Nickel phytoextraction by Typha domingensis in lateritic mining residues: first insights from a field trial

The global energy transition is expected to substantially increase the demand for critical metals, particularly nickel, which plays a key role in the production of batteries for electric vehicles. This growing pressure on mineral resources also leads to the generation of large volumes of mining residues, raising concerns about soil contamination and long-term environmental impacts. Nature-based solutions, such as phytomining / agromining, have emerged as promising strategies to both mitigate soil contamination and promote the recovery of valuable metals from mining wastes.

In this study, we investigate the potential of Typha domingensis for nickel phytoextraction from lateritic nickel mining residues, predominantly composed of nickel-bearing goethite. A field experiment was established with four treatments and four replicates: (i) fertilised control, (ii) fertilisation combined with citric acid addition, (iii) fertilisation combined with microbial inoculation, and (iv) fertilisation combined with both microbial inoculation and citric acid. Plants are cultivated for 120 days to maximise their metal translocation potential to aboveground biomass, representing the first of three planned cutting cycles per year.

The experimental design aims to evaluate how organic acids and microorganisms may enhance nickel bioavailability and plant uptake under field conditions, and also test a non-hyperaccumulator plant as a phytoextractor. Plant biomass from the first harvest will be collected in March 2026, and plant tissues will be analysed for nickel concentration following microwave-assisted acid digestion (EPA 3052) and analysis by ICP-OES.

This contribution presents the experimental framework and first insights from the ongoing field trial, highlighting its relevance for the assessment of cost-effective and scalable remediation strategies for nickel-contaminated soils and mining residues. By integrating phytoextraction into the broader context of the energy transition, this study contributes to the discussion on sustainable land management and the reuse of mining wastes through nature-based solutions.