Assisting Phytoremediation of Heavy Metals Using Chemical Amendments

Abstract

Phytoremediation is one of the safer, economical, and environment-friendly techniques in which plants are used to recover polluted soils, particularly those containing toxic organic substances and heavy metals. However, it is considered as a slow form of remediation, as plants take time to grow and flourish. Various amendments, including the augmentation of certain chemical substances i.e., ethylenediamine tetraacetic acid (EDTA), ethylene glycol tetra acetic acid (EGTA), and sodium dodecyl sulfate (SDS) have been used to induce and enhance the phytoextraction capacity in plants. Several reports show that chemical amendments can improve the metal accumulation in different plant parts without actually affecting the growth of the plant. This raises a question about the amount and mechanisms of chemical amendments that may be needed for potentially good plant growth and metal phytoremediation. This review provides a detailed discussion on the mechanisms undertaken by three important chemical amendments that are widely used in enhancing phytoremediation (i.e., EDTA, EGTA, and SDS) to support plant growth as well as soil phytoremediation. A core part of this review focuses on the recent advances that have been made using chemical amendments in assisting metal phytoremediation.

Phytoremediation of Cadmium: Physiological, Biochemical, and Molecular Mechanisms

“…Several investigations have been carried out on EDTA as a heavy metals chelator from polluted water and soils for effective phytoextraction [204,206,207]. In several studies, it has been reported that the application of EDTA in contaminated soils leads to elevated Cd accumulation in the aerial parts of plants [207,208].…”

Coupling Plant Biomass Derived from Phytoremediation of Potential Toxic-Metal-Polluted Soils to Bioenergy Production and High-Value by-Products—A Review

“…It has been demonstrated that in superior plants, different phytoremediation routes are presented, although the time used to phytoremediate polluted soils normally becomes longer due to the slow growth of most of the species [122]; these aspects need to be dealt with to convert this environmental biotechnology into a more attractive and affordable option. Studies are being implemented to turn this drawback into opportunities; for example, Pilipović et al [123] reported long-term poplar phytoremediation in which biomass productivity and carbon storage during a rotation of Populus deltoides Bartr.…”

Heavy Metal Contamination of Medicinal Plants and Potential Implications on Human Health

“…Soil is the main source of contamination, where from heavy metals can move to the surface of the roots by diffusion or ion exchange between the surface of the root and soil-water. Plants use active absorption to assimilate essential metals, but they can also take up other toxic elements available in the soil (Figure 1) [51]. At the same time, heavy metals can move through cationic channels in the cell membrane inside the cell [16,52,53].…”

“…Sources of heavy metals, and foliar, root uptake of heavy metals in plants (from Hasan et al[51], according to the provisions MDPI "This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited") Metals-plants interactions during metal transport from polluted medium to plant https://doi.org/10.37358/RC.20.7.8222…”