Bacteria Removal and Viability Attenuation by Means of an Electrostatic Barrier

Abstract

This study is focused on bacterial control through the removal and attenuation of viability by means of a commercial electrostatic air cleaner inserted in the ductwork of a central heating and air-conditioning system. Adapting the system to include an electrostatic barrier resulted, on an average, in removal of 88% of the bacteria in the airflow. In addition, the ratio of viable to non-viable organisms, calculated on the basis of epifluorescence measurements, was changed appreciably by passage through the electrostatic filter. Evaluation of performance was followed by two different strategies of sampling-analysis: a plate count method and epifluorescence microscopy. The system overall was highly efficient in removing the bacteria, since those few that evaded the filter underwent attenuation of around 50% of their viability on passage through it. This work suggests a strong positive effect when an electrostatic barrier is inserted in a ventilation duct.