■Technical Summary□ Table of Contents【Sewage Treatment Methods】(1) Membrane bio-reactor process(2) Suspended solid method （standard activated sludge process）(3) Bio-film method(high-rate trickle filter process)(4) Wastewater Stabilization Pond
(5) Untreated Discharge(6) Sewage Treatment Tank
(7) Compost(8) Latrine for Night-soil Separation(9) Ground Treatment(10) Septic Tank （Decomposing Tank）(11) Pit Latrine(12) Vault Toilet(13) Night-soil Collection Equipment （Vacuum Pumping Truck）(14) Night-soil Treatment Facility（anaerobic digestion system, aerobic digestion system,
standard denitrification treatment system）

1
3
5
7
10
11
13
15
17
19
21
23
25
27

Technical performance

Applicable conditions

Summary(1) Technical Name: Membrane bio-reactor process
Items
Technical
features
MeritsCost

The MBR process is a suspended growth activated sludge system that utilises
microporous membranes for solid/liquid separation in lieu of secondary clarifiers.
Improved Water Quality
Option for Wastewater Reuse
Reduces Plant Space Requirements
Fewer Operational Problems

Examplecountries

Japan and many countries over the world

Water
Electricity
Suitable
locations

Required
Required more than activated sludge processes to operate membrane equipment.
Places where water can be reused for industrial water, irregation, and eivironmental
ammenities. There must be a river nearby in which the treated water can bedischarged. Site procurement and consensus from the surrounding inhabitants must beeasy. Sites with an access aisle having good ground condition with few floods.

Points toremember

Facilities are arranged on a plane; therefore, sites with bad ground conditions should
be avoided because the foundation costs will be high.

SewageTreatment Flow

Initial Sedimentation Pond → Aeration Tank→ Membrane Equipment

SludgeTreatment
Flow
Treatment

Sludge condensation process is not necessary because of operation within density ofrange from 1.0 to 1.5 % of activated sludge

targetPerformanceFinaltreatment・
Disposal
Daily
maintenanceSpecialmaintenance

Misc.Drainage/Rain water

Contents

Initial costService life

Small scaled equipment with a scale of under 3000m3 of treated water per day ingeneral. (e.g. : Japan) BOD: 5mg/L or below, SS: 5mg/L or below
Treated water can be recycled except for drinking.
Treated water is discharged into rivers. Reusable for irrigation.
Sludge is disposed of in landfill sites. Reusable as compost or soil conditioners.
Screen cleaning.
Check pumps and valves / Measure water quality of Discharge
Keep daily operation log
Backwashing of membrane modules

Cycle time of backwashing depenses on membrane material.
Less costly due to smaller scale of plants than the suspended soil method
Civil Engineering: 50 years, Machinery and Electricity: 15years, Membrane Module:
5years (e.g. : Japan)

Running cost 300 JPY per m3 including sludge treatment cost (e.g. :on experiment in Japan)
Miscellaneous Accepted as part of sewage water.
drainageRain water

In the case of a combined sewer system, the amount equivalent to that on a sunny day
can be treated up to the secondary treatment, and the excess amount is discharged
after the initial treatment.

OthersSpace-saving design allows the upper area to be easily utilized.
Desity of activated sludge/MLSS in aeration zone is range of 8000 to 15000 mg/l.

Example of Conventional Activated Sludge

Example of Membrane Bioreactor Process

Technical performance

Applicable conditions

Summary(2) Technical Name: Suspended solid method (standard activated sludge process)
Items
Contents
Technical
features
MeritsRemoval of organic substances using activated sludge (mass of microorganisms)
floating in the reactor tank.
Quality of the treated water is stabilized. Less space required.
Reduction of annoying odors.

Examplecountries

In Japan, 72% of the treatment plants exceeding 10000m3/day capacity utilize thestandard activated sludge process, and 68% of those with less than 10,000 m3/day
capacity utilize the oxidation ditch process.
Required
Required to operate equipment such as pumps, blowers, valves etc.
Places where water can flow naturally by gravity. There must be a river nearby in which
the treated water can be discharged. Site procurement and consensus from thesurrounding inhabitants must be easy. Sites with an access aisle having good groundcondition with few floods.

Water
Electricity
Suitable
locations

Points toremember

Facilities are arranged on a plane; therefore, sites with bad ground conditions should
be avoided because the foundation costs will be high.

