Phytoremediation of Engineered Nanoparticles Using Typha latifolia and Carex rostrata

Abstract

Engineered nanoparticles (ENPs) are in demand for numerous industrial, commercial, and domestic applications. Concern has arisen, however, regarding potential adverse environmental impacts from the inadvertent release of ENPs into water bodies. Certain plants have been identified with the capability to absorb metallic ENPs via roots, thus indicating possible application for phytoremediation. The reported study evaluates the potential for two aquatic plant species, viz. cattail (Typha latifolia) and sedge (Carex rostrata) for uptake of Ag, ZnO, TiO2, Pd/BiVO4/BiOBr, and Pd/Cu2O ENPs, each of which were added weekly for 15 weeks. The research was conducted by comparing media doped with metals as nanoparticles and in ionic form. Sedge accumulated greater quantities of Ag, TiO2, and ZnO ENPs in shoots compared with roots. In contrast, cattail roots accumulated proportionally greater concentrations of all ENPs (in particular ZnO, BiVO4, and Cu2O) and ionic metals compared to shoots. Such differences may be attributed, in part, to the root architectures of the two plant species. The translocation factor of ENPs in some treatments (Cu2O, sedge; TiO2, cattail) was >1.0, indicating a potential for phytoextraction. However, the bioconcentration factor for all ENPs was <1.0. Both species hold promise for the phytoextraction of certain ENPs.