Phytoextraction from mine spoils: insights from New Caledonia

Area of Science:

• Biogeochemistry
• Green Chemistry
• Ecological Restoration

Background:

• Mineral resource scarcity drives innovation in supply and recycling.
• Metal-rich biomass from phytoextraction is a novel source for green chemistry applications.
• Phytoextraction offers potential but lacks economic viability.

Purpose of the Study:

• To explore phytoextraction from mine spoils using endemic New Caledonian metallophytes.
• To assess the potential of Geissois pruinosa (Ni accumulator) and Grevillea exul (Mn accumulator) for biomass production.
• To evaluate the dual benefits of metal accumulation and mine reclamation.

Main Methods:

• Cultivation of Geissois pruinosa and Grevillea exul on mine spoils for 20 months.
• Analysis of Nickel (Ni) and Manganese (Mn) concentrations in plant tissues.
• Correlation analysis of metal concentrations with leaf age.

Main Results:

• Geissois pruinosa accumulated up to 1513 mg kg(-1) of Ni.
• Grevillea exul accumulated up to 2000 mg kg(-1) of Mn.
• Metal concentrations in leaves showed a correlation with leaf age.

Conclusions:

• Phytoextraction using endemic metallophytes is a viable strategy for producing metal-rich biomass.
• This biomass can be utilized for ecocatalyst synthesis, adding economic value to phytoextraction.
• The selected species show potential for concurrent mine reclamation and ecological restoration.