SewageTreatment Flow

Initial Sedimentation Pond→ Aeration Tank→ Final Sedimentation Pond→ Contacting
Tank

SludgeTreatm Sludge Condensation Tank→ Digestion Tank→ Sun-drying Bed
ent Flow(In Japan, incineration is more common than sun-drying)
Treatment
targetPerformanceFinaltreatment・
Disposal
Daily
maintenanceSpecialmaintenance

Misc.Drainage/Rain water

Cost

Initial costService life
Running cost

Middle/Large scaled equipment with a scale of over 10000m3 of treated water. (e.g. :Japan)
BOD: 15mg/L or below, SS: 40mg/L or below
Treated water can be recycled except for drinking.
Treated water is discharged into rivers. Reusable for irrigation.
Sludge is disposed of in landfill sites. Reusable as compost or soil conditioners.
Screen cleaning. Check pumps and valves / Measure water quality of Sedimentation
Pond daily operation log
Keep
Based on the density of MLSS, perform desludging or adjust the amount of returnsludge.
26 billion JPY for those with a scale of 100,000m3/day (e.g. : Japan)(Sludge treatment includes condensation and dehydration)
Civil Engineering: 50 years, Machinery and Electricity: 15years(e.g. : Japan)

830 million JPY per year for those with a scale of 100,000m3/day(e.g. : Japan)(Sludge treatment includes condensation and dehydration)
Miscellaneous Accepted as part of sewage water.
drainageRain water
OthersIn the case of a combined sewer system, the amount equivalent to that on a sunny day can betreated up to the secondary treatment, and the excess amount is discharged after the initial
treatment.

Space-saving design allows the upper area to be easily utilized.
<Facility Tour available at>・Nijino Gesuidoukan in Ariake Koto Ward, Tokyo http://www.nijinogesuidoukan.jp<List of Tokyo Water Reclamation Centers which accept visitors>
http://www.gesui.metro.tokyo.jp/odekake/sise_list.htm
・ Mikawashima Water Reclamation Center(Exhibit pictures showing the transition of
sewage Water
treatment
plants) Center(state of the art facility)
・Ariake
Reclamation<Sewer Culvert Tour>・ Mizuno Yakata in Kuramae Taito Ward, Tokyo
http://www.gesui.metro.tokyo.jp/odekake/s_kuramae.htm

Figure T-1 Sample Configuration of Standard Activated Sludge System(upper)
and Oxidation Ditch System(lower)
Reference: “Sewage Facilities Planning・Design Manual and Description-post edition, 2001”
Japan Sewage Works Association

1

Abukuma River

11

2

Reactor tank

123

Initial Sedimentaion
Pond office
Administration

13
15

Outlet16

7

Sludge treatment
Sludgebuilding
Concentration
Tank
Outlet17

Chlorine Contacting
Tank
Final Sedimentation

8

Outlet Pipe

18

Pond
Inlet
Beam

9

Final Sedimentation
Pond
Inlet
Pipe

19

Distribution

20

Oxydation Ditch

4
5
6

10

14

Grit Chamber Pump・
BlowerDevice
Chlorination
Private Power
Generation
DrainageCanalTechnical performance

Applicable conditions

Summary(3) Technical Name: Bio-film method(high-rate trickle filter process)
Items
Contents
Technical
Removing organic substances by using the bio-film on the surface of a filter made fromfeaturescrushed stone.
Merits

Maintenance is easier and is more flexible to fluctuations when compared to thestandard activated sludge process. Odor is a concern.

Examplecountries

Japan(Many were constructed before the 40th year of the Showa Era.)

Water
Electricity

Required
Rotary sprinkler rotates spraying sewage water when a hydraulic head pressure of 50
to 100cm is applied.

Suitable
locations

Same as that of the standard activated sludge process.

Points torememberDue to concerns of odor or flies, it is preferred to be located away from urban
areas.(can be reduced by circulating treated water)
Water levels vary greatly from facility to facility compared to those using the standard
activated sludge process.

SewageTreatment
Flow

Initial Sedimentation Pond → Trickle Filter → Final Sedimentation Pond → Contiguous
Tank

SludgeTreatment
Flow

Sludge Condensation Tank→ Digestion Tank→ Sun-drying Bed

Treatment
targetNo limitations

PerformanceFinaltreatment・
Disposal

BOD: 60mg/L or below, SS: 120mg/L or below
Treated water can be recycled except for drinking.
Treated water is reusable for irregation.
Sludge is disposed of in landfill sites.
Screen cleaning
Check pumps and valves
Measure water quality
Keep daily operation log
Check the rotary sprinkler

Daily
maintenance

Misc.Drainage/
Rain water

Cost

SpecialmaintenanceInitial costLess costly than the standard activated sludge process.

Service life
Running cost
Misc.
Drainage

Civil engineering: 50 years, Machinery and Electricity: 15years
Less costly than standard activated sludge process
Treatable as part of sewage water.

