17.7.1 Copper (Cu)
A copper is one of the most important traces of essential element, and it is required in
minor quantity. The excess range of this metal can be harmful to both plants and soil
(Brunetto et al. 2014). It is found that the earthworms help to decrease the copper
content from the fly ash (Tripathi et al. 1997; Gupta et al. 2005).
17.7.2 Cadmium (Cd)
Cadmium is considered a very toxic element for the soil system. It interferes in plant
growth and damages the soil structure (Goswami et al. 2016). Suzuki et al. (1980)
and Singh et al. (2016) found a sharp decline in the Cd content during the
vermicomposting of fly ash.
17.7.3 Chromium (Cr)
Chromium exhibits in two states III and VI. The chromium III is non-toxic, whereas
the latter is toxic. This chromium interconversion is highly required for healthy plant
growth, which is accomplished with the help of earthworms (Kumar et al. 2017). The
apparent reduction in the Cr content was seen in the fly ash vermicomposting (Singh
et al. 2016).
17.7.4 Lead (Pb)
Pb is one of the most toxic elements for the life system. It is not only harming the
ecosystem but also affects badly to each component of the living system deeply. It
was found in many studies of vermicomposting that the earthworms are useful in the
conversion of non-toxic stable products. Many researchers have studied that the
earthworms can be capable of decreasing the Pb content from the fly ash mixture
during vermicomposting (Gupta et al. 2005; Bhattacharya and Chattopadhyay
2006). Bozym (2017) found that Eisenia fetida is capable of converting the toxic
Pb to nontoxic form.
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291
A copper is one of the most important traces of essential element, and it is required in
minor quantity. The excess range of this metal can be harmful to both plants and soil
(Brunetto et al. 2014). It is found that the earthworms help to decrease the copper
content from the fly ash (Tripathi et al. 1997; Gupta et al. 2005).
17.7.2 Cadmium (Cd)
Cadmium is considered a very toxic element for the soil system. It interferes in plant
growth and damages the soil structure (Goswami et al. 2016). Suzuki et al. (1980)
and Singh et al. (2016) found a sharp decline in the Cd content during the
vermicomposting of fly ash.
17.7.3 Chromium (Cr)
Chromium exhibits in two states III and VI. The chromium III is non-toxic, whereas
the latter is toxic. This chromium interconversion is highly required for healthy plant
growth, which is accomplished with the help of earthworms (Kumar et al. 2017). The
apparent reduction in the Cr content was seen in the fly ash vermicomposting (Singh
et al. 2016).
17.7.4 Lead (Pb)
Pb is one of the most toxic elements for the life system. It is not only harming the
ecosystem but also affects badly to each component of the living system deeply. It
was found in many studies of vermicomposting that the earthworms are useful in the
conversion of non-toxic stable products. Many researchers have studied that the
earthworms can be capable of decreasing the Pb content from the fly ash mixture
during vermicomposting (Gupta et al. 2005; Bhattacharya and Chattopadhyay
2006). Bozym (2017) found that Eisenia fetida is capable of converting the toxic
Pb to nontoxic form.
17 Earthworm-Assisted Amelioration of Thermal Ash
291