A method for preparing a solid amine adsorbent of CO.sub.2 includes introducing a gas mixture containing 10 vol. % to 50 vol. % of CO.sub.2 is introduced into a sodium aluminate solution having a concentration in a range of 10 g/L to 100 g/L at room temperature to obtain a reaction solution. This occurs continuously until a pH value of the reaction solution is lowered to 9.5 to 9.8 to obtain a product solution containing a precipitate. The precipitate is filtered and washed. The filtered and washed precipitate is mixed with an organic alcohol at a mass ratio of 1:5 to 1:30 to obtain a suspension. The suspension is heated to an azeotropic point of water and the organic alcohol, and evaporated, boiled, and refluxed to obtain pore-enlarged pseudo boehmite. This is calcined to obtain aluminum oxide powder. The aluminum oxide powder is impregnated in an organic amine solution and dried.

The present invention provides a method, and device for the separation and recovery of heavy metal ions by membrane-forming mineralization fixation, which belongs to the field of acid wastewater treatment technology containing heavy metal ions, comprises the following steps: mixing the composite mineral particles with the heavy metal acidic wastewater, performing a first hydration reaction under a standing condition, and performing adsorption-precipitation-crystallization on the heavy metal ions in the heavy metal acidic wastewater by the obtained colloidal liquid membrane to obtain particles with an outer layer having a mineralized membrane; the particles having a mineralized membrane in the outer layer have a spacing between the mineralized membrane and the particles; separating the particles having a mineralized membrane in the outer layer, and then respectively recovering the same; the process for the preparation method of the composite mineral particles comprises the following steps: mixing sodium carbonate/sodium silicate, bentonite, carbide slag and water, performing a second hydration reaction, and then successively performing granulation, aging, and dehydration condensation to obtain composite mineral particles; the particle size of the bentonite and carbide slag are independently 74 m. The present invention can realize the separation and recovery of heavy metal ions by membrane-forming mineralization fixation and waste control by waste.

The disclosure relates to the design and synthesis of selected ligands, dendrimers, polymers and other solid phase substrates for selective chelation of rare earth elements (i.e. lanthanides), and use of those selective ligands for synthesis of resins, polymers and other types of solid supports for separation and recovery of lanthanides from aqueous media. Recovery of critical elements from aqueous media occurs in a simple two-step process: pre-concentration of REE on the adsorbent and recovery by acid elution. The present invention can be used for design of selective ligands immobilized on solid substrates for extraction of various constituents, such as lanthanides, actinides, radionuclides, trace metals, etc., from aqueous media.

In one aspect, a functionalized porous material includes a synthetic porous material, the synthetic porous material comprising a surface, wherein at least a portion of the synthetic porous material surface is a substrate; and a mixed-metal hydroxide, wherein the mixed-metal hydroxide is affixed to the substrate.