上海交通大学学报

上海交通大学学报

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基于线性扫描伏安法的电渗土体-电极界面电势降试验分析

  

  1. 1.浙江大学 滨海和城市岩土工程研究中心，杭州 310058; 

    2.浙江科技大学 土木工程与建筑学院，杭州 310023; 

    3. 余杭区林业水利局, 杭州 311100

  • 作者简介:徐朝阳（2000—），博士生，从事软基处理研究
  • 基金资助:
    国家自然科学基金（52478366, 52078455, 51708507）资助项目

Experimental Analysis of Potential Drop at Soil Electrode Interface of Electroosmosis Based on Linear Sweep Voltammetry

  1. 1. Coastal and urban Geotechnical Engineering Research Center, Zhejiang University, Hangzhou 310058, China; 

    2. School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023, China;

    3. Yuhang Forestry and Water Conservancy Bureau, Hangzhou 311100, China

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摘要： 传统的电渗界面理论认为土体-电极处的界面电势降全部由欧姆电阻产生，然而目前诸多研究指出界面电势降应当由多种成分组成。电解相关的 研究表明电解液-电极界面电势降是由平衡电位和多种过电位（欧姆过电位、浓度过电位、活化过电位）组成。电渗中的土体-电极界面类似于电解界面也会发生电化学反应，故而电渗界面电势降可能与电解界面相同，存在多种特殊电位。基于此，本文引入了扫描线性伏安（LSV）法对电渗界面电势降的组成进行了试验探究。实测结果表明电渗系统中板式电动土工合成（EKG）电极界面处存在平衡电位这一成分，占比约为18%。过电位相关的极化曲线呈显著的线性。经分析，电渗界面的过电位显著大于电解对照组的。说明电渗界面存在除欧姆过电位以外其他的过电位类型，包括浓度过电位和活化过电位。结合理论和相关的试验研究，显著的浓度过电位是电渗系统过电位偏大的主要原因。基于极化曲线，深入分析了极化电阻的变化规律。其结果进一步证明了电渗中浓度过电位的重要影响。这些发现充分证实了电化学因素是土体-电极界面电势降的关键影响因素，突破了传统欧姆效应的认知局限。这为将电化学因素考虑进电渗系统奠定了理论和试验基础，提供了通过优化界面电化学性能来改善电渗效率的新视角。

关键词: 电渗, 界面电势降, 电化学, 平衡电位, 过电位

Abstract: The traditional theory of electroosmosis interfaces holds that the potential drop at the soil–electrode interface is entirely due to ohmic resistance. However, numerous studies have suggested that this potential drop comprises multiple components. Research on electrolysis has shown that the potential drop at the electrolyte-electrode interface consists of the equilibrium potential and various overpotentials, including ohmic, concentration, and activation overpotentials. Given the electrochemical similarities between electroosmosis and electrolysis interfaces, the potential drop at the electroosmosis interface is likely to involve similar components. To investigate this, the present study introduced linear sweep voltammetry (LSV) to analyze the composition of the potential drop at the electroosmosis interface. Experimental results revealed the presence of an equilibrium potential at the interface of plate-type electrokinetic geosynthetic (EKG) electrodes, accounting for approximately 18% of the total potential drop. The polarization curve associated with the overpotential displayed a distinct linearity, showing that the overpotential at the electroosmosis interface was significantly greater than that observed in the electrolysis control group. This suggests the presence of additional types of overpotentials beyond the ohmic component, particularly concentration and activation overpotentials. Theoretical and experimental analyses confirmed that the prominent concentration overpotential is the primary contributor to the elevated overpotential in electroosmosis systems. Further analysis of the polarization resistance, derived from the polarization curve, reinforced the critical role of concentration overpotential. These findings provide a deeper understanding of the potential drop composition at the soil-electrode interface and offer both theoretical and experimental foundations for incorporating electrochemical considerations into electroosmosis system design. This research presents a new perspective for optimizing interfacial electrochemical performance to enhance electroosmotic efficiency.

Key words: electroosmosis, interface potential drop, electrochemistry, equilibrium potential, overpotential 

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