Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
The Connecticut Agricultural Experiment Station, New Haven, CT 06504, USA.
J Hazard Mater. 2022 Mar 5;425:127973. doi: 10.1016/j.jhazmat.2021.127973. Epub 2021 Dec 1.
Nano-enabled phytoremediation is an emerging remediation strategy for soils that are moderately contaminated with persistent organic contaminants, and there is a significant need for increased mechanistic understanding and for case studies. Herein, we evaluated the remediation of PCB28-contaminated soil using combined alfalfa and Fe-based materials, including zero-valent iron at 20 nm, 100 nm, and 5 µm, and also iron oxide nanomaterials including α-FeO, γ-FeO, and FeO around 20-30 nm. Compared with alfalfa remediation alone (63.2%), Fe-based nanomaterials increased PCB28 removal values to 72.4-93.5% in planted soil, with α-FeO treatment promoting the most effective pollutant removal. Mechanistically, the crystalline Fe-based nanoparticles were transformed into amorphous forms in the plant rhizosphere, resulting in greater availability and enhanced iron nutrition. This nutritional shift induced root metabolic reprogramming of amino acid and carbohydrate cycling, and related functional bacterial enrichment of Ramlibacter, Dyella, Bacillus, and Paraburkholderia in rhizosphere. A significant positive correlation between amorphous iron and root metabolites-associated microbes with PCB28 removal was evident, implying that iron supplementation selected for rhizospheric microorganisms favored PCBs degradation. Overall, this rhizoremediation promotion strategy of Fe species-metabolites-microbes highlights the potential for the hybrid application of nano-enabled phytotechnology in the remediation of soils contaminated with persistent organic xenobiotics.
纳米增强植物修复是一种新兴的土壤修复策略，适用于中度污染持久性有机污染物的土壤，因此需要深入了解其修复机制，并进行更多案例研究。在此，我们评估了利用紫花苜蓿和铁基材料（包括 20nm、100nm 和 5μm 的零价铁以及 20-30nm 的α-FeO、γ-FeO 和 FeO 等氧化铁纳米材料）联合修复 PCB28 污染土壤的效果。与单独的紫花苜蓿修复（63.2%）相比，铁基纳米材料使种植土壤中 PCB28 的去除率提高到 72.4-93.5%，其中α-FeO 处理的去除效果最佳。从机理上讲，结晶态的铁基纳米颗粒在植物根际转变为非晶态，从而增加了铁的有效性并改善了铁营养。这种营养转变诱导了根代谢对氨基酸和碳水化合物循环的重新编程，以及 Ramlibacter、Dyella、Bacillus 和 Paraburkholderia 等与根际相关的功能细菌的富集。非晶态铁与根代谢物相关微生物与 PCB28 去除之间存在显著的正相关关系，这表明铁的补充选择了有利于 PCBs 降解的根际微生物。总的来说，这种铁物种-代谢物-微生物的根际修复促进策略强调了纳米增强植物技术在持久性有机污染物污染土壤修复中的混合应用潜力。
