Culligan® C&I Portable Exchange Deionizers

A deionizer produces very low total dissolved solids (TDS) water for very high quality and/or ultra-pure water needs.

Deionization is an ion exchange process using synthetic plastic beads. There are two different types of resin beads - cation resin, which has an affinity for positively charged ions and anion resin, which has an affinity for negatively charged ions. When the cation resin is "recharged" with an acid bath regeneration, the hydrogen ion becomes "attached" to the resin beads. In the case of the anion regeneration, sodium hydroxide (caustic soda) is used and the hydroxyl ion becomes "attached". In both the cation and anion resins, they have the lowest affinity for those ions. When water containing virtually any other ions flows over the resin beads, they will release the hydrogen and hydroxyl ions and attach (remove) virtually all other ions.

Deionizers are typically configured in a dual bed or mixed bed arrangement. The dual bed systems will have two separate tanks- one with only cation resin, and one with only anion resin. In the very highest quality and/or ultrapure water applications, mixed beds (uni-beds) are commonly used. These tanks contain a mixture of both cation and anion resins in one vessel. In so doing, a much higher quality/purity of water is produced.

In many cases and applications, portable exchange deionization service makes the most sense, due to the following advantages:

• Eliminate on-site chemical storage and handling
• No permanent plumbing/installation
• Portable tank size and configuration can be easily and economically changed as volumes and quality needs change
• No capital expenditures required on long-term equipment or hardware
• No hazardous waste or regeneration effluent

Deionization and deionized water can also be supplied by an in-plant system. These systems automatically regenerate on a pre-set frequency or are manually initiated and complete the operation automatically.