Hyperaccumulation of Cadmium and Lead in Ruderal Species of the Maria Auxiliadora Campus of the Universidad Politécnica Salesiana Guayaquil, Ecuador

Heavy metal contamination in urban soils is a growing concern. Hyperaccumulating ruderal species offer an alternative for bioremediation of these soils. To characterize Cd and Pb hyper-accumulating ruderal species in the soil adjacent to the María Auxiliadora campus of the Universidad Politécnica Salesiana Guayaquil, Ecuador. Soil samples and more than 50 ruderal species were collected. The three most representative species (Distimake aegyptius, Bidens bipinnata and Chenchrus echinatus) were selected for translocation factor, bioconcentration, germination and mortality analyses. Cd and Pb concentrations were determined by inductively coupled plasma spectroscopy. The soil is contaminated by Cd and Pb, due to a nearby company. Cd concentrations ranged from 1 to 2 ppm. The three selected species showed hyperaccumulation capacity, with Chenchrus echinatus standing out as an accumulator and Distimake aegyptius as a transporter. The results confirm the presence of ruderal hyper-accumulating species in the study area with potential for bioremediation. The implementation of phytoextraction strategies with Distimake aegyptius and phytostabilization with the other species is suggested. The presence of hyperaccumulating ruderal species offers a viable alternative for the bioremediation of soils contaminated by heavy metals.