Abstract: In the carbon dioxide gas fixation method and carbon dioxide gas fixation apparatus, seawater (7) is electrolyzed, anodic electrolyzed water (7a) and cathodic electrolyzed water (7b) produced by electrolysis of the seawater are separated, alkaline material is inputted into the anodic electrolyzed water to adjust pH, carbon dioxide gas is blown into the cathodic electrolyzed water to fix the carbon dioxide gas as carbonate, and the anodic electrolyzed water after pH adjustment and the cathodic electrolyzed water after carbonate fixation are intermixed, and discharged in a state where a pH of the intermixed water is identical to a pH of the seawater. As a result, it is possible to offer a carbon dioxide gas fixation method and a carbon dioxide gas fixation apparatus which fix carbon dioxide gas with little impact on the environment, and without risk of re-release.

Abstract: In the carbon dioxide gas fixation method and carbon dioxide gas fixation apparatus, seawater (7) is electrolyzed, anodic electrolyzed water (7a) and cathodic electrolyzed water (7b) produced by electrolysis of the seawater are separated, alkaline material is inputted into the anodic electrolyzed water to adjust pH, carbon dioxide gas is blown into the cathodic electrolyzed water to fix the carbon dioxide gas as carbonate, and the anodic electrolyzed water after pH adjustment and the cathodic electrolyzed water after carbonate fixation are intermixed, and discharged in a state where a pH of the intermixed water is identical to a pH of the seawater. As a result, it is possible to offer a carbon dioxide gas fixation method and a carbon dioxide gas fixation apparatus which fix carbon dioxide gas with little impact on the environment, and without risk of re-release.

Abstract: In the magnesium recovery method and magnesium recovery apparatus, anode electrolyzed water (7a) and cathode electrolyzed water (7b) produced by electrolysis of seawater are separated, alkaline material is inputted into the anode electrolyzed water to adjust pH, magnesium is precipitated as magnesium hydroxide in the cathode electrolyzed water, and recovered, and the anode electrolyzed water after pH adjustment and cathode electrolyzed water after carbonate fixation are intermixed, and discharged in a state where a pH of the intermixed water is identical to a pH of the seawater. As a result, magnesium can be recovered from seawater while minimizing impact on the environment.