Emilia fosbergii Nicolson, a novel and effective accumulator for phytoremediation of mercury-contaminated soils

Abstract

Soil contamination by toxic metals threatens global public health, highlighting the need for cost-effective and ecologically sound site remediation. In this study, we assessed phytoremediation of Hg-contaminated soils by Emilia fosbergii Nicolson (Asteraceae). Pot experiment was conducted using a substrate of sand and vermiculite (1:1 volume ratio), treatments consisted of five Hg concentrations (0, 1, 3, 5, and 7 mg kg⁻¹). Metal transfer rates were calculated, including accumulation (BAF), translocation (TF) and bioconcentration (BCF) factors. E. fosbergii roots exhibited greater Hg accumulation than other tissues, but biomass production and plant health were not significantly affected at the concentrations tested, as indicated by elongation factors and tolerance index. The results revealed BAF values between 2.18 and 7.14, TF values ranged between 0.15 and 0.52, and the BCF index varied between 8.97 and 26.58. Treatments with Hg content of 5 mg kg⁻¹ and 7 mg kg⁻¹ recorded the highest total Hg concentrations of 66 mg kg⁻¹ and 65.53 mg kg⁻¹ (roots), and 9.18 mg kg⁻¹ and 33.88 mg kg⁻¹ (aerial), respectively. E. fosbergii demonstrated promise for Hg phytoremediation due to its high accumulation capacity, indicated by regular TF and high BCF and BAF indexes, thus classifying it as a high Hg accumulator.

Graphical Abstract

HIGHLIGHTS

• Phytoextractor and phytostabilizer plant, high accumulator of Hg.

• Weed with great capacity for proliferation and adaptability.

• E. fosbergii showed tolerance to Hg in the substrate.

• Promising plant for phytoremediation of soils contaminated by Hg.

• Novel species for recovery of soils degraded by Hg exposure.

Keywords:

• Asteraceae
• bioaccumulation
• bioconcentration
• remediation
• translocation
• weeds

Acknowledgments

The authors thank the Financier of Studies and Projects (Finep), the Mato Grosso State Research Support Foundation (FAPEMAT) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for the financial support.

Authors contributions

Evandro Alves de Oliveira.: Conceptualization, Investigation, Methodology, Visualization, Writing- Original draft preparation. Ricardo Lopes Tortorela de Andrade.: Methodology, Supervision, Validation, Writing—Review & Editing. Leandro Dênis Battirola.: Supervision, Writing—Review & Editing. Larissa Cavalheiro da Silva.: Data Curation. Ednaldo Antônio de Andrade.: Formal analysis.

Competing interests

The authors have no relevant financial or non-financial interests to disclose.

Data availability statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.