氟污染土壤的电动力学修复机理及过程调控

Too much fluorine in the soil will produce potential harm to human body and environment and lead to deterioration of soil materials, and people's regional fluorosis is caused by taking in fluorine from environment for a long time. So it is of great practical significance to remediate the contaminated soil and resume soil's original functions. Aiming at fluorine contaminated soil, the research studied the in situ remediation of fluorine contaminated field soil by electrokinetic remediation, explored the remediation mechanisms, the regulating system during the remediation process, the factors affecting the effects of remediation, and made field experiments on the in situ remediation of fluorine contaminated soil and so on. Based on the previous studies, the present research will increase people's understanding about the mechanism of electrokinetic remediation technology, especially the regulating system of the remediation process, therefore spurring the application of electrokinetic technology in the remediation of contaminated soil. This study will provide reliable scientific evidence for seeking the most appropriate technology to remediate contaminated soil and reducing the influence of fluorine on soil and human health.

土壤中含有过量的氟对人体健康和环境会产生潜在的危害，地方性氟中毒就是人体长期从环境中摄入过量氟所致，土壤氟含量过高会导致土壤物化性质的恶化。因此，修复氟污染土壤，恢复土壤的原有功能具有十分重要的现实意义。本项目针对氟污染土壤，研究电动力学技术对氟污染土壤的原位修复，探讨电动力学修复氟污染土壤的机理、修复过程中的调控机制、影响电动力学原位修复效果的因素，以及进行氟污染土壤的原位修复现场实验等。在前期工作基础上通过本项目的研究，将加深人们对氟污染土壤电动力学修复技术机理的了解，特别是在如何调控其修复过程方面有更深的理解，从而促进电动力学技术在污染土壤修复方面的应用。该工作将为我国寻找最佳的氟污染土壤修复技术，降低氟对土壤和人类健康的影响提供可靠的科学依据。

在我国大多数地区，土壤氟是饮用水和食物中氟的主要来源，虽然氟是人体必须的微量元素，但过量氟的摄入对人体健康会产生潜在危害，如地方性氟中毒就是人体长期从环境中摄入过量氟所致，同时过高的氟含量会导致土壤性质的恶化。为了修复氟污染土壤，降低土壤中氟的含量和恢复土壤的正常功能，本项目利用电动力学修复技术对氟污染土壤进行了处理，深入研究了土壤中氟污染物在电解液作用下的吸附—解吸及电动力学修复机理，分析了不同修复电压、不同电解液组成及浓度对电动力学修复效果的影响，同时对电动力学修复过程进行了调控。结果表明：土壤氟的解吸是电动力学修复氟污染土壤的一个关键性限制因子。电场作用下，氟以氟化物、F–、AlF2+等不同形态在电迁移和电渗析的共同作用下分别离开土壤进入电解液，从而使污染土壤得以修复。电迁移是氟污染物从土壤中去除的主要机理。电动力学作用也使土壤营养元素的含量和分布发生了显著变化。研究结果为加深人们对氟污染土壤电动力学修复技术机理的理解、促进电动力学技术在污染土壤修复方面的应用提供了科学依据，同时在寻找最佳的氟污染土壤修复技术、降低氟对土壤和人类健康的影响方面具有重要的科学意义和实践价值，并为原位修复其它阴离子污染物污染土壤提供了一条新思路。