Arsenic Speciation in a Fly Ash Settling Basin System

  • Brian P. Jackson
  • John C. Seaman
  • William Hopkins


The sluicing of coal fly ash to settling basins is a major method for disposal of this industrial by-product. Fly ash often contains elevated concentrations of trace elements such as As, Se, and Mo, which can be solubilized upon contact with water and also become elevated in the surficial sediments. Both the soluble and sediment-sorbed trace elements can be bioavailable and potentially toxic to animals inhabiting the ash basins. This study examines the aqueous speciation of As in the surface and interstitial waters and the solid phase As speciation in the sediments of a fly ash basin system. Ion chromatography coupled to inductively coupled plasma mass spectrometry (IC-ICP-MS) was used to determine arsenite As(III), arsenate As(V), dimethylarsenate (DMA), and momomethylarsenate (MMA) in the aqueous samples. Hydoxylamine hydrochloride and oxalic acid extractions were used to assess the proportion of amorphous Fe, amorphous Al and amorphous aluminosilicates in depth sectioned samples of a sediment core taken from the ash basins. The concentration of As solubilized by these extractants was also measured. Surface water As concentrations were low with an average of 13 and 3 μg 1−1 determined in the summer and fall 2000. Arsenate was the major As species in the surface waters; DMA and As(III) were detected in the summer sampling but no DMA was detected in the fall sampling. Pore water As concentrations were much higher than the surface waters, reaching a maximum of 110 μg 1−1 at a sediment depth of 8–12cm. Arsenate was the major dissolved species at the sediment-water interface but decreased with depth, while the proportion of AS(III) increased to a maximum at a depth of 8–12 cm. The increase in total dissolved As with depth was mirrored by an increase in soluble Mo and an increase in pH, and the depth of maximum As concentration marked the onset of an increase in soluble Fe. This suggests that the observed increased As solubility may result from the decrease in sorption by amorphous Fe phases due to the onset of reductive dissolution, coupled with the prevalence of As(III), that may be poorly sorbed by the remaining mineral phases in the sediment. This observation was supported by the selective extraction data of the sediment core sections, which indicated that As was mostly bound to amorphous Fe phases in the sediment. The oxalate extraction also showed that a significant proportion of total Al was present as amorphous phases and that < 20% of amorphous Al was present as amorphous aluminosilicates.


