Abstract: Soil contamination by heavy metals is one of the global environmental problems, which is a major threat to environmental quality, human health, and national food security. To mitigate the adverse effects of heavy metals contamination, a variety of soil remediation technologies have been developed based on fundamental knowledge of physical, chemical, and biological sciences in the past decades, aiming to reduce the concentrations or bioavailability of heavy metals. Here, we reviewed ten remediation techniques, including encapsulation, landfilling, soil replacement, electrokinetic remediation, thermal treatment, vitrification, soil washing, stabilization/solidification, phytoremediation, and bioremediation. The principles, technical feasibility, and applicable conditions of all the technologies were evaluated, and the merits and disadvantages were discussed. In addition, we proposed that the basic earth science could contribute to the remediating of heavy metals contaminated soils as a natural attenuation process. Finally, we pinpointed how to choose a suitable remediation technology and how to fulfill key knowledge gaps and to overcome practical challenges.

Key words: heavy metal, soil contamination, remediation, earth science, natural attenuation.