Keywords Phytoremediation · Anthropogenic sources · Rhizoremediation · Toxic
contaminants · Environmental safety
1 Introduction
The environment all over the world faces severe pollution as a result of the rapid
growth of industries and modern technological development, with the inevitable
release of huge amounts of toxic metal effluents. This level of pollution kindles
environmental and public health concerns about these metal contaminants. The
heavy metals (HMs) have very important applications in industry, agriculture, and
domestic and technical development. Effluents from geogenic, agricultural, industrial, pharmaceutical, and even domestic and atmospheric processes are the major
sources of heavy metal contamination. Also, many of the point source areas such as
mining, smelting, foundries, and other metal-based industrial operations are the
signature source of heavy metals into the environment. The intact heavy metals
that are naturally present in the Earth’s crust are not classified as a source, whereas
those resulting from various anthropogenic activities such as mining and smelting,
production, domestic use, and agriculture are considered to be contaminants. Various industrial plants such as refineries, power plants, petrol combustion, nuclear
stations, high tension lines, plastics, microelectronics, paper processing, and wood
preserving contribute greatly to HM pollution. The release of metals from the Earth’s
crust caused by various natural processes such as weathering, soil erosion of metal
ions, leaching, atmospheric deposition, corrosion of metals, sediment re-suspension,
and evaporation also contributes significantly to HM pollution. Many of the metals
such as magnesium (Mg), iron (Fe), chromium (Cr), copper (Cu), selenium (Se),
nickel (Ni), manganese (Mn), zinc (Zn), cobalt (Co), and molybdenum (Mo) are
necessary for various physiological and biochemical functions because these elements function as essential micronutrients, the inadequacy of which results in
various diseases and syndromes. Hence, heavy metals should be removed from the
environment in a safe manner without affecting soil bioavailability.
Phytoremediation is a significant method employing plants and other vegetation
for in situ treatment in various metal-contaminated sites such as soil, sediments, and
water resources. The roots of these plants and vegetation access the organic nutrient
or metal pollutant, which after absorption will be sequestered, degraded,
immobilized or mobilized, and metabolized. Research in the past decade has helped
us to understand the uptake and fate of many toxic metals by phytoremediation to a
greater extent. Better understanding of the absorption, uptake, transformation, and
fate of toxic metal contaminants is discussed in full detail in this chapter. For every
technological achievement there are pros and cons; similarly, the advantages of
phytoremediation are its eco-friendliness, aesthetics, cost-effectiveness, and longterm applicability. Its application mainly covers contaminated sites, where other
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M. K. Awasthi et al.
contaminants · Environmental safety
1 Introduction
The environment all over the world faces severe pollution as a result of the rapid
growth of industries and modern technological development, with the inevitable
release of huge amounts of toxic metal effluents. This level of pollution kindles
environmental and public health concerns about these metal contaminants. The
heavy metals (HMs) have very important applications in industry, agriculture, and
domestic and technical development. Effluents from geogenic, agricultural, industrial, pharmaceutical, and even domestic and atmospheric processes are the major
sources of heavy metal contamination. Also, many of the point source areas such as
mining, smelting, foundries, and other metal-based industrial operations are the
signature source of heavy metals into the environment. The intact heavy metals
that are naturally present in the Earth’s crust are not classified as a source, whereas
those resulting from various anthropogenic activities such as mining and smelting,
production, domestic use, and agriculture are considered to be contaminants. Various industrial plants such as refineries, power plants, petrol combustion, nuclear
stations, high tension lines, plastics, microelectronics, paper processing, and wood
preserving contribute greatly to HM pollution. The release of metals from the Earth’s
crust caused by various natural processes such as weathering, soil erosion of metal
ions, leaching, atmospheric deposition, corrosion of metals, sediment re-suspension,
and evaporation also contributes significantly to HM pollution. Many of the metals
such as magnesium (Mg), iron (Fe), chromium (Cr), copper (Cu), selenium (Se),
nickel (Ni), manganese (Mn), zinc (Zn), cobalt (Co), and molybdenum (Mo) are
necessary for various physiological and biochemical functions because these elements function as essential micronutrients, the inadequacy of which results in
various diseases and syndromes. Hence, heavy metals should be removed from the
environment in a safe manner without affecting soil bioavailability.
Phytoremediation is a significant method employing plants and other vegetation
for in situ treatment in various metal-contaminated sites such as soil, sediments, and
water resources. The roots of these plants and vegetation access the organic nutrient
or metal pollutant, which after absorption will be sequestered, degraded,
immobilized or mobilized, and metabolized. Research in the past decade has helped
us to understand the uptake and fate of many toxic metals by phytoremediation to a
greater extent. Better understanding of the absorption, uptake, transformation, and
fate of toxic metal contaminants is discussed in full detail in this chapter. For every
technological achievement there are pros and cons; similarly, the advantages of
phytoremediation are its eco-friendliness, aesthetics, cost-effectiveness, and longterm applicability. Its application mainly covers contaminated sites, where other
78
M. K. Awasthi et al.