Rain water
OthersIIn the case of a combined sewer system, the amount equivalent to that on a sunny day
can be treated up to the secondary treatment, and the excess amount is discharged
after the initial treatment.
<Facility Tour available at>
Jonan Water Reclamation Center in Takasaki
Yuzawa Water Quality Management Center in Shibukawa
Monokikizawa Water Quality Management Center in Shibukawa etc.

Figure T-2 Trickle Filter process
Source: “Operation of Municipal Wastewater Treatment Plants Volume II: Liquid Processes – Sixth Edition”,

Water Environmental Federation (WEF)Summary(4) Technical Name: Wastewater Stabilization Pond
Items
Contents
Technical
The easiest treatment method utilizing natural processes.
features
MeritsAlthough it requires a large area, power is not needed when using natural processes.

Examplecountries

There are no examples in Japan, but it is employed in many countries.
Not required
Basically power is not required within treatment plants, but pumps are required in somecases for discharging.

Suitable
locations

Largest area is required among the treatment methods.
In rapidly urbanized areas, it is preferred to arrange sites for construction well inadvance because site procurement will become harder along with the surging land
prices.
Irregularly shaped sites can be modified by the shape of the ponds.

Points torememberDue to the odor, it is preferred that Anaerobic Ponds to be located 1000m away, andFacultative Ponds 500m away from the residential area.

SewageTreatment
Flow

There are various combinations of Anaerobic Ponds→ Facultative Ponds→ Maturation
Ponds

SludgeTreatment
Flow

Daily sludge treatment is not necessary, but desludging is required once every 5 to 10
years.

Treatment
targetNot suitable for treating large amounts of sewage water because it requires bigger
space.

PerformanceFinaltreatment・
Disposal

BOD removal rate: 94%, removal rate of fecal coliform bacterium: 99.95%
Treated water can be recycled for irrigation.
Sludge is concentrated, digested, sun-dried and disposed of as landfill.

Daily
maintenance

Remove floating substances and waterweeds; remove weeds on the edge of the pond.

Specialmaintenance----Initial costLess costly compared to the standard activated sludge or high-rate trickle filter
processes.(except for land expenses)

Service life

50 years
Less costly compared to standard activated sludge high-rate trickle filter processes.
Treatable as part of sewer water.

Cost

Technical performance

Appl Water
icabl Electricity

Misc.Drainage/
Rain water

Running cost

Misc.
DrainageRain water
OthersFew examples of wastewater stabilization pond utilization for combined processes.
Cities where urbanization is not easily predictable, treatment methods can be changed
according to the development situation.
No examples in Japan.

A: Anaerobic Pond F: Facultative Pond M: Maturation Pond
Figure T-3 Combinations of Wastewater Stabilization Pond Process
Table
T-1 Removal Rate per combination ofWastewater Stabilization Ponds
Combinati
Coliformons
BOD (%)
Bacteria
12ºC
20 ºC
25 ºC
12 ºC
20 ºC
25 ºC
Anaerobic Pond
A
45
62
70
60
86
93
A+F
80
88
90
96
99.5
99.2
86
92
94
99
99.97599.95
A+F
F ++ M
M
+M+M
94
95
95+
99.95
99.9996 99.99999
Facultative Pond
F
75
80
84
91
97
98
86
90
93
98.2
99.94
99.98
F +FM+ +MM
+M
93
95
95+
99.9
99.998 99.99993

A: Anaerobic Pond (2 days) F: Facultative Pond (7 - 15 days) M:
Maturation Pond (5 days after Facultative Pond)
Note) Ordinary household sewages
Source: J. P. Arthur, "(World Bank Technical Paper No. 7) Notes on the
Design and Operation of Waste Stabilization Ponds in Warm Climates ofDeveloping Countries", November 1983

Table T-2 Detention period & Site space required to achieve the water emission standard.
Combinations
Water
Detention period (days)
Square measure (ha)Required
supplied
power
12℃
20℃
25℃
Unit
12℃
20℃
25℃
(kw)
(1000)10
2.2
1.6
1.1
25
5.5
4
2.6
A+F+M
29.7
18.8
13
50
10.7
7.7
5.1
100
20.9
15.1
10.1
250
50.8
36.5
24.3
10
3.9
2
1.4
25
9.5
4.9
3.5
F+M
48.9
25.4
17.6
50
18.5
9.4
6.8
100
36.4
18.5
13.3
250
88.2
44.9
32.2
10
2.6
1.8
1.3
25
25
6.3
4.3
3.2
63
A: Anaerobic Pond

F: Facultative Pond

M: Maturation Pond

BOD5 25mg/l, Coliform Bacteria Count 5,000/100ml
Water emission standard:
Assumed conditions:
Water consumption volume
130 lpcd
Sewage conversion ratio
80 ％Daily BOD loading amount per person
40 gpcd
Water depth
A (4.0 m), F (1.8 m), M (1.5 m)
Detention period
M (5 days)
Coliform Bacteria in sewage water
2 x 107/100 ml
Source: J. P. Arthur, "(World Bank Technical Paper No. 7)
Notes on the Design and Operation of Waste Stabilization Ponds
in Warm Climates of Developing Countries", November 1983

Technical performance

Applicable conditions

Summary(5) Technical Name: Untreated Discharge
Items
Contents
Technical
Apply sedimentary sand, screening or precipitation treatment of sewage water before
featuresdischarging into the ocean.
MeritsExcept for implementing precipitation treatment, sewage/sludge treatments are notrequired.

