reactor configurations in order to enhance decontamination with less ozone requirements and energy consumption. The study also discusses advancing DBD decontamination applications with its potential to overcome existing drawbacks that has limited this technology despite advantages of low temperatures and non- toxic residuals.
