GirdlerSulfide

The Girdler sulfide process, often referred to as the GS process, is an industrial water treatment method used to remove dissolved radium-226 and other trace metals from water streams. It relies on the controlled precipitation of metal sulfides by introducing sulfide-forming agents, producing insoluble solids that can be separated from the liquid.

Developed in the mid-20th century for applications in the nuclear materials and mining industries, the GS process was widely employed to treat radium-bearing waters associated with uranium mining and processing as well as certain geothermal or brine systems. The technique is named for its developers and became a recognized approach for reducing радиум levels to meet environmental and process specifications.

The core principle involves forming metal sulfides through the addition of sulfide ions under carefully regulated pH and redox conditions. Under these conditions, radium and other soluble metals form low-solubility sulfides that precipitate out of solution. The water then passes through contactors or settling stages where the precipitated sulfides are separated as sludge, while the clarified liquor proceeds to further treatment or discharge. The process often requires staged operation and careful control of sulfide supply to balance efficiency with selectivity.

Operational considerations include the use of hydrogen sulfide or other sulfide donors, corrosion-resistant equipment, and robust safety measures due to the toxicity and odor of hydrogen sulfide. Sludge handling and disposal are also important aspects of plant design and environmental management.

In modern practice, the GS process has been largely superseded in many settings by ion exchange and alternative precipitation methods but remains referenced in historical designs and in industries where sulfide-based precipitation is still applicable. See also: radium removal, ion exchange, sulfide precipitation, water treatment.