Department of Civil and Environmental Engineering Faculty at the University of Delaware

Paul Imhoff

344A DuPont Hall
Newark, Delaware 19716
Phone: 302-831-0541
Research Website


1992 | Ph.D | Princeton University
1988 | M.A | Princeton University
1986 | M.S | University of Wisconsin at Madison
1983 | B.S. | University of Cincinnati


Transport of fluids and contaminants in multiphase systems; mass transfer processes in soil and groundwater; sustainable landfilling; green stormwater treatment; mathematical modeling


  • Environmental and Water Resources
  • Sustainability
  • Water


* Indicates author was an undergraduate or graduate student advised by Dr. Imhoff.

  1. Yan, Y., Nakhli, S.A.A., Jin, J., Mills, G., Wilson, C.S., Legates, D.R., Manahiloh, K.N., and P.T. Imhoff (2021) Predicting the impact of biochar on the saturated hydraulic conductivity of natural and engineered media, Geoderma, in review.
  2. Saxena, S., Srivastave, P.K., Dentel, S.K.,Imhoff, P.T., and D. K. Cha (2021) Field demonstration of breathable laminate-lined container-based toilets in Kanpur, India, Journal of Water, Sanitation and Hygiene for Development, in press.
  3. Nakhli*, S.A.A., Tian, J., Jin*, and P.T. Imhoff (2021) Preparing and characterizing repacked columns for experiments in biochar-amended soils, MethodsX, DOI:
  4. Nakhli*, S.A.A., Goy*, S., Manahiloh, K.N., and P.T. Imhoff (2021) Spatial heterogeneity of biochar (segregation) in biochar-amended media: an overlooked phenomenon, and its impact on saturated hydraulic conductivity, Journal of Environmen- tal Management, DOI: 10.1016/j.jenvman.2020.111588.
  5. Nakhli*, S.A.A., and P.T. Imhoff (2020) Models for predicting water retention in pyrogenic carbon (biochar) and biochar-amended soil at low water contents, Water Resources Research, DOI: 10.1029/2020WR027726.
  6. Yi*, S., Chang*, N. Y., and P.T. Imhoff (2020) Predicting water retention of biocharamended soil from independent measurements of biochar and soil properties, Advances in Water Resources, DOI: 10.1016/j.advwatres.2020.103638.
  7. Tian, J., Jin, J., Chiu, P.C., Cha, D.K., Guo, M., and P.T. Imhoff (2019) A pilot-scale, bi-layer bioretention system with biochar and zero-valent iron for enhanced nitrate removal from stormwater, Water Research, DOI: 10.1016/j.watres.2018.10.030.
  8. Bakhshayesh, B.E., Imhoff, P. T., and S.K. Dentel (2018) Assessing clogging of laminated hydrophobic membrane during fecal sludge drying, Science of the Total Environment, DOI: 10.1016/j.scitotenv.2018.01.209.
  9. Taylor, D.M., Chow, F.K., Delkash, M., and P.T. Imhoff (2018) Atmospheric modeling to assess wind dependence in tracer dilution method measurements of landfill methane emissions, Waste Management, DOI: 10.1016/j.wasman.2017.10.036.
  10. Marzooghi, S., Shi, C., Dentel, S.K., and P.T. Imhoff (2017) Modeling Biosolids Drying Through a Laminated Hydrophobic Membrane, Water Research, DOI: 10.1016/j.watres.2016.12.049
  11. Taylor, D.M., Chow, F.K., Delkash, M., and P.T. Imhoff (2016) Numerical Simulations to Assess the Tracer Dilution Method for Measurement of Landll Methane Emissions, Waste Management, DOI: 10.1016/j.wasman.2016.06.040
