Electrokinetically derived PFAS retention index (SRI) for the soil system at the molecular level
DOI:
https://doi.org/10.3846/da.2026.2480Language:
EnglishAbstract
Retention studies of per- and polyfluoroalkyl substances (PFAS) in heterogeneous soil systems are important for PFAS risk assessment. Investigations should follow a well-defined approach because PFAS behave complexly in soil systems, especially given varying physicochemical properties. Conventional retention studies have primarily focused on describing PFAS retention behaviour based only on coefficient values and absolute concentration. Theoretical approaches and related principles can be properly aligned to provide a well-defined description of PFAS behaviour while identifying comprehensive parameters for molecular-level studies of PFAS in heterogeneous soil media. Therefore, this study primarily focused on introducing a well-defined index value for the behaviour description of PFAS while identifying the zeta potential (ZP) as a predominant parameter for molecular-level studies of PFAS in complex media such as soil. The novel index value, System Retention Index (SRI), for four PFAS have been derived by normalising the calculated ZP of PFAS, considering the calculated ZP values in clay soil at pH 5.0. The System Retention Index (SRI) map was introduced for the spatial prediction of PFAS retention and mobility conditions. SRI value enables comparison of PFAS retention status while providing molecular-level insights, overcoming limitations associated with chain length and retention coefficient values in the conventional approach.
Keywords:
zeta potential (ZP), System Retention Index (SRI), molecular level, per- and polyfluoroalkyl substances (PFAS)Abou-Khalil, C., Kewalramani, J., Zhang, Z., Sarkar, D., Abrams, S., & Boufadel, M. C. (2023). Effect of clay content on the mobilization efficiency of per- and polyfluoroalkyl substances (PFAS) from soils by electrokinetics and hydraulic flushing. Environmental Pollution, 322, Article 121160. https://doi.org/10.1016/J.ENVPOL.2023.121160
Amaechi, P. U., Elenwo, C. E., & Dimkpa, S. O. N. (2024). Langmuir and Freundlich Isotherm models’ description of P. Adsorption capacity of wetland and upland soil in Rivers State. Global Journal of Agricultural Research, 12(3), 14–29. https://doi.org/10.37745/gjar.2013/vol12n31429
Biegel-Engler, A., & Frauenstein, J. (2024). PFAS in soil and groundwater: Comprehensive challenges and progress in regulation and management in Germany. In H. Ginzky, F. De Andrade Corrêa, E. Dooley, I. L. Heuser, P. Kameri-Mbote, R. Kibugi, & O. C. Ruppel (Eds.), International yearbook of soil law and policy 2022 (pp. 285–304). Springer. https://doi.org/10.1007/978-3-031-40609-6_12
Bukackova, M., Rusnok, P., & Marsalek, R. (2018). Mathematical methods in the calculation of the zeta potential of BSA. Journal of Solution Chemistry, 47(12), 1942–1952. https://doi.org/10.1007/s10953-018-0830-0
Darrow, M. M., Guo, R., & Trainor, T. P. (2020). Zeta potential of cation-treated soils and its implication on unfrozen water mobility. Cold Regions Science and Technology, 173, Article 103029. https://doi.org/10.1016/j.coldregions.2020.103029
Fabregat-Palau, J., Ershadi, A., Finkel, M., Rigol, A., Vidal, M., & Grathwohl, P. (2025). Modeling PFAS sorption in soils using machine learning. Environmental Science & Technology, 59(15), 7678–7687. https://doi.org/10.1021/acs.est.4c13284
Feng, G., Zhou, B., Yuan, R., Luo, S., Gai, N., & Chen, H. (2024). Influence of soil composition and environmental factors on the adsorption of per- and polyfluoroalkyl substances: A review. Science of the Total Environment, 925, Article 171785. https://doi.org/10.1016/j.scitotenv.2024.171785
Feria, R., García-Jiménez, M. G., Solana, G., & Oropeza, M. T. (2008). The effect of zeta potential on the electrokinetic process for removal of phenanthrene in soil. ECS Transactions, 15(1), 417–425. https://doi.org/10.1149/1.3046658
Gidudu, B., & Chirwa, E. M. N. (2022). The role of pH, electrodes, surfactants, and electrolytes in electrokinetic remediation of contaminated soil. Molecules, 27(21), Article 7381. https://doi.org/10.3390/molecules27217381
Hazrati, S., Kumpiene, J., Leiviskä, T., & Carabante, I. (2025). Reciprocal influence of per- and polyfluoroalkyl substances (PFAS) and soil organic matter on their fate in soils. Environmental Science and Pollution Research, 32(40), 23265–23277. https://doi.org/10.1007/s11356-025-37024-9
Interstate Technology and Regulatory Council. (2023). Per- and Polyfluoroalkyl Substances (PFAS). https://pfas-1.itrcweb.org/fact sheets/?gad_source=1&gad_ campaignid=15499818841&gclid=Cj0KCQjwucDBBhDxA RIsANqFdr2DqX-MgrtpScZKIlm_dNB0hmOkOKYDERV2tIum-PMCaeYpghysWsYaApwtEALw_wcB#
Kaluarachchi, R. K. D. G., & Baltrėnaitė-Gedienė, E. (2026). Electrokinetic-principle-based prediction of PFAS behavior in soil. International Journal of Environmental Science and Technology, 23(6), Article 436. https://doi.org/10.1007/s13762-026-07225-x
Kamble, S., Agrawal, S., Cherumukkil, S., Sharma, V., Jasra, R. V., & Munshi, P. (2022). Revisiting zeta potential, the key feature of interfacial phenomena, with applications and recent advancements. ChemistrySelect, 7(1), Article e202103084. https://doi.org/10.1002/slct.202103084
Kaya, A., & Yukselen, Y. (2005). Zeta potential of soils with surfactants and its relevance to electrokinetic remediation. Journal of Hazardous Materials, 120(1–3), 119–126. https://doi.org/10.1016/J.JHAZMAT.2004.12.023
Kim, S. O., Kim, J. J., Yun, S. T., & Kim, K. W. (2003). Numerical and experimental studies on cadmium (II) transport in kaolinite clay under electrical fields. Water, Air, and Soil Pollution, 150(1–4), 135–162. https://doi.org/10.1023/A:1026181800685
Liang, D., Li, C., Chen, H., Sørmo, E., Cornelissen, G., Gao, Y., Reguyal, F., Sarmah, A., Ippolito, J., Kammann, C., Li, F., Sailaukhanuly, Y., Cai, H., Hu, Y., Wang, M., Li, X., Cui, X., Robinson, B., Khan, E., … Wang, H. (2024). A critical review of biochar for the remediation of PFAS-contaminated soil and water. Science of the Total Environment, 951, Article 174962. https://doi.org/10.1016/J.SCITOTENV.2024.174962
Lunardi, C. N., Gomes, A. J., Rocha, F. S., De Tommaso, J., & Patience, G. S. (2021). Experimental methods in chemical engineering: Zeta potential. Canadian Journal of Chemical Engineering, 99(3), 627–639. https://doi.org/10.1002/cjce.23914
Malvern Instruments. (2015). Zeta potential: An-introduction-in-30min.
