How does activated carbon work?
Activated carbon filters are well known for their use in controlling gaseous odours. Traditionally, they are used as a sponge, absorbing gaseous odours as air passes through. The downside is that they quickly get saturated, and so need regular replacement. Newer ozone-based (ozonolysis) technologies are proving to be an increasingly popular and effective alternative for gaseous odour control.
However, recent research is showing that activated carbon is very good at removing ozone from air – making activated carbon filters a useful complement to ozone-based systems. Used in this way, carbon filters last longer, as ozone acts to remove odours in the gas phase and further oxidises any residual odour molecules which become trapped on the activated carbon surface.
Where we use activated carbon
- In sensitive discharge areas, to remove any residual ozone left in air passing through ventilation systems after treatment by ozonolysis (Xtract 2100 and Techniclean). Most of the ozone generated is consumed during the ozonolysis process, and any that isn’t consumed will quickly disperse or convert back to oxygen. This means it’s not always necessary to take any specific action to guard against small quantities being discharged into the outside air. However, where the discharge point is, for example, at street level, adjacent to a window, or close to an air intake louvre, an activated carbon filter acts as a final barrier, to prevent ozone escaping.
- To extend the dwell time within ducted systems so that ozonolysis can work successfully even where duct runs are short. Placed in a duct run as far downstream as possible from the Xtract 2100 ozone injection device, the activated carbon traps the gaseous odours on their way through. This effectively results in an unlimited dwell time during which the odour molecules continue to be bombarded with ozone and so broken down by the ozonolysis process.
- In the traditional way but only as a final belt and braces filter, collecting any odour molecules that may have escaped the ozonolysis process.
