Phytoremediation of nanoparticle-contaminated soil using the halophyte plant species Suaeda glauca

Although concerns about the exposure of natural ecosystems to nanomaterials are increasing, research on how to remove toxic substances from the ecosystem is lacking. In this study, we investigated the phytoremediation ability of Suaeda glauca, a salt marsh plant, to remove nanomaterials introduced into the coastal ecosystem through the sewage system. TiO2 nanoparticles (NPs) and ZnO NPs, which are commonly used in agriculture, cosmetics and industry are used for test materials. In comparison with the land plant Brassica campestris, which has been extensively used for heavy metal remediation, S. glauca was more resistant to nanomaterials and showed higher nanoparticle uptake. The Zn content of S. glauca plants was significantly higher than that of B. campestris plants in the 100 mg/kg ZnO NP treatment, and only S. glauca has survived 1000 mg/kg ZnO NP treatment. Furthermore, Ti contents of S. glauca plants was significantly higher than that of B. campestris plants in the 100 mg/kg TiO2 NP treatment. Additionally, S. glauca showed higher dry weight than B. campestris in every treatments after exposure to nanomaterials, indicating better total remediation capacity. Our results suggest that S. glauca, and potentially other salt marsh plants, can be effectively used to remove nanoparticles from coastal ecosystems.