Exploring the phytoremediation potential of plant species in soils impacted by gold mining in Northern Colombia

Contamination of soils with toxic metals poses significant threats to human health and ecosystems. Plant-based remediation strategies can play a vital role in mitigating these risks, and the use of plants as a remediation strategy can help reduce these risks. In this study, we investigate the remediation potential of native plants in accumulating and translocating metal(loid)s at a Colombian site impacted by gold mining. The remediation capacity is evaluated using the translocation factor (TF) from roots to shoots and the bioconcentration factor (BCF) from soil to roots. Metal(loid) concentrations in the soil followed the order: Fe > As > Hg > Cd > Pb > Zn > Mn > Cu. In plant tissues, Hg showed higher accumulation in leaves (3.5 mg/kg) compared to roots (2.8 mg/kg). Pb (17.7 mg/kg), As (3.8 mg/kg), Fe (2.5 mg/kg) and Cd (1.2 mg/kg) concentracions were also higher in roots. Metal concentrations in the stems, were generally below 1.0 mg/kg, except for Pb (15.0 mg/kg) and Hg (1.0 mg/kg). The highest BCF values for Hg were observed in Spondias mombin L. (18.7), Cecropia peltata L. (8.3) and Gliricidia sepium (Jacq.) Walp (4.4). On the other hand, Senna alata (L.) Roxb., Psidium guajava L. and Morinda citrifolia L. exhibited notable BFC values for As with 44.7, 6.3 and 5.9, respectively. Musa x paradisiaca L. had the highest BCF for Cd (1.8). M. citrifolia (4.3) and Annona muricata L. (3.2) exhibited the highest TF for Hg, while Tabebuia rosea (Bertol.) Bertero ex A.DC. (4.9) and Paspalum fasciculatum Willd. ex (3.1) demonstrated elevated TF values for Pb. In conclusion, plants such as P. fasciculatum, A. muricata, M. citrifolia, G. sepium and T. rosea exhibit great potential for application in phytoremediation strategies in tropical regions impacted by gold mining activities.