(Sludge Treatment Center)

Furano District Environmental Hygiene Association

Overview of theFacility

Water treatment
facilities

2ndfloor

Pretreatment
room

Deodorization
machineroom

Pretreatment room

Receiving yard

Boiler room

Name:
Furano District
Environmental HygieneCenter
Location:
Kamigo-ku, Furano City,Hokkaido
Compound area:
30,183 m2
Building area:
6,321 m2

Dehydratorroom

No floor

No floor
Fan heaterroom

Room for asewage residue
hopperReceiving Central
yard monitoring
room

Treatment method
Water treatment facilities:
Standard denitrification
treatment method +advanced sewage treatment
Composting facilities:
Rapid composting method

Pump room

Room for treated water tank

Dehydrator room

Deodorization facilities

Room for receivingand transformingelectricity

1stfloor

Treatment capacity
Sewage: 46 kL/day
Sludge from septic tanks:
14 kL/day
Kitchen waste:
22 t/dayHeated blowerroom

Room forpretreatment ofkitchen waste
Kitchen waste
deodorization machineroom

Compostmaturation
warehouse

Bark storage
Room fortreated watertank

Room for primary fermentation
Central monitoring room
Room for secondary fermentation

Sortingroom

Composting facilities

1stbasement

Blower roomReceiving yard

Room for kitchen waste pretreatment

Room for primary fermentation

Room for primary fermentation (top)

Sorting room

Bark storage

Compost maturation warehouse

Pump room
Room for secondary fermentation
Watertreatment
plant

Barkstorage

Composting plant

Compostmaturation
warehouse

Room for kitchen
waste pulverizer

Flow Diagram for the Water Treatment Facilities
Deodorization
facilities
AlkaliAcid cleansing
cleansing tower
tower

Facilities for receiving and pretreatment
Conveyer for dehydrated
sewage residue
Hopper for dehydrated
sewage residue
Conveyer with a cutter
for dehydrated sewageresidue

SewagescreenScrew press for
sewageSewageSewagepulverizer

Odor with medium
concentration

Carrying out
from the facility

Storage tank for reserve (A)Tower for absorbing odor
with low concentration
using activated carbon

Odor with highconcentration
Odor with highconcentration

Quality of Effluent

Odor with low
concentration

Biologicaldeodorization
tower

AerationblowerDeodorization
chimneypH:
Circulation Water
liquidSulfuricacid

SS: 10 mg/L or less

BOD: 10 mg/L or less

T-N: 10 mg/L or less

COD: 30 mg/L or less

T-P: 1 mg/L or less

No. of coliform bacteria:

100/mL or less

Water
Sodium hydroxide
Sodium hypochlorite

Tank for various
waste water

Automatic packing
machine for dehydrated
sewage residue

5.8 - 8.6

Acid circulation
pump

Denitrification
tank

Alkali circulationpump

Tower for absorbing
odor with medium
and highconcentration using
activated carbon

Sewage receiving tank

Advanced sewage treatment
facilities

Main treatment facilities

Grit removal device
Water fordilution

SewageSewage storage Sewage scum injection
pump
crushingtankpump
Screen for sludge
from septic tanks
Screw press for
sludge fromseptic tanks

Sludge fromseptic tanks

Pulverizer forsludge fromseptic tanks

Water

Filtration tower Filtration tower
BA

Various waste water

MethanolWaste water from
biological deodorization(water treatment)

Waste waterfrom deodorization(composting)

