With the fast development of nanotechnology, nanomaterials are being increasingly applied for the remediation of contaminated soils. However, few researches have been reported on the complex interactions of carbon nanotubes with heavy metal (loid)s in phytoremediation. Here, we conduct a pot experiment to investigate the effects of multi-walled carbon nanotubes (MWCNTs) on the plant growth and behavior of heavy metal (loid)s in hyperaccumulator-soil system. Cd hyperaccumulator Solanum nigrum L. (S. nigrum) were cultivated in Cadmium (Cd) and Arsenic (As) contaminated soils amended with MWCNTs at 100, 500, and 1000 mg kg⁻¹ for 60 days, respectively. The application of MWCNTs increased the shoot length and plant dry biomass by 5.56%∼25.13% and 5.23%∼27.97%. Whereas, root and leaf growth were inhibited in 1000 mg kg⁻¹ MWCNTs treatments. Meanwhile, MWCNTs at 500 mg kg⁻¹ significantly enhanced the accumulation of heavy metal (loid)s in S. nigrum（18.29% for Cd and 32.47% for As）and alleviated co-contamination induced toxicity, by motivating plant growth, stimulating antioxidant enzymatic activities, and increasing micronutrient content (p < 0.05). The bio-concentration factor of As was decreased (15.31–28.08%) under MWCNTs application, which plays an important role in the alleviation of phytotoxicity. Besides, bioavailable Cd and As were reduced in rhizosphere soils, and the most significant reduction (16.29% for Cd and 8.19% for As) were shown in 500 mg kg⁻¹ MWCNTs treatment. These findings demonstrate that suitable concentration of MWCNTs can enhance remediation efficiency. Our study gives a strong evidence to promote the phytoremediation for co-contaminated soils by using nanomaterials.

随着纳米技术的飞速发展，纳米材料正越来越多地应用于污染土壤的修复。然而，关于碳纳米管与植物修复中重金属（胶体）的复杂相互作用的研究很少。在这里，我们进行了一个盆栽实验，以研究多壁碳纳米管（MWCNT）对植物的生长和超蓄积-土壤系统中重金属（loid）s行为的影响。镉超富集植物龙葵L.（龙葵）在镉（Cd）和砷（As）中培养污染土壤，在100 500多壁碳纳米管，修正，和1000mg千克^-1分别持续60天。施用多壁碳纳米管可增加枝条长和植物干生物量5.56％〜25.13％和5.23％〜27.97％。而在1000 mg kg ^-1 MWCNTs处理中，根和叶的生长受到抑制。同时，以500 mg kg ^-1的MWCNTs显着增强了黑链霉菌中重金属（胶体）的积累。（Cd为18.29％，As为32.47％），并通过促进植物生长，刺激抗氧化剂的酶活性和增加微量营养素含量来减轻共污染引起的毒性（p <0.05）。在多壁碳纳米管的应用下，砷的生物富集系数降低了（15.31–28.08％），这在减轻植物毒性中起着重要作用。此外，根际土壤中可利用的Cd和As减少，在500 mg kg ^-1 MWCNTs处理中减少最为明显（Cd为16.29％，As为8.19％）。这些发现表明适当浓度的MWCNT可以提高修复效率。我们的研究提供了强有力的证据，表明使用纳米材料可以促进对被污染土壤的植物修复。