Examplecountries

The Philippines(Manila)
No examples in Japan.
Not required
Power is used for precipitation treatment or pumping.
Places facing the open sea without public beaches.

Water
Electricity
Suitable
locations
Points toremember

It is necessary to check the diffusion and effect by implementing marine contamination
analysis based on the tidal current investigation. Sea outfall is prohibited in the
Mediterranean Sea.

SewageTreatment
Flow

Screen→ (Sedimentation Pond)→(Pumping)

SludgeTreatment
Flow

----

Treatment
targetNo limitations

PerformanceFinaltreatment・
DisposalSame as crude sewage without precipitation treatment.
----

Daily
maintenance

Screen cleaning.
Check the equipment.
A diver must be used to inspect the sea outfall pipes.

Misc.Drainage/
Rain water

Cost

SpecialmaintenanceInitial cost----Service life
Running cost
Misc.
Drainage------Treatable as part of sewage water.

Rain water
OthersFew examples of direct discharge among combined systems.
----

Applicableconditions

Summary(6) Technical Name: Sewage Treatment Tank
Items
Contents
Technical
Treating drainage water from houses, apartment complexes, housing complexes orfeaturescommercial facilities within the site. Performance can be arranged based on thedrainage standards. Planning through operation can be achieved within a short periodof time.
MeritsPlanning through operation can be achieved within a short period of time.
Sewer culvert works are mitigated, leading to a reduction of construction cost.
Damage from earthquakes can be minimized.

Examplecountries

Indonesia, Romania, South Korea, China, Australia etc. (Applicable to the regions in
the West where Septic Tank + Ground Treatment)

Water
Electricity
Suitable
locations

Required
Basically required but can be substituted by installing a natural depuration system.
----

Points toremember

A consistent system from cultivating human resources for designing, construction,
maintenance and sludge treatment that are appropriate to each building usage.

Misc.Drainage/
Rain water

Cost

Technical performance

Night soil
Drainage water ⇒ Initial treatment ⇒ Secondary treatment ⇒ Tertiary treatment ⇒treatment flow Sterilization⇒ Discharge(Advanced treatments can be set in if necessary)
Treatment
targetDepending on the equipment scale.

Performance

General Value(ordinary treatment)
e.g. BOD :( 90,60,30),20,15,10,5mg/L or below,
COD :30,20,10 mg/L or below , T-N::20,15,10 or below ,T-P :1,0.5 mg/L or below

Finaltreatment・
DisposalTreatment and disposal of excessive sludge are required.

Daily
maintenanceContact a special maintenance provider in case of abnormal noise, vibration or odor.

Specialmaintenance

Periodical maintenance(individual residences: once every 4 months, middle/large sizedbuildings: once every 1 to 2 weeks), Cleaning(desludging), legal inspection (once a
year)

Initial cost

Vary from individual residences to middle/large-sized buildings.
(See TECHNOLOGIES on WEPA’s website)

Service life

Building frames: FRP(Fiber Reinforced Plastic),DCPD(Decyclo Pentadiene)will last
over 30 years

Running cost
Misc.
Drainage

Same as the initial cost.
In general, night-soil and other misc. drainage are treated altogether.
Night-soil can be treated alone (Misc. drainage water is discharged without treatment)

Rain water

Rainwater is drained into a separate line.
Hazardous substances are treated separately.

OthersExporting sewage treatment tanks manufactured in a factory involves enormous costs.
Local production or cast-in-place constructions are necessary.
<Contact for Facility Tour>Japan Education Center of Environmental Sanitation(Sumida Ward, Tokyo)
http://www.jeces.or.jp/

Figure T-4 Section view of Anaerobic Filter-bed Aeration

Figure T-5 Product samples of contacting or filtering materials

(7) Technical Name: Compost

Applicable conditions

Summary

Items
Technical
features
MeritsContents
Mixing and agitating night-soil with cedar chips or sawdust to treat and reduce theamount through evaporation and aerobic fermentation.
Water is not required for toilet/night-soil treatment.
It can be introduced at a low cost by operating manually instead of using mechanicalagitation.