  12. Tian, J., Miller, V., Chiu, P.C., Maresca, J.A., Guo, M., and P.T. Imhoff (2016) Nutrient Release and Ammonium Sorption of Poultry Litter and Wood Biochars in Stormwater Treatment, Science of the Total Environment, DOI: 10.1016/j.scitotenv.2016.02.129.
  13. Delkash, M., Zhou, B., Han, B., Chow, F.K., Rella, C.W., and Imhoff, P.T. (2016) Short-Term Landll Methane Emissions Dependency on Wind, Waste Management, DOI:10.1016/j.wasman.2016.02.009.
  14. Yazdani, R., Imhoff, P., Han, B., Mei, C., and D. Augenstein (2015) Quantifying Capture Efficiency of Gas Collection Wells with Gas Tracers, Waste Management, vol. 43, pp. 319-327, doi:10.1016/j.wasman.2015.06.032.
  15. Mei, C., Yazdani, R., Han, B., Mostafid, M.E., Chanton, J., VanderGheynst, J., and P.T. Imhoff (2015) Performance of Green Waste Biocovers for Enhancing Methane Oxidation, Waste Management, vol. 39, pp. 205-215, DOI:10.1016/j.wasman.2015.01.042.
  16. Yi, S., Witt, B., Chiu, P.C., Guo, M. and P.T. Imhoff, (2015)  The Origin and Reversible Nature of Poultry Litter Biochar Hydrophobicity, Journal of Environmental Quality, vol. 512-513, pp. 454-463, DOI:10.1016/j.scitotenv.2015.01.093.
  17. Wang, Y., Lin, Y., Chiu, P.C., Imhoff, P.T., and M. Guo, (2015) Phosphorus Release Behaviors of Poultry Litter Biochar as a Soil Amendment, Science of the Total Environment, vol. 512-513, 454-463, DOI:10.1016/j.scitotenv.2015.01.093.
  18. Saquing, J.M., Chanton, J.P., Yazdani, R., Barlaz, M.A., Scheutz, C., Blake, D.R., and P.T. Imhoff, (2014)  Assessing Methods to Estimate Emissions of Non-methane Organic Compounds From Landfills, Waste Management, vol. 34, no. 11, pp. 2260-2270, DOI:10.1016/j.wasman.2014.07.007.
  19. Akhavan, M, Imhoff, P.T., Andres, A.S., and S. Finsterle, (2013)  Model Evaluation of Denitrification Under Rapid Infiltration Basin Systems, Journal of Contaminant Hydrology, vol. 152, p. 18-34, DOI: 10.1016/j.jconhyd.2013.05.007.
  20. Farthing, M.W., Seyedabbasi, M.A., Imhoff, P.T., and C.T. Miller, (2012) Influence of Porous Media Heterogeneity on NAPL Dissolution Fingering and Upscaled Mass Transfer, Water Resources Research, W08507, DOI:10.1029/2011WR011389.
  21. Mostafid, M.E., Shank, C., Imhoff, P.T., and R. Yazdani, (2012) Gas Transport Properties of Compost Woodchip and Green Waste for Landfill Biocovers and Biofilters, Chemical Engineering Journal, vol. 191, pp. 314-325.
  22. Akhavan, M., P.T. Imhoff, S. Finsterle, and A.S. Andres, (2012) Application of a Coupled Overland Flow Vadose Zone Model to Rapid Infiltration Basin Systems, Vadose Zone Journal, vol. 11, p. vzj2011.0140.
  23. Jung, Y. Han, B., Mostafid, M.E., Yazdani, R., and  P.T. Imhoff, (2012) Photoacoustic Infrared Spectroscopy for Conducting Gas Tracer Tests and Measuring Water Saturations in Landfills, Waste Management, vol. 32, no. 2, pp. 297-304.
  24. Jung, Y. Imhoff, P.T., and S. Finsterle, (2011) Estimation of Landfill Gas Generation Rate and Gas Permeability Field of Refuse Using Inverse Modeling, Transport in Porous Media, vol. 90, pp. 41-58.
  25. Han, B., Scicchitano, V., and P.T. Imhoff, (2011), Measuring Fluid Flow Properties of Waste and Assessing Alternative Conceptual Models of Pore Structure, Waste Management, vol. 31, no. 3, pp. 445-456.
