Chromium-free impregnated activated universal respirator carbon for adsorption of toxic gases and/or vapors in industrial applications

A method of preparation of an activated carbon adsorbent for use in removing noxious gases and vapors from a contaminated air stream comprising the steps:

• A. Preparing a solution containing at least one compound selected from each of the groups Of compounds said three groups consisting of sulfuric acid or sulfuric acid salt compounds:
• molylxlenum compounds;
• and compounds of copper and compounds of zinc;
• B. impregnating activated carbon at least once with said solution;
• C. drying the activated carbon after impregnation by heating said activated carbon at up to about its ignition temperature;
• and
• D. thereafter impregnating said activated carbon adsorbent with water in an amount, by weight, up to 25% based on dry weight of said impregnated adsorbent.

A filter for removing noxious gases and vapors from contaminated gas stream$ comprising an activated carbon adsorbent impregnated with at least one compound from each of three groups of compounds, said three groups consisting of (a) sulfuric acid and sulfuric acid salt compounds;

• (b) compounds of molybdenum;
• and (c) copper compounds and zinc compounds;
• and wherein said at least one sulfuric acid or salt thereof is present in amounts, by weight, not more than 10% as sulfate;
• said at least one molybdenum compound is present in amounts of not more than 10% as molybdenum and wherein the total amount of said selected copper or zinc compound(s) is present in a total amount not greater than 20%, by weight, as total copper and zinc.