Phytoremediation of Heavy Metal Contaminated Soils

Abstract

Mining, industry, and agriculture have led to the accelerated release of metals into ecosystems, causing serious environmental problems and posing a threat to human and animal health. Excessive metal concentrations in contaminated soils can result in a deterioration of soil quality and the possible contamination of the food chain. Physical and chemical methods of remediation are not only highly expensive but they destroy the soil structure and microbial ecosystem. The development of low-cost remediation strategies is thus inevitable, and “phytoremediation,” especially “phytoextraction,” are considered to be economically viable and ecologically sustainable options for the remediation of heavy metal contaminated soils.

About 400+ taxa have been found to hyperaccumulate heavy metals from contaminated soil so far. In order to make phytoremediation more efficient, chemical amendments like chelating agents and organic acids are also used to enhance the availability of metals to plants used for phytoremediation. The use of arbuscular mycorrhizal fungi is another promising approach. The isolation of metal-accumulating genes in various hyperaccumulating plants and their incorporation into high-biomass crops through genetic engineering techniques hold promise for the phytoextraction of large amounts of metals from the soil. The main advantage of phytoremediation is that it is a green technology that does not have any adverse effects on ecosystem functioning but still allows the removal of pollutants from contaminated sites. In order to make phytoremediation more attractive, it has to be made less time consuming. The fastest phytoremediation approaches can only be developed when the soil scientist, agronomist, plant physiologist, and biotechnologist work hand-in-hand.