The present invention generally relates to purification systems, and to sanitization and/or sealing of the purification system. The purification system includes an electrodeionization device which can comprise one or a plurality of stages. The electrodeionization device can be constructed with a resilient sealing member forming a water-tight seal between rigid thermally and dimensionally stable compartment spacers. The construction of the electrodeionization device may allow cycling of hot water and/or other liquids, which, in some cases, can improve efficiency and performance of the electrodeionization device. Moreover, the cycling of hot water and/or other liquids may be used to sanitize the electrodeionization device to at least a pharmaceutically acceptable condition and, preferably, in certain instances, to meet at least minimum requirements according to U.S. Pharmacopoeia guidelines by inactivating any microorganisms present within the electrodeionization device.