Characterisation of the Filter Elements of End-of-Life Biological and Chemical Protection Masks Used by the Army
The main purpose of the present study is to assess the usefulness of filter cartridges from end-of-life biological and chemical protection masks, for other applications (with increased added value) instead of landfill deposition. Filters with different ages up to fifty years, were dismantled and divided in their components. Physico-chemical characterisation of each filter cartridge component was performed using different techniques such as: optical microscopy, Fourier transform infrared spectroscopy, pyrolysis, particle size distribution by laser diffraction, surface area determination from the nitrogen adsorption isotherms at 77K, determination of open porosity by helium pycnometry, and dynamic mechanical thermal analysis in the temperature range from -100°C to 200°C. It is shown that the loss of resilience of the rubber sealant is the main factor that controls the shelf life of filter cartridges. On the other hand, most of the charcoal in the activated carbon cloth remains active and can be useful for other less severe applications such as the removal of dissolved components from freshwater and/or marine systems.
António Torres Marques, António Fernando Silva, António Paulo Monteiro Baptista, Carlos Sá, Fernando Jorge Lino Alves, Luís Filipe Malheiros and Manuel Vieira
M. Cabral et al., "Characterisation of the Filter Elements of End-of-Life Biological and Chemical Protection Masks Used by the Army", Materials Science Forum, Vols. 587-588, pp. 778-782, 2008