Dissolution of Wollastonite in a Packed Bed Contactor
Publication: Journal of Environmental Engineering
Volume 132, Issue 4
Abstract
In a packed-bed reactor grains of the calcium silicate mineral wollastonite dissolved incongruently. A silicon-rich residue layer appeared to form on the grain surfaces and this quickly limited the overall rate of mineral dissolution. Approximately 54% of the silicon associated with the dissolved calcium was retained on the grains and about 46% went into solution with the calcium. As the amount of Ca dissolved per unit area of grain surface approached approximately the effluent concentration of Ca decreased to a value that was significantly less than the equilibrium concentration (approximately ) and the effluent pH decreased from approximately 10 to slightly greater than the influent value of 6.8. The effluent Ca and Si concentrations were effectively predicted by a finite difference model that used layer-by-layer calculation of a residue layer mass transfer resistance (for the Ca ion) acting in series with an extraparticle mass transfer resistance. The effluent pH was predicted using chemical equilibrium calculations and the assumption that the dissolved Si controls the proton balance across the column.
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Acknowledgments
This paper is based on results obtained in a study sponsored by the United States Environmental Protection Agency through the New England Water Treatment Technology Assistance Center at the University of New Hampshire. The help received from M. Robin Collins, Director of the Center, is greatly appreciated.
References
Bailey, A., and Reesman, A. L. (1971). “A survey study of the kinetics of wollastonite dissolution in and buffered systems at 25°C.” Am. J. Sci., 271, 464–472.
Boksay, Z., Bouquet, G., and Dobos, S. (1968). “The kinetics of the formation of leached layers on glass surfaces.” Phys. Chem. Glasses, 9, 69–71.
Casey, W. H., Westrich, H. R., Banfield, J. F., Ferruzzi, G., and Arnold, G. W. (1993). “Leaching and reconstruction at the surface of dissolving chain-silicates minerals.” Nature (London), 366, 253–256.
Chiodini, R. A. (1998). “The use of sodium silicate for the control of lead and copper.” J. New England Water Works Assoc., 112(2), 147–152.
Correns, C. W. (1963). “Experiments on the decomposition of silicates and discussion of chemical weathering.” Clays Clay Miner., 10, 443–459.
Frederickson, A. F. (1951). “Mechanism of weathering.” Bull. Geol. Soc. Am., 62, 221–232.
Hochella, M. F., Jr. (1990). “Atomic structure, microtopography, composition, and reactivity of mineral surfaces.” Rev. Mineral., 23, 86–132.
Kothari, S. (1991) “Kinetics of limestone dissolution.” MS thesis, Department of Civil and Environmental Engineering, Syracuse Univ.
Letterman, R. D., Driscoll, C. T., Haddad, M., and Hsu, H. A. (1986). Limestone bed contactors for control of corrosion at small water utilities, A Report for the Water Engineering Research Laboratory, Office of Research and Development-USEPA, Cincinnatti, Ohio, 1–167.
Letterman, R. D., Haddad, M., and Driscoll, C. T. (1991). “Limestone contactors: Steady-state design relationships.” J. Environ. Eng., 117(3), 339–349.
Osterhus, S. W. (2001). “The effect of mineralization and silicate addition for corrosion control in soft low carbonate waters.” Water Sci. Technol.: Water Supply, 1(3), 59–73.
Paces, T. (1973). “Steady-state kinetics and equilibrium between ground water and granite rock.” Geochim. Cosmochim. Acta, 37, 2641–2663.
Peters, S. C., Blum, J. D., Driscoll, C. T., and Likens, G. E. (2002). “Dissolution of wollastonite during the experimental manipulation of Hubbard Brook Watershed 1.” Biogeochemistry, 67(3), 309–329.
Schecher, W. D., and Driscoll, C. T. (1995). “ALCHEMI: A chemical equilibrium model to assess the acid-base chemistry and speciation of aluminum in dilute solutions.” Chemical equilibrium and reaction models, R. H. Loeppert, A. P. Schwab, and S. Goldberg, eds., SSSA Special Publication No. 42, Soil Science Society of America, Madison, Wis., 57–82.
Schock, M. R., Clement, J., Lytle, D. A., Sandvig, A. M., and Harmon, S. M. (1998). “Replacing polyphosphate with silicate to solve problems with lead, copper and source water iron.” Proc., American Water Works Association, Water Quality Technology Conf., Denver, Colo., 1333–1346.
Slaats, P. G. G., Brink, H., and van den Hoven, T. J. J. (2001). “Copper corrosion control in the Netherlands.” Water Sci. Technol.: Water Supply, 1(3), 75–82.
Sriram, A. (2005). “Dissolution of wollastonite in packed bed contactor.” MS thesis, Department of Civil and Environmental Engineering, Syracuse Univ.
Standard methods for the examination of water and wastewater, 19th Ed. (1995). A. D. Eaton, L. S. Clesceri, and A. E. Greenberg, eds., American Public Health Association, Washington, D.C., 3-87–3-91.
Weissbart, E. J. (1997). “The leached layer formed on wollastonite in an acid environment.” MS thesis, Geological Sciences, Virginia Polytechnic Institute and State Univ.
Weissbart, E. J., and Rimstidt, J. D. (2000). “Wollastonite: Incongruent dissolution and leached layer formation.” Geochim. Cosmochim. Acta, 64, 4007–4016.
Wollast, R. (1967). “Kinetics of the alteration of K-feldspar in buffered solutions at low temperature.” Geochim. Cosmochim. Acta, 31, 635–648.
Xie, Z., and Walther, J. V. (1994). “Dissolution stoichiometry and adsorption of alkali and alkaline earth elements to the acid-reacted wollastonite surface at 25°C.” Geochim. Cosmochim. Acta, 58, 2587–2598.
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Information
Published In
Journal of Environmental Engineering
Volume 132 • Issue 4 • April 2006
Pages: 460 - 467
Copyright
© ASCE.
History
Received: Jun 18, 2004
Accepted: Aug 16, 2005
Published online: Apr 1, 2006
Published in print: Apr 2006
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