Non-enhanced phytoextraction of cadmium, zinc, and lead by high-yielding crops

Abstract

Heavy metal soil contamination from mining and smelting has been reported in several regions around the world, and phytoextraction, using plants to accumulate risk elements in aboveground harvestable organs, is a useful method of substantially reducing this contamination. In our 3-year experiment, we tested the hypothesis that phytoextraction can be successful in local soil conditions without external fertilizer input. The phytoextraction efficiency of 15 high-yielding crop species was assessed in a field experiment performed at the Litavka River alluvium in the Příbram region of Czechia. This area is heavily polluted by Cd, Zn, and Pb from smelter installations which also polluted the river water and flood sediments. Heavy metal concentrations were analyzed in the herbaceous plants' aboveground and belowground biomass and in woody plants' leaves and branches. The highest Cd and Zn mean concentrations in the aboveground biomass were recorded in Salix x fragilis L. (10.14 and 343 mg kg in twigs and 16.74 and 1188 mg kg in leaves, respectively). The heavy metal content in woody plants was significantly higher in leaves than in twigs. In addition, Malva verticillata L. had the highest Cd, Pb, and Zn concentrations in herbaceous species (6.26, 12.44, and 207 mg kg, respectively). The calculated heavy metal removal capacities in this study proved high phytoextraction efficiency in woody species; especially for Salix × fragilis L. In other tested plants, Sorghum bicolor L., Helianthus tuberosus L., Miscanthus sinensis Andersson, and Phalaris arundinacea L. species are also recommended for phytoextraction.

Physiological Aspects of Absorption, Translocation, and Accumulation of Heavy Metals in Silphium perfoliatum L. Plants Grown in a Mining-Contaminated Soil

“…S. perfoliatum plants tend to take on significant amounts of Cu, Zn, Pb and Cr, correlated with the level existing in soils, but also show a high affinity for Zn and Pb, and lower for Cu and Cr (Tables 2-5). The study by Mayerová et al [93] on several herbaceous plant species (including S. perfoliatum) grown in situ in heavy metals Ps showed a high variability in the absorption capacity of pollutants from one year to the other, under the influence of climatic conditions, so that the availability and absorption was higher for Zn compared to Cu. However, there are studies that demonstrate the reduced absorption and accumulation capacity of Zn in certain plant families, such as Asteracea (S. perfoliatum), Juncaceae, Callitrichaceae, and Hydrocaritaceae [94].…”

The Combined Effect of ZnO and CeO2 Nanoparticles on Pisum sativum L.: A Photosynthesis and Nutrients Uptake Study

“…TI is defined as the ratio between the root length of treated plants and that of plants in the control group [60,61]. The effectiveness of metal translocation from roots to shoots was assessed using TF, defined as the ratio of average element content in shoots to that in roots [62,63].…”

Risk assessment of white willow (Salix alba) in food

“…It remained, however, one more path to follow regarding the risk assessment of S. alba . From the fellow's agricultural knowledge, she was aware that different species of Salix are used for phytoremediation and phytostabilisation or are used to clean up soil contaminated with hazardous compounds, particularly heavy metals (Kacalkova et al., ; Mayerova et al., ). Therefore, as Salix species are known for their ‘remarkable capacity to concentrate toxic heavy metals’ (Chen et al., ), it was interesting to check if there is a risk that bark consumed by humans may contain excessive toxic heavy metals.…”