  26. Yazdani, R., Mostafid, M.E., Han, B.,  Imhoff, P.T., Chiu, P., Augenstein, D., Kayhanian, M., and G. Tchobanoglous, (2010), Quantifying Factors Limiting Aerobic Degradation During Bioreactor Landfilling, Environmental Science&Technology, vol. 44, no. 16, pp. 6215-6220.
  27. Sondhi, A., Imhoff, P.T., Dentel, S.K., and H.E. Allen (2010) , Assessment of Methods for Collecting Fallout Brake Pad Wear Debris for Environmental Analysis, Journal of Environmental Science and Health, Part A, vol. 45, No. 2, pp. 239-249.
  28. Jung, Y., Imhoff, P.T., Augenstein, D.C., and R. Yazdani (2009), Influence of High-Permeability Layers for Enhancing Landfill Gas Capture and Reducing Fugitive Methane Emissions from Landfills, Journal of Environmental Engineering, vol. 135, No. 3.
  29.  Seyedabbasi, M.A., Farthing, M.W., Imhoff, P.T., and C.T. Miller (2008), The Infuence of Wettability on NAPL Dissolution Fingering, Advances in Water Resources, vol.31, pp. 1687-1696.
  30. Imhoff, P.T., Reinhart, D.R., Englund, M., Gurin, R., Gawande, N., Han, B., Jonnalagadda, S., Townsend, T., and R. Yazdani (2007), Methods for Measuring Liquid in Bioreactor Landfills- A Critical Review, Waste Management, vol. 27, pp. 729-745.
  31. Han, B., Imhoff, P.T., and R. Yazdani (2007), Field Application of Partitioning Gas Tracer Test for Measuring Water in a Bioreactor Landfill, Environmental Science&Technology, vol. 41, no. 1, pp. 277-283.
  32.  Han, B., Jafarpour, B., Gallagher, V.N., Imhoff, P.T., Chiu, P.C., and D. Fluman (2006), Measuring Seasonal Variations of Moisture in a Landfill with the Partitioning Gas Tracer Tests, Waste Management, vol. 26, pp. 344-355
  33. Li, L., and P.T. Imhoff (2005), Water Saturation Measurement by Gas Tracers in Unsaturated Porous Media – Effect of Mass Transfer Limitations, Vadose Zone Journal, vol. 4, pp. 1107-1118.
  34. Jafarpour, B., P.T. Imhoff and P.C. Chiu (2005), Mathematical Modeling of 2,4-Dinitrotolune Reduction with High-Purity and Cast Iron, Journal of Contaminant Hydrology, vol. 76, pp. 87-107.
  35. Imhoff, P.T., and K. Pirestani, (2004) Influence of Mass Transfer Resistance on Detection of Nonaqueous Phase Liquids with Partitioning Tracer Tests, Advances in Water Resources, vol. 27, no. 4, pp. 429-444.
  36. Imhoff, P.T., A. Jakubowitch, M.L. Briening, and P. Chiu (2003), Partitioning Gas Tracer Tests for Measuring Water in Municipal Solid Waste, Journal of the Air&Waste Management Association, vol. 53, pp. 1391-1400.
  37. Imhoff, P.T., M.W. Farthing, and C.T. Miller (2003), Modeling NAPL Disssolution Fingering with Upscaled Mass Transfer Rate Coeffcients, Advances in Water Resources, vol. 26, no. 10, pp. 1097-1111.
  38. Imhoff, P.T., K. Pirestani, Y. Jafarpour, and K.M. Spivey (2003), Tracer Interaction Effects During Paritioning Tracer Tests for NAPL Detection, Environmental Science&Technology, vol. 37, no. 7, pp. 1441-1447.
  39. Imhoff, P.T., K. Pirestani, Y. Jafarpour, and K.M. Spivey (2003), Tracer Interaction Effects During Paritioning Tracer Tests for NAPL Detection, Environmental Science & Technology, vol. 37, no. 7, pp. 1441-1447.
  40. Imhoff, P.T., A.L. Sawicki, M. Mercer, and M. Fitzpatrick (2003), Scaling DNAPL Migration from the Laboratory to the Field, Journal of Contaminant Hydrology, vol. 64, p. 73-92.

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