contaminated surfaces; it is possible to recycle the products from the phytoextraction
processes; and it is possible to use for a wide variety of pollutants (metals,
radionuclides, OSs) (Azubuike et al. 2018).
4.7
Biomonitoring Soil Pollution with Heavy Metals
HMs, such as Fe, Cu, Pb, Zn, mercury, Cd, or nickel, are important pollutants from
the extractive industry (mining, ore mining, extractive industries), but these
pollutants may also result from other industries, such as the chemical industry,
energy industry, etc. They are emitted by polluting agents in air, water, or soil
under different physicochemical forms. Unlike the vast majority of pollutants in
other categories, HMs emitted in air, water, and soil do not undergo biodegradation
processes. HMs can be transformed into organometallic compounds (less toxic), can
undergo a series of oxidation or reduction reactions, or can be fixed to clay minerals
present in soils and sediments. These latter processes are those that contribute to the
self-purification of the environment in case of heavy metal contamination.
Virtually every metal has its own environmental behavior and produces a specific
biogeochemical circuit but increasingly influenced by the anthropogenic factor.
There are species able to accumulate in their bodies certain substances in
concentrations tens of thousands of times their concentration in the environment.
The pollution study has confirmed the existence of this process also in the case of
pollutants, including HMs. Thus, two concepts are used to designate this process:
bioconcentration and bioaccumulation. Bioconcentration means the direct increase
in the concentration of a pollutant as it moves from the biotope to a body; in
terrestrial organisms, it is the passage from air or soil into the body of plants by
absorption or the passage from air into the animal body by inhalation.
Bioaccumulation is specific for animal organisms and includes direct absorption of
the pollutant plus food accumulation. In the case of a trophic network within a
biocoenosis, the bioaccumulation phenomenon can be repeated several times, at
each passage from one trophic level to another, from a prey to a predatory organism.
In such cases, we are dealing with a bioassay process (Boim et al. 2016).
4.8
Bioindicators for Terrestrial Environments
Lichens are strong bioaccumulators due to their ability to take up pollutants present
in atmospheric air. With a particular sensitivity to pollutants, lichens are used as
bioindicators for different pollutants: SO 2 , NO X , HF, Cl 2 , O 3 , peroxyacetate, HMs,
radioactive elements, fertilizers, pesticides, and herbicides. The species of cortical
lichens Parmelia physodes, Parmelia caperata, and Evernia prunastri have served
as bioindicators to monitor Pb air pollution. Cladonia rangiferina and Cladonia nitei
can be used as bioindicators for U, Fe, Pb, and Ti.
Mercury can be accumulated by the lichens: Alectoria capillaris, Alectoria
tremontii, Hypogymnia physodes, Cladonia sp., and Collema sp.
4 Advanced Technologies for Ecological Reconstruction and Bioremediation of. . .
103
processes; and it is possible to use for a wide variety of pollutants (metals,
radionuclides, OSs) (Azubuike et al. 2018).
4.7
Biomonitoring Soil Pollution with Heavy Metals
HMs, such as Fe, Cu, Pb, Zn, mercury, Cd, or nickel, are important pollutants from
the extractive industry (mining, ore mining, extractive industries), but these
pollutants may also result from other industries, such as the chemical industry,
energy industry, etc. They are emitted by polluting agents in air, water, or soil
under different physicochemical forms. Unlike the vast majority of pollutants in
other categories, HMs emitted in air, water, and soil do not undergo biodegradation
processes. HMs can be transformed into organometallic compounds (less toxic), can
undergo a series of oxidation or reduction reactions, or can be fixed to clay minerals
present in soils and sediments. These latter processes are those that contribute to the
self-purification of the environment in case of heavy metal contamination.
Virtually every metal has its own environmental behavior and produces a specific
biogeochemical circuit but increasingly influenced by the anthropogenic factor.
There are species able to accumulate in their bodies certain substances in
concentrations tens of thousands of times their concentration in the environment.
The pollution study has confirmed the existence of this process also in the case of
pollutants, including HMs. Thus, two concepts are used to designate this process:
bioconcentration and bioaccumulation. Bioconcentration means the direct increase
in the concentration of a pollutant as it moves from the biotope to a body; in
terrestrial organisms, it is the passage from air or soil into the body of plants by
absorption or the passage from air into the animal body by inhalation.
Bioaccumulation is specific for animal organisms and includes direct absorption of
the pollutant plus food accumulation. In the case of a trophic network within a
biocoenosis, the bioaccumulation phenomenon can be repeated several times, at
each passage from one trophic level to another, from a prey to a predatory organism.
In such cases, we are dealing with a bioassay process (Boim et al. 2016).
4.8
Bioindicators for Terrestrial Environments
Lichens are strong bioaccumulators due to their ability to take up pollutants present
in atmospheric air. With a particular sensitivity to pollutants, lichens are used as
bioindicators for different pollutants: SO 2 , NO X , HF, Cl 2 , O 3 , peroxyacetate, HMs,
radioactive elements, fertilizers, pesticides, and herbicides. The species of cortical
lichens Parmelia physodes, Parmelia caperata, and Evernia prunastri have served
as bioindicators to monitor Pb air pollution. Cladonia rangiferina and Cladonia nitei
can be used as bioindicators for U, Fe, Pb, and Ti.
Mercury can be accumulated by the lichens: Alectoria capillaris, Alectoria
tremontii, Hypogymnia physodes, Cladonia sp., and Collema sp.
4 Advanced Technologies for Ecological Reconstruction and Bioremediation of. . .
103