Use of a concrete-based element for treatment of gases and volatile compounds
A method includes using an element which includes a monoblock concrete body with a volume greater than 1 L and a surface porosity greater than 8%, which body includes in the body and/or on a surface thereof a compound having a BET specific surface greater than 100 m 2 /g, and which element does not include a photocatalytic agent, to absorb from the atmosphere a gas selected from the group consisting of nitrogen oxides, carbon oxides, sulphur oxides, and ozone, or a volatile organic compound.
1. A method comprising using an element which comprises a monoblock concrete body with a volume greater than 1 L and a surface porosity greater than 8%, which body comprises in the body and/or on a surface thereof a compound having a BET specific surface greater than 100 m 2 /g, and which element does not comprise a photocatalytic agent, to adsorb from the atmosphere nitrogen dioxide, wherein the compound is selected from the group consisting of active carbon, modified active carbon, silica gel, pyrogenic silica, diatomite, zeolite and alumina and porous hybrid solids, and wherein the adsorption rate of nitrogen dioxide per unit surface is greater than 0.5 ppbv/cm 2 .
2. The method according to claim 1 , wherein the BET specific surface exchange area of the compound is greater than 500 m 2 /g.
3. The method according to claim 1 , wherein the compound comprises particles having an average diameter greater than 1 μm.
4. The method according to claim 1 , wherein the concrete has a surface porosity greater than 10%.
5. The method according to claim 1 , wherein the average diameter of the pores in the surface of the body is greater than 0.10 μm.
6. The method according to claim 1 , wherein the compound is distributed in the totality of the concrete body.
7. The method according to claim 1 , wherein the concrete body is obtained by casting concrete in a mould, and in which the compound is disposed in a demoulding composition.
8. The method according to claim 1 , wherein the element is obtained by mixing a hydraulic binder, aggregates, the aforesaid compound and water.
9. The method according to claim 1 , wherein said compound is active carbon.
10. A method comprising adsorbing nitrogen dioxide using an element which comprises a monoblock concrete body having a surface porosity greater than 8%, which body comprises in the body and/or at least on a surface thereof a compound having a BET specific surface greater than 100 m 2 /g, and which element does not comprise a photocatalytic agent, and said compound is selected from the group consisting of active carbon, modified active carbon, silica gel, pyrogenic silica, diatomite and alumina and porous hybrid solids, wherein the adsorption rate of nitrogen dioxide per unit surface is greater than 0.5 ppbv/cm 2 .
11. The method according to claim 10 , wherein said compound is active carbon.