78% BOD 5 , 68% COD and 90% TSS (Liu et al. 2013). A study has been conducted
by Zhao et al. (2014) to treat synthetic wastewater through macrophyte-assisted
vermifiltration using different combinations of vertical sub-surface flow constructed
wetlands platned with macrophyte Acorus calamus and earthworm Eisenia fetida.
Results of the study revealed the removal of up to 87% COD, 86% total nitrogen
(TN) and 83% total phosphorus (TP).
Nitrogen removal from wastewater is mainly responsible for the nitrifiers and
denitrifiers microbes present in the earthworm’s intestinal guts (Ihssen et al. 2003).
Earthworms are able to aerate the system through its borrowing action which
enhances the nitrification process and creates a favourable microenvironment for
the growth of aerobic nitrobacteria (Samal et al. 2017a). Wang et al. (2010b) have
combined macrophyte Phragmites australis and earthworm species Eisenia fetida to
treat domestic sewage with an OLR of approximately 192 g/m
2 /d and hydraulic
loading rate (HLR) of 1 m
3 /m
2 /d, and the results showed an average reduction of
about 90% COD, 93% SS and 92% NH 4
+ -N. Wang et al. (2013) reported 63–66%
removal efficiency of TN and 72–78% removal of NH 3
À N from synthetic domestic
wastewater. Liu et al. (2013) also reported about 92% NH 4
+
-N removal from
domestic wastewater. Further, the removal of phosphorus depends upon the sorption
capacity, surface area and size of vermifilter bed material along with chemical
reaction like ligand exchange reaction, complexation and precipitation (Samal
et al. 2017a). Vermifiltration system combined with macrophytes Perionyx
sansibaricus and Cyperus rotundus reported the reduction of wastewater pollutants
like COD, total suspended solids (TSS), total dissolved solids (TDS) and NO 3
À by
more than 85% (Tomar and Suthar 2011). Wang et al. (2013) reported 80–82%
removal of TP using bedding material which consists of cobblestone, detritus, silver
sand and earthworm bed while removal of 87% of TP using cobblestone, soil and
sawdust. Furlong et al. (2014) obtained a removal efficiency of TP in the range of
56–59% in human faeces.
The most crucial parameter in the sewage treatment from the human health point
of view is pathogen removal. In this context, a comprehensive review of available
literature by Swati and Hait (2018) underscores that earthworms are capable of
pathogen reduction from various wastes. Arora et al. (2014) reported around 99%
removal of Escherichia coli (E. coli), total coliform (TC), faecal coliform (FC) and
faecal streptococci (FS) from synthetic wastewater spiked with sewage in a
vermifiltration system. Further, Kumar et al. (2016) have treated domestic wastewater with vermifiltration and achieved a reduction of FC by 99%. An experimental run
of 365 days of vermifiltration showed the reduction of COD by more than 87 and
99% thermotolerant coliforms using domestic wastewater (Furlong et al. 2014).
1.3.2 Applicability of Vermifiltration for Industrial Effluents
Initially limited to the treatment of the domestic wastewater, the vermifiltration
technique has gradually evolved to be studied for the treatment of the industrial
1 Applicability of Vermifiltration for Wastewater Treatment and Recycling
11
by Zhao et al. (2014) to treat synthetic wastewater through macrophyte-assisted
vermifiltration using different combinations of vertical sub-surface flow constructed
wetlands platned with macrophyte Acorus calamus and earthworm Eisenia fetida.
Results of the study revealed the removal of up to 87% COD, 86% total nitrogen
(TN) and 83% total phosphorus (TP).
Nitrogen removal from wastewater is mainly responsible for the nitrifiers and
denitrifiers microbes present in the earthworm’s intestinal guts (Ihssen et al. 2003).
Earthworms are able to aerate the system through its borrowing action which
enhances the nitrification process and creates a favourable microenvironment for
the growth of aerobic nitrobacteria (Samal et al. 2017a). Wang et al. (2010b) have
combined macrophyte Phragmites australis and earthworm species Eisenia fetida to
treat domestic sewage with an OLR of approximately 192 g/m
2 /d and hydraulic
loading rate (HLR) of 1 m
3 /m
2 /d, and the results showed an average reduction of
about 90% COD, 93% SS and 92% NH 4
+ -N. Wang et al. (2013) reported 63–66%
removal efficiency of TN and 72–78% removal of NH 3
À N from synthetic domestic
wastewater. Liu et al. (2013) also reported about 92% NH 4
+
-N removal from
domestic wastewater. Further, the removal of phosphorus depends upon the sorption
capacity, surface area and size of vermifilter bed material along with chemical
reaction like ligand exchange reaction, complexation and precipitation (Samal
et al. 2017a). Vermifiltration system combined with macrophytes Perionyx
sansibaricus and Cyperus rotundus reported the reduction of wastewater pollutants
like COD, total suspended solids (TSS), total dissolved solids (TDS) and NO 3
À by
more than 85% (Tomar and Suthar 2011). Wang et al. (2013) reported 80–82%
removal of TP using bedding material which consists of cobblestone, detritus, silver
sand and earthworm bed while removal of 87% of TP using cobblestone, soil and
sawdust. Furlong et al. (2014) obtained a removal efficiency of TP in the range of
56–59% in human faeces.
The most crucial parameter in the sewage treatment from the human health point
of view is pathogen removal. In this context, a comprehensive review of available
literature by Swati and Hait (2018) underscores that earthworms are capable of
pathogen reduction from various wastes. Arora et al. (2014) reported around 99%
removal of Escherichia coli (E. coli), total coliform (TC), faecal coliform (FC) and
faecal streptococci (FS) from synthetic wastewater spiked with sewage in a
vermifiltration system. Further, Kumar et al. (2016) have treated domestic wastewater with vermifiltration and achieved a reduction of FC by 99%. An experimental run
of 365 days of vermifiltration showed the reduction of COD by more than 87 and
99% thermotolerant coliforms using domestic wastewater (Furlong et al. 2014).
1.3.2 Applicability of Vermifiltration for Industrial Effluents
Initially limited to the treatment of the domestic wastewater, the vermifiltration
technique has gradually evolved to be studied for the treatment of the industrial
1 Applicability of Vermifiltration for Wastewater Treatment and Recycling
11