The present invention provides a filter system for treating air entering an electrochemical air separation device. The filter is provided with first and second filter sections. The first filter section is formed from a plurality of sheets of woven mesh containing surface deposits of one or more substances that are effective to interact and combine with one or more airborne contaminants to remove the same from the air. The second filter section is configured to filter particulate matter and is situated adjacent to the first filter element. The first and second filter sections are peripherally retained within a retaining structure so that the air to be treated passes through the first filter section and then the second filter section. The retaining structure can be releasably attached to a connection flange that is in turn attached to the air inlet of the electrochemical air separation device.