Phytoremediation of radium contaminated soils: recent advances and prospects

Radioactive radium (Ra) mainly comes from the mining and milling of uranium and other metal or non-metal mines, phosphate production and fertilizer use, production of oil and gas, coal combustion, wastewater treatment, and various wastes from the above activities, which is ubiquitous in the environment. Phytoremediation is a green and cheap remediation technology for metal/radionuclide-contaminated sites. Radium is often of particular interest and there are many literatures on parameters of Ra concentration in plants and transfer factors from soil to plant from a radiological impact assessment point of view. However, review articles on phytoremediation of Ra-polluted soil are relatively few. This review focused on radium-polluted soil phytoremediation, involving two main strategies of phytoextraction and phytostabilization, which covered the potential (hyper)accumulators for Ra, characteristics of Ra uptake from soil by plants, influencing factors, and phytostabilization application. In future research works, more attention should be paid to the deep insights and mechanism researches of Ra uptake/immobilization by plants. This review will deepen the understanding of the relationship of radium-soil-plants, and to enhance the potential application of phytoremediation as an alternative treatment technology for remediation of Ra-polluted soil site.