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Ion Exchange

The ion exchange (IE) system is actually a combination of processes that treats all the water going into the home.This system is normally installed by a water treatment professional.The system in place was donated by Culligan of the Piedmont in Greenville, SC, and costs approximately $4000.The ion exchange system is composed of a sediment filter, followed by a mixed bed ion exchange filter (95% cation to 5% anion resin), an aeration unit, granular activated carbon (GAC), and ultraviolet light for disinfection.A picture of the installed system is shown below.

Ion Exchange System

The IE system was quite effective in removing uranium.The average uranium concentration in the water of this home before treatment was 1,112 ug/L.After treatment, the average concentration was 2.33 ug/L.The average overall removal rate of uranium using the IE system was 99.8%.A graph of this data is presented below, along with a summary of the treatment data.

Uranium Removal by the Ion Exchange System (average removal = 99.8%)

Ion Exchange Treatment Data for Uranium

Ion Exchange Treatment Data for Uranium

Uranium Concentration - Before Treatment, ug/L

Uranium Concentration - After Treatment, ug/L

72 hrs



1 week



2 weeks



3 weeks



1 month



2 months



4 months 872 3.65
6 months 343 2.51

The IE system for removal of radon in water was moderately effective, with an average removal of 93.5 %.The radon in water level of this home was low compared to the home where the reverse osmosis system was installed, with an average concentration of 2,125 pCi/L.After treatment, the average radon in water concentration was 129.7 pCi/L, which is below the proposed MCL forradon of 300 pCi/L.A graph of the radon in water data is presented below, along with a summary of the treatment data.

Radon Removal by the Ion Exchange System (average removal = 93.5%)

Ion Exchange Treatment Data for Radon

Ion Exchange Treatment Data for Radon

Because the different processes in the ion exchange system remove different radionuclides, the Department tested for each radionuclide at each step in the process.Below is a graphical presentation of the results for both uranium and radon after each process in the system.Since the sediment filter and the ultraviolet light do not appreciably change the uranium or radon levels, for simplicity they are not included below.

Effectiveness of Ion Exchange System Processes

The graph above illustrates the effectiveness of each step of the treatment process.For instance, after ion exchange, the uranium level has significantly decreased, but does not fall below the MCL for uranium until after the carbon filtration (GAC).For radon, one can see that ion exchange alone has no effect on the radon level.However, the radon level drops significantly after aeration (as expected), and falls below the proposed MCL for radon after the carbon filtration.This means if you want only to treat your water for radon, aeration and or carbon filtration are all that is needed for effective treatment, which significantly lowers the cost of the system.

Bureau of Water . Phone: (803) 898-4300 . Fax: (803) 898-3795 . Contact Us

For additional information, contact:  E-mail  (803) 898-3300  Fax (803) 898-3300