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Bioremediation for Sustainable Environmental Cleanup

Table 5.5. Application of Phytoremediation for removing PAHs from soil.

Type of phytoremediation

Plant

Contaminant

References

Phytostabilization

Robinia pseudoacacia Nyirsegi

Phenanthrene

Wawra et al. 2018

Phytodegradation

Erythrina crista-galli L.

Petroleum-contaminated

soil

de Farias et al. 2009

Lupinus luteus

PAHs

Gutiérrez-Ginés et al. 2014

Acorus calamus

Phenanthrene and pyrene

Jeelani et al. 2017

Maize

Phenanthrene and pyrene

Houshani et al. 2021

Vallisneria spiralis and Hydrilla

verticillate

Phenanthrene and pyrene

He and Chi 2019

Sorghum

Pyrene

Salehi et al 2020

Rhizodegradation

Avicennia marina

Pyrene

Jia et al. 2016

Mangrove (Kandelia candel (L.)

Druce)

Phenanthrene and pyrene

Lu et al. 2011

Maize (Zea Mays L.) Inoculated

with Piriformospora Indica

Petroleum-contaminated

soil

Zamani et al. 2018

Rhizophora mangle

Ʃ16 PAHs

Verâne et al. 2020

Melia azadirachta with

bacteria Bacillus flexus and

Paenibacillus sp. S1I8

Benzo(a)pyrene

Kotoky and Pandey 2020

Lolium multiflorum

Total petroleum

hydrocarbon

Hussain et al. 2022

5.3.1 Mechanism of Phytoremediation

The mechanism of the phytoremediation process varies with the chemical properties of the contaminant

as well as plant characteristics (Figure 5.3). Thus, different strategies under phytoremediation have

been discussed below.

5.3.1.1 Phytoextraction

In phytoextraction, contaminants are absorbed by roots followed by their translocation and

accumulation in their aboveground biomass (Sreelal and Jayanthi 2017).

Screening of suitable plant species is the key and most straightforward strategy for successful

phytoextraction, i.e., the plant must be efficient in accumulating contaminants in the aerial parts.

Besides hyperaccumulation, the plant to act as eminently suitable for phytoextraction must

also possess traits like (1) rapid growth and production of large biomass; (2) vast root systems;

(3) easy cultivation and harvesting management; (4) preferably be repulsive to herbivores to avoid

the entrance in food chain (Seth 2012). However, natural hyperaccumulating plants lack these

characteristics thus limiting the phytoextraction potential (Chaney et al. 2005). To overcome the

problem, research has focused to modify or engineer large biomass producing non-hyperaccumulator

plants to achieve the above-mentioned attributes. To date, numerous hyperaccumulator plants ranging

from annual herbs to perennial shrubs and trees, have been used for phytoextraction. Phytoextraction

is considered advantageous as it does not alter the landscape, preserves the ecosystem and is cost-

effective, thus considered as the most commercially promising technique. However, several factors

such as lower bioavailability and absorption of metal in the roots limit the metal’s phytoextraction

by plants. However, the technique has been so far used for heavy metals (Jacobs et al. 2017, Guo

et al. 2020).