Sodiumhydroxide

Biologicaldeodorization tower

Sedimentation tank
Sludge collecting
facility

Antifoamer

Methanol

Antifoamer

Scum
pump

Receiving tankfor sludge fromseptic tanks

Denitrification
tank

Sodium hypochlorite

Ozone generator

Discharge

Returnsludge
pump

Aeration device

Storage tank forreserve (B)Automatic
dissolution machinefor coagulant aid

Sodiumhydroxide
Poly ferricsulfateCirculation
pump

Nitrification tank

Storage tankfor sludge
from septictanks

SecondaryRe-aeration tankdenitrification tank

Scum tank

Tank for Tank forsampling contact

Chemicalmixing Condensationtank
Condensation andchamber

Sedimentation
tank
Excess sludge
suction pump

Tank forfilteredwater

Tank for
Tank forozonolysis crude water
beforefiltration

sedimentation
tank

Sludge thickener

Tank fordischarge

Pump fordischarge

Dehydration facilities
Pump for crushing
Pump for injecting
scum of septic tankseptic tank sludge
sludgeKitchen waste drainwaterSodiumhydroxide

Poly ferricsulfateDenitrification
tank

Sludge dehydrator A

Sludge dehydrator B

Water
Water
Automatic
dissolution machinefor oil/fat removal
agent

Waste water from theprimary fermentation
tanks
Waste water fromdeodorization
Drainage ofreverse filtration

Receivingtank for septic Neutralization Condensation Oil/fat
tank
tank
tank sludge
removalDehydrated
Storage tank for septic
devicesludgetank sludge
conveyer No. 1

Sodiumhydroxide
Poly ferricsulfateCondensedsludgeFiltrate fromdehydration

Dehydrated sludge
conveyer No. 1

Oil/fat removed
sludgeTank for various
waste water

Sludge thickener

Sludge storage
tankSludge andchemicalmixing
chamber A

Water Treatment Facilities■ Facilities for Receiving and Pretreatment
Sewage and the sludge from septic tanks are put into the receiving tank. Grit, etc. is removed in thegrit removal tank. Foreign matter in the sewage, etc. is pulverized by the pulverizer and is removed
using the screen. The remaining sewage is then stored in the storage tank, before it is treated at themain treatment facilities and at other facilities. The sewage residue which has been removed using
the screen is dehydrated using the screw press. The grit is removed by the grit removal device andthen cleansed. The sewage residue and the grit are then carried out from the facility.
■ Main Treatment Facilities
Sewage and sludge from septic tanks, together with dilution water, are injected into the denitrification
tank. Bacteria which is called “activated sludge” removes nitrogen and organic matter from thesewage, etc. in the denitrification tank and in the nitrification tank. Liquid is circulated between the
two tanks, by pumping back the liquid from the nitrification tank to the denitrification tank. In the
denitrification tank, nitrogen in the circulating liquid is removed (denitrification) using the organic
matter contained in the injected sewage, etc. The nitrification tank mainly decomposes and removes
the organic matter and also oxidizes the ammonia nitrogen (nitrification). Treatment in thenitrification tank is followed by treatment in the secondary denitrification tank and the re-aeration
tank, where the nitrogen is removed and organic matter is decomposed and removed once more. The
sludge in overflow water is decomposed in the sedimentation tank and is sent back to thedenitrification tank (“return sludge”). Excess sludge is removed from the process.

Sludge andchemicalmixingchamber B

Tank for various
waste water

Machine for
automatic
dissolution ofcoagulant

Dehydrated sludge
conveyer No. 2
Dehydrated
sludge hopper■ Advanced Sewage Treatment Facilities
Elements which could not be removed fully at the main treatment facilities are removed
here. Firstly, the elements to be removed are condensed using coagulant, etc. Theseelements are then removed through a sedimentation process in the condensation andsedimentation tank. Secondly, chroma elements in the upper clearer layer of the fluid areremoved through ozonolysis. Finally, the remaining suspended matter is removed
through sand filtration.

■ Facilities for Supplying Agents and Water
The facilities supply the water, agents, etc. which are needed for operation.

■ Dehydration Facilities

After thickening the excess sludge and condensed sludge inthe sludge thickener, the sludge is dehydrated using thesludge dehydrator. The filtrate is collected in the tank forvarious waste water before being treated at the main
treatment facilities. The dehydrated sludge generated in thisprocess is composted at the composting facilities.

How do bacteria clean sewage?
Dirty matter