Root zone phytoremediation

Phytoremediation in the root zone. Proteins and enzymes produced by the plant can be exuded by the roots into the rhizosphere. These plant products target contaminants in the surrounding soil, leading to precipitation or immobilization in the root zone. This mechanism within phytostabilization may reduce the fraction of the contaminant in the soil that is bioavailable. 

These maximum depths are not likely to occur in most cases. The effective depth for phytoremediation using most nonwoody plant species is likely to be only 30 or 61 cm (1 or 2 ft). Most accumulators have root zones limited to the top foot of soil, which restricts the use of phytoextraction to shallow soils. The effective depth of tree roots is likely to be in the few tens of feet or less, with one optimistic estimate that trees will be useful for extraction of groundwater up to 9 m (30 ft) deep.41-58... 

Another application or example of phytoremediation is phytostabilization by reforestation, such as the reclamation of metalliferous mine wastes. Phytostabilization is the stabilization of contaminants in surface soils (especially in root zones) by preventing them from leaching down profiles or entering surface runoff. The additional benefits of reforestation in reclamation include supplying local timber needs, the provision of employment in rural areas, the enhancement of the surrounding scenery, the establishment of perimeter wind breaks and shelter belts, the provision of food and shelter for wildlife, and the reduction of surface water and resulting erosion (Williamson and Johnson, 1981). 

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