Restoration and conservation actions: Chilean studies on phytoremediation of metal-polluted, acidic soils

The topic of restoration and conservation actions is very broad. In this chapter, we limit the discussion to phytoremediation of soils polluted by copper mining, focusing on two remediation options: phytostabilization and phytoextraction. We present Chilean studies for each of these two options of remediation of metal-polluted, acidic soils in a site located in proximity of a copper smelter. Specifically, the Puchuncaví Valley, located on the coast of Central Chile, received strong atmospheric depositions from the Ventanas smelter from 1964 to 1999. The soils of the valley are currently acidic, with scarce vegetation. They are severely eroded and contain high total concentration of metals, such as Cu, Zn, Pb, and Cd, and metalloids, such as arsenic. Currently, a large-scale remediation is needed to reverse the strong historic degradation of polluted soils around the Ventanas industrial complex. In this chapter, we demonstrate that phytostabilization is a technique that could be effective for large-scale remediation of the metal-polluted, acidic soils of the Puchuncaví Valley. On the other hand, we conclude that the phytoextraction technique is unfeasible because of the long time necessary for cleaning up soil metals with plants, besides other restrictions.