Wastewater Sludge Recycling/Reuse in Japan · 2012-04-18 · Wastewater Sludge Recycling/Reuse in...
Transcript of Wastewater Sludge Recycling/Reuse in Japan · 2012-04-18 · Wastewater Sludge Recycling/Reuse in...
Wastewater Sludge Recycling/Reuse
in Japan
Workshop on Urban Fecal Sludge Management
23rd February 2010, Hanoi, Vietnam
Takehiko Kawai Director
Recovery of Resource and Energy from Sewerage Sludge, in order to ensure stable treatment and to solve Global Warming
Recycling of Resource and Energy from Sewerage
Amount of Sewerage Sludge Production
Fiscal Year
3
15 15 16 17 20
24 24
30
38
45 48
50 52
56 60
64
67 70
74 77
78
78
0
10
20
30
40
50
60
70
80
90
0
500
1,000
1,500
2,000
2,500
88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09
Recyc
le r
atio
(%)
Am
ount
of se
wag
e s
ludg
e (th
ousa
nd
dry-
solid
ton)
Recycle ratio of Sewage Sludge
Cement
Landfill
Fertilizer
Bricks, tiles
Other
Fuel
Fertilizermanagementlaw
Waste disposaland Cleaninglaw
Dioxinmanagementlaw
Managementstandard forprevention ofHeavy metalaccumulationin soil foragriculture
Law forprevention ofagriculturallandcontamination
(Note)Environmentalstandard for soilcontamination
Content Elution amount Content Content Content Elution amountAlkilmercury ND NDTotal Mercury 2 mg/kgDS 0.005mg/l 0.005mg/lCadmium 5 mg/kgDS 0.3mg/l 1mg/kg-rice 0.01mg/lLead 100mg/kgDS 0.3mg/l 0.01mg/lOrganic Phosphorus 1mg/l NDChromium (Ⅳ) 1.5mg/l 0.05mg/lChromium 500mg/kgDSArsenic 50mg/kgDS 0.3mg/l 15mg/kgDS 0.01mg/lCyanogen 1mg/l NDPCB 0.003mg/l NDCopper 125mg/kgDSZinc 120mg/lNickel 300mg/kgDSSelenium 0.3mg/l 0.01mg/lDioxin 3ng-TEQ/g 1ng-TEQ/g
Officialstandard fornormalfertilizer
Officialstandard fornormalfertilizer
for Ash, Slag,etc.
Standard forSoil itself
Only for paddyfieldStandard forsoil itself
The titles of the laws mentioned above are not the full titles.
Quality of product (3)
Heavy metals and other undesirable substances
Thickening
Digestion
Dewatering
Drying
Carbonization
Incineration Sintering
Dried and composted sludge
Supernatant
Utilization for agriculture and greenery
Recycling of Resource and Energy from Sewage
Phosphorus
recycling system
Carbonization of Sewer Sludge
11
Gifu Prefecture
Fertilizer produced from
sewage sludge is used for
the production of vegetables
in Gifu, and the vegetables
are famous for their
excellent quality.
Kobe-city
Biogas Station
Biogas Refinery
Tokyo Solid Fuel
Electric Power Generation
Problems with Digestion Gas
Problems for utilization
① Warming facilities and gas tank are corroded by digestion Gas which
contains hydrogen
② Digestion gas which contains Siloxane creates problem by
crystallization to warming facilities and gas blower.
③ Methane concentration is approximately 60%. Consequently, heating
capacity is lower with about half of the capacity of the city gas.
Malfunctioning by Siloxane
Digestion Tank
Desulfurizer
Waste Gas Burner
LP Gas Tank
Boiler for warming Digestion Tank
Refining Digestion Gas to Bio Natural Gas
■2004 Kobe
city
Kobelco
Eco-Solutions
■2005
Kobe
City
Kobelco
Eco-
Solutions
Public Works
Research
Institute
Refining Digestion Gas to
Natural Gas (Joint Research)
Refining Digestion gas to Natural Gas and commercialization for
car fuel (joint Research)
Gas refining system
Kobe Bio Gas Station
Refining System of Digestion Gas (water scrubbing process flow)
Treated WW
Compressor
Sewage Sewage treatment
Treated WW
Kobe Biogas Kobe Biogas Station
Digestion tanks
Water pump
Scrubber
Treated water
Low pressure tank
Solubility-difference (CH4 and CO2)
pressure solu
bil
ity
Sludge
To treatment system
Pump
Kobe city bus
Effective use of Kobe Biogas Vehicle for officials Taxi
Truck for sludge cake
Garbage wagon
Home dispatch
Drain pipe
sweeping
machines
Project: Pouring into the City Gas
Properties Unit Digestion Gas
(Pre-Desulfurization) Kobe Bio Gas
Acceptance standard value by Osaka Gas
Methane Vol% 59.7 98.2 -
Carbon dioxide Vol% 37.0 0.6 ≦0.5
Oxygen Vol% 0.4 0.2 ≦0.01
Nitrogen Vol% 0.8 1.0 ≦1.0
Hydrogen Sulfide ppm 330 <0.1 ≦0.65
Siloxane mg/Nm3 14.53 0.005以下 -
High rank calorific value MJ/Nm3 23.8 39.3 45.0
Smell mg/Nm3 - - 12~16
Actual proof facility of Pouring into the city gas.
