School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Areas, Shanghai Jiao Tong University, Shanghai, 200240, China.
School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Areas, Shanghai Jiao Tong University, Shanghai, 200240, China.
Chemosphere. 2021 Aug;276:130130. doi: 10.1016/j.chemosphere.2021.130130. Epub 2021 Feb 26.
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 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 MWCNTs treatments. Meanwhile, MWCNTs at 500 mg kg 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 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.
随着纳米技术的快速发展，纳米材料越来越多地被应用于污染土壤的修复。然而，关于碳纳米管在植物修复中与重金属（类）复杂相互作用的研究还很少。在这里，我们进行了盆栽实验，研究了多壁碳纳米管（MWCNTs）对超积累土壤系统中植物生长和重金属（类）行为的影响。在分别添加 100、500 和 1000 mg/kg 的 MWCNTs 的 Cd 超积累植物茄属植物龙葵（S. nigrum）在 Cd 和 As 污染土壤中进行培养 60 天。MWCNTs 的应用增加了地上部分长度和植物干生物量，分别增加了 5.56%∼25.13%和 5.23%∼27.97%。然而，在 1000 mg/kg MWCNTs 处理下，根和叶的生长受到抑制。同时，MWCNTs 在 500 mg/kg 时显著增加了 S. nigrum 对重金属（类）的积累（Cd 增加 18.29%，As 增加 32.47%），并通过刺激植物生长、刺激抗氧化酶活性和增加微量元素含量缓解了共污染诱导的毒性（p < 0.05）。在 MWCNTs 应用下，As 的生物浓缩系数降低（15.31%-28.08%），这在缓解植物毒性方面起着重要作用。此外，根际土壤中有效态 Cd 和 As 减少，在 500 mg/kg MWCNTs 处理下减少最为明显（Cd 减少 16.29%，As 减少 8.19%）。这些发现表明，合适浓度的 MWCNTs 可以提高修复效率。我们的研究为利用纳米材料促进对复合污染土壤的植物修复提供了有力证据。
