Activated carbon is a special form of carbon that is used to filter impurities.  If you have a Brita filter or something similar, it most likely uses active carbon (or its close relative activated charcoal) to do the actual filtering.  Activated charcoal is the active ingredient in Odor Eaters.

The secret to the efficiency- the surface area created by the molecular structure.  One teaspoon of activated carbon has an acre of surface area.  A gram has the surface area of a football field.

So put that in your pipe and smoke it.  Actually, don’t.  That would not be a good idea.