Patent ID: 7316732

Claim:
An activated carbon filter adapted to treat a gas stream having a varying relative humidity comprising: a first plurality of carbon granules, each granule supporting both manganese dioxide and potassium hydroxide, the manganese dioxide on the first plurality of carbon granules being a primary catalyst for oxidation of a contaminant in the gas stream when the gas stream has a relative humidity of greater than about 5%, but less than about 30%; a second plurality of carbon granules, each granule supporting both potassium iodide and potassium hydroxide, the potassium iodide on the second plurality of carbon granules being a primary catalyst for oxidation of the contaminant in the gas stream when the gas stream has a relative humidity of greater than about 30%; and a third plurality of carbon granules, each granule supporting phosphoric acid, the phosphoric acid on the third plurality of granules adapted to remove at least one alkaline gas from the gas stream, wherein the first, second and third plurality of granules are mixed together in a carbon granule bed.