Phytoremediation: Curing soil problems with crops

Abstract

Among the different contaminants in the environment, heavy metals (HMs) are unique due to the fact that they cannot be broken down to non-toxic forms. According to the reports published worldwide, these metals are released into the environment by both natural and anthropogenic sources, especially, mining and industrial activities, and automobile exhausts (for lead). They leach into underground waters, moving along water pathways and eventually depositing in the aquifer, or are washed away by run-off into surface waters thereby, resulting in water and subsequently soil pollution. The HM contamination is increasing day by day because of increase in population, industrialization and urbanization. Therefore, posing a serious threat to health and environment. Researchers worldwide have used different methods for removing these hazardous elements. Although, these methods for cleaning up of contaminated environment including soil and water are usually expensive and do not give optimum results. Currently, phytoremediation is an effective and affordable technology used to remove inactive metals and metal pollutants from contaminated soil and water. It includes phytoextraction, rhizofiltration, phytostabilization, phytovolatization, and phytodegradation/ phytotransformation. This technology is ecofriendly and exploits the ability of plants to remediate pollutants from contaminated sites. More than 400 plant species have been identified to have potential for soil and water remediation. Among them, Thlaspi, Brassica, Sedum alfredii H., and Arabidopsis species have been mostly studied. Our paper aims to cover the causes of HM pollution and phytoremediation technology, including HM uptake mechanism and several reports describing its application at field level.