Chemistry and stability of precipitates from aqueous solutions of 2, 4, 6-trimercaptotriazine, trisodium salt, nonahydrate (TMT-55) and mercury (II) chloride

Kevin R. Henke, David Robertson, Matthew K. Krepps, David A. Atwood

Research output: Contribution to journalArticlepeer-review

74 Scopus citations


2, 4, 6-trimercaptotriazine, trisodium salt, nonahydrate (TMT-55) is a planar C3 symmetric compound that is used commercially to precipitate mercury and other heavy metals from waste waters and contaminated natural waters. A series of laboratory experiments and analyses were performed to evaluate the chemistry and stability of mercury trimercaptotriazine “Hg-TMT” precipitates that result from the addition of aqueous solutions of TMT-55 to aqueous solutions of mercury(II) chloride (HgCl2). Several Hg-TMT species exist, most of which were previously unrecognized. The leaching properties, chemistry and long-term stability of the solids are very diverse. As examples, the white and yellow varieties of Hg-TMT are often unstable in both water and air, and may release more than 6000 μg/l of mercury into distilled and deionized water leachates. Although waste waters and contaminated ground waters are likely to contain less mercury than the HgCl2 solutions used in this study, individuals should recognize that any Hg-TMT compounds are likely to be chemically complex and perhaps unstable under aqueous or atmospheric conditions.

Original languageEnglish
Pages (from-to)3005-3013
Number of pages9
JournalWater Research
Issue number11
StatePublished - Aug 1 2000

Bibliographical note

Funding Information:
The authors wish to thank personnel at Oak Ridge National Laboratory, the Materials Characterization Facility at the University of Kentucky, the Department of Chemistry at North Dakota State University, the Department of Geology and Geological Engineering at the University of North Dakota, and Element Analysis Corporation of Lexington, Kentucky, for advice and the use of their equipment. Mr Ernest W. Haug generously provided samples of TMT-55. Gail R. Hutchens, Dr. Mark P. Elless, and Dean Grier performed sample analyses. Research support was provided by Dr. Ralph R. Turner and the Environmental Restoration Division, US Department of Energy, under contract DE-AC05-84OR21400 with Lockheed Martin Energy Systems, Inc. The research was further supported by the lead author’s two year appointment to the Postgraduate Research Program at Oak Ridge National Laboratory, Oak Ridge, Tennessee, administered by the Oak Ridge Institute for Science and Education. Funding was also provided by the University of Kentucky and the Eppley Foundation forResearch, New York. The authors also thank two anonymous reviewers of this manuscript for their helpful comments, especially one of them for providing theoretical chemical reactions.


  • Chemical precipitation
  • Mercury
  • TMT-55
  • Trimercaptotriazine
  • Water treatment

ASJC Scopus subject areas

  • Environmental Engineering
  • Civil and Structural Engineering
  • Ecological Modeling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution


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