Reclaimed Water Supply Facility

Reclaimed water has many practical uses.
Uses for Reclaimed Water
Toilet Water
Ponds
Train washing
Fountains
Ariake Water Reclamation Center
Reclaimed Water Supply Facility
Ariake Water Reclamation Centor
Murmuring ponds
Plant watering
Machine cooling
Building washes
Advanced Water Treatment Building
and
Reclaimed Water Supply Facility
How Is Reclaimed Water Used ?
Ariake
Water Reclamation Center
[ Water Reclamation Center facilities ]
[ Water Reclamation Center f grounds ]
◆ Toilet flushing
◆ Machine cooling and shft sealing water
◆ Facility wash water
◆ Ponds and murmur ponds
◆ Fountains
◆ Plant watering
600mm pipes
Reclaimed water line
[ Businesses and multifamily housing complexes ]
◆ Toilet flushing
◆ Washing Yurikamome Line train cars
450mm pipes
Rinkaifukutoshin District 448 hectares
[ Pumping stations ]
◆ Toilet flushing
◆ Facility cleaning
Recycled water is provided to commercial building
( stores and offices ), multifamily housing
complexes, schools, hospitals and parks. It is used
mostly for flushing toilets and cleaning but also to
wash Yurikamome Line train cars. Recycled water
is also used at the Ariake Water Reclametion
Centaer and Pumping station for a number of
purposes.
Metopolitan Tokyo is working toward an ideal water environment by providing
stable water supplies and realizing effective utilization of water resources. As
part of these efforts, the Tokyo Bureau of Sewerage produces reclaimed water
from treated wastewater and supplies it to building in redevelopment district.
Three treatment facilities in Tokyo provide reclaimed water : Ariake
( Rinkaifukutosshin district ), Ochiai ( Nishi-Shinjuku and Nakano-Sakaue
districts ) and Shibaura ( Shinagawa Sta. East, Osaki and Shiodome districts ).
Ariake Water Reclamation Center has been supplying Rinkaifukutoshin with
reclaimed water via an area-wide circulation loop since 1996. The district is
designated as a core metropolitan cebter for urban facilities development and is
noted for its future-oriented, self-contained and low-water design. Garbage
disposal and wastewater treatment, for example, are part of a closed system in
which waste processes are handled locally. Reclaimed water is supplied to
commercial buildings, and the Rinkaifukutoshin district is also the only area in
Tokyo where reclaimed water is provided to homes.
The Reclaimed Water Supply Facility is located in the first and second floors of
the Advanced Treatment Building. The third, fourth and fifth floors of the building
house the Koto City Sports Center Training Gym and a heated pool that are
open to the public.
Facility Information
Various Uses
for Reclaimed Water
・Location : 2-3-5 Ariake, Koto City, Tokyo
・Site area : 4.7 ha
・Planned coverage : 681 ha ( Rinkaifukutoshin district ( 448 ha ) + surrounding districts ( 233 ha ) )
・Planned treatment capacity : 120,000 m3/day
・Current treatment capacity : 30,000 m3/day
・Planned reclaimed water volume : 30,000 m3/day
・Current reclaimed water facility capacity : 15,000 m3/day
・Start of operations : February 1996
・Main uses of reclaimed water : toilet flushing, train washing ( Yurikamome Line Cars ), miscellaneous use
・Selling price : 273 yen/m3 for commercial use, 315 yen/month per household in housing complexes
・Number of supplied facilities ( end of 1998 ) : 74 ( 61 comercial buildings, 13 housing complexes )
・Supplied volume of reclaimed water : 2,470 m3/day
Reclaimed water can be used for
much more than flushing toilets. It
slso used to wash trains cars,
water plants and wash down road
surfaces. In 2004, the Bureau of
Sewerage established its Earth
Plan, which promotes the effective
use of reclaimed water for
environmentally friendly urban
development.
Biological Filtration Tank
Remaining organic matter ( BOD ) and suspended solids in
secondary effluent can be effectively removed in biological filtration
tanks. In this filter, secondary effluent is passed down through a
packed bed of granular anthracite. Diffusing air up through the
bottom of the bed causes the formation of a biofilm of anaerobic
organisms that break down dissolved organic matter.
