Environmental Engineering Reference
In-Depth Information
5
Phytoremediation:
A Biotechnological Intervention
Dharmendra Singh, Pritesh Vyas, Shweta Sahni
and Punesh Sangwan
Abstract
Phytoremediation, a growing sector of bioremediation, exploits the natural
ability of a large variety of plants to filter chemicals through their root sys-
tems and to aerate the soil, allowing different microorganisms to grow. Phy-
toremediation has many advantages over other existing technologies in terms
of safe and nondisturbing natural surroundings of contaminated sites. The
modification in technology leads to different methods of phytoremediation,
including phytotransformation, rhizoremediation, phytostabilization, phyto-
extraction and rhizofiltration. The application of a selected method depends
on the nature and site of contaminant. To understand the mechanism of hyper-
accumulation, various studies have been conducted on model (
Arabidopsis
thaliana
) and commonly grown plants such as
Populus
,
Brassica
,
Hydrilla
etc. in phytoremediation. Further, based on mechanism and identified genes
such as those involved in uptake, sequestration, remobilization and homeo-
stasis, transgenic plants were designed and used efficiently to remove heavy
metals and organic chemicals from the soil. However, further efforts are re-
quired for advancements in efficiency and robustness of transgenic plants
and to popularize the phytoremediation technology on a commercial scale.
5.1 Introduction
Worldwide technological advancements, uncon-
trolled anthropogenic activity (mining, metal
extraction, fertilizers, pesticide industries, house-
hold activities and vehicles) and natural events
(seepage from rocks, volcanic eruption and forest
fires) cause environmental deterioration in terms
of heavy and toxic metal contamination in soil,
aqueous water streams and groundwater, thus
posing a major community problem that needs to
be addressed. The main threats to environment
and human health from heavy toxic metals and
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