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Natural zeolites are an adsorbent of choice for many cost effective air pollution control technologies treating the hazardous air pollutants (HAP) and listed volatile organic compounds (VOC). The need for technologically improved air purification systems has been indicated by keen client interest in the use of zeolites in controlling indoor air pollutants or "sick building syndrome". Existing filtration systems typically contain activated carbon as the adsorbent media. Because most grades of activated carbon contain large internal pores, they tend to trap a wide variety of larger molecules. Zeolites, on the other hand, contain a very small internal pores, in all cases from 3 to 5 angstroms. For this reason zeolite is a highly selective adsorbent of specific gas-phase molecules and elements. Many of the identified indoor air pollutants, including formaldehyde, chloroform, ammonia and carbon monoxide, are in a size range that is most effectively sieved by zeolite. Many promising zeolite and zeolite/carbon air purification and odor controlling systems are being developed to meet the need. Beneficial qualities include: • Selectivity for pollutant gases of
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