Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-26T17:21:54.516Z Has data issue: false hasContentIssue false

In situ analysis of thioarsenite complexes in neutral to alkaline arsenic sulphide solutions

Published online by Cambridge University Press:  05 July 2018

B. C. Bostick*
Affiliation:
Dartmouth College, Department of Earth Sciences, Hanover NH 03755, USA Stanford University, Department of Geological and Environmental Sciences, Stanford CA 94305-2115, USA
S. Fendorf
Affiliation:
Stanford University, Department of Geological and Environmental Sciences, Stanford CA 94305-2115, USA
G. E. Brown Jr
Affiliation:
Stanford University, Department of Geological and Environmental Sciences, Stanford CA 94305-2115, USA Stanford Synchrotron Radiation Laboratory, SLAC, 2575 Sand Hill Road, Menlo Park, CA 94025, USA

Abstract

The solubility of arsenic in anoxic soil and sediment pore waters is strongly influenced by complexation with dissolved sulphide. Despite their importance in arsenic chemistry, thioarsenite complexes have not been well characterized, and considerable questions remain regarding their structure, protonation state, and relative stabilities. Here we use X-ray absorption spectroscopy to examine the type and structure of aqueous arsenic-sulphur complexes in sulphidic solutions under neutral to alkaline pH. Arsenic formed a variety of thioarsenites, including AsS(SH)(OH), As(SH)S22—, AsS33—and As(SH)4 complexes. The relative fraction of each species varied strongly with the S:As ratio — with the fraction of AsS(SH)(OH) greatest at low S:As and trithioarsenites dominating As speciation when S:As ratios exceeded 3 in solution. As much as 40% of the total As also was present as AsS3S3+x(SH)3—x—x in solutions at S:As ratios of 3 or greater. Sulphide complexation was somewhat dependent on pH, with sulphide complexation generally increasing with pH. The speciation observed in these experiments is similar to, though distinct from, speciation predicted based on As2S3 solubility (inferred to contain AsS2 and AsS3S3+x(SH)—x3—x) and chromatographic separation of arsenic species (which does not identify polymeric species). Thus, these data indicate that stability constants for arsenic sulphide complexes must be reappraised.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Aggett, J. and Obrien, G.A. (1985) Detailed model for the mobility of arsenic in lacustrine sediments based on measurements in lake ohakuri. Environmental Science and Technology, 19, 231238.CrossRefGoogle ScholarPubMed
Ankudinov, A.L., Ravel, B., Rehr, J.J. and Conradson, S.D. (1998) Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure. Physical Review B, 58, 75657576.CrossRefGoogle Scholar
Balistrieri, L.S., Murray, J.W. and Paul, B. (1994) The geochemical cycling of trace-elements in a biogenic meromictic lake. Geochimica et Cosmochimica Acta, 58, 39934008.CrossRefGoogle Scholar
Bostick, B.C. and Fendorf, S. (2003) Arsenite sorption on troilite (FeS) and pyrite (FeS2). Geochimica et Cosmochimica Acta, 67, 909921.CrossRefGoogle Scholar
Bostick, B.C., Fendorf, S. and Manning, B.A. (2003) Arsenite adsorption on galena (PbS) and sphalerite (ZnS). Geochimica et Cosmochimica Acta, 67, 895907.CrossRefGoogle Scholar
Clarke, M.B. and Helz, G.R. (2000) Metal-thiometalate transport of biologically active trace elements in sulphidic environments. 1. Experimental evidence for copper thioarsenite complexing. Environmental Science and Technology, 34, 14771482.CrossRefGoogle Scholar
Cleverley, J.S., Benning, L.G. and Mountain, B.W. (2003) Reaction path modelling in the As-S system: A case study for geothermal as transport. Applied Geochemistry, 18, 13251345.CrossRefGoogle Scholar
Cullen, W.R. and Reimer, K.J. (1989) Arsenic speciation in the environment. Chemical Reviews, 89, 713764.CrossRefGoogle Scholar
Eary, L.E. (1992) The solubility of amorphous As2S3from 25 to 90°C. Geochimica et Cosmochimica Acta, 56, 2267–80.CrossRefGoogle Scholar
Erickson, B.E. and Helz, G.R. (2000) Molybdenum(vi) speciation in sulfidic waters: Stability and lability of thiomolybdates. Geochimica et Cosmochimica Acta, 64, 11491158.CrossRefGoogle Scholar
Francesconi, K.A. and Kuehnelt, D. (2004) Determination of arsenic species: A critical review of methods and applications, 2000—2003. Analyst, 129, 373395.CrossRefGoogle ScholarPubMed
Helz, G.R., Tossell, J.A., Charnock, J.M., Pattrick, R.A.D., Vaughan, D.J. and Garner, CD. (1995) Oligomerization in As(III) sulfide solutions — theoretical constraints and spectroscopic evidence. Geochimica et Cosmochimica Acta, 59, 45914604.CrossRefGoogle Scholar
