Phytoremediation of Soils Contaminated with Heavy Metals from Gold Mining Activities Using Clidemia sericea D. Don

Abstract

Soils contaminated by potentially toxic elements (PTEs) as a result of anthropogenic activities such as mining are a problem due to the adverse effects on human and environmental health, making it necessary to seek sustainable strategies to remediate contaminated areas. The objective of this study was to evaluate the species Clidemia sericea D. Don for the phytoremediation of soils contaminated with PTEs (Hg, Pb, and Cd) from gold mining activities. The study was conducted for three months, with soils from a gold mining area in northern Colombia, and seeds of C. sericea, under a completely randomized experimental design with one factor (concentration of PTEs in soil) and four levels (control (T0), low (T1), medium (T2), and high (T3)), each treatment in triplicate, for a total of twelve experimental units. Phytotoxic effects on plants, bioconcentration (BCF), and translocation (TF) factors were determined. The results obtained for the tissues differed in order of metal accumulation, with the root showing the highest concentration of metals. The highest values of bioconcentration (BCF > 1) were presented for Hg at T3 and Cd in the four treatments; and of translocation (TF > 1) for Hg and Pb at T0 and T1; however, for Pb, the TF indicates that it is transferable, but it is not considered for phytoextraction. Thus, C. sericea demonstrated its potential as a phytostabilizer of Hg and Cd in mining soils, strengthening as a wild species with results of resistance to the stress of the PTEs evaluated, presenting similar behavior and little phytotoxic affectation on the growth and development of each of the plants in the different treatments.