IONEX Research Corp
IONEX manufactures custom air filtration equipment
http://www.ionexres.com/

ThomasNet.com
Welcome to the premier industrial resource for Activated Carbon. We supply a broad range of activated carbon including activated carbon filters, air filters, air treatment, cartridge filters and activated carbon bags. Use this comprehensive vertical directory to find activated carbon air purification, as well as desiccants, drum filters, water purifiers and activated carbon filter media.
http://www.thomasnet.com/products/activated-carbon-10660207-1.html

Lenntech
Water treatment and air purification systems for water recycling, water disinfection, odour control, water filtration using environmentally friendly technologies such as ozon generator and uv disinfectants, biofilters and membrane systems.
http://www.lenntech.com/

United Manufacturing International 2000
UMI-2000 is a supplier of activated carbon, ion exchange resins and adsorption filter vessels.
http://umi20001.tripod.com/