Graus Chemicals, LLC

REMOTOX® for Removing Heavy Metals from Wastewate - Soil and Groundwater - Site Remediation

REMOTOX® is a calcium polysulfide based liquid that consists of multiple sulfur compounds, which strongly bond to heavy metals in water. The metal sulfides formed have a very low solubility and persist as stable solids, which allows for a more environmentally sound disposal.

  • High reactivity with heavy metal ions and extremely low solubility of resulting metal sulfides over a wide pH range. See Sulfide vs. Hydroxide Precipitation.
  • Can break and precipitate chelated and/or complexed metals.
  • Removes chromates and dichromates without preliminary reduction of the chromium to its trivalent state.
  • Reduces mercury to low parts per billion.
  • Provides better settling and dewatering aspects of the metal precipitate. See Source Reduction Technology Report.
  • Converts cyanide wastes into less toxic thiocyanate ions. See Application of Polysulfide for Pretreatment of Spent Cyanide Liquors.
  • Dissolved calcium ions can act as a coagulant/flocculant aid.
  • REMOTOX can be adapted to enhance any existing treatment system.

  • Its residues are inert and non-toxic.
  • A strong yet relatively inexpensive precipitant.
  • Not DOT regulated.
  • Unlike dithiocarbamate or its related salts, it does not contain or release carbon disulfide.
  • REMOTOX, in comparison to other sulfides, provides more stability in acidic medium.
  • It presents a lower H2S exposure potential, and is also considerably less malodorous.

REMOTOX is designed to bring practical, and cost-effective advantages to wastewater treatment, while ensuring discharge limits on heavy metals are consistently met.

When mixed with water, REMOTOX decomposes to form bisulfide, aqueous hydrogen sulfide and other sulfur compounds, Heavy metal ions are precipitated as metal sulfide by these breakdown products. Metal sulfides are far less soluble than metal hydroxides. Metal hydroxides change solubility with changes in pH. Metal sulfides remain insoluble within a wide pH range. See Solubility of Metal Hydroxides and Sulfides as a Function of pH.

While effective treatment can be achieved over a wide pH range, best results are typically obtained within water sytem pH 7-10. Ensuring adequate contact time and thorough mixing is critical to successful treatment. Dewatering the resulting precipitate can be expedited by employing an anionic flocculant. Please ask us for flocculants suitable for use with REMOTOX.