Cynara cardunculus as a sustainable solution for phytoremediation of antimony contaminated areas.

Cynara cardunculus (cardoon) is a promising bioenergy crop, well-adapted to the Mediterranean climate. Recent studies suggest its potential for phytoremediation of soils contaminated with heavy metals such as Cd, Ni, and As. This study explores the potential of cardoon for remediating soils contaminated with antimony. The following aspects were investigated: (i) effect of Sb contamination on phytomass production, (ii) effect of Cynara cultivation on the stabilization of Sb in soils and (iii) assessment of Fe(II) addition in enhancing soil remediation and plants growth. Experiments were conducted in 1.5-liter pots containing 1.3 kg of soil. Four-week-old cardoon seedlings were exposed to Sb at concentrations of 10, 20, and 40 mg/kg. Parallel treatments included Fe(II) addition at a fixed Fe/Sb molar ratio 1.5. The results showed that increased levels of Sb in soil had a negative impact on phytomass production, but simultaneous addition of Fe(II) prevailed over the toxicity of Sb and promoted plant growth. On the other hand, the water-soluble amount of Sb was reduced in the soils where cardoon was grown. Furthermore, Fe(II) addition enhanced Sb immobilization and plant growth. The findings highlighted the dual benefits of C. cardunculus in sustainable land management and renewable energy production on contaminated sites.