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26 Novel Biotechnological Approaches for Removal of Emerging Contaminants

26.6.5.1

Phytoextraction and Phytoaccumulation

Phytoextraction and phytoaccumulation are probably the best known phytoremedia-

tion processes for EC with inorganics. In these processes, plants will remove metals

from the soil and accumulate in their parts which will be harvested subsequently.

Metal-rich plant materials obtained by these methods can be appropriately disposed

or incinerated, or depending on the economical value of the metal and its concen-

tration in plant tissues, they can be phytomined and recovered from the plant ashes

[10–12]. In some cases, if the element extracted from the plant material is a valuable

nutrient for plants, the harvested metal-containing biomass can be used as a source

of fertilizer in deficient areas [13].

26.6.5.2

Phytostabilization

This method uses metal-tolerant plants and its associated microorganisms to reduce

pollutant mobility and bioavailability by means of its immobilization technique in

the root zone. This process prevents leaching of metals to groundwater reservoirs

and reduces the possible risks of offsite contamination through erosion.

26.6.5.3

Phytovolatilization

Phytovolatilization is a method of reduction of EC using plant-mediated processes

that favor the volatilization of pollutants. This process is possible only for some par-

ticular organic compounds and mercury, in which after plant uptake, pollutant is

released in a volatile form.

26.6.5.4

Phytofiltration

Phytofiltration is the process of using plant roots to absorb and adsorb pollutants

from waters. This process is mainly used for removing metals and inorganics from

industrial and water treatment effluents. When seedlings could achieve this process,

the technique is called blastofiltration.

26.6.5.5

Phytodegradation

Phytodegradation is the degradation of pollutants by plant–microbe systems during

which enzymatic activities can facilitate organic biodegradation. Phytoscrubbing is

the process of removal of atmospheric pollutants by plants, as in the case of organics

such as benzene that can be efficiently removed from air by Dracena sanderiana

plants. Another recent example of phytoscrubbing is from plants of Ericaceae family

which were screened for the removal of gaseous pollutants.

26.7

Conclusion

ECs will pose major problem in the environment, since there are no standard

procedures for monitoring or the treatment of these contaminants. For other

contaminants, there are standard operating procedures and several laws to monitor,

treat, and also to control the emission. The ECs will be formed due to the rapid

growth of population and urbanization which intern will lead to the higher usage of

sources of ECs. It is our prime duty to make the society aware of the health hazards