Electrodialysis is a method of extracting ions from a solution via an electrochemical reaction. Ions are extracted by migrating through anionic or cationic selective membranes in the presence of an electric field. Thus, only anions can traverse an anionic membrane, whereas only cations can traverse a cationic membrane. By connecting several membranes in parallel and allowing positive and negative ions to pass alternately, certain ions can be removed from water. In some compartments, ions are concentrated while in others, they are eliminated. Particles that are electrically neutral are not eliminated.