A chlorite salt-absorbent particle is prepared by absorbing a water soluble chlorite salt or a concentrated chlorite salt solution in an absorbent particle. The absorbent can be a silica gel particle or other particulate absorbent that can release the chlorite salt as an aqueous solution over time by simply contacting the chlorite salt-absorbent particle with water. The chlorine salt is extracted from the chlorite salt-absorbent particle over a period of minutes while being flushed with water. A chlorine dioxide generator in the form of a cartridge includes the chlorite salt-absorbent particles and an acid resin or a redox resin. Water can be introduced into an inlet of the cartridge and passes sequentially through the chlorite salt-absorbent particles and the acid resin or the redox resin with the discharge of a chlorine dioxide solution from the outlet of the cartridge.