Inductively Couple Plasma Mass Spectrometry Sediment Core Interstitial Water Coal Combustion Waste Settling Basin 
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  1. 1.
    ACAA. (1998) 1998 Coal Combustion Product (CCP) Production and Use. American Coal Ash Association, International. Alexandria, VA.Google Scholar
  2. 2.
    Eary, L. E., Rai, D., Mattigod, S. V., and Ainsworth, C.C., Geochemical factors controlling the mobilization of inorganic constituents from combustion residues: review of the minor elements, J. Environ. Qual., 19, 202, 1990.CrossRefGoogle Scholar
  3. 3.
    Jackson, B. P., and Miller W. P., Arsenic and selenium in coal fly ash extracts by ion chromatography-inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom., 13, 1107, 1998.CrossRefGoogle Scholar
  4. 4.
    Huggins, F, E., Shah, N., Huffinan, G. P., and Robertson, J., D., XAFS spectroscopic characterization of elements in combustion ash and fine particulate matter, Fuel Processing Technol. 65–66, 203, 2000.Google Scholar
  5. 5.
    Goodarzi, F., and Huggins, F. E., Monitoring the species of arsenic, chromium, and nickel in milled coal, bottom ash and fly ash from a pulverized coal fired-power plant in western Canada. J. Environ. Monitoring 3, 1, 2001.CrossRefGoogle Scholar
  6. 6.
    Mahuli, S., Agnihotri, R., Chauk, S., Ghost-Dastidar, A., and Fan, L. S., Mechanism of arsenic sorption by hydrated lime, Environ. Sci. Technol., 31, 3226, 1997.CrossRefGoogle Scholar
  7. 7.
    Turner, R. R., Oxidation state of arsenic in coal fly ash in coal fly ash leachate, Environ. Sci. Technol., 15, 1062, 1981.CrossRefGoogle Scholar
  8. 8.
    Silberman, D., and Harris, W., R., Determintion of arsenic (III) and arsenic (V) in coal and oil fly ashes, Intern. J. Environ. Anal. Chem., 17, 73, 1984.CrossRefGoogle Scholar
  9. 9.
    Wang, J., Tomlinson, M. J., Caruso, J. A., Extraction of trace elements in coal fly ash and subsequent speciation by high-performance liquid chromatography with inductively coupled plasma mass spectrometry, J. Anal. Atom, Spectrom. 10, 601, 1995.CrossRefGoogle Scholar
  10. 10.
    Van der Hoek, E. E., and Comans, E., N., J., Modeling arsenic and selenium leaching from acidic fly ash by sorption on iron (hydr)oxide in the fly ash matrix, Environ. Sci. Technol. 30, 517, 1996.CrossRefGoogle Scholar
  11. 11.
    Warnren, C. J. and Dudas, M. J., Formation of secondary minerals in artificially weathered fly ash, J. Environ. Qual., 14, 405, 1985.CrossRefGoogle Scholar
  12. 12.
    Zevenbergen, C., Bradley, J. P., Piet Van Reeuwijk, L., Shyam, A. K., Hjelmar, O., and Comans, R. N. J., Clay formation and metal fixation during weathering of coal fly ash. Environ. Sci. Technol. 33, 3405, 1999.CrossRefGoogle Scholar
  13. 13.
    Rowe, C. L., Kinney O. M., Flori A. P., Congdon, J. D., Oral deformities in tadpoles (Rana catesbeiana) associated with coal ash deposition: effects on grazing ability and growth. Freshwater Biol. 36, 723, 1996.CrossRefGoogle Scholar
  14. 14.
    Hopkins W A, Mendonca M. T., Rowe C. L, Congdon J. D. 1998. Elevated trace element concentrations in southern toads, Bufo terrestris, exposed to coal combustion wastes. Arch. Environ. Contam. Toxicol. 35: 325–329.CrossRefGoogle Scholar
  15. 15.
    Gallagher, P. A., Schwegel, CA., Wei, X. Y., Creed, J. T., Speciation and preservation of inorganic arsenic in drinking water sources using EDTA with IC separation and ICP-MS detection, J. Environ. Monitoring, 3, 731, 2001CrossRefGoogle Scholar
  16. 16.
    Jackson, B. P., and Miller W. P. Soluble arsenic and selenium species in fly ash/organic waste-amended soils using ion chromatography inductively coupled plasma mass spectrometry. Environ. Sci. Technol. 33, 270, 1999.CrossRefGoogle Scholar
  17. 17.
    Mattusch, J., Wenrich R., Determination of anionic, neutral and cationic species of arsenic by ion chromatography with ICPMS detection in environmental samples, Anal. Chem. 70, 3649, 1998.CrossRefGoogle Scholar
  18. 18.
    McGeehan, S. L., Naylor, D. V., Simultaneous determination of arsenite, arsenate, selenite, and selenate in soil extracts by suppressed ion chromatography. J. Environ. Qual. 21, 68, 1992.CrossRefGoogle Scholar
  19. 19.
    Winger, P. V., and Lasier, P., J., A vacuum-operated pore-water extractor for estuarine and freshwater sediments. Arch. Envrion. Contam. Toxicol. 21 321, 1991.CrossRefGoogle Scholar
  20. 20.
    Jackson B. P., Bertsch P. M.. Determination of arsenic speciation in poultry wastes by IC-ICP-MS. Environ. Sci. Technol. 35, 4868, 2001.CrossRefGoogle Scholar
  21. 21.
    Alberts J. J., Newman M. C., Evans D. W., Seasonal variations of trace elements in dissolved and suspended loads for coal ash ponds and pond effluents. Water Air Soil Pollut. 26, 111, 1985.CrossRefGoogle Scholar
  22. 22.
    Sandhu, S. S., and Mills, G. L., Mechanisms of mobilization and attenuation of inorganic contaminants in coal ash basins, in Emerging technologies in hazardous waste management II, Tedder, D. W. and Pohland, F. G. Eds. American Chemical Society, Washington D.C. pp. chap. 17.Google Scholar
  23. 23.
    McGeehan, S. L., Naylor, D. V., Sorption and redox transformation of arsenite and arsenate in two flooded soils. J. Environ. Qual. 58, 337, 1994.Google Scholar
  24. 24.
    Xu, H. Allard, B., Grimvall, A, Effects of the acidification and natural organic materials on the mobility of arsenic in the environment. Water Air Soil Pollut. 57–58, 269, 1991.Google Scholar
  25. 25.
    Bowell, R. J., Sorption of arsenic by iron oxides and oxyhydroxides in soils. Appl. Geochem. 9, 279, 1994.CrossRefGoogle Scholar
  26. 26.
    Jackson, B. P. and Miller, W. P., Effectiveness of phosphate and hydroxide for desorption of arsenic and selenium species from iron oxides, Soil Sci. Soc. Am. J. 64, 1616, 2000.CrossRefGoogle Scholar
  27. 27.
    Wada, K. Allophane and imogolite, In Minerals in soil environments, Dixon, J. B. and Weed, S. B. Eds., Soil Science Society of America, Madison, Wi., 1989, 1051.Google Scholar
  28. 28.
    Chao, T. T., and Zhou, L., Extraction techniques for selective dissolution of amorphous iron oxides from soils and sediments, Soil Sci. Soc. Am. J. 47, 225, 1983.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2003

Authors and Affiliations

  • Brian P. Jackson
    • 1
  • John C. Seaman
    • 1
  • William Hopkins
    • 1
  1. 1.Savannah River Ecology LaboratoryUniversity of GeorgiaAikenUSA

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