Carbon Adsorption
Carbon adsorption is used primarily for removal of gases and vapors. It is effective against volatile organic compounds (VOCs) but is not used for control of airborne dust or microorganisms. It is, in fact, not advisable to use carbon adsorption where particulate matter is present and may clog the adsorbent bed.
Carbon adsorption depends on the use of materials like activated charcoal which possess an enormous amount of surface area per unit mass. The presence of this surface area allows gas molecules to adhere to the surface. Though carbon adsorbers are unlikely to have a significant effect on airborne microbes, they can be effective at removing VOCs generated by fungi and bacteria, and so decrease the health threats.
Although it is not used for intercepting particulate matter, the use of carbon adsorption for the control of airborne viruses, which are not much larger than VOCs, is a potential application which remains to be studied. A mere tenfold increase in pore size might be sufficient to adsorb viruses.
References
- Heinsohn, R.J., Kabel, R.L. (1996). Sources and Control of Air Pollution. The Pennsylvania State University.
- Tamai, H. 1996. Synthesis of extremely large mesoporous activated carbon and its unique adsorption for giant molecules. Chemistry of Materials. v8 n2 p454.
- Delanghe, B. 1996. Removal of organic micropollutants by adsorption onto fibrous activated carbon. Water Supply v14 n2 p177.
- Gomez, A.F. 1995. Adsorption of Botulinum Toxin to activated charcoal with a mouse bioassay. Annals of Emergency Medicine 25:818.
- VanOsdell, D.W., L.E.Sparks. (1995). Carbon Adsorption for Indoor Air Cleaning. ASHRAE Journal, February 1995. p34-40.
- Stenzel, M.H. 1993. Remove organics by activated carbon adsorption. Chemical Engineering Progress. v89 n4 p36.
- Liu, R.T. 1990. Removal of volatile organic compounds in IAQ concentrations with short carbon bed depths. Proceedings of Indoor Air 90. Toronto, Canada. p177-182.