Ozone Generator
Quality of Reclaimed Water
( Item )
( FY2008 Performance )
BOD ( mg/l )
COD ( mg/l )
pH *
E. coli *
Chromaticity ( index ) *
Turbidity ( index ) *
Odor *
Chloride ions ( mg/l )*
Free residual chlorine ( mg/l ) *
Combined residual chlorine ( mg/l ) *
1
7
7.4
Not detected
4
0.6
Offenseless
150
0.48
0.57
( Self-Monitoring )
Self-Directed
Environmental Management
---------Not detected
less than 5
less than 2
Offenseless
less than 250
more than 0.1
more than 0.4
We have set management
standards that exceed the water
quality values required by law in
order to provide the best quality of
reclaimed water possible.
Ozone ( O3 ) can be created by discharging oxygen ( O2 ). Heated
air is sent into the many discharge tubes inside the generator, and
a high voltage ( 1 kHz, AC6-7V ) is applied to synthesize ozone.
This ozone is then diffused into biofiltered water that has been
pumped into the ozone contact tank to decolor, deodorize and
disinfect the water.
Ozone Destructor
As ozone is a harmful substance, any unreacted ozone remaining
in the contact tank must be collected and made harmless. Off-gas
from the contact tank is passed through an activated charcoal bed
in the ozone destructor, where any remaining ozone is absorbed
and neutralized. The air is Than released into the atomsphere.
* Samples taken from the center pumping station.
Flowchart of Water Reclametion Facility
Water treatment facility
Secondary treatment tank
Advanced
treatment building
Biological filtration tank ( future )
B line ( 5,000m3/day x 6 tanks )
Infusion point for hypochlorous
Pumping Station
Biological filtration tank
B line ( 5,000m3/day x 6 tanks )
Activated
filter tank
( future )
Treatment
tank
A-2
Backwash
tank
A
Treatment
tank
A-1
Exhaust
Reclaimed water
hypochlorous acid infusion point
Distribution
tank
Chlorine
contact
tank
To ventilation
/ air supply
Ozone destroyer
Clean water infusion
(850m3/day)
Hypochlorous
acid tank
7 m3
External air
Advanced
treatment
building
Bypass route
Discharge to
Ariake-Nishi Canal
From ventilation / air supply
Ozone generator
Backwash
tank
B
Treatment
tank
B-1
Treatment
tank
B-2
Ozone
contact
tank
Service
reservoir
B-1
Misc. use water
( Maintenance Bldg.
misc. use water tank )
Service
reservoir
B-2
Water for miscellaneous use
( Maintenance Bldg. 9F )
To water quality lab
( Maintenance Bldg. 4F )
Reclaimed water receiving tank
( Maintenance Bldg. 4F )
Residual chlorine
meter
To sludge storage tank
The station automatically pumps a fixed amount of returning water
from the circulation loop to maintain water pressure. Additionally,
supply and return lines are fitted with residual chlorine meters that
continuously monitor the water to ensure appropriate
consentrations of residual chorine.
Ozone Generator
( Advanced Treatment Bldg. 2F )
To biological filter tank
Residual
chlorine meter
( for supply
water )
Connecting pipe to treatment tank 1
Connecting pipe to treatment tank 2
P8 / Grit chamber
Reclaimed water
pressure adjustment tower
( Φ 800 × Φ 350 )
[ Closed ]
Internal reclaimed water
receiving tank pump unit
From
miscellaneous
use water
Feed pump
Ozone generator
Return water pipe ( Φ 450 )
Emergency line
Rinkaifukutoshin
district
( customers )
Additional facilities in 2008
Receiving
well
To water quality lab
Reclaimed water distribution tank
A-6
Water supply pipe ( Φ 600 )
Fiber-Membrane Rapid Filter
A-5
A-4
A-3
A-2
A-1
This filter was installed in 2001 to ensure water quality and prevent
contaminetion with chironomid ( bloodworm ) eggs and parasites.
The filter membrane is made up of 3mm thick polypropylene fabric
squares of 5mm that are supended in the filter devce. Water is
forced up into the device, where the filter captures any
contaminants in the reclaimed water.