Common radium salts and compounds in water

Radium in water is a radiological contaminant, usually considered as dissolved Ra(II) and by isotope activity. The compounds below explain aqueous behaviour; they are not common bulk constituents of drinking water or chemicals proposed for routine use.

See also radium in water and the radium element page.

Selected salts and compounds

This is a practical selection, not a ranking of abundance in every water. Qualitative solubility descriptions refer to the stated compound; hydration, temperature, pH and complexation can change its behaviour. A soluble starting salt does not necessarily remain unchanged after addition to water.

Removal, purification and recovery

Cation exchange, reverse osmosis and lime softening are recognised radium-removal options. Barium sulfate co-precipitation and manganese-based processes can also be relevant to appropriate feed waters. Selection depends on hardness, salinity, sulfate, competing ions, required activity reduction and residual handling.

Report results by isotope and in appropriate activity units, such as Bq/L, rather than comparing a bulk-salt solubility directly with a water-quality target. Removal concentrates radioactivity in resin, sludge, scale, regenerant or membrane concentrate; it does not eliminate it. Radium and radon are different treatment problems. A project-specific radiological and residual-management assessment is needed before choosing a process.

Information for process selection

Useful inputs include flow, pH, temperature, salinity, total and dissolved radium, other metals, suspended solids and known complexing constituents. Define the treated-water target and whether recovery is an objective. Laboratory or pilot testing can establish performance for the actual feed rather than a simplified salt solution.