A capacitive adsorption module assembly is proposed. The capacitive adsorption module assembly includes a plurality of capacitive adsorption modules, each having a disk-shaped spacer configured to form a flow path through which feed flows, a cation exchange membrane attached to any one of an upper surface and a lower surface of the spacer, a first electrode attached to the cation exchange membrane, an anion exchange membrane attached to the other of the upper surface and the lower surface of the spacer, and a second electrode attached to the anion exchange membrane, wherein the capacitive adsorption modules are vertically stacked such that adjacent capacitive adsorption modules share or contact the first electrode or the second electrode, and at least one first terminal and second terminal passing through the stacked modules being provided.