Advertisement

Netherland Journal of Aquatic Ecology

, Volume 27, Issue 2–4, pp 267–277 | Cite as

Geochemistry of mercury in an intertidal flat of the Scheldt estuary

  • M. Leermakers
  • M. Elskens
  • S. Panutrakul
  • F. Monteny
  • W. Baeyens
Schelde

Abstract

Sediments were sampled on the ‘Groot Buitenschoor’, an intertidal flat located at about 60 km from the Scheldt's river mouth. Hg concentrations ranged from 30 to 1756 ng g−1. The concentrations were strongly correlated with fine grain fraction, organic matter content and sulphide concentrations. Incubation experiments were performed in order to determine the potential methylation rate of Hg as well as biotic and abiotic factors influencing this transformation. About 1 to 2% of the added inorganic Hg is converted into methylmercury. This conversion rate points to the same equilibrium ratio as was observed in natural sediments, indicating an equilibrium between methylation and demethylation reactions in the sediments. Incubation of a sterilised sediment sample significantly decreased the methylation rate, but the methylmercury concentrations observed are still ten times higher than the natural (unspiked) sediment. This result could be due to a chemical (non-enzymatic) methylation of mercury. Sulphate reducing bacteria are the main species responsible for the methylation of Hg at this site. Addition of Na2MoO4, a specific inhibitor of sulphate reducing bacteria, decreased the methylation rate to the abiotic level (sterilised sediment). High sulphate reduction rates, however, lead to lower methylation rates. Increased formation of sulphides due to microbial sulphate reduction leads to enhanced HgS formation and this reaction competes with the methylation process. HgS is in fact the major product formed by the reaction of sulphate reducing bacteria with Hg species. About 50% of the Hg spiked to the sediments is transformed into HgS during the incubation experiments, and that compound is practically unavailable for methylation in contrast to other bound forms of Hg.

