Evaluation of Physical Capture Efficiency and Disinfection Capability of a Novel Iodinated Filter Medium

A novel filter medium has been developed that combines the use of filtration and iodine disinfection to provide protection against airborne pathogens. The physical capture efficiency and disinfection capability of this iodinated resin medium were evaluated. Significant capture efficiency (97%) was observed for both the iodine-treated and untreated media tested, and there was no significant difference in capture efficiency between them. The efficiency was greater than 99% in many cases. The pressure drag was less than 10% that of the glass-fiber HEPA filter (0.0054 in H2O/(in/min) vs 0.065 in H2O/(in/min)). Biological disinfection by the medium was evaluated using Micrococcus luteus and Echerichia coli vegetative bacterial cells. High biological deactivation efficiency was observed (99.997%). Viable penetration through the biocidal filters was observed in only 2 of 10 experiments. A near-contact mechanism in which iodine is displaced from a triiodide complex is proposed to explain the higher biological removal efficiency compared to the physical capture efficiency exhibited by the iodinated filters. The results show that an antimicrobially augmented filter medium can provide effective protection against airborne pathogens with a significantly lower pressure drop than that imposed by conventional high-eficiency filtration systems.