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TDR detection of nonaqueous phase liquids in sandy soils using the eigendecomposition method

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Environmental Geology

Abstract

In this study, the presence of nonaqueous phase liquids (NAPL) in sandy soils are detected using a TDR probe system and the eigendecomposition method of analysis. As a demonstration, five NAPLs with different physicochemical properties (acetone, benzene, heptane, trichloroethylene, and xylene; Table 1) were used. Samples were prepared in such a way that the soil pore fluid has different contents of deionized water and NAPLs. For each experiment, a pulse signal with known characteristics was used and reflected signals were captured by an oscilloscope and analyzed using the eigendecomposition method. Autoregressive modeling and singular value decomposition were used to calculate the eigenvalues. The most significant eigenvalues were identified based on their power spectrum. The relative eigenvalue of the first mode (Eow), which is a measure of the power carried by the signal, was calculated and correlated to NAPL type and content, and octanol water partition coefficient (log Kow). The results indicated that for the same NAPL content, as log Kow increases, Eow decreases due to increase of hydrophobicity. For the same log Kow, as the organic content in soil pore fluid increases, Eow increases due to decrease of dielectric properties of the pore fluids.

Table 1 Physicochemical properties of organic fluids used

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References

  • Elrick EE, Kachanoski RG, Pringle EA, Ward A (1992) Parameter estimation of field scale transport models based on time domain reflectometry measurements. Soil Sci. Soc. Am. J., 56:1663-1666

    Google Scholar 

  • Elsner JB, Tsonis AA (1996) Singular spectrum analysis. Plenum Press, London

  • Gould P (1967) The geographical interpretation of eigenvalues. Institute of British Geographers Transactions, 42:53–85

  • Heimovaara TJ, Bouten W (1990) A computer-controlled 36- channel time domain reflectometry system for monitoring soil water contents. Water Resources Research, 26:2311-2316

  • Kachanoski RG, Pringle E, Ward A (1992) Field measurement of solute travel times using time domain reflectometry. Soil Sci. Soc. Am. J., 56:47-52

    Google Scholar 

  • Kay SM (1988) Modern spectral estimation. Prentice-Hall, New York, pp 153–270

  • Mallants D, Vanclooster M, Meddahi M, Feyen J (1994a) Estimating solute transport parameters on undisturbed soil columns using time domain reflectometry. J. Contaminant Hydrology, 17:91–109

    Google Scholar 

  • Mallants D, Toride N, Vanclooster M, van Genuchten M Th, Feyen J (1994b) Using TDR to monitor solute transport in long undisturbed soil columns during steady saturated flow. In: Proceedings of the 15th International Congress of Soil Science, Acapulco, Mexico, July 10–16, 147–148

  • Marple SL Jr (1987) Digital spectral analysis with applications. Prentice-Hall, New York, pp 172–284

  • Mohamed AMO (2002) Keynote paper: Time domain reflectometry: operation principles and its potential application for determination of subsurface concentrations of pollutants. In: H Alawaji (ed.), Geotechnical and Geoenvironmental Engineering in Arid Lands, A.A. Balkema, Rotterdam, pp 315–326.

  • Mohamed AMO, Antia HE (1998) Geoenvironmental engineering. Elsevier, Amsterdam, 707 p

  • Mohamed AMO, Hawas Y (2004) Neuro-fuzzy logic model for evaluating water content of sandy soils. Computer Aided Civil and Infrastructure Engineering, 19:343–356

    Google Scholar 

  • Mohamed AMO, Said RA, Al-Shawawreh NK (2000) Development of an electrical polarization technique for subsurface pollutants detection. In: Mohamed AMO, Hosani KI Al (eds.), Geoengineering in Arid Lands, A.A. Balkema, Rotterdam, pp 633–639

  • Mohamed AMO, Said RA, Al-Shawawreh NK (2001) A TDR system for subsurface pollutants detection (II): application and analysis. In: Dowding CH (ed), Second Int. Symp. and Workshop on Time Domain Reflectometry for Innovative Geotechnical Applications, Infrastructure Technology Institute, Evanston, IL, pp 371–380

  • Mohamed AMO, Said RA, Al-Shawawreh NK (2002) Development of a methodology for evaluating subsurface concentrations of pollutants using electrical polarization technique. Geotechnical Testing Journal, GTJODJ, 25(2):157–167

    Google Scholar 

  • Mohamed AMO, Said RA, Al-Shawawreh NK, El-Bassiouni MY (2003a) Evaluation of water content and ionic concentrations of soils via frequency domain analysis of TDR waveforms. International Journal of Subsurface Sensing Technologies and Applications, 4(2):159–186

    Google Scholar 

  • Mohamed AMO, Said RA, El-Bassiouni MY (2003b) Eigendecomposition of TDR waveforms: A novel method to determine water content and pore fluid concentration of sandy soils. Environmental Geology, 45:132–143

    Google Scholar 

  • Press WH, Teukolsky SA, Vetterling WT, Flannery BP (1992) Numerical recipes in C: The art of scientific computing, 2nd Edition. Cambridge University Press, Cambridge, 994 p

    Google Scholar 

  • Richards WD, Seary AJ (1997) Convergence analysis of communication networks. In: Barnett GA (ed) Advances in Communication Sciences, Vol. 15, Ablex, Norwood, NJ, pp 141-189

  • Said RA, Al-Shawawreh NK, Mohamed AMO (2001) A TDR system for subsurface pollutants detection (I): design and modelling. In: CH Dowding (ed), Second Int. Symp. and Workshop on Time Domain Reflectometry for Innovative Geotechnical Applications, Infrastructure Technology Institute, Evanston, IL, pp 361–370

  • Sun ZJ, Young GD, McFariane RA, Chambers BM (2000) The effect of soil electrical conductivity on moisture determination using time-domain reflectometry in sandy soil. Can. J. Soil. Sci., 80:13–22

    Google Scholar 

  • Vanclooster M, Mallants D, Diels J, Feyen J (1993) Determining local-scale solute transport parameters using time domain reflectometry. J. Hydrol., 148:93–107

    Google Scholar 

  • Wraith JM, Comfort SD, Woodbury BL, Inskeep WP (1993) A simplified waveform analysis approach for monitoring solute transport using time-domain reflectometry. Soil. Sci. Soc. Am. J., 57:637-642

    Google Scholar 

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Acknowledgments

This study was supported by a research grant from Research Affairs, UAE University.

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Correspondence to A. M. O. Mohamed.

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Mohamed, A.M.O., Said, R.A. TDR detection of nonaqueous phase liquids in sandy soils using the eigendecomposition method. Env Geol 47, 30–37 (2004). https://doi.org/10.1007/s00254-004-1123-z

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