Strontium (Sr) in Water Treatment

Quick Answer

Strontium (Sr) is an alkaline earth metal with atomic number 38. PubChem lists its standard state as solid and its relative atomic mass as 87.62.

Strontium can contribute to mineral scale, and radioactive strontium requires specialized radiological control. Ion exchange, precipitation, nanofiltration or reverse osmosis may be used depending on isotope, concentration and water chemistry.

Interesting Facts

• Strontium salts give fireworks a vivid red color.
• Stable strontium and radioactive strontium-90 share nearly the same chemistry, but only the latter creates a radiological hazard.
• Sr²⁺ resembles Ca²⁺, so it can enter hardness scales and compete with calcium during softening or ion exchange.

Water-treatment Design Implications

An element name alone is not enough to select treatment equipment. Confirm chemical form or speciation, total and dissolved concentration, pH, alkalinity, competing ions and the product-water target. Send the water-analysis results to Watermart to identify additional testing and shortlist processes before equipment is specified.

Summary Data Sources

• PubChem — Strontium
• IUPAC Periodic Table of Elements
• US EPA — Radionuclides Rule

Practical Reference for a Water Analysis

Identify the isotope and reporting basis. Elemental concentration, gross radioactivity, and isotope-specific activity are not interchangeable. Confirm whether the target is stable or radioactive and whether the result is reported as mass per volume or activity per volume.

Validate treatment on the actual matrix. A process name is not a performance guarantee. Competing ions, organic ligands, redox conditions, pH, suspended solids, and required recovery can change removal sharply. Use bench or pilot testing for unusual industrial streams, and make a mass balance for concentrate, sludge, regenerant, or spent media.

Treat residuals as part of the design. A separator concentrates rather than destroys a radionuclide. Determine monitoring, worker-protection, transport, storage, and disposal requirements with the relevant Indonesian authorities and a qualified radiological specialist.