Simulation and experimental study of the effect of porous media grain size on solute displacement under same hydraulic conditions

Ghaedi, Saeed; Afrasiab, Payman; Delbari, Masoumeh; Bagheri, Hossain

doi:10.22077/jaaq.2025.9512.1114

Document Type : Original Article

Authors

¹ PhD Candidate, Water Engineering Department, University of Zabol, Zabol, Iran.

² Associate Professor, Water Engineering Department, University of Zabol, Zabol, Iran.

³ PhD Graduate, Water Engineering Department, Bu-Ali Sina University, Hamedan, Iran.

10.22077/jaaq.2025.9512.1114

Abstract

Despite differences in the physical characteristics of porous media, flow intensity and average velocity can be identical at various points within aquifers. Under such conditions, solute transport is influenced by pore-scale factors such as grain size and pore water velocity. Therefore, in order to better understand adsorption/desorption coefficients and solute transport processes, simulation is essential.

This study was conducted to investigate the effect of porous media grain size on solute transport under uniform hydraulic conditions using laboratory experiments and both equilibrium and nonequilibrium numerical simulation models. The laboratory columns were made of PVC, with a length of 25 cm and an internal diameter of 8 cm, and the porous media consisted of natural sand and gravel particles. Potassium nitrate was used as the tracer and injected into the soil columns in a pulse-input manner.

According to experimental results, the peak concentration (C/C₀) in fine, medium, and coarse-grained media was 0.50, 0.27, and 0.30, respectively, and their distribution coefficients (K_D) were 23.2, 1.8, and 2.1 L/kg, respectively. These results indicate greater dilution of solutes in coarse-grained media and increased retention in fine-grained media.

Simulation results showed that nonequilibrium dual-site (RMSE = 0.01) and single-site models (RMSE = 0.01–0.03) provided better accuracy compared to the equilibrium model (RMSE = 0.01–0.09), suggesting the presence of time-dependent kinetic processes in solute transport. Therefore, incorporating both kinetic and equilibrium-based models is recommended for simulating solute transport in porous media.

Keywords

Main Subjects

ًQanat and aquifer

References

Bagheri, H., Abyaneh, H. Z., Izady, A., & Brusseau, M. L. (2019). Modeling the transport of nitrate and natural multi-sized colloids in natural soil and soil amended with vermicompost. Geoderma, 354, 113889. https://doi.org/10.1016/j.geoderma.2019.113889

Bagheri, H., Zare Abianeh, H., Izadi, A., and Bagheri, H. (2024). Simulation of the effect of vermicompost on the transport of reactive sodium in saturated and near-saturated soil. Iranian Water Research Journal, 17(4). https://doi.org/10.22034/iwrj.2023.14379.2524. (In Persian)

Batany, S., Peyneau, P. E., Lassabatère, L., Béchet, B., Faure, P., & Dangla, P. (2019). Interplay between molecular diffusion and advection during solute transport in macroporous media. Vadose Zone Journal, 18(1), 1-15. https://doi.org/10.2136/vzj2018.07.0140

Bear, J. (2013). Dynamics of fluids in porous media. Courier Corporation.

Bear, J., & Braester, C. (1972). On the flow of two immiscible fluids in fractured porous media. In Developments in soil science (Vol. 2, pp. 177-202). Elsevier.

Bear, J., & Cheng, A. H. D. (2010). Modeling groundwater flow and contaminant transport (Vol. 23, p. 834). Dordrecht: Springer. https://doi.org/10.1007/978-1-4020-6682-5

Finkel, M., Grathwohl, P., & Cirpka, O. A. (2016). A travel time‐based approach to model kinetic sorption in highly heterogeneous porous media via reactive hydrofacies. Water Resources Research, 52(12), 9390-9411. https://doi.org/10.1002/2016WR019147

Florido, A., Valderrama, C., Arévalo, J. A., Casas, I., Martínez, M., & Miralles, N. (2010). Application of the site's non-equilibrium sorption model for the removal of Cu (II) onto grape stalk wastes in a fixed-bed column. Chemical Engineering Journal, 156(2), 298-304. https://doi.org/10.1016/j.cej.2009.10.020

Freeze, R. A., & Cherry, J. A. (1979). Groundwater prentice. Englewood Cliffs, Englewood Cliffs.

