The application of phytoremediation on large scale is limited by availability of the
plants with the remediation potential and size of such plants. Native plants may not
have the required ability to tolerate, detoxify, and accumulate contaminants
[93]. Plant performance is improved by selective breeding and transgenic approach
[4, 94, 95]. Biochemical and genetic mechanisms for important processes involved
in phytoremediation are being understood, and the rate-limiting processes are optimized [96]. The soil properties affect the uptake. The higher clay content soils have
the capacity to hold higher concentration of elements than sandy soil. The colloidal
particle of clay can retain up to 1,000 mg Hg, 317 mg Cu, 560 mg Cd, 1,030 mg Pb,
326 mg Zn, and 173.3 mg Cr(III) for each kg soil. The efficacy of clay to absorb trace
elements is dependent on the cation exchange charge of particular clay minerals
[50]. The alkaline conditions, high organic matter content, and silty or silty loamy
texture of soils may reduce the availability of heavy metals to plants [97].
The root zone is one of the highlighted zones in phytoremediation process.
Rhizosphere is a soil microenvironment in which the properties of soil and the
activities of the plant roots and microorganisms interact with each other in a
coordinated manner [98]. Contaminants can be absorbed and stored or metabolized
inside the plant tissue. Plant enzymes are secreted from the roots which facilitate in
the degradation of contaminants and assist in phytoremediation mechanism
[99]. These enzymes are associated with the wall and catalyze the formation of
products. The plant roots or the microorganisms in rhizosphere uptake the products
[100–102].
Table 1 Some of plants species used for phytoremediation
Plant
Compound
References
Alfalfa (Medicago
sativa L.)
Pyrene, phenanthrene
Gao et al. [82]
Azolla filiculoides, an
aquatic plant
Sulfadimethoxine at concentrations of 50–450 mg/L Forni et al. [83]
Chrysopogon
zizanioides (vetiver
grass)
5–15 mg/L tetracycline
Datta et al. [84]
Calendula officinalis
L.
Cd and Pb
Mani et al. [85]
Canola plant
Cr, Co, Ni, and Pb
Adiloğlu [86]
Improved Nicotiana
spp. plants
Cu, Cd, Zn
GardeaTorresdey et al.
[87]
Linum usitatissimum
(flax)
59–355 mg/L of diclofenac, 41–247 mg/L of ibuprofen, and 30–181 mg/L acetaminophen
Kotyza et al.
[88]
Populus nigra
0.03–30 mg/L of ibuprofens
Iori et al. [89]
Rhizobium meliloti
Various PAHs
Teng et al. [90]
Pteris vittata
Arsenic soil
Yang et al.[91]
Typha spp.
0.5–2 mg/L of clofibric acid and ibuprofen
Dordio et al.
[92]
Phytoremediation of Soil for Metal and Organic Pollutant Removal
57
plants with the remediation potential and size of such plants. Native plants may not
have the required ability to tolerate, detoxify, and accumulate contaminants
[93]. Plant performance is improved by selective breeding and transgenic approach
[4, 94, 95]. Biochemical and genetic mechanisms for important processes involved
in phytoremediation are being understood, and the rate-limiting processes are optimized [96]. The soil properties affect the uptake. The higher clay content soils have
the capacity to hold higher concentration of elements than sandy soil. The colloidal
particle of clay can retain up to 1,000 mg Hg, 317 mg Cu, 560 mg Cd, 1,030 mg Pb,
326 mg Zn, and 173.3 mg Cr(III) for each kg soil. The efficacy of clay to absorb trace
elements is dependent on the cation exchange charge of particular clay minerals
[50]. The alkaline conditions, high organic matter content, and silty or silty loamy
texture of soils may reduce the availability of heavy metals to plants [97].
The root zone is one of the highlighted zones in phytoremediation process.
Rhizosphere is a soil microenvironment in which the properties of soil and the
activities of the plant roots and microorganisms interact with each other in a
coordinated manner [98]. Contaminants can be absorbed and stored or metabolized
inside the plant tissue. Plant enzymes are secreted from the roots which facilitate in
the degradation of contaminants and assist in phytoremediation mechanism
[99]. These enzymes are associated with the wall and catalyze the formation of
products. The plant roots or the microorganisms in rhizosphere uptake the products
[100–102].
Table 1 Some of plants species used for phytoremediation
Plant
Compound
References
Alfalfa (Medicago
sativa L.)
Pyrene, phenanthrene
Gao et al. [82]
Azolla filiculoides, an
aquatic plant
Sulfadimethoxine at concentrations of 50–450 mg/L Forni et al. [83]
Chrysopogon
zizanioides (vetiver
grass)
5–15 mg/L tetracycline
Datta et al. [84]
Calendula officinalis
L.
Cd and Pb
Mani et al. [85]
Canola plant
Cr, Co, Ni, and Pb
Adiloğlu [86]
Improved Nicotiana
spp. plants
Cu, Cd, Zn
GardeaTorresdey et al.
[87]
Linum usitatissimum
(flax)
59–355 mg/L of diclofenac, 41–247 mg/L of ibuprofen, and 30–181 mg/L acetaminophen
Kotyza et al.
[88]
Populus nigra
0.03–30 mg/L of ibuprofens
Iori et al. [89]
Rhizobium meliloti
Various PAHs
Teng et al. [90]
Pteris vittata
Arsenic soil
Yang et al.[91]
Typha spp.
0.5–2 mg/L of clofibric acid and ibuprofen
Dordio et al.
[92]
Phytoremediation of Soil for Metal and Organic Pollutant Removal
57