Nascimento, A. C., & Moreira, J. V. (2015). Influence of zeta potential in physical and mechanical properties of recycled paper. International Journal of Innovative Research in Engineering & Management (IJIREM), 2(5), 2350–0557.
Nguyen, T. M. H., Bräunig, J., Thompson, K., Thompson, J., Kabiri, S., Navarro, D. A., Kookana, R. S., Grimison, C., Barnes, C. M., Higgins, C. P., McLaughlin, M. J., & Mueller, J. F. (2020). Influences of chemical properties, soil properties, and solution pH on soil–water partitioning coefficients of per- and polyfluoroalkyl substances (PFASs). Environmental Science & Technology, 54(24), 15883–15892. https://doi.org/10.1021/acs.est.0c05705
Niarchos, G., Sörengård, M., Fagerlund, F., & Ahrens, L. (2022). Electrokinetic remediation for removal of per- and polyfluoroalkyl substances (PFASs) from contaminated soil. Chemosphere, 291(3), Article 133041. https://doi.org/10.1016/j.chemosphere.2021.133041
Pollastri, S., Gualtieri, A. F., Gualtieri, M. L., Hanuskova, M., Cavallo, A., & Gaudino, G. (2014). The zeta potential of mineral fibres. Journal of Hazardous Materials, 276, 469–479. https://doi.org/10.1016/J.JHAZMAT.2014.05.060
Rathnayaka Kaluarachchige, D. G. K., & Baltrėnaitė-Gedienė, E. (2025). Interactive mechanisms between PFAS and soil characteristics: A review. In Sustainable Environment: Proceedings of the 28th Conference for Junior Researchers “Science – Future of Lithuania”. Vilnius Gediminas Technical University. https://doi.org/10.3846/da.2025.031
Schaefer, C., Drennan, D., Nickerson, A., Maizel, A., & Higgins, C. P. (2021). Diffusion of perfluoroalkyl acids through clay-rich soil. Journal of Contaminant Hydrology, 241, Article 103814. https://doi.org/10.1016/j.jconhyd.2021.103814
Sleep, J. A., Miklavcic, S. J., & Juhasz, A. L. (2023). Modelling of PFAS-surface interactions: Effect of surface charge and solution ions. Chemosphere, 319, Article 137910. https://doi.org/10.1016/j.chemosphere.2023.137910
Sörengård, M., Niarchos, G., Jensen, P. E., & Ahrens, L. (2019). Electrodialytic per- and polyfluoroalkyl substances (PFASs) removal mechanism for contaminated soil. Chemosphere, 232, 224–231. https://doi.org/10.1016/j.chemosphere.2019.05.088
Sørmo, E., Silvani, L., Bjerkli, N., Hagemann, N., Zimmerman, A. R., Hale, S. E., Hansen, C. B., Hartnik, T., & Cornelissen, G. (2021). Stabilization of PFAS-contaminated soil with activated biochar. Science of the Total Environment, 763, Article 144034. https://doi.org/10.1016/J.SCITOTENV.2020.144034
Spanos, N., & Koutsoukos, P. G. (1999). Calculation of zeta potential from electrokinetic measurements on titania plugs. Journal of Colloid and Interface Science, 214(1), 85–90. https://doi.org/10.1006/JCIS.1999.6169
Wang, Y., Munir, U., & Huang, Q. (2023). Occurrence of per- and polyfluoroalkyl substances (PFAS) in soil: Sources, fate, and remediation. Soil and Environmental Health, 1(1), Article 100004. https://doi.org/10.1016/j.seh.2023.100004
Zhang, M., & Yazaydin, A. O. (2024). The effect of perfluoroalkyl chain length and the type of acid group on PFAS adsorption from water. Chemical Engineering Journal, 499, Article 155851. https://doi.org/10.1016/J.CEJ.2024.155851
Zhou, D., Brusseau, M. L., Zhang, Y., Li, S., Wei, W., Sun, H., & Zheng, C. (2021). Simulating PFAS adsorption kinetics, adsorption isotherms, and nonideal transport in saturated soil with tempered one-sided stable density (TOSD) based models. Journal of Hazardous Materials, 411, Article 125169. https://doi.org/10.1016/j.jhazmat.2021.125169
Downloads
CrossMark check
Published
Conference Event
Section
Copyright
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
