氯盐-硫酸盐共存环境中脱盐引起的结合氯离子失稳规律及高效脱盐方法研究

In the process of electrochemical chlorides removal, it has great significance to study the stability of binding chlorides for increasing the chlorides removal efficiency and improving the safety and service life of the reinforced concrete structures. In this project, the destabilization law of binding chlorides caused by the electrochemical chlorides removal in the environment of coexistence of chlorides and sulfates and the high efficient methods of chlorides removal would be systematically studied. On the basis of the study of binding chlorides concentration profile and its time-dependent variation law, this project is aimed to study the destabilization law of binding chlorides caused by the electrochemical chlorides removal, to create the model of the relationship between the binding chlorides and the free ones, to study the binding chlorides destabilization thermodynamics and kinetics based on the test results and relative theory study, to reveal the destabilization law of binding chlorides caused by the electrochemical chlorides removal in the environment of coexistence of chlorides and sulfates, to study the destabilization mechanisms by comparing the composition and micro-structure of binding chloride before and after test, to enhance the efficiency of chlorides removal by several methods and to find the high efficient chlorides removal methods by using the finite element method with considering the releasement of binding chlorides to simulate the process of electrochemical chlorides removal. The research achievement will provide the theoretical foundation and technical support to the improvement of electrochemical chlorides removal.

电化学脱盐过程中结合氯离子稳定性的研究对脱盐效率的改善、结构物安全性和使用寿命的提高等具有重要意义。本项目针对氯盐-硫酸盐共存环境，系统研究硫酸盐存在情况下电化学脱盐引起的结合氯离子失稳规律及高效脱盐方法。在掌握混凝土内部结合氯离子的分布特征及依时变化规律的基础上，开展电化学脱盐引起的结合氯离子失稳规律研究，建立结合氯离子与自由氯离子之间的关系模型，依据试验结果及相关理论研究结合氯离子的失稳热力学和动力学，揭示脱盐引起的结合氯离子失稳规律，通过比较结合氯离子通电前后的组成、结构等，探明结合氯离子的失稳机理，探索采用多种方式提高脱盐效率，并运用有限元方法对脱盐过程进行模拟，同时考虑结合氯离子失稳释放的影响，综合比较提出高效的电化学脱盐方法。研究成果可为提高电化学脱盐效率提供理论依据和技术支持。

研究氯盐-硫酸盐共存环境中电化学脱盐对结合氯离子稳定性的影响及高效脱盐方法，对确保电化学脱盐技术在复杂环境下的有效运行和准确预测、提高电化学修复效果以及提升结构使用寿命等具有十分重要的意义。本项目基于氯盐-硫酸盐共存环境，研究了合理的氯离子含量的测定方法，采用外渗法研究了硫酸盐浓度、浸泡方式、水灰比和初始氯离子浓度等对结合氯离子分布的影响规律，分析了侵蚀不同时间后砂浆中结合氯离子的空间分布特征；采用内掺法研究了电化学脱盐过程中水灰比、硫酸根离子浓度、矿物掺合料、初始氯离子浓度、电流密度和通电时间等因素对结合氯离子稳定性的影响规律和结合氯离子的失稳机理。探讨了采用脉冲通电、间断通电及优化控制温度等方式提高电化学脱盐效率的思路和方法。建立了电化学脱盐过程模型，分析了脱盐前后体系中氯离子的空间分布。项目在氯盐-硫酸盐共存环境中氯离子含量的测定方法、氯盐-硫酸盐共存环境中电流作用对结合氯离子稳定性的影响规律和失稳机理、脉冲通电方式提高电化学脱盐效率的方法等方面取得了创新成果。项目揭示了氯盐-硫酸盐共存环境中电化学脱盐对结合氯离子稳定性影响的规律及失稳机理，提出了高效脱盐的新思路和新方法，研究成果能够为电化学脱盐效率的提升提供理论依据和技术支持。项目已经发表论文14篇、录用待发表论文3篇，其中SCI收录论文12篇，申请发明专利3项，已培养硕士2名、正在培养博士研究生1名，硕士研究生4名。