fetida. And the results revealed a higher accumulation of micronutrients such as Zn
and Cu. Rorat et al. (2017) ranked the bioaccumulation potential of Eisenia andrei in
the following order, Cd > Cu > Zn > Ni > Cr > Pb when the organism worked on
the sewage sludge. A similar result was observed by Yuvaraj et al. (2018), during the
vermistabilization of paper mill sludge-spiked cow dung with Perionyx excavates.
The reduction noticed in the heavy metal content was as follows: Cd (2.9–27.8%),
Cu (0.22–42.3%), Pb (1.3–56.3%) and Cr (0.8–46.2%). Whereas, a 10–50% reduction of heavy metals in the fly ash + Cow dung mixture is noticed after
vermicomposting with E. fetida (Gupta et al. 2005). The authors have suggested
an inverse relationship that exists between the organic fraction and the reduction in
the metal content. It is reported by Edwards and Bohlen (1996) that the gut microbes
of earthworms facilitate the degradation of the wastes. During ingestion and decomposition of wastes, the metals along with the soluble fractions could be accumulated
in the tissues, resulting in metal reduction. This concept could be validated on
studying the amount of organic content and the rate of metal loss during the
vermicomposting.
Suthar et al. (2014) have reported the reduction in the heavy metals such as Cd,
Cr, Cu and Pb present in the paper mill sludge by about 32–37%, 47.3–80.9%,
68.8–88.4% and 95.3–97.5%, respectively, during the vermistabilization by Eisenia
fetida. Singh and Kalamdhad (2013), Suthar et al. (2014), Manakova et al. (2014)
and Lv et al. (2016) have reported heavy metal bioaccumulation in earthworm
tissues resulting in the reduction of the heavy metal content in the experimental
materials. Lemtiri et al. (2016) reported accumulation of Zn and Cu in the earthworm
tissues following their introduction into the heavy metal contaminated soil for about
42 days.
Many researchers have reported the high quantity of heavy metals
bioaccumulation in earthworm tissues resulting in an acceptable level of heavy
Fig. 16.2 (a, b) Concentration of heavy metal in earthworm tissues
274
S. Sugumar et al.
and Cu. Rorat et al. (2017) ranked the bioaccumulation potential of Eisenia andrei in
the following order, Cd > Cu > Zn > Ni > Cr > Pb when the organism worked on
the sewage sludge. A similar result was observed by Yuvaraj et al. (2018), during the
vermistabilization of paper mill sludge-spiked cow dung with Perionyx excavates.
The reduction noticed in the heavy metal content was as follows: Cd (2.9–27.8%),
Cu (0.22–42.3%), Pb (1.3–56.3%) and Cr (0.8–46.2%). Whereas, a 10–50% reduction of heavy metals in the fly ash + Cow dung mixture is noticed after
vermicomposting with E. fetida (Gupta et al. 2005). The authors have suggested
an inverse relationship that exists between the organic fraction and the reduction in
the metal content. It is reported by Edwards and Bohlen (1996) that the gut microbes
of earthworms facilitate the degradation of the wastes. During ingestion and decomposition of wastes, the metals along with the soluble fractions could be accumulated
in the tissues, resulting in metal reduction. This concept could be validated on
studying the amount of organic content and the rate of metal loss during the
vermicomposting.
Suthar et al. (2014) have reported the reduction in the heavy metals such as Cd,
Cr, Cu and Pb present in the paper mill sludge by about 32–37%, 47.3–80.9%,
68.8–88.4% and 95.3–97.5%, respectively, during the vermistabilization by Eisenia
fetida. Singh and Kalamdhad (2013), Suthar et al. (2014), Manakova et al. (2014)
and Lv et al. (2016) have reported heavy metal bioaccumulation in earthworm
tissues resulting in the reduction of the heavy metal content in the experimental
materials. Lemtiri et al. (2016) reported accumulation of Zn and Cu in the earthworm
tissues following their introduction into the heavy metal contaminated soil for about
42 days.
Many researchers have reported the high quantity of heavy metals
bioaccumulation in earthworm tissues resulting in an acceptable level of heavy
Fig. 16.2 (a, b) Concentration of heavy metal in earthworm tissues
274
S. Sugumar et al.