International Water Summit
Abu Dhabi, 21st Jan 2014
Introducing the Japanese approach
to Waste Water System;
Recycle of Sewage Sludge &
Sewer Rehabilitation
Yosuke Matsumiya
Basics
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JP Population:130 million
Service Accessibility Ratio: 76%
Number of WWTPs: 2,145
Sewer Length: 443,000 km
Annual Sludge Gen: 2.3 million DS ton
Recycle of Sewage Sludge
Sewer Rehabilitation
• Most sludge is recycled as construction material.
• Small farming limits agricultural recyle.
• Incineration is common for stabiliaztion due to high pop
density.
• Cement companies charge utilities.
20%
Landfill
80%
Recycled
20%
Agri.
30%
Other
Const.
Dry Solids Basis
From website of MLIT, Gov of Japan
50%
Cement
Example-1: Sludge Melting
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slag for construction gravel & sand, easily recyclable.
containing HM pollution.
Slag is sellable.
Problem is energy intensive
Air
Coolant
Ash
Exhaust
Coolant
Slag
http://www.kobelcoeco.co.jp/english/product/gesui/se
nkai.html
From Kobelco Website in Japanese
For more info, http://infohouse.p2ric.org/ref/26/japan/Waste-117.html
Example-2: Filling Soil
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Incineration ash plus waste soil to be filling soil for installation.
Recycle completes within operator domain.
No need to worry about market.
Example-3: Concrete Products
• Manufactured using ash from incinearaion ash.
• Utility buys with priority to advance recycles.
But organics is not recycled much.
• Quick stabiliation by incineration has been main.
• Digestion/biogas use has been sidelined.
10%
Agri.
10%
Biogas
80% Unused
Need to Increse Energy Use
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Reduction of the GHGs by Green Energy Use
Loss of Nuclear Power
Explosion of Nuclear Plant after Tsunami
Unique Biomass Energy Use,
not conventional Biogas Use
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Biogas
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Biogas Powered Fuel Cell
Micro Gas Engine
Food Waste Disposer
Biochar
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Exp-1: A WWTP, 100,000m3/d, KUMAMOTO.
• Fuel cells, 4 units of 100kw, supply half power.
• No emission. Promising tec.
• OPEX is coming down.
For more info, http://www.fujielectric.com/company/tech/pdf/r49-2/08.pdf
Exp-2: A WWTP, 98,000 m3/d, in SAGA.
 Resonably priced micro gas engines, 16 units of 25kw.
 Generate half of power.
For more info, http://yanmar.com/product/energy/bioGasMicroCogenerationPackage/
Exp-3: A WWTP, 22,000m3/d in KUROBE.
 As biomass recycle center in the city.
 Disposer installation encouraged at houses,
to increase biogas & to reduce solid waste generation.
 Accepting food factory waste.
 Biogas supply half power.
 Dried sludge is transported & used at Coal Fire Power Plant.
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WWTP
Power
Biogas
Generator
Thickened Sludge
Digester
Dehydrator Drier
PFI
Food Waste
Dried
Sludge
Power Plant
Biochar Production Projects have
been increasing
Carbon neutral fuel at coal fire power plant
Carbon negative for soil fertility improvement
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Capacity of Biochar Production on
Dewatered Sludge basis
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Tokyo: 300t/d since 2007
Hiroshima: 100t/d since 2012
Aichi: 100t/d since 2012
Kumamoto: 50t/d since 2013
Several others already in pipeline
http://www.tsk-g.co.jp/en/tech/eco-jouge/deido/odei.html
Recycle of Sewage Sludge
Sewer Rehabilitation
Total Installation
Annual Installation (*1000km)
Total
Rapid sewer aging feared due to
short term intensive installation 440,000km
10,000km
Over 50 yrs
50’
60’
70’
80’
90’
00’ 10’
Trenchless rehab has started.
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Lining with cured-in-place pipes (CIPP)
Lining with spirally-wound pipes
Lining with close-fit pipes
Pros and cons exist for the methods.
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Spirally-wound pipes
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Reliable but costly
Can install with live flow
Any shape of section
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CIPP
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Less costly
Difficult in QC
Need to Stop Sewage
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Close-fit
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Moderately reliable & costly
Need to stop sewage
winch
Boiler
liner
Overall Trend & Discussion in JP
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Big Diamater
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Small Diameter
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Spirally Wound Pipes
CIPP followed by Close-Fit
QC & Long-Term Performance is
discussed
Discussion of Surface Irregularity
ISO 11296-4, 6mm or 2% of Dia., greater
1.2m
D=300mm
Manometer
Water
Liner Model
23m
Experiment Result
In case of 6mm in
roughness depth at
10cm intervals, flow
capacity reduces to
80%.
Thanks!