Examplecountries

Japan

Water
Electricity
Suitable
locations

Not required
Required for mixing and agitating but it can be substituted by manual operation.
Equipment for dehydration is required in humid regions.

Points toremember

Do not use chemicals for cleaning.

Technical performance

Night soil
Toilet→ Compost Tank→ Evaporation・Residues
treatment flow
Treatment
targetApprox. 50 times/day(depending on the equipment scale)

Performance

General Value(ordinary treatment); Design Value BOD around 10mg/L

Final
treatment・
DisposalTreated /disposed as Soil Conditioner or Industrial Waste.

Daily
maintenance

Screen cleaning.
Check pumps and valves / Measure water quality of Sedimentation Pond
Keep daily operation log
Equipment inspection. Change compost materials.

Misc.Drainage/
Rain water

Cost

SpecialmaintenanceInitial cost

Equipment 3,200,000 JPY(spec: 50times/day)(Japan)

Service life
Running cost–
Japan(approx. 100,000JPY/year)

Misc.
Drainage

Non treatable

Rain water

Rainwater cannot be treated with this technology. Some measures must be taken toprevent rainwater from flowing into the equipment.

Others<Sample facilities (Tokyo metropolitan regions) >Shimin Kenko no Mori (Citizen’s Forest for Health) in Aso Ward, Kawasaki
Akiruno-shi Water Purification Plant, Tokyo
Koiwa Shobu-en in Edogawa Ward, Tokyo
Okinoshima Park in Tateyama, Chiba

ToiletCompostTank

Evaporation,
residue removal

Figure T-6 Treatment flow

Figure T-7 Toilet appearance

Figure T-9 Compost Tank

Figure T-8 InsideApplicable conditions

Summary(8) Technical Name: Latrine for Night-soil Separation
Items
Contents
Technical
Separating night-soil for recycling.
features
Setting 2 pits with openings in the ground in parallel, and install toilet bowls on them.
Use the pits alternately at an interval of approx. 6 months.
Urine is separated for removal to be used as liquid fertilizer.
When the pit is full, promote composting within the tank.
MeritsExamplecountries

There is no need for concern about groundwater contamination. Less odor and fly
occurrence.
More
examples in Asian countries such as North Vietnam.

WaterElectricity
Suitable
locations

Not required
Not required
Places with environments for fermentation and dehydration.

Points toremember

The idea of turning night-soil into compost must be accepted.
Provide thorough instruction on generation and utilization methods of liquid fertilizer orcompost.
In regions where people have the custom of washing their buttocks with water after
defecation, the water must be prevented from entering the pit. In regions with thecustom of wiping with paper, the paper used for wiping must be collected and treatedseparately.
It is hard to ensure the utilization method. Management of compost generation isrequired.
(1) Toilet Bowl→ (2) Pit→ (3)Composting
Adjust the water (dehydration) by throwing ashes into the pit after defecation. It iseffective to promote dehydration with the solar heat. Use one of the tanks for around 6
months, and when it’s full, cover it with ashes until bacteria compost it(around 6
months)Depending on the tank capacity.

Misc.Drainage/
Rain water

Cost

Technical performance

Night-soil
Treatment
Flow
Treatment
targetPerformanceFinaltreatment・
Disposal

Susceptible to climate conditions.
Urine is utilized for liquid fertilizer.
Solid waste is utilized for compost or soil conditioner after implementing degradation
treatment for around 6 months.

Dailymaintenance

Save ashes to throw in the pit.
In the case of a toilet bowl or hole being prepared for each pit, be sure to seal the filled
up one to keep them from being used.

SpecialmaintenanceCheck the progress of composting.

Initial cost

Reasonable

Service life
Running cost
Misc.
Drainage

Reasonable
Non treatable-

Rain water
OthersNo examples in Japan

Figure T-10 Example of Latrine for Night-soil Separation
Source: Excreta disposal in emergencies/Loughborough University

Misc.Drainage/
Rain water

Cost

Technical performance

Applicable conditions

Summary(9) Technical Name: Ground Treatment
Items
Contents
Technical
After treatment in an Anaerobic Digester Tank, the treated water passes through thefeaturesspray tube buried underground so that it is soaked in the ground and treated by
microbes.
MeritsDue to its simple structure, it is hard to break and the maintenance is comparativelyeasy.
It can be utilized in regions without electricity by using foot pumps.

Examplecountries

Japan

Water
Electricity
Suitable
locations

Required(Approx. 250cc of cleaning water per use)
Required for operating electric pumps.(Not required when using a foot pump)Places where the ground is suitable for night-soil treatment and space for installing
ground treatment equipment is available.
Not suitable to regions with heavy rainfall.
There is also a concern that the equipment may become unserviceable due to snow or
freezing.