Networking of renewable biomass energy
Agriculture Green
Water
Foods
Wastewater System
Water Reclamation
Energy- Regenerating
Kobe city
Study on Economical Biomass Methane Fermentation in Small City
by Suzu City and JIWET (Japan Institute of Wastewater Engineering Technology)
The most important issue for sewage sludge treatment is the increase of treatment cost. Suzu City, which is located in a coastal area, expects to face an increase of cost for its sludge treatment. Suzu City is therefore promoting waste recycling by combining sewage sludge with other biomass and raw garbage from businesses to obtain methane fermentation. By using biogas energy to dry sewage sludge for utilization as a fertilizer, Suzu City expects to realize important cost saving for sludge treatment and other biomass treatment. The facility specifications were decided in 2005. The facility performance has been evaluated since the time it went into operation in 2007 to 2008. The purpose of this study is to evaluate the effects of such facility.
Location of Suzu City
Gas tank Machine building
Methane fermentation
Heating
building
Dryer
Control building
2/2wastwater
treatment
Sludge treatment building
消毒施設
1/2wastwater treatment
Photo.1 Biomass methane fermentation treatment plant in Suzu City.
Sludge treatment flow in Suzu City Wastewater Influent
Oxidation ditch Final sedimentation tank Discharge
Sewage sludge
Sewage sludge from
wastewater treatment
plant in rural area.
Garbage
septic tank sludge
Machine building
Night soil
Heating
Thickening facilityReceiving &mixing tank
Receiving tank
Receiving tank
Receiving hopper
Storage tank
Storage tank
Solubilization tank
Methane fermentation
tank
Gas holder
Storage tank
Dewatering
Machine
DryerDrying
Dried
sludgeFree distribution
Thickening tank
Crushing &
separation
Screen
Screen Mixing tank Boiler for
heating
Biomass , Biogas , Energy
Legend
Heating
Wastewater InfluentOxidation ditch Final sedimentation tank Discharge
Sewage sludge
Sewage sludge from
wastewater treatment
plant in rural area.
Garbage
septic tank sludge
Machine building
Night soil
Heating
Thickening facilityReceiving &mixing tank
Receiving tank
Receiving tank
Receiving hopper
Storage tank
Storage tank
Solubilization tank
Methane fermentation
tank
Gas holder
Storage tank
Dewatering
Machine
DryerDrying
Dried
sludgeFree distribution
Thickening tank
Crushing &
separation
Screen
Screen Mixing tank Boiler for
heating
Biomass , Biogas , Energy
Legend
Heating
Figure 1 Schematic diagrams of biomass methane fermentation treatment facility
The results of a pot test show no hindrance for plant growth with dried sludge. It was also confirmed that dried sludge is thoroughly useful as a fertilizer.
Drying conditions has shown and confirmed that dried sludge meets EPA standards and is totally safe for health.
Possibility of utilizing dried sludge as a fertilizer
Photo.2 Results of a pot test showing
no hindrance to plant growth by dried
sludge.
Photo.3 Dried
sludge.
Life ycle cost(LCC) and life cycle CO2(LCCO2) impacts
68,662
60,124
55,377
40,633
47,000
49,100 24
23,015
0 50,000 100,000 150,000 200,000 250,000
Individualtreatment
centralizedtreatment.
Cost during year(¥/year)
Construction costUtility cost
Driving management consignment expenseDisposal cost
149,881(77%)
194,054(100%)
2,402
5,525
17,066
12,284 2,374
1,099
5
408
0 5,000 10,000 15,000 20,000 25,000
Individualtreatment
centralizedtreatment.
CO2 exhaust (t-CO2)
Amount of construction exhaustAmount of driving exhaustAmount of update exhaustAmount of abandonment exhaust
20,187(96%)
20,975(100%)
Fig.1 Comparison of LCC
Fig.2 Comparison of LCCO2