Helz, G.R., Valerio, M.S. and Capps, N.E. (2002) Antimony speciation in alkaline sulfide solutions: Role of zerovalent sulfur. Environmental Science and Technology, 36, 943948.CrossRefGoogle ScholarPubMed
Krupp, R.E. (1988) Solubility of stibnite in hydrogen-sulfide solutions, speciation, and equilibrium-constants, from 25 to 350°C. Geochimica et Cosmochimica Acta, 52, 30053015.CrossRefGoogle Scholar
Meng, X.G., Jing, C.Y. and Korfiatis, G.P. (2003) A review of redox transformation of arsenic in aquatic environments. Pp. 7083 in: Biogeochemistry of Environmentally Important Trace Elements (Yang, C. and Braids, O.C., editors). ACS series 835, American Chemical Society, Washington, D.C.CrossRefGoogle Scholar
Mironova, G.D., Zotov, A.V. and Gul'ko, N.V. (1990) The solubility of orpiment in sulfide solutions at 25-150°C and the stability of arsenic sulfide complexes. Geochemistry International, 27, 6173.Google Scholar
Morse, J.W. and Luther, G.W. (1999) Chemical influences on trace metal-sulfide interactions in anoxic sediments. Geochimica et Cosmochimica Acta, 63, 33733378.CrossRefGoogle Scholar
Mosselmans, J.F.W., Helz, G.R., Pattrick, R.A.D., Charnock, J.M. and Vaughan, D.J. (2000) A study of speciation of Sb in bisulfide solutions by X-ray absorption spectroscopy. Applied Geochemistry, 15, 879889.CrossRefGoogle Scholar
Raab, A., Genney, D.R., Meharg, A.A. and Feldmann, J. (2003) Identification of arsenic species in sheep-wool extracts by different chromatographic methods. Applied Organometallic Chemistry, 17, 684692.CrossRefGoogle Scholar
Raab, A., Meharg, A.A., Jaspars, M., Genney, D.R. and Feldmann, J. (2004) Arsenic-glutathione complexes — their stability in solution and during separation by different hplc modes. Journal of Analytical Atomic Spectrometry, 19, 183190.CrossRefGoogle Scholar
Ressler, T. (1998) Winxas: A program for X-ray absorption spectroscopy data analysis unde. MS-Windows. Journal of Synchrotron Radiation, 5, 118122.CrossRefGoogle Scholar
Rochette, E.A., Bostick, B.C., Li, G.C. and Fendorf, S. (2000) Kinetics of arsenate reduction by dissolved sulfide. Environmental Science and Technology, 34, 47144720.CrossRefGoogle Scholar
Sherman, D.M., Ragnarsdottir, K.V. and Oelkers, E.H. (2000) Antimony transport in hydrothermal solutions: An EXAFS study of antimony(V) complexation in alkaline sulfide and sulfide-chloride brines at temperatures from 25°C to 300°C at p-sat. Chemical Geology, 167, 161167.CrossRefGoogle Scholar
Spycher, N.F. and Reed, M.H. (1989) As(IH) and Sb(HI) sulfide complexes — an evaluation of stoichiometry and stability from existing experimental data. Geochimica et Cosmochimica Acta, 53, 21852194.CrossRefGoogle Scholar
Stauffer, R.E. and Thompson, J.M. (1984) Arsenic and antimony in geothermal waters of Yellowstone National Park, Wyoming, USA. Geochimica et Cosmochimica Acta, 48, 25472561.CrossRefGoogle Scholar
Sullivan, K.A. and Aller, R.C. (1996) Diagenetic cycling of arsenic in Amazon shelf sediments. Geochimica et Cosmochimica Acta, 60, 14651477.CrossRefGoogle Scholar
Tossell, J.A. (1997) Theoretical studies on arsenic oxide and hydroxide species in minerals and in aqueous solution. Geochimica et Cosmochimica Acta, 61, 16131623.CrossRefGoogle Scholar
Tossell, J.A. (2000) Metal-thiometalate transport of biologically active trace elements in sulfidic environments. 2. Theoretical evidence for copper thioarsenite complexing. Environmental Science and Technology, 34, 14831488.CrossRefGoogle Scholar
Tossell, J.A. (2003) Calculation of the energetics for the oxidation of Sb(III) sulfides by elemental S and polysulfides in aqueous solution. Geochimica et Cosmochimica Acta, 67, 33473354.CrossRefGoogle Scholar
Webster, J.G. (1990) The solubility of As2S3 and speciation of As in dilute and sulfide-bearing fluids at 25°C and 90°C. Geochimica et Cosmochimica Acta, 54, 10091017.CrossRefGoogle Scholar
Wilkin, R.T. and Ford, R.G. (2002) Use of hydrochloric acid for determining solid-phase arsenic partitioning in sulfidic sediments. Environmental Science and Technology, 36, 49214927.CrossRefGoogle Scholar
Wilkin, R.T., Wallschlager, D. and Ford, R.G. (2003) Speciation of arsenic in sulfidic waters. Geochemical Transactions, 4, 17.CrossRefGoogle Scholar
Wood, S.A., Tait, C.D. and Janecky, D.R. (2002) A Raman spectroscopic study of arsenite and thioarsenite species in aqueous solution at 25°C. Geochemical Transactions, 3, 3139.CrossRefGoogle Scholar