Jellali, S., Diamantopoulos, E., Kallali, H., Bennaceur, S., Anane, M., & Jedidi, N. (2010). Dynamic sorption of ammonium by sandy soil in fixed bed columns: Evaluation of equilibrium and non-equilibrium transport processes. Journal of Environmental Management, 91(4), 897-905. https://doi.org/10.1016/j.jenvman.2009.11.006

Kulasiri, D., & Verwoerd, W. (2002). Modeling Solute Transport in Porous Media. In North-Holland series in applied mathematics and mechanics (Vol. 44, pp. 1-25). North-Holland. https://doi.org/10.1016/S0167-5931(02)80002-X

Ladu, J. L. C., & Zhang, D. R. (2011). Modeling atrazine transport in soil columns with HYDRUS-1D. Water Science and Engineering, 4(3), 258-269. https://doi.org/10.3882/j.issn.1674-2370.2011.03.003

Lee, S., Kim, D. J., & Choi, J. W. (2012). Comparison of first-order sorption kinetics using the concept of the two-site sorption model. Environmental Engineering Science, 29(11), 1002-1007. https://doi.org/10.1089/ees.2011.0301

Li, Q., LI, F., ZHANG, Q., QIAO, Y., Du, K., Zhu, N.,... & HE, X. (2021). Water and salt transport simulation in the wheat growing area of the North China Plain based on the HYDRUS model. Chinese Journal of Eco-Agriculture, 29(6), 1085-1094. https://doi.org/10.13930/j.cnki.cjea.200828

Murphy, N. P., Furman, A., Moshe, S. B., & Dahlke, H. E. (2024). Comparison of reactive transport and non-equilibrium modeling approaches for the estimation of nitrate leaching under large water application events. Journal of Hydrology, 628,30583. https://doi.org/10.1016/j.jhydrol.2023.130583

Rezaei, E., Zeinalzadeh, K., & Ghanbarian, B. (2021). Effects of particle shape and size distribution on hydraulic properties of grain packs: An experimental study. arXiv preprint arXiv:2111.01288. https://doi.org/10.48550/arXiv.2111.01288

Shekhar, S., Mailapalli, D. R., & Raghuwanshi, N. S. (2024). Simulation and optimization of ponding water and nutrient management in rice irrigated with alternate wetting and drying practice under a humid subtropical region in India. Paddy and Water Environment, 22(1), 189-207. https://doi.org/10.1007/s10333-023-00961-7

Simunek, J., & van Genuchten, M. T. (2008). Modeling nonequilibrium flow and transport processes using HYDRUS. Vadose zone journal, 7(2), 782-797. https://doi.org/10.2136/vzj2007.0074

Simunek, J., Brunetti, G., Jacques, D., van Genuchten, M. T., & Šejna, M. (2024). Developments and applications of the HYDRUS computer software packages since 2016. Vadose Zone Journal, 23(4), e20310. https://doi.org/10.1002/vzj2.20310

Simunek, J., Van Genuchten, M. T., & Sejna, M. (2005). The HYDRUS-1D software package for simulating the one-dimensional movement of water, heat, and multiple solutes in variably-saturated media. University of California-Riverside Research Reports, 3, 1-240.

Simunek, J., Van Genuchten, M. T., & Šejna, M. (2016). Recent developments and applications of the HYDRUS computer software packages. Vadose Zone Journal, 15(7), vzj2016-04. https://doi.org/10.2136/vzj2016.04.0033

Syafiuddin, A., Boopathy, R., & Hadibarata, T. (2020). Challenges and solutions for sustainable groundwater usage: Pollution control and integrated management. Current Pollution Reports, 6, 310-327. https://doi.org/10.1007/s40726-020-00167-z

Urdiales, C., Urdiales-Flores, D., Tapia, Y., Cáceres-Jensen, L., Šimůnek, J., & Antilén, M. (2025). Transport mechanisms of the anthropogenic contaminant sulfamethoxazole in volcanic ash soils at equilibrium pH evaluated using the HYDRUS-1D model. Journal of Hazardous Materials, 487, 137077. https://doi.org/10.1016/j.jhazmat.2024.137077

Wang, S., Huang, L., Zhang, Y., Li, L., & Lu, X. (2021). A mini-review on the modeling of volatile organic compound adsorption in activated carbons: Equilibrium, dynamics, and heat effects. Chinese Journal of Chemical Engineering, 31, 153-163. https://doi.org/10.1016/j.cjche.2020.11.018

Yu, H., Li, C., Yan, J., Ma, Y., Zhou, X., Yu, W.,... & Dong, P. (2023). A review on adsorption characteristics and influencing mechanism of heavy metals in farmland soil. RSC advances, 13(6), 3505-3519. https://doi.org/10.1039/D2RA07095

Journal of Aquifer and Qanat

Simulation and experimental study of the effect of porous media grain size on solute displacement under same hydraulic conditions

References

References

Volume 6, Issue 1 - Serial Number 10
October 2025
Pages 41-50

Simulation and experimental study of the effect of porous media grain size on solute displacement under same hydraulic conditions

References

References

Volume 6, Issue 1 - Serial Number 10October 2025Pages 41-50

Volume 6, Issue 1 - Serial Number 10
October 2025
Pages 41-50