Figure 1

Phytoremediation technology in a three-dimensional scale can be used for remediating HM polluted soil and groundwater.
In the shallow soil layer, the HMs can be extracted and/or immobilized by herbaceous plants with shallow root systems. However, in the deep soil layer, the HMs can be extracted and/or stabilized by tree species with deep root systems to prevent soil and groundwater pollution. The red up-triangles () represent the HM pollutant.