Physical and microbial collection efficiencies of an electrostatic precipitator for abating airborne particulates in postharvest agricultural processing

We constructed a single-stage, laboratory-scale electrostatic precipitator (ESP) and evaluated its physical and microbial collection efficacies. Ground rice husk was examined as a representative model of airborne particles carrying microorganisms (bacteria, molds and yeasts). Physical and microbial collection efficacies were evaluated at different voltages applied to the negative discharge electrode without ozone generation. The best collection efficiencies were observed at an applied voltage of −6.0 kV, resulting in collection efficiencies of over 90% for the physical sample and 99.95% for bacteria. No molds or yeasts in the ground rice husk passed through the ESP operating at −6.0 kV applied voltage.