Phytoremediation of Heavy Metals-Polluted Soil

The world’s rapid growing population, expanding economics, and anthropogenic activities contribute to heavy metals (HMs) pollution, which are nonbiodegradableand persistent, and threaten the environment. The rising level of HMs in the environment emphasizes on indigenous technologies, but conventional technologies are too expensive and laborious, and result in secondary pollution. Phytoremediation is a plant-based technology, which is environment-friendly, economical, and effective for the remediation of HMs. The suitability of phytoremediation depends on biomass production, accumulation rate, and tolerance to target metals. Uptake of metals can be enhanced by exploring effective hyperaccumulators and extending molecular studies on accumulation mechanism, tolerance, and sensitivity of HMs. Hyperaccumulator plants achieve greater performance at low cost than conventional technologies for in situ metal removal. This chapter highlights the sources of HMs and their effects on plants and phytoremediation process. The biogeochemical factors are responsible for limiting the process, which can be overcome by the genetic engineering,that is, changing the oxidation state of metals, enhancing metal transporters and chelators, encoding metal sequestration proteins (metallothionein and phytochelatin), transport proteins (zinc-iron permease and Zn transporter).