Skip to main content Accessibility help
×
Home

Electrokinetic generation of reactive iron-rich barriers in wet sediments: implications for contaminated land management

  • D. W. S. Faulkner (a1), L. Hopkinson (a1) and A. B. Cundy (a2)

Abstract

Here we describe preliminary research into the in situ electrokinetic generation of continuous iron-rich precipitates to act as sub-surface barriers for the containment of contaminated sites. This is achieved using sacrificial iron electrodes emplaced either side of a soil/sediment mass to introduce iron into the system, and their dissolution and re-precipitation under the influence of an applied (DC) electric field. Continuous vertical and horizontal iron-rich bands (up to 2 cm thick) have been generated over a timescale of 300—500 h, at voltages of <5 V with an electrode separation of between 15 and 30 cm. The thickness of the iron-rich band increases as the applied voltage is increased. Geotechnical tests in sand indicate that the iron-rich band produced is practically impervious (coefficient of permeability of 10—9 ms—1 or less), and has significant mechanical strength (unconfined compressive strength of 10.8 N mm—2). By monitoring the current, the integrity of the iron-rich band may be assessed, and by continued application of current, the barrier may 'self heal'. The iron-rich barrier is composed of amorphous iron, goethite, lepidocrocite, maghemite and native iron.

Copyright

Corresponding author

References

Hide All
Acar, Y.B. and Alshawabkeh, A.N. (1993) Principles of electrokinetic remediation. Environmental. Science and Technology, 11, 26382647.
Acar, Y.B., Gale, R.J., Alshawabkeh, A.N., Marks, R.E., Puppala, S., Bricka, M. and Parker, R. (1995) Electrokinetic remediation — basics and technology status. Journal of Hazardous Materials, 40, 117–137.
Alshawabkeh, A.N., Yeung, A.T. and Bricka, M.R. (1999) Practical aspects of in situ electrokinetic extraction. Journal of Environmental Engineering, 125, 27–3.
Bendell-Young, L. and Harvey, H.H. (1992) The relative importance of manganese and iron oxides and organic matter in the sorption of trace metals by surficial lake sediments. Geochimica et Cosmochimica Acta, 56, 1175–1186.
Cairney, T. and Hobson, D.M (1998) In-ground barriers. Pp. 128139 in: Contaminated Land: Problems and Solutions, 2nd edition. E. and F.N. Spoon, London.
Casagrande, L. (1947) The application of electro-osmosis to practical problems in foundations and earthwork. Building Research Technical paper no.30, Dept. of Scientific and Industrial Research, HMSO, London
Casagrande, L. (1952) Electrical stabilisation in earth-work and foundation engineering. Proceedings of the M.I.T. conference on soil stabilisation 1952. Pp. 2636 in: Methods of Treatment of Unstable Ground (Bell, F.G., editor), Newnes Butterworths, London 1975
Cundy, A. and Hopkinson, L. (2005) Electrokinetic iron pan generation in unconsolidated sediments: implications for contaminated land remediation and soil engineering. Applied Geochemistry, 20, 841–848.
Franklin, J.A. and Brook, N. (1985) Method for determining point load strength index — International Society for Rock Mechanics Commission on testing methods (Revision of the Point Load Test method). International Journal of Rock Mechanics and Mining Science, 22, 51—60.
Head, K.H. (1982) Manual of Soil Laboratory Testing. Volume 2, Pentech Press, Plymouth, UK, pp. 450455.
Helland, B.R., Alvarez, P.J.J. and Schnoor, J.L. (1994) Reductive dechlorination of carbon tetrachloride with elemental iron. Journal of Hazardous Materials, 41, 205–216.
Hopkinson, L. and Cundy, A. (2003) FIRS (ferric iron remediation and stabilisation): a novel electrokinetic technique for soil remediation and engineering: CLAIRE research bulletin RB2, May edition.
Ingles, O.G. and Metcalf, J.B. (1972) Soil Stabilization - Principles and Practice. Butterworths, London.
Jacob, K.H., Dietrich, S. and Krug, H.J. (1994) Self organised mineral fabrics. Pp. 259268 in: Fractals and Dynamic Systems in Geoscience (Kruhl, J.H., editor). Springer Verlag, Berlin.
Johnson, T.L., Fish, W., Gorby, Y. and Tratneyek, P. (1998) Degradation of carbon tetrachloride by iron metal: Complexation effects on the oxide surface. Journal of Contaminant Hydrology, 29, 379–398.
Kovalick, W.W. (1995) In Situ Remediation Technology: Electro-kinetics. US Environmental Protection Agency, Office of Solid Waste and Emergency Response Technology Innovation Office, Washington.
Lamont-Black, J. (2001) EKG: The next generation of geosynthetics. Ground Engineering, 34, 22—23.
Masliyah, J.H. (1994) Electrokinetic Transport Phenomena. Aostra Technical Publications Series no. 12, Alberta Oil Sands Technology and Research Authority, Edmonton, Canada.
McGuire, M.M. (2003) Applications of surface analysis in the environmental sciences: dehalogenation of chlorocarbons with zero-valent iron and iron-containing mineral surfaces. Analytica Chimica Acta 496 301–313.
Mulligan, C.N., Yong, R.N., and Gibbs, B.F. (2001) Remediation technologies for metal-contaminated soils and groundwater: an evaluation. Engineering Geology, 60, 193–207.
Probstein, R.F. and Hicks, R.E. (1993) Removal of contaminants from soils by electric fields. Science, 260, 498–503.
Reddy, K.R. and Chinthamreddy, S. (1999) Electrokinetic remediation of heavy metal-contaminated soils under reducing environments. Waste Management, 19 269–282.
Terzaghi, K. and Peck, R.B. (1967) Soil Mechanics in Engineering Practice, 2nd edition. John Wiley, New York
Van Cauwenberghe, L. (1997) Electrokinetics: Technology overview report: Groundwater Remediation. Technologies Analysis Centre, Pittsburgh, PA, USA.
Virkutyte, J., Sillanpaa, M. and Latostenmaa, P. (2001) Electrokinetic soil remediation – a critical overview. Science of the Total Environment, 289, 97–121.

Keywords

Electrokinetic generation of reactive iron-rich barriers in wet sediments: implications for contaminated land management

  • D. W. S. Faulkner (a1), L. Hopkinson (a1) and A. B. Cundy (a2)

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed