Cadmium and Mercury phytostabilization from soil using Miscanthus × giganteus

Area of Science:

• Environmental Science
• Agronomy
• Biotechnology

Background:

• Bioenergy crops offer innovative phytotechnology solutions for soil remediation and climate change adaptation.
• Miscanthus × giganteus (MxG) is a promising candidate for phytoremediation due to its high biomass productivity.
• Contaminated soils pose environmental challenges, necessitating effective remediation strategies.

Purpose of the Study:

• To determine the effects of cadmium (Cd) and mercury (Hg) on MxG growth, biomass, and phytoremediation potential.
• To evaluate MxG's suitability for phytostabilization and biomass production on contaminated soils.

Main Methods:

• A randomized complete block design experiment was conducted with varying concentrations of Cd (0, 10, 100 mg kg⁻¹ soil) and Hg (0, 2, 20 mg kg⁻¹ soil).
• The study spanned three vegetative years, analyzing yield, and Cd and Hg concentrations in MxG.
• Metal accumulation and removal in aboveground biomass were quantified.

Main Results:

• Yields ranged from 6.3-15.5 t_DM ha⁻¹, with significant differences observed across treatments and years.
• Plant Cd concentrations varied from 45-6758 µg kg⁻¹, and Hg concentrations ranged from 8.7-108.9 µg kg⁻¹.
• MxG accumulated modest amounts of Cd (up to 293.8 µg pot⁻¹ year⁻¹) and Hg (up to 4.7 µg pot⁻¹ year⁻¹) in aboveground biomass.

Conclusions:

• Miscanthus × giganteus demonstrates potential for phytostabilization and biomass production on soils moderately contaminated with Cd and Hg.
• MxG can effectively accumulate and remove these heavy metals, contributing to soil remediation efforts.
• The findings support the use of MxG as a valuable energy crop in phytotechnology applications.