The invention concerns a novel method for purifying air and gasses, consisting of an optimized air ventilation slab, with its air ventilation pipes, air ventilation pipettes and air diffusion plugs; optionally a complementary cellular material enabling the material to be supported providing biofiltration, purification or treatment of air, and optionally a device for diffusing liquids and/or bacteria and/or enzymes, allowing the biofilter to act as the equivalent of a gas scrubbing tower.