Ion Exchange Process In Water Treatment

Ion exchange is a method widely used in household laundry detergents and water filters to produce soft water.

Ion exchange process in water treatment.

This is accomplished by exchanging calcium ca 2 and magnesium mg 2 cations against na or h cations see water softening. Ion exchange is a water treatment method where one or more undesirable ionic contaminants are removed from water by exchange with another non objectionable or less objectionable ionic substance. Although different water treatment products utilize this process in different ways the action itself remains the same. Ion exchange is a process used extensively in nuclear facilities industrial processes and medical and pharmaceutical operations to control the purity and ph of water by removing undesirable ions and replacing them with acceptable ones.

All anions are replaced by hydroxide oh ions. Ion exchange is a water treatment process commonly used for water softening or demineralization but it also is used to remove other substances from the water in processes such as dealkalization deionization and disinfection. Ion exchanger in water treatment process the ion exchanger regeneration procedure involves three steps 1 the softener is taken out of service and a swift flow of water is passed upward through the zeolite bed. The process of ion exchange is one of the most utilized techniques in water and wastewater treatment as well as in separation processes as chemical synthesis medical research food processing mining agriculture etc.

While the chemistry of individual ion exchange reactions varies from one application to the next ix is a treatment process where dissolved ions are replaced by other more desirable ions of a similar electrical charge. Both the contaminant and the exchanged substance must be dissolved and have the same type of electrical charge positive or negative. In the ion exchange process sodium ions are used to coat an exchange medium in the softener. Water softeners usually use sodium na as the exchange ion.

There is no picture for this anion exchange as it is very similar to the cation exchange picture in figure 5 above. Sodium ions are supplied from dissolved sodium chloride salt also called brine. But what exactly is it. In the first section of the present chapter the kinetics and thermodynamics of ion exchange are presented.

At the end of the exchange process the resin beads have loaded all cations and anions from the water and released h and oh ions. Unwanted ions that are dissolved in the water are replaced with new beneficial or harmless ions of an equivalent charge.