conventional wastewater treatment options being practised till now in rural areas are
listed in Table 2.1.
Adopting vermifiltration system has advantages when compared with other
commonly used biological wastewater treatment systems. According to Yang et al.
(2008), there is no sludge formation in the vermifiltration system which makes it
more convenient to operate when compared to conventional activated sludge treatment methods. Moreover, total nitrogen and total phosphorus was reported to be
tripped off 10% higher in vermifilters compared to activated sludge systems; NH
4 -N
was also removed three times more in vermifilters (Li et al. 2009).
Table 2.1 Conventional wastewater treatment options in rural areas
Treatment
system
Prerequisite
Benefits
Limitations
Cesspools Location of a cesspool
should be downhill from a
well; in any case, a distance of
15 m to prevent bacterial pollution of the well
The distance between a
well and a cesspool placed
directly uphill from it should
be not less than 45 m, to prevent chemical pollution, too
Cesspools should be kept
at least 6 m away from dwelling foundations as it may
leach out
No power
requirement
No quality
control is required
Simple operational mechanism
that hardly goes
wrong
Safe from the
danger of intermittent usage
No immediate
negative environmental impact
In densely inhabited
communities where wells are
used as sources of drinking
water supply their construction is not permitted
Regular emptying is
required
Capital and operational
cost are high
Expensive construction
of underground storage
Septic
tank
Partial treatment
Requirement of seepage
No power
requirement
Poor effluent
quality
Pipe blockage
due to thick scum
formation
Possibility of groundwater contamination
Limited quality control
Suitable for individual
houses and small communities
Most useful and satisfactory unit for rural/hilly areas
Seepage
pit
Location of seepage pits
should preferably be downhill
and, in any case, at least 15 m
(50 ft.) away from drinking
water sources and wells
Adequate contact area
with the surrounding soil to
absorb the effluent in to the
soil. In clayey soil, larger pits
will be needed
No power
requirement
No quality
control is required
Almost nil
maintenance
The construction of
seepage pits is not permitted
where groundwater is used
for domestic purposes
Possibility of groundwater pollution
2 Vermifiltration for Rural Wastewater Treatment
23
listed in Table 2.1.
Adopting vermifiltration system has advantages when compared with other
commonly used biological wastewater treatment systems. According to Yang et al.
(2008), there is no sludge formation in the vermifiltration system which makes it
more convenient to operate when compared to conventional activated sludge treatment methods. Moreover, total nitrogen and total phosphorus was reported to be
tripped off 10% higher in vermifilters compared to activated sludge systems; NH
4 -N
was also removed three times more in vermifilters (Li et al. 2009).
Table 2.1 Conventional wastewater treatment options in rural areas
Treatment
system
Prerequisite
Benefits
Limitations
Cesspools Location of a cesspool
should be downhill from a
well; in any case, a distance of
15 m to prevent bacterial pollution of the well
The distance between a
well and a cesspool placed
directly uphill from it should
be not less than 45 m, to prevent chemical pollution, too
Cesspools should be kept
at least 6 m away from dwelling foundations as it may
leach out
No power
requirement
No quality
control is required
Simple operational mechanism
that hardly goes
wrong
Safe from the
danger of intermittent usage
No immediate
negative environmental impact
In densely inhabited
communities where wells are
used as sources of drinking
water supply their construction is not permitted
Regular emptying is
required
Capital and operational
cost are high
Expensive construction
of underground storage
Septic
tank
Partial treatment
Requirement of seepage
No power
requirement
Poor effluent
quality
Pipe blockage
due to thick scum
formation
Possibility of groundwater contamination
Limited quality control
Suitable for individual
houses and small communities
Most useful and satisfactory unit for rural/hilly areas
Seepage
pit
Location of seepage pits
should preferably be downhill
and, in any case, at least 15 m
(50 ft.) away from drinking
water sources and wells
Adequate contact area
with the surrounding soil to
absorb the effluent in to the
soil. In clayey soil, larger pits
will be needed
No power
requirement
No quality
control is required
Almost nil
maintenance
The construction of
seepage pits is not permitted
where groundwater is used
for domestic purposes
Possibility of groundwater pollution
2 Vermifiltration for Rural Wastewater Treatment
23