The links to these case studies include various application technologies. However, effective treatment is based on site-specific water chemistry and metal removal needs.  


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REMOTOX® for Heavy Metal Removal from Wastewater

REMOTOX is a water-soluble 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. 


Product Advantages:
  • High reactivity with heavy metal ions and extremely low solubility of resulting metal sulfides. See Sulfide vs. Hydroxide Precipitation.
  • Removes chromates and dichromates without preliminary reduction of the chromium to its trivalent state.
  • Reduces mercury to low parts per billion.
  • Effective treatment can be achieved over a wide pH range.
  • Ability to break and precipitate chelated and/or complexed metals.
  • Dissolved calcium ions act as a coagulant/flocculant aid.
  • May provide better settling and dewatering aspects of the metal precipitate compared to other reagents. 
  • Can convert cyanide wastes into less toxic thiocyanate ions.
  • REMOTOX can be adapted to enhance any existing treatment system. 


Product Features:
  • Not DOT regulated.
  • Its residues are inert and non-toxic.
  • Unlike dithiocarbamate or its related salts, it does not contain or release carbon disulfide.
  • Compared to other sulfides, it provides more stability in acidic medium.
  • REMOTOX is a strong, yet relatively inexpensive precipitant.


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. Most heavy metal ions are precipitated as metal sulfides by these breakdown products. Metal sulfides are much 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. In the case of chromium, REMOTOX reduces hexavalent chromium to trivalent state which then precipitates as chromium hydroxide in a one-step reaction.


While effective treatment can be achieved over a wide pH range, best results are typically obtained within water system 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.


For technical assistance, product samples or pricing information, please contact us at 623-328-5175 or by email at info@grauschemicals.com.