Anion exchange resin example may be used for demineralization or dealkalization, while weak base anion resins work best for removing acids and organics from water. Anion exchange resin example are primarily used to remove alkalinity from boiler feedwater with a low-to-moderate amount of total dissolved solids (TDS). Anion exchange resin example may also be used to remove carbonate, bicarbonate, sulfates and nitrates from feedwater.
Strong acid cation resins can be used for dealkalization (most commonly in hydrogen form) or for split stream dealkalization. However, both methods of dealkalization require the use of hazardous acids to regenerate resin beds, as well as the use of a degassifier to remove carbon-dioxide created during the treatment process.
Weak acid cation resins can also be used for demineralization and dealkalization. In most water treatment cases, weak acid cation resins are used to remove divalent ions associated with alkalinity. Weak acid cation resins work best when water has a hardness and alkalinity ratio of 1:1 or higher.