Phytoremediation: a sustainable environmental technology for heavy metals decontamination

摘要

Toxic metal contamination of soil is a major environmental hazard. Chemical methods for heavy metal’s (HMs) decontaminationsuch as heat treatment, electroremediation, soil replacement, precipitation and chemical leaching are generallyvery costly and not be applicable to agricultural lands. However, many strategies are being used to restore pollutedenvironments. Among these, phytoremediation is a promising method based on the use of hyper-accumulator plantspecies that can tolerate high amounts of toxic HMs present in the environment/soil. Such a strategy uses green plantsto remove, degrade, or detoxify toxic metals. Five types of phytoremediation technologies have often been employed forsoil decontamination: phytostabilization, phytodegradation, rhizofiltration, phytoextraction and phytovolatilization. Traditionalphytoremediation method presents some limitations regarding their applications at large scale, so the applicationof genetic engineering approaches such as transgenic transformation, nanoparticles addition and phytoremediationassisted with phytohormones, plant growth-promoting bacteria and AMF inoculation has been applied to amelioratethe efficacy of plants as candidates for HMs decontamination. In this review, aspects of HMs toxicity and their depollutionprocedures with focus on phytoremediation are discussed. Last, some recent innovative technologies for improvingphytoremediation are highlighted.