Electro-osmotic permeability model based on ions migration

Electro-osmotic permeability is a very important parameter in soil drainage and electrochemical remediation. The present widely used equation for calculating the electro-osmotic permeability is based on the Helmholtz-Smoluchowski model derivation, which not only leads to large calculation errors, but also cannot explain why there is an optimum salinity value for the electro-osmotic permeability. In this paper, based on the Nernst-Planck equation and the capillary theory of the Helmholtz-Smoluchowski model, a new theoretical equation for calculating the electro-osmotic permeability is derived considering the ions migration in the soil during electro-osmotic drainage. The obtained model focuses on the essential characteristics of electro-osmotic processes and can better explain the electro-osmotic phenomenon from an electrochemical perspective compared to the Helmholtz-Smoluchowski model and other modified models. The parameters of the proposed model include the properties of soil particles, pore solution, and soil conductivity; most can be determined theoretically, except for the soil conductivity which is lack of research during electro-osmosis. Compared with the measured values, the proposed model has smaller calculation error and wider application compared to other existing models.

Automated summary

A new theoretical equation for calculating electro-osmotic permeability is proposed in this study, considering ions migration in the soil during electro-osmotic drainage. The model focuses on essential characteristics of electro-osmotic processes and provides better explanation of electro-osmotic phenomenon compared to existing models. The proposed model has smaller calculation error and wider application range, making it a more accurate option for estimating electro-osmotic permeability.