1.5.3 Rhizofiltration
Rhizofiltration or phytofiltration is the process of employing plant biomass for
removal of contaminants, primarily toxic metals from the surface waters or wastewater [61]. In rhizofiltration, the removal of pollutants from water sources occurs by
plant roots. The heavy metals are removed by absorption, concentration, and precipitation by the root of the plant. Figure 3 presents the schematic representation of
rhizofiltration.
Phytofiltration can be conducted in situ. The plants are grown in the contaminated
surface water body. Rhizosphere plays an essential role, if the contaminated groundwater is in the vicinity of the root zone to carry out in situ process. In some cases, the
contaminated groundwater may be pumped into troughs where larger and longer root
plant species is affirmed. This will initiate the significant absorption of the metals or
contaminants by the roots. In addition, metals may also be removed from the
groundwater through precipitation by the liquid secreted by plant tissues, which
triggers the precipitation, and precipitates are removed by filtration after it passes
through the plant troughs. Depending on the plant species used, the roots can be
harvested, and the shoots may be further transplanted to grow into new roots. For
better operational results, the plants in the system can be replaced. Aquatic plants
like Myriophyllym brasiliensis, Juncus xiphioides, and Typha latifolia have showed
the ability to phytoremediate Se in wetlands by accumulation and volatilization
[60]. Sunflowers were used near Chernobyl to extract radioactive strontium and
Fig. 3 Rhizofiltration
Phytoremediation of Soil for Metal and Organic Pollutant Removal
53
Rhizofiltration or phytofiltration is the process of employing plant biomass for
removal of contaminants, primarily toxic metals from the surface waters or wastewater [61]. In rhizofiltration, the removal of pollutants from water sources occurs by
plant roots. The heavy metals are removed by absorption, concentration, and precipitation by the root of the plant. Figure 3 presents the schematic representation of
rhizofiltration.
Phytofiltration can be conducted in situ. The plants are grown in the contaminated
surface water body. Rhizosphere plays an essential role, if the contaminated groundwater is in the vicinity of the root zone to carry out in situ process. In some cases, the
contaminated groundwater may be pumped into troughs where larger and longer root
plant species is affirmed. This will initiate the significant absorption of the metals or
contaminants by the roots. In addition, metals may also be removed from the
groundwater through precipitation by the liquid secreted by plant tissues, which
triggers the precipitation, and precipitates are removed by filtration after it passes
through the plant troughs. Depending on the plant species used, the roots can be
harvested, and the shoots may be further transplanted to grow into new roots. For
better operational results, the plants in the system can be replaced. Aquatic plants
like Myriophyllym brasiliensis, Juncus xiphioides, and Typha latifolia have showed
the ability to phytoremediate Se in wetlands by accumulation and volatilization
[60]. Sunflowers were used near Chernobyl to extract radioactive strontium and
Fig. 3 Rhizofiltration
Phytoremediation of Soil for Metal and Organic Pollutant Removal
53