CO2 & denitrators - dumb question time...

["Kevin Buckley" <kevin at buckley70_freeserve.co.uk>]

The current issue of a U.K fish (& recently plants) mag. is running a review
of denitrators.

A common theme is that the various columns, in addition to being low (free
of?) Oxygen, need to have a "source of Carbon".

I guess pumping CO2 gas in there directly & combining the functions of
dinitrator, CO2 reactor & "feeding" Carbon (in the form of dissolved
CO2/Carbonic Acid) to the denitrifying bacteria isn't a possibility?

Regards, Kevin