Demeneralising Plants

A standard dual bed ion exchange unit consists of a strong acid cation resin that exchanges hydrogen for positively charged cations present. The second step is a strong basic anion resin that exchanges hydroxide for negatively charged anions present in the water stream. The hydrogen (H+) from the cation exchanger and hydroxide (OH-) from the anion exchanger create the HOH or deionized water to be reused in the process.

There are certain processes that generate an abundance of either a cation or an anion. If this occurs, a more selective weak acid cation can be used to exchange the multi-divalent heavy metals that are in abundance. This pre-treating of the heavy metals will assist in the exchanging of the mono-divalent cations. A weak basic anion before the strong basic anion can be implemented to assist in better deionizing the water fed back to the process.