Devices, systems and methods for reducing the concentration of a chemical entity in fluids

A method for removal of at least a portion of carbon dioxide from an aqueous fluid, comprising:

• placing at least one structure through which carbon dioxide can pass to be removed from the fluid in contact with the fluid, the structure comprising a porous layer, a gas permeable, nonporous layer adjacent a surface of the porous layer, and immobilized carbonic anhydrase on a first surface of the nonporous layer such that the immobilized carbonic anhydrase comes into contact with the fluid, wherein the first surface exhibits carbonic anhydrase activity of at least 20% of maximum theoretical activity of the first surface of the membrane based on monolayer surface coverage of carbonic anhydrase.

A method of manufacturing a structure for use in removal of carbon dioxide from an aqueous fluid, the structure comprising a porous layer, a gas permeable and nonporous layer adjacent a surface of the porous layer, comprising:

• immobilizing carbonic anhydrase on a first surface of a polymeric material of the nonporous layer via adsorption, covalent bonding, ionic bonding or chelation such that the first surface exhibits carbonic anhydrase activity of at least 20% of maximum theoretical activity of the first surface based on monolayer surface coverage of carbonic anhydrase.

A device for removal of at least a portion of gaseous carbon dioxide from an aqueous fluid in which carbon dioxide can be reversibly converted to at least one other chemical entity, comprising:

• at least one structure through which gaseous carbon dioxide can pass to be removed from the fluid and at least one surface spaced from the structure, the spaced surface comprising carbonic anhydrase immobilized thereon, the spaced surface being positioned in the vicinity of a first surface of the structure, at least a portion of the carbonic anhydrase immobilized on the spaced surface being active to convert the at least one other chemical entity to gaseous carbon dioxide in the vicinity of the first surface of the structure.

A device for removal of at least a portion of chemical entity from a fluid, comprising:

• at least one structure through which the chemical entity can pass as a gas to be removed from the fluid, the composite structure comprising a porous layer, a permeable, nonporous layer adjacent a surface of the porous layer, and immobilized enzyme on a first surface of the nonporous layer to be contacted with the fluid such that the immobilized enzyme comes into contact with the fluid, wherein the first surface exhibits enzyme activity of at least 20% of maximum theoretical activity of the first surface based on monolayer surface coverage of enzyme, and wherein the chemical entity is inter-convertible within the fluid to at least one other chemical entity that is not gaseous, the enzyme being adapted to catalyze a reaction of the other chemical entity to the chemical entity as a gas.