Points toremember

Measures must be taken to prevent sewage water or sludge from leaking out of thesystem.
Soil replacement or desludging is required in the long run.

Night-soil
Treatment
Flow

Toilet→ Anaerobic Treatment→ Spray Tube→ Cleaning Water Recycling

Treatment
targetApprox. 160times /day (depending on the facility scale)

PerformanceFinaltreatment・
Disposal

General Value(ordinary treatment); Design Value BOD around 10mg/L
Sludge (Night-soil Treatment Facilities)

Daily
maintenanceChecking tube blockage or maintenance does not require advanced skills.

SpecialmaintenanceCheck the operation conditions.

Initial cost

Equipment 4,210,000JPY (spec: approx. 160 times/day)

Service life
Running cost
Misc.
Drainage

Japan (approx. 20,000JPY/year)
Although it depends on the drain load, it is basically non-treatable.

Rain water
OthersBecause rainwater cannot be treated with this method, measures must be taken toprevent large amounts of rainwater from entering the soil treatment equipments.
<Contact for Facility Tour>
Reinforce Co., Ltd.(Kamakura-shi, Kanagawa)
http://www.reinforce.co.jp/

Cleaningwater

ToiletAnaerobic
treatment

Soiltreatment

Figure T-11 Treatment Flow

Figure T-12 Ground Treatment Tank

Figure T-13 Ground Treatment Tank

Figure T-14 Ground Tank

Technical performance

Applicableconditions

Summary(10) Technical Name: Septic Tank(Decomposing Tank)
Items
Contents
Technical
Night-soil flushed with cleaning water is treated for a period of 1 to 3 days in a tankfeaturesburied underground.
Treated water is discharged or allowed to seep underground.
The main purpose is to remove solid substances by precipitation. Therefore, sludge willaccumulate at the bottom of the tank. Oil contents float to the surface to create scum.
Sludge and scum must be removed accordingly.
Quality of the treated water is bad due to anaerobic treatment.
It is not safe from a microbiological viewpoint.
MeritsFlush toilets create a comparatively cozy space. Generation of odor or flies can besuppressed though it is influenced by maintenance conditions.
Misc. Drainage can be treated simultaneously.
Examplecountries

Developing countries in general

Water
Electricity
Suitable
locations

Water sufficient to flush excretory substances into the decomposing tank is necessary.
Not required
Places where treated water can be discharged or seep underground.
It must be placed at least 30m away from water well sources.

Points toremember

It should not be used widely without sanitary considerations, because it can lead tocontamination of surrounding waters unless managed adequately.

Night-soil
Treatment
Flow

Toilet bowl→ Decomposing tank(Removing solid substances)→ Discharge orUnderground seepage

Treatment
targetDepending on the equipment scale

PerformanceFinaltreatment・
Disposal－Removal and disposal of sludge and scum are necessary.

Daily
maintenance－Specialmaintenance・Removal and disposal of sludge and scum are necessary.(Sludge and scum must be
removed when sludge accumulates to 1/2 to 1/3 of the effective water depth between
the liquid surface and the bottom) A vacuum truck is preferred for sludge removal.
However, it must be done manually in case vacuum trucks are not available. In thatcase, special attention must be paid for diseases resulting from excrement.
Sludge should not be totally washed off nor disinfected. Digestion by anaerobic bacteria
will continue by leaving a small amount of sludge in the tank.
Africa (approx. 12,700JPY/person)
Asia (approx. 11,400 JPY/person)
Latin America・Caribbean countries (approx. 17,600 JPY/person)

Misc.Drainage/
Rain water

Cost

Initial costService life
Running cost
Misc.
DrainageRain water
OthersDepending on septic tank materials.
Water bill, removal fee of sludge and scum.
Treatable but water contamination due to increased water discharge will be a concern.
Non-treatable
No examples in Japan

Figure T-15 Septic Tank
Source：Excreta disposal in emergencies / Loughborough University

(11) Technical Name: Pit Latrine
Items
Contents
Technical
Penetrating fluid in urine through the walls or bottom of the pit to the ground. Residualfeaturessludge is accumulated in the tank. Solid substances will be reduced by anaerobic
digestion.
It can be used for a long time and is hard to break. The equipment can be installed at acomparatively low cost. Periodical cleaning of the upper buildings and slabs as well as
ventilation is needed to minimize odor creation. The number of flies can be reduced bycovering the opening of the ventilation pipe with a net and making the upper building
dark.
It is easy to understand how to use.

Examplecountries

Developing countries in general

Water
Electricity
Suitable
locations

Not required (except for Flush Latrine)
Not required
Places where the ground can be dug with low groundwater level in regions free fromflooding.
In the case of utilizing Pour flush toilets, water for flushing must be ensured.

