Research progress on strengthening phytoremediation technologies for heavy metals contaminated soil

The traditional remediation technologies of the soil contaminated heavy metals were mainly physical, chemical and biological. The phytoremediation technologies are reliable biological technologies for removing the heavy metal pollution in soil in recent years and become the frontier and hot research areas of resource, environmental and biological sciences internationally. Due to their low cost, wide adaptability and no secondary pollution, the phytoremediation technologies have been widely studied. To screen out or breed suitable plant species which can tolerate and accumulate multiple metals, with fast growth and wide adaptation is of most importance for phytoremediation. The current remediation technologies of heavy metals in soil were summarized. In view of the restriction problems of phytoremediation of heavy metals in soil, the research progress of strengthening phytoremediation technologies were reviewed. The physical, chemical, and biotechnology methods for increasing the plant biomass and heavy metal accumulation were discussed, focusing on the mechanism and application effects of genetic engineering technology, chelate induced technology, root exudates and arbuscular mycorrhizae strengthening phytoremediation, and prospecting future research directions.