植物修复多环芳烃污染土壤的根际效应机制研究进展

多环芳烃类有机污染物在土壤中可长期存在，进而通过食物链对人类健康产生重大潜在风险。对多环芳烃污染土壤进行植物修复是一种环境友好且经济有效的污染补救策略。进行植物根际效应机制研究对于开发可持续性多环芳烃污染土壤的植物修复技术具有重要指导意义。对近年来的相关研究工作进行了总结，结果表明:多种禾本科植物具有较强的多环芳烃污染耐受性和较好的修复效能，利用多植物混植的联合修复方式表现出优于单一植物的修复优势。低分子量有机酸类根系分泌物通过与土壤中多环芳烃污染物形成反馈回路决定植物修复体系中多环芳烃的命运。修复植物根系分泌物可塑造特定的根际微生物区系，根际微生物可通过多种机制来降解土壤环境中的多环芳烃。针对在植物修复多环芳烃污染土壤研究过程中尚存在一些问题，提出了未来植物修复根际效应机理研究中应该关注的重点和方向，旨在为优化多环芳烃污染土壤植物修复技术提供科学依据与理论参考。

The Mechanism of Rhizosphere Effect on Phytoremediation of Polycyclic Aromatic Hydrocarbons in Soil: A Review

The organic pollutants of polycyclic aromatic hydrocarbons (PAHs) can existinthesoil environment for a long time. They could pose a great threat to human health and cause inestimable damage once they were infiltratedinto the food chain. Phytoremediationis an environmentally friendly and cost-effective approach for the remediation of PAHs contaminated soil due to the rhizospheric effect on removing PAHs pollutants from soil. So it is significant to study the mechanism of rhizosphere effecton the phytoremediation of PAHs contaminated soil. This review summarized therelative researchprogress, showing that various plants of monocotyledons poaceae had better toleranceand remediation potential to remove PAHs from the contaminated soil. It was demonstrated that the combinationremediation of multiple plants could be the most advantageous approach than that of single plant. The root exudates with low-molecular-weight organic acids (LMWOAs) released by the remediation plants combined with PAHs pollutants in the surrounding environments formeda feedback loop to determine the fate of PAHs in the phytoremediation. The root exudates of the remediation plants could be used to establish the specific rhizospheric microflora that could degrade PAHs byseveral different mechanisms. Aiming at a series of problems existed at present in the rhizosphere effects of PAHs phytoremediation, the key points and directions concerned in the future research were proposed, based on the review of the perspectives of roots, root exudates, rhizosphere microorganisms and their interactions, in order to provide a scientific basis and a theoretical reference for the development of phytoremediation technology inthe PAHs polluted soil.