Demineralization systems are very widely employed not only for conditioning water for high ââ,‰â,¬Å" pressure boilers but also for conditioning various process and rinse water. The ion ââ,‰â,¬Å" exchange system is chosen very accordingly to the volumes and composition of the raw water, the effluent- quality require for different uses and the comparative capital and operation cost. If silica removal is not required, the system may consist of a hydrogen ââ,‰â,¬Å" cation ââ,‰â,¬Å" exchanger unit and a weekly basic anion exchanger unit usually followed by a degasifier, to remove by aeration most of the carbon dioxide formed from the bicarbonates. It consists of the following:

• A hydrogen ââ,‰â,¬Å" cation ââ,‰â,¬Å" exchanger unit and a strongly basic anionââ,‰â,¬Å"exchanger unit or
• A single unit containing an intimately mixed bed of a hydrogen cation ââ,‰â,¬Å" exchanger and a strongly basic anion exchanger