Abstract:

It is the urgent to clear heavy metals from soil because the contamination of heavy metals in soil has the characteristics of complex polluting process, prominent threat and difficult to remediate. Electrokinetic-assisted phytoremediation (EKAPR) proposed to address the respective disadvantages of electrokinetic and phytoremediation, and synergistically to play the advantages of both. Meanwhile, it dedicated to solving the prominent problems such as contaminants incompletely cleaned of electrokinetic and remediation slowly and limited repair scope of phytoremediation. In this paper, the research processing, influence types, interaction characteristics and relationship, and enhanced mechanism of the remediate heavy metal contaminated soil of EKAPR were summarized. The review showed that there were both beneficial and unfavorable interaction effects between electrokinetic and plants in EKAPR system. In addition, they had many synergistic effects in terms of overcoming their limitations. The electric field type, electrode configuration, applied electric field strength, pH evolution and additives controlled the remediation process of EKAPR. Electrokinetic assisted can improve the phyto-accumulation of heavy metal and remediation efficiency of contaminated soil effectively by changing the spatial and morphological distribution of heavy metals, promoting nutrient absorption and stimulating rhizosphere secretion. Therefore, EKAPR was considered as a novel, green and sustainable innovation in-situ restoration technology of heavy metal, which had great development potential in realizing contaminated site remediation. The analysis revealed the less previous research works at present. Several technical problems and application challenges still existed. The key to overcome the difficult points and promote the practical application of EKAPR technology were that increasing study on the effect characteristics analysis and regulation of key variables of EKAPR, the variation cumulative characteristics and strengthening mechanism of plant nutrient and heavy metal distribution under electrokinetic assisted.

Key words: Electrokinetic-assistedphytoremediation, soil, heavy metal, remediation characteristics, mechanism

摘要：

土壤重金属污染具有污染过程复杂、危害突出和修复困难等特点，修复刻不容缓。电动力学辅助植物修复（EKAPR）致力于弥补电动力学和植物修复各自劣势，协同发挥二者优势，解决电动力学无法彻底清除土壤重金属和植物修复缓慢、作用范围有限等突出问题。本文通过分层总结，归纳了电动力学辅助植物修复重金属的研究现状、影响类型与作用特征、相互作用关系及强化修复机制等。综述表明，EKAPR体系电动力学和植物相互作用，存在有利或不利于重金属清除的影响，在克服自身的局限方面两者也存在很多协同效应；EKAPR过程主要受电场类型、电场布置与强度、pH演变、添加剂等的控制。电动力学通过改善重金属的空间及形态分布，促进养分吸收及刺激根际分泌等作用机制，可有效提高重金属植物吸收富集及污染土壤修复效果。EKAPR被认为是新颖、绿色、可持续的原位重金属污染场地修复技术，在实现污染场地修复方面具有较大发展前景。分析表明，现有研究工作开展较少，若干技术问题和应用挑战仍然存在。加大关键变量影响特征分析及调控、电动力学辅助下植物营养与重金属分布变化机制、累积特征及强化机制研究是克服难点及推动EKAPR技术应用的关键。

关键词: 电动力学辅助植物修复, 土壤, 重金属, 修复特征, 机制