Keywords Vermifiltration · Vermifilter · Wastewater · Earthworms · Rural · On-site
2.1 Introduction
Wastewater generated from rural areas is disposed of as it is with no proper
treatment. In most of the underdeveloped/developing countries, it is usually disposed
of into roads, nearby water sources, fields and open spaces near the residence. This
leads to nuisance in the surrounding environment and may lead to health issues to the
residents as sewage carries disease-causing pathogens in addition to high organic
loads. Before its disposal, sewage has to be treated otherwise its high organic
contents may lead to depletion of the DO values in the discharging water bodies
which would have a negative effect on the survival of all aquatic organisms in the
water bodies. Since 100 years, different technologies for sewage treatment have been
well developed, however, there is a need to focus for innovative and cost-effective
on-site treatment processes (Leach and Enfield 1983; Kruzic and Schroeder 1990).
Traditional methods used for sewage treatment in the rural areas include oxidation
ponds, lagoons, stabilization ponds, activated sludge process, upflow anaerobic
sludge beds, sequencing biological reactors, land treatment, etc. Many developing
nations cannot afford to construct and maintain large and costly sewage treatment
plants (STPs), and even in developed nations, to have a sustainable wastewater
management in future, one needs to focus on decentralized systems. Moreover, most
countries prefer sewage treatment processes which can provide effluent standard at
minimal cost. The major expenses in centralised facilities like activated sludge
process, trickling filter, lagoon, ozone oxidation; floatation, sedimentation, and
wetland system are capital cost, operation and maintenance (O&M) costs, and the
procurement of land. It is also difficult to operate especially in areas with low
population densities and dispersed households especially in rural and hilly areas.
Above all the technical difficulties to construct, operate and manage such centralized
facilities in such areas, there is also lack of funds. In such cases having decentralized
facilities for individual households or a cluster of homes to treat their domestic
wastewater on-site will reduce the organic loads (BOD and COD) on the discharging
water bodies as well as easier to monitor. The decentralized approach for wastewater
treatment which employs a combination of on-site and/or cluster systems is gaining
more attention. The new trend is towards decentralized and on-site treatment systems
where there is scope for flexibility in management and simple in operation. Adopting
decentralized system can bring a long-term solution for rural areas/small communities and is reliable as well as cost-effective. On-site treatment of wastewater is a
low-cost technology with low energy consumption, simple and reliable that even
private owners with little skill for operation can afford (Schudell and Boller 1989). In
the context of developing countries particularly in rural areas, vermifiltration could
be an ideal technology for the treatment of domestic effluents, owing to its costeffective and ecologically sustainable characteristics. When compared to prevailing
biological treatment options, vermifiltration is much more environment-friendly and
20
M. Khwairakpam
2.1 Introduction
Wastewater generated from rural areas is disposed of as it is with no proper
treatment. In most of the underdeveloped/developing countries, it is usually disposed
of into roads, nearby water sources, fields and open spaces near the residence. This
leads to nuisance in the surrounding environment and may lead to health issues to the
residents as sewage carries disease-causing pathogens in addition to high organic
loads. Before its disposal, sewage has to be treated otherwise its high organic
contents may lead to depletion of the DO values in the discharging water bodies
which would have a negative effect on the survival of all aquatic organisms in the
water bodies. Since 100 years, different technologies for sewage treatment have been
well developed, however, there is a need to focus for innovative and cost-effective
on-site treatment processes (Leach and Enfield 1983; Kruzic and Schroeder 1990).
Traditional methods used for sewage treatment in the rural areas include oxidation
ponds, lagoons, stabilization ponds, activated sludge process, upflow anaerobic
sludge beds, sequencing biological reactors, land treatment, etc. Many developing
nations cannot afford to construct and maintain large and costly sewage treatment
plants (STPs), and even in developed nations, to have a sustainable wastewater
management in future, one needs to focus on decentralized systems. Moreover, most
countries prefer sewage treatment processes which can provide effluent standard at
minimal cost. The major expenses in centralised facilities like activated sludge
process, trickling filter, lagoon, ozone oxidation; floatation, sedimentation, and
wetland system are capital cost, operation and maintenance (O&M) costs, and the
procurement of land. It is also difficult to operate especially in areas with low
population densities and dispersed households especially in rural and hilly areas.
Above all the technical difficulties to construct, operate and manage such centralized
facilities in such areas, there is also lack of funds. In such cases having decentralized
facilities for individual households or a cluster of homes to treat their domestic
wastewater on-site will reduce the organic loads (BOD and COD) on the discharging
water bodies as well as easier to monitor. The decentralized approach for wastewater
treatment which employs a combination of on-site and/or cluster systems is gaining
more attention. The new trend is towards decentralized and on-site treatment systems
where there is scope for flexibility in management and simple in operation. Adopting
decentralized system can bring a long-term solution for rural areas/small communities and is reliable as well as cost-effective. On-site treatment of wastewater is a
low-cost technology with low energy consumption, simple and reliable that even
private owners with little skill for operation can afford (Schudell and Boller 1989). In
the context of developing countries particularly in rural areas, vermifiltration could
be an ideal technology for the treatment of domestic effluents, owing to its costeffective and ecologically sustainable characteristics. When compared to prevailing
biological treatment options, vermifiltration is much more environment-friendly and
20
M. Khwairakpam