Deionisation (ion exchange) is used to remove unwanted organic and/or inorganic constituents from water and food products.
Field of application
In the dairy industry deionisation is applied in whey processing. For the application of whey solids in human food and in infant formulae, on by low levels of mineral constituents are required. Deionisation is also widely used in the food industry for the treatment of boiler feed-water for power and steam generation and for the production of deionised process water. Deionisation is also applied to remove of minor ionised organic substances from food.
Description of techniques, methods and equipment
Deionisation is normally carried out by passing the product through a column containing ion exchange resin beads. The beads contain a large number of active sites which are capable of holding a wide variety of inorganic molecules (metals and non-metals) and ionised organic constituents. The columns are operated batch-wise and need to be regenerated when the beads are exhausted (or saturated). This is normally carried out by treatment of the columns/beads with a variety of chemicals which remove the impurities and regenerate the active sites.