Points torememberMosquito emergence is unavoidable. Rain water may flow in and cause the toilets tooverflow. Underground water may be contaminated. When a pit becomes full, a new
toilet needs to be facilitated. It must be located more than 18m away from any water
source.

Night-soil
Treatment
Flow

Toilet bowl→ Pit→ Fluid goes to the soak field. Solid substances are accumulated.

Treatment
targetPerformanceFinaltreatment・
Disposal

Depending on the equipment scale－
When a pit becomes full, cover up with soil and leave for around 2 years.
To use the same tank continuously, sludge must be removed.
This is not the original usage.

Daily
maintenanceIf the upper structure has a door, keep it closed to improve airflow, as well as make itdark to prevent fly emergence.
Opening for air inlet must not be closed. Check the anti-fly net set to the upper end of
the ventilation pipe.
Remove cobwebs in the ventilation pipe.

SpecialmaintenanceTrap management(Pour flush latrine)
Removal and disposal of the sludge as required.

Initial cost

Pit latrine (approx. 4,300JPY/person)(Countries in Africa)
Pit latrine with improved ventilation(approx. 6,300 JPY/person) (Countries in Africa)
Pour flush latrine (approx. 10,000JPY/person) (Countries in Africa)

Service life
Running cost

(Around 2 years)－－

Misc.Drainage/
Rain water

Cost

Technical performance

Applicable conditions

Summary

Merits(cost perperson(JPY))
Misc.
Drainage

Non-treatable

Rain water－

OthersNo examples in Japan

Figure T-16 Pit Latrine

Figure T-17 Pit Latrine with Improved Ventilation

Figure T-18 Pour Flush Latrine
Source：Excreta disposal in emergencies / Loughborough University

Misc.Drainage/
Rain water

Cost

Technical performance

Applicable conditions

Summary(12) Technical Name: Vault Toilet
Items
Contents
Technical
Consisting of toilet bowl, piping, pit and ventilation device. Stored night-soil must befeaturesremoved periodically.
Tank capacity is for 2 to 3 months.
Flush down system using a small amount of water (Simplified Flush Toilet) is available.
MeritsBecause night-soil is not mixed with water, it can be pooled effectively.

Examplecountries

Japan, China, South Korea

Water
Electricity
Suitable
locations

Not required
Not required
In regions where a sewage system is not established.
Collection・Treatment systems must be established.

Points toremember

Measures to prevent odor and unsanitary insects must be taken.

Night-soil
Treatment
Flow

Toilet bowl→ Dropping down by gravity→ Storage→ Collection

Treatment
target－PerformanceFinaltreatment・
Disposal－
Night-soil Treatment Facilities, Sewage System

Daily
maintenance－SpecialmaintenanceRegular vacuuming

Initial cost

Depending on the material of the pit.

Service life
Running cost
Misc.
Drainage－
Vacuuming costs
Non-treatable

Rain water
OthersConsider the ground levelFigure T-19 Schematic View of Vault Toilet

Misc.Drainage/
Rain water

Cost

Technical performance

Applicable conditions

Summary(13) Technical Name: Night Soil Collection Equipment (Vacuum Pumping Truck)
Items
Technical
features

Contents
Vehicles with tank and vacuum equipment for collection and transportation of night-soil.
Reduce the pressure inside the tank with a vacuum pump so that the night-soil isdirectly aspirated into the tank through a hose using the pressure difference. There is avacuum dumper type that has greater suction. Discharging is accomplished by opening
the hatch.

Merits

Efficient removal・transportation

Examplecountries

Japan, China, South Korea, Indonesia, Vietnam

Water
Electricity
Suitable
locations－－
Vehicle maintenance system must be established.

Points toremember－Night-soil
Treatment
Flow

Pit→ Vacuum Equipment→ Storage Tank→ Transportation

Treatment
targetTank Capacity: 1.8－10m3, Vacuum Power: 700mmHg

PerformanceFinaltreatment・
Disposal－
Night-soil Treatment Facilities

Daily
maintenance

Clean the inside of the tank and replace the e ngine oil.

Specialmaintenance

Maintenance of the vacuuming equipment.

Initial cost

4 ton truck: approx. 7million JPY

Service life
Running cost
Misc.
Drainage

Around 7 years.
－－

Rain water
Others－－Figure T-20 Vacuum Truck

Figure T-21 Vacuum Dumper Truck

(14) Technical Name: Night-soil Treatment Facilities((i)Anaerobic digestion system, (ii)Aerobic digestion system, (iii)Standard denitrification system)
Contents
Facilities where night-soil and sludge stored in pits or individual wastewater treatment
units are collected and treated altogether. ((i)Take out biogas using anaerobic microbes
and utilize it for heating the digestion tank. (ii)Decompose organic substances using
aerobic microbes. (iii)Facilities where night-soil and sludge stored in pits or individual
wastewater treatment units are collected and treated altogether. Nitrogen is removed
using nitrification bacteria and denitrifying bacteria.)

