6.1 In Situ Phytoremediation
In situ phytoremediation involves placement of green plants in contaminated soil or
sediment or in soil or sediment that is in contact with contaminated groundwater for
the purpose of remediation. In this approach, the contaminated material is not
removed prior to phytoremediation. Several native plants that grown on distillery
waste-contaminated sites under natural environment have indicated the
phytoremediation potential as natural hyperaccumulators of HMs from complex
organic wastes (Fig. 20.3), because these plants are naturally adapted in terms of
growth, survival, and reproduction under the environmental stresses, compared to
plants introduced from another environment. Chandra and Kumar (2017c) evaluated
the phytoextraction potential of 15 potential native plants, namely, Datura stramonium, Achyranthes sp., Kalanchoe pinnata, Trichosanthes dioica, Parthenium
hysterophorus, Cannabis sativa, Amaranthus spinosus L., Croton bonplandianum,
Solanum nigrum, Ricinus communis, Saccharum munja, Basella alba, Setaria
viridis, Chenopodium album, and Blumea lacera grown on stabilized distillery
sludge. The HM accumulation from distillery sludge and the distribution of these
metals in roots, shoots, and leaves followed variable patterns. They observed
that C. bonplandianum, S. munja, D. stramonium, Achyranthes sp., A. spinosus L.,
T. dioica, B. alba, C. sativa, C. album, S. viridis, P. hysterophorus, and B. lacera
have been noted as root accumulators for Fe, Zn, and Mn, while Achyranthes sp.,
K. pinnata, B. alba, B. lacera, D. stramonium, T. dioica, C. album, C. sativa,
P. hysterophorus, and S. munja are shoot accumulators of Fe. In addition,
A. spinosus L. was found to be a shoot accumulator for Mn and Zn. Similarly, all
plants were determined to be leaf accumulators of Mn, Zn, and Fe, except for
A. spinosus L. and R. communis. Further, the bioconcentration factor (BCF) of all
native plants was found <1, while the translocation factor (TF) was >1. This gives a
strong evidence of hyperaccumulation for the tested metals from complex distillery
waste. Furthermore, the transmission electron microscopic (TEM) observations of
the root of R. communis, Solanum nigrum, C. sativa, and P. hysterophorus showed
the formation of multi-vacuoles and multi-nucleolus and deposition of HM granules
in cellular component of roots as a plant adaptation mechanism for phytoextraction
of HM-rich polluted site. This study recommended that these native plants be used as
tools for in situ phytoremediation and eco-restoration of industrial wastecontaminated sites. Another study conducted by Chandra et al. (2018b) showed
that distillery sludge not only contains the mixture of complex organic pollutants but
also retains high quantity of Pb (31.22), Ni (15.60), Fe (5264.49), Mn (238.47), Cu
(847.46), and Zn (43.47 mg kg
À1 ) which enhances the toxicity of sludge to the
environment. The major identified organic compounds were benzoic acid, 3,4,5-tris
(TMS oxy), TMS ester; stigmasterol TMS ether; hexanedioic acid, dioctyl ester;
benzene, 1-ethyl-2-methyl; 5α-cholestane, 4-methylene; campesterol TMS; and
β-sitosterol and lanosterol. These compounds are listed under the EDCs also as per
USEPA (2012b). Authors collected nine representative native plant species (grasses
and weeds), viz., B. alba, Calotropis procera, Tinospora cordifolia, Rumex
516
V. Kumar and R. Chandra
In situ phytoremediation involves placement of green plants in contaminated soil or
sediment or in soil or sediment that is in contact with contaminated groundwater for
the purpose of remediation. In this approach, the contaminated material is not
removed prior to phytoremediation. Several native plants that grown on distillery
waste-contaminated sites under natural environment have indicated the
phytoremediation potential as natural hyperaccumulators of HMs from complex
organic wastes (Fig. 20.3), because these plants are naturally adapted in terms of
growth, survival, and reproduction under the environmental stresses, compared to
plants introduced from another environment. Chandra and Kumar (2017c) evaluated
the phytoextraction potential of 15 potential native plants, namely, Datura stramonium, Achyranthes sp., Kalanchoe pinnata, Trichosanthes dioica, Parthenium
hysterophorus, Cannabis sativa, Amaranthus spinosus L., Croton bonplandianum,
Solanum nigrum, Ricinus communis, Saccharum munja, Basella alba, Setaria
viridis, Chenopodium album, and Blumea lacera grown on stabilized distillery
sludge. The HM accumulation from distillery sludge and the distribution of these
metals in roots, shoots, and leaves followed variable patterns. They observed
that C. bonplandianum, S. munja, D. stramonium, Achyranthes sp., A. spinosus L.,
T. dioica, B. alba, C. sativa, C. album, S. viridis, P. hysterophorus, and B. lacera
have been noted as root accumulators for Fe, Zn, and Mn, while Achyranthes sp.,
K. pinnata, B. alba, B. lacera, D. stramonium, T. dioica, C. album, C. sativa,
P. hysterophorus, and S. munja are shoot accumulators of Fe. In addition,
A. spinosus L. was found to be a shoot accumulator for Mn and Zn. Similarly, all
plants were determined to be leaf accumulators of Mn, Zn, and Fe, except for
A. spinosus L. and R. communis. Further, the bioconcentration factor (BCF) of all
native plants was found <1, while the translocation factor (TF) was >1. This gives a
strong evidence of hyperaccumulation for the tested metals from complex distillery
waste. Furthermore, the transmission electron microscopic (TEM) observations of
the root of R. communis, Solanum nigrum, C. sativa, and P. hysterophorus showed
the formation of multi-vacuoles and multi-nucleolus and deposition of HM granules
in cellular component of roots as a plant adaptation mechanism for phytoextraction
of HM-rich polluted site. This study recommended that these native plants be used as
tools for in situ phytoremediation and eco-restoration of industrial wastecontaminated sites. Another study conducted by Chandra et al. (2018b) showed
that distillery sludge not only contains the mixture of complex organic pollutants but
also retains high quantity of Pb (31.22), Ni (15.60), Fe (5264.49), Mn (238.47), Cu
(847.46), and Zn (43.47 mg kg
À1 ) which enhances the toxicity of sludge to the
environment. The major identified organic compounds were benzoic acid, 3,4,5-tris
(TMS oxy), TMS ester; stigmasterol TMS ether; hexanedioic acid, dioctyl ester;
benzene, 1-ethyl-2-methyl; 5α-cholestane, 4-methylene; campesterol TMS; and
β-sitosterol and lanosterol. These compounds are listed under the EDCs also as per
USEPA (2012b). Authors collected nine representative native plant species (grasses
and weeds), viz., B. alba, Calotropis procera, Tinospora cordifolia, Rumex
516
V. Kumar and R. Chandra