Keywords

Estuarine sediments mercury methylmercury methylation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. ANDREN, A. and R. HARRIS, 1975. Observations on the association of mercury and organic matter dissolved in natural waters. Geochim. Cosmochim. Acta, 39: 1253–1258CrossRefGoogle Scholar
  2. BAEYENS, W., S. PANUTRAKUL, M. ELSKENS, M. LEERMAKERS, J. NAVEZ and F. MONTENY, 1991. Geochemical processes in muddy and sandy tidal flat sediments. Geo-Mar. Lett., 11: 188–193.Google Scholar
  3. BAEYENS, W. and M. LEERMAKERS, 1989. Determination of metallic mercury and some organomercury compounds using atomic absorption spectrometry after amalgamation on a gold column. J. Atom. Absorp. Spectrom., 4: 635–640.Google Scholar
  4. BELLAMA, J.M., K.L. JEWETT, W.F. MANDERS and J.D. NIER, 1988. A comparison of the rates of methylation of Hg(II) species in aquatic media by various organotin and organosilicon moeities. Sci. Tot. Environ., 73: 39–51.Google Scholar
  5. BERMAN, M. and R. BARTHA, 1986. Control of the methylation process in a mercury polluted aquatic sediment. Environ. Pollut. (ser. B), 11: 41–53.Google Scholar
  6. BERMAN, M., T. CHASE and R. BARTHA, 1990. Carbon flow in Hg biomethylation byDesulfovibrio desulfuricans. App. Environ. Microbiol. 56: 298–300.Google Scholar
  7. BLOOM, N. and E. CRECELIUS, 1983. Determination of Hg in seawater at sub nanogram per liter levels. Mar. Chem., 14: 49–59.CrossRefGoogle Scholar
  8. BOWEN, H.J.M., 1979. Environmental Chemistry of the Elements. Academic Press, London.Google Scholar
  9. CALLISTER, S. M. and M.R. WINFREY, 1986 Microbial methylation of mercury in Upper Wisconsin River Sediments. Water Air Soil Pollut., 29: 453–465.CrossRefGoogle Scholar
  10. CLINE, J.D., 1969. Spectrophotometric determination of H2S in natural waters. Limnol. Oceanogr., 14: 454–458.Google Scholar
  11. COMPEAU, G. and R. BARTHA, 1983. Effects of sea salt anions on the formation and stability of methylmercury. Bull. Environ. Contam. Toxicol., 31: 486–493.CrossRefPubMedGoogle Scholar
  12. COMPEAU, G. and R. BARTHA R., 1985. Sulphate reducing bacteria: Principal methylators of mercury in anoxic estuarine sediments. Appl. Environ. Microbiol., 50: 498–502.PubMedGoogle Scholar
  13. COMPEAU, G. and R. BARTHA, 1987. Effects of salinity on mercury methylating activity of sulphate reducing bacteria in estuarine sediments. Appl. Environ. Microbiol., 53: 261–265.PubMedGoogle Scholar
  14. CRAIG, P.J. and P.D. BARTLETT, 1978. The role of H2S in the environmental transport of Hg. Nature. 275: 635–638.CrossRefGoogle Scholar
  15. CRAIG, P.J. and P.A. MORETON, 1985. The role of speciation in mercury methylation in sediments and water. Environ. Pollut. (ser. B). 10: 141–158.Google Scholar
  16. CRAIG, P.J. and P.A. MORETON, 1986. Total mercury, methylmercury and sulphide levels in British estuarine sediments-III. Water Res. 20: 1111–1118.CrossRefGoogle Scholar
  17. CRAIG, P.J., 1986. Organomercury compounds in the Environment, Longman Group, Essex.Google Scholar
  18. ELSKENS, M., M. LEERMAKERS, S. PANUTRAKUL, F. MONTENY and W. BAEYENS, 1991. Microbial activity in sandy and muddy estuarine sediments. Geo-Mar. Lett., 11: 194–198.Google Scholar
  19. FAGERSTROM, T. and A. JERNELOV, 1971. Formation of methylmercury from pure HgS in aerobic organic sediment. Water Res., 5: 121–122.CrossRefGoogle Scholar
  20. FURUTANI, A. and J.W.D. RUDD, 1980. Measurements of Hg methylation in lake water and sediment samples. Appl. Environ. Microbiol. 40: 770–776.PubMedGoogle Scholar
  21. GOULDEN, P.D. and D. H. ANTHONY, 1980. Chemical speciation of Hg in natural waters. Anal. Chim. Acta, 20: 129–139.Google Scholar
  22. HORVAT, M., K. MAY, M. STOEPPLER and A.R. BYRNE, 1988. Comparative study of methylmercury determinations in biological and environmental samples. Appl. Organometal. Chem., 2: 515–524.CrossRefGoogle Scholar
  23. HOWELL, G.N., J. MAXWELL and A. O'CONNOR, 1986. Methylmercury generation by transmethylation reactions of organo-lead and organotin compounds with inorganic mercury as monitored by multinuclear magnetic resonance and electrochemical techniques. Austr. J. Chem., 39: 1167–1175.Google Scholar
  24. JACKSON, T.A., 1988. The Hg problem in recently formed reservoirs in Northern Manitoba (Canada): effects of impoundment and other factors on the production of methylmercury by microorganisms in sediments. Can. J. of Fish. Aquat. Sci., 45: 97–121.Google Scholar
  25. JERNELOV, A., 1970. Release of methylmercury from sediments with layers containing inorganic mercury at different depths. Limnol. Oceanogr., 15: 958–960.Google Scholar
  26. KERRY, A., P.M. WELBOURN, B. PRUCHA and G. MIERLE, 1991. Microbial methylation of mercury in acid stressed lakes. Role of sulphate reducing bacteria. Water Air Soil Pollut., 56: 565–575.CrossRefGoogle Scholar
  27. LOVLEY, D. and E. PHILLIPS, 1986. Availability of ferric iron for microbial reduction in bottom sediments of the freshwater tidal Potomac river. Appl. Environ. Microbiol., 52: 751–757.PubMedGoogle Scholar
  28. MANTOURA, R.F., A. DICKSON and J.P. RILEY, 1978. The complexation of metals with humic materials in natural waters. Estuar. Coastal. Mar. Sci., 6: 387–408.Google Scholar
  29. MILLER, D.R. and AKAGI, 1979. pH effects on Hg distribution, not methylation. Ecotoxicol. Environ. Safety, 7: 36–38.Google Scholar
  30. NAGASE, H., Y. OSE, T. SATO and T. ISHIKAWA, 1982. Methylation of Hg by humic substances in an aquatic environment. Sci. Tot. Environ., 25: 133–142.Google Scholar
  31. NAGASE, H., Y. OSE, T. SATO and T. ISHIKAWA, 1984. Hg methylation by compounds in humic material. Sci. Tot. Environ., 32: 147–156.Google Scholar
  32. NAKAMURA, K., M. SAKAMOTO, H. UCHIYAMO and O. YAGI, 1990. Organomercurial-volatilizing bacteria in the mercury polluted sediment of Minamata Bay, Japan. Appl. Environ. Microbiol., 56: 304–305.PubMedGoogle Scholar
  33. PANUTRAKUL, S. and W. BAEYENS, 1991. Behaviour of heavy metals in a mud flat of the Scheldt estuary, Belgium. Mar. Pollut. Bull., 22: 128–134.Google Scholar
  34. RAMLAL, P.S., J.W. RUDD and R.E. HECKY, 1986. Methods for measuring specific rates of mercury methylation and degradation and their use in determining the factors controlling net rates of mercury methylation. Appl. Environ. Microbiol., 51: 110–114.PubMedGoogle Scholar
  35. REVIS, N.W., T.R. OSBORNE, G. HOLSWORTH and C. HADDEN, 1989. Distribution of Hg species in soil from a Hg contaminated site. Water Air Soil Pollut., 45: 105–113.Google Scholar
  36. SPANGLER, W.J. and J.L. SPIGNARELLI, 1973. Methylmercury: bacterial degradation in lake sediments. Science, 180: 192–193.Google Scholar

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • M. Leermakers
    • 1
  • M. Elskens
    • 1
  • S. Panutrakul
    • 1
  • F. Monteny
    • 2
  • W. Baeyens
    • 1
  1. 1.Analytische Scheikunde (ANCH)Vrije Universiteit BrusselBrusselsBelgium
  2. 2.MechelenBelgium

Personalised recommendations