ION EXCHANGE RESINIon exchange resin works by removing ionized species from water by exchanging these species for H+ and OH- ions. These resins have a minute pore size of approximately 1 mm with large ionic group exchange sites in the resins. The operation and regeneration method of ion exchange resin is shown in Figure 1.1. Figure 1.1: ion exchange resin work cycle. Currently, there are two methods for ion exchange to work, one being a batch and the other a column method. . For the batch method, the resin and solution are mixed then stirred in a container where ion exchange can take place until equilibrium. Once equilibrium is reached, the resin is removed from the solution and the degree of exchange is determined by the selectivity of the resin itself towards the ions present in the solution. Thus, the capacity of the resin is limited by the selectivity which is as shown in Table 1.1 below. Batch processing is not favored due to the low efficiency of the regeneration process. A column process works similar to a plug flow reactor where it amounts to processing the solution through an infinite number of batch tanks. The column process is much preferred due to its high efficiency and the reduced reactor size allowing the same conversion to be achieved as a batch process. Even when using a resin with low selectivity for ions in solution, the desired degree of separation is still possible. Select...... middle of paper ...... unlike the recycling method since this process starts from a strong brine to a weak brine regeneration. Anytime a high concentration of iron or manganese is present in the ion exchange fluid, this process is not practical due to the valence electronic charges of iron and manganese relative to those of the brine.References1 ) Sharon O'Skipton. (2008). Drinking water treatment: water softening (ion exchange). University of Nebraska Institute of Agriculture and Natural Resources.2) International Atomic Energy Agency. (2002). Application of Ion Exchange Processes for Radioactive Waste Treatment and Management of Spent Ion Exchangers: Technical Report Series 408. VIC Library ISSN 0074-19143) Remco Engineering. (nd). Ion exchange: basic concepts. Available at www.remco.com/ix.htm4) ELGA. (2012). How an ion exchanger works. Available at www.elgawater.com/ion-exchanger-fr