Removal of Heavy Metals from Mine Tailings in Central Chile Using Solidago chilensis Meyen, Haplopappus foliosus DC, and Lycium chilense Miers ex Bertero

Mining activities have been a part of the history of Chile since time immemorial, generating pollution and environmental liabilities. Due to the lack of regulation, many tailings are deposited close to rivers or/and on unstable ground, near which towns have been built, generally in locations with no budget for their treatment. This study tested three plant species from Northern and Central Chile to remove total chromium, nickel, and zinc from tailings: Solidago chilensis, Haplopappus foliosus, and Lycium chilense, which complements the few existing studies on heavy metals removal with native or endemic Chilean shrubs. The experiments were conducted ex situ, and the initial and final concentrations of metals were determined in tailings and plants to obtain the removal efficiency, translocation and bioconcentration factors. Among these species, the best performance was obtained using Solidago chilensis, achieving removal efficiencies of 24% for Cr, 19% for Ni, and 17% for Zn, showing the ability to phytostabilize chromium and the higher resistance concerning the toxicity threshold. Haplopappus foliosus and Lycium chilense presented a slight tendency to stabilize chromium. Only Solidago chilensis showed little ability to extract Zn.