through the initial layer, where the organic matter is converted into humus by
earthworm, is followed by the filtration through filter media which supports microorganism’s growth and subsequently secondary treatment occurs. Recent studies
have shown that the vermifiltration technique can emerge as a suitable and sustainable alternative for wastewater treatment and recycling. Thus, the chapter presents an
overview of the vermifiltration technique with various filter design configurations,
applicability and performance evaluation of the technique for the treatment and
recycling of sewage and industrial effluents, explaining the mechanisms involved.
Additionally, the performance of an integrated macrophyte-vermifiltration system
for wastewater treatment and recycling has also been presented. Further, the effects
of different filter design and operational parameters on the system performance have
been summarized. Moreover, future research perspectives have been provided
towards the improvement of the efficacy of the system for wastewater treatment
and recycling.
1.2 Overview of Vermifiltration Technique
Vermifiltration system comprises an earthworm active zone along with filter media
bed which supports microbial community for domestic and industrial wastewater
treatment. The species of earthworms employed in vermifiltration include Eisenia
fetida, Lumbricus rubellus, Eudrilus eugeniae and Eisenia andrei with filter bed
consisting of soil, compost and cow dung which are available for pollutant degradation in earthworm active zone (Singh et al. 2019b; Xing et al. 2011). In filter media
design, different materials like sand, gravel, cobblestone and quartz sand are commonly used (Singh et al. 2019b). In vermifiltration system, wastewater is firstly
passed through earthworm active zone followed by filter media bed. Depending on
the wastewater flow direction, vermifiltration system, in general, can be of two types:
horizontal flow system (HFS) and vertical flow system (VFS). In HFS, wastewater
flows horizontally through the bed while in VFS wastewater is fed vertically through
the bed as shown in Figs. 1.1 and 1.2, respectively. A hybrid system combining both
horizontal and vertical flow systems in the sequence is used for the treatment of
wastewater. The flow of wastewater in the hybrid system is either from a horizontal
Influent
Effluent
Worm active zone Sand + Gravel
Fig. 1.1 Schematic of a typical horizontal flow vermifiltration system
1 Applicability of Vermifiltration for Wastewater Treatment and Recycling
5
earthworm, is followed by the filtration through filter media which supports microorganism’s growth and subsequently secondary treatment occurs. Recent studies
have shown that the vermifiltration technique can emerge as a suitable and sustainable alternative for wastewater treatment and recycling. Thus, the chapter presents an
overview of the vermifiltration technique with various filter design configurations,
applicability and performance evaluation of the technique for the treatment and
recycling of sewage and industrial effluents, explaining the mechanisms involved.
Additionally, the performance of an integrated macrophyte-vermifiltration system
for wastewater treatment and recycling has also been presented. Further, the effects
of different filter design and operational parameters on the system performance have
been summarized. Moreover, future research perspectives have been provided
towards the improvement of the efficacy of the system for wastewater treatment
and recycling.
1.2 Overview of Vermifiltration Technique
Vermifiltration system comprises an earthworm active zone along with filter media
bed which supports microbial community for domestic and industrial wastewater
treatment. The species of earthworms employed in vermifiltration include Eisenia
fetida, Lumbricus rubellus, Eudrilus eugeniae and Eisenia andrei with filter bed
consisting of soil, compost and cow dung which are available for pollutant degradation in earthworm active zone (Singh et al. 2019b; Xing et al. 2011). In filter media
design, different materials like sand, gravel, cobblestone and quartz sand are commonly used (Singh et al. 2019b). In vermifiltration system, wastewater is firstly
passed through earthworm active zone followed by filter media bed. Depending on
the wastewater flow direction, vermifiltration system, in general, can be of two types:
horizontal flow system (HFS) and vertical flow system (VFS). In HFS, wastewater
flows horizontally through the bed while in VFS wastewater is fed vertically through
the bed as shown in Figs. 1.1 and 1.2, respectively. A hybrid system combining both
horizontal and vertical flow systems in the sequence is used for the treatment of
wastewater. The flow of wastewater in the hybrid system is either from a horizontal
Influent
Effluent
Worm active zone Sand + Gravel
Fig. 1.1 Schematic of a typical horizontal flow vermifiltration system
1 Applicability of Vermifiltration for Wastewater Treatment and Recycling
5