Calcium Polysulfide is fairly safe to handle out in the field. It is a non-toxic remedial amendment that oxidizes under aerobic conditions to form calcium, elemental sulfur and sulfate. Numerous applications have been conducted successfully at various industrial remediation and mining reclamation sites over the past 40 years, and no detrimental impact to the environment and public health and safety have been observed. Calcium Polysulfide is also widely used in agricultural applications on fruit trees, grapes and berries, and as a soil amendment for treating sodic and saline-sodic soils. See Calcium Polysulfide as Agricultural Soil Amendment.


When introduced into the environment, Calcium Polysulfide dissociates to form bisulfide, aqueous hydrogen sulfide and other sulfur compounds. Heavy metal ions are precipitated as less soluble, less toxic metal sulfides by these breakdown products. Metal hydroxides change solubility with changes in pH, whereas metal sulfides remain insoluble within a wide pH range. See Solubility of Metal Hydroxides and Sulfides as a Function of pH.  


While effective treatment by Calcium Polysulfide can be achieved over a wide pH range, best results are typically obtained within pH 7-10. Adjustments to the pH of the treatment system can enhance the metal precipitation process. See pH Guidelines for Treatment of Soluble Metal Streams.

The US EPA has identified Calcium Polysulfide as a reagent suitable for use in in-situ chemical reduction (ISCR), stabilization and solidification of multiple contaminants. Several abstracts and studies are available through CLU-IN Technologies, the Hazardous Waste Clean-Up Information website, sponsored by the US EPA. 


Bench scale evaluation, case studies and dosage guidelines on Calcium Polysulfide for the remediation of hexavalent chromium can also be found in the Chromium (VI) Handbook, available for purchase at Amazon.com or at Routledge.com.


Calcium Polysulfide has also been tested for hydrodechlorination/detoxification of polychlorinated compounds in fly ash. See abstract on Hydrodechlorination/detoxification of PCDDs, PCDFs, and co-PCBs in fly ash by using calcium polysulfide


For additional information, studies and assessments, samples or pricing information, please do not hesitate to contact us at 1-623-328-5175 or by email at info@grauschemicals.com.

Remotox® for cost-effective stabilization/immobilization of heavy metal-contaminated soil, sediment and groundwater.

Soil Remediation

Chromium, zinc, copper, lead, cadmium, mercury and arsenic are among the most common metal contaminants found at  industrial remediation and mining reclamation sites. 


Remotox®, a Calcium Polysulfide Solution, precipitates these highly soluble metals as less soluble, less toxic metal sulfides. In the case of chromium, the metal precipitates as chromium hydroxide. 

Application Advantages:

Remotox Calcium Polysulfide for the stabilization of heavy metals.

Calcium Polysulfide for in situ chemical reduction of chlorinated organic compounds.

Calcium Polysulfide to remove a wide range of metals in multiple valance states.

Calcium Polysulfide for removal of heavy metals from fly ash.

Calcium Polysulfide application guidelines for treatment of hexavalent chromium.

Chromium, zinc, copper, lead, cadmium, mercury and arsenic are among the most common metal contaminants found at  industrial remediation and mining reclamation sites. 


Remotox®, a Calcium Polysulfide Solution, precipitates these highly soluble metals as less soluble, less toxic metal sulfides. In the case of chromium, the metal precipitates as chromium hydroxide.