Comparing the risk of metal leaching in phytoremediation using Noccaea caerulescens with or without electric field. (February 2019)

• Record Type: Journal Article
• Authors: Luo, Jie; Xing, Xinli; Qi, Shihua; Wu, Jian; Gu, X.W. Sophie
• Is Part Of: Chemosphere. Volume 216(2019)
• Page Start: 661
• Page End: 668
• Publication Date: 2019-02
• Subjects: Phytoremediation -- Hyperaccumulator -- Heavy metal -- Electrokinetic -- Leaching; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.10.167
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Hyperaccumulators can mobilize all metals in soil through secreting exudates to form soluble compounds but only hyperaccumulate part of them. Metals that cannot be accumulated are defined as non-hyperaccumulated metals and can increase the leaching risk in phytoremediation. Cd and Zn hyperaccumulator Noccaea caerulescens (formerly Thlaspi caerulescens ) was utilized to remediate multi-metal polluted soil in the present study, and the leaching risk of non-hyperaccumulated metals including Cu and Pb was investigated during the phytoremediation process. Comparing with Thlaspi arvense, a non-hyperaccumulator, N. caerulescens significantly decreased the concentrations of Cd and Zn in leachate gathered from precipitation simulation experiments without electric field, but meanwhile dramatically increased the concentrations of Cu and Pb in soil solution. Electric field with low (2 V) and moderate (4 V) voltages increased the biomass yield and metal uptake capacity of N. caerulescens simultaneously and therefore further reduced the concentrations of Cd and Zn in the leachate. Although the volume of leachate decreased significantly in pots with electric field, the leaching risk of Pb and Cu was deteriorated. Thus, decontaminating multi-metal polluted soil with electric field and hyperaccumulator should be conducted with caution due to potential secondary environmental risk caused by activated non-hyperaccumulated metals. Graphical abstract: Highlights: Noccaea caerulescens mobilized Pb and Cu in soil but not hyperaccumulated them. Pots planted with N. caerulescens leached more Pb and Cu than with Thlaspi arvense. External electric fields stimulated the growth of N. caerulescens. The total volume of leachate was reduced by electric fields. More Pb and Zn leached from pots treated by N. caerulescens with electric field.