Merits

Efficient treatment of highly concentrated liquid waste is available.
Effective utilization of Biogas.

Examplecountries

Japan

Water
Electricity
Suitable
locations

Water of 10 to 20 times is required for dilution.
40 to 60kWh/m3
Collection system must be established. Water volume of 10 to 20 times of waste isrequired for dilution. ((i)Anaerobic Digestion: Regions with high temperature)

Points toremember

Plant Installation space and advanced maintenance technique will be required.

Night-soil
Treatment
Flow

Acceptance→ Pre-treatment→((i)Anaerobic digestion (ii)Aerobic digestion (iii)Bio
denitrification treatment)→Secondary treatment→ Discharge(Excess sludge:
Concentration→ Dehydration→(Drying))

Treatment
target－Performance

General Value (ordinary treatment); Treated water quality: BOD20mg/L or below,
SS70mg/L (in case activated sludge treatment is executed as Secondary Treatment.)((iii)Standard Denitrification System: T-N60mg/L or below)

Finaltreatment・
DisposalSludge: Composting, Incineration

Daily
maintenance

Resident operation management(Device control, Data management, water quality
management etc.)

SpecialmaintenanceRegular inspection of the equipment.

Initial cost

1 to 2 billion JPY for those with a scale of 100m3/day(e.g. : Japan)

Service life
Running cost
Misc.
Drainage

Civil Engineering: 30 years, Machinery and Electricity: 10 years
37 to 73 million JPY for those with a scale of 100m3/day(e.g.: Japan)
Non-treatable

Rain water

Consider the ground level.

Misc.Drainage/
Rain water

Cost

Technical performance

Applicable conditions

Summary

Items
Technical
featuresOthers

Requiring high running cost((ii)Reasonable compared to anaerobic system)<Examples in Japan><Standard Denitrification System>
・Ashikaga City Tobu Clean Center, Tochigi prefecture, 175 kiloliter/day, Date ofcompletion: March, 1993
80 Yamakawa-cho Ashikaga-shi 0284-41-5740
・Ota City Second Clean Center, Gunma prefecture, 120 kiloliter/day, Date ofcompletion: March, 1995
(1296-1 Takabayashi Higashi-cho, Ota-shi 0276-38-0420)
・Washimiya Eisei Kumiai Night-soil Treatment Plant, Kurihashi, Saitama prefecture, 53
kiloliter/day, Date of completion: March, 1995
(2525 Happo Oaza Washimiya-cho, Kita Katsushika-gun, 0480-58-1309)
・Kisai-cho Clean Center, Night-soil Treatment Plant 75kiloliter/day, Date of completion:
March, 1991
(1790 Oaza Mouchi, Kazo-shi Saitama pref. 0480-61-3671)
・Chiba City Clean Center
173kiloliter/day, Date of completion: August, 1995
(893 Murata-cho Chuo-ku Chiba-shi, 043-261-2256)
・Futtsu City Clean Center
68kiloliter/day, Date of completion: March, 1997
(12-1 Shintomi Futtsu City, 0439-88-1350)＜Others＞
ST(Septic Tank) Sludge adaptive High-load Filtration System
・Kumagaya City Night-soil Treatment System
42 Kiloliter/day, Year of completion: 2005
・Hanyu City Night-soil Treatment Plant
60 kiloliter/ day, Year of completion: 2005
High load Treatment System
・Futtsu City Clean Center
35 kiloliter/day, Year of completion: 2005

Figure T-22 Anaerobic Digestion Treatment System

1
2
3
4
5
6
7
8
9
10

Inlet ・Residue Removal
Storage
Initial Digestion Tank
Secondary Digestion Tank
Steam for heating
Desulfurizer
Gas tank
Boiler
Dilution Water
Aeration Tank

11
12
13
14
15
16
17
18
19

Sedimentation Tank
Disinfection Tank
Discharge
Measuring Tank
Digested sludge
Dehydrated Sludge
Returned Sludge
Dehydrated Sludge
Concentration Tank

Figure T-23 Aerobic Digestion Treatment
1
2
3
4
5
6
7
8

Inlet ・Residue Removal
Storage
Aerobic digestion tank
Initial Sedimentation Tank
Returned Sludge
Dehydrated Sludge
Digested Sludge
Measuring Tank

9
10
11
12
13
14
15

Dilution Water
Aeration Tank
Concentration Tank
Returned Sludge
Secondary Sedimentation Tank
Disinfection Tank
Discharge

Figure T-24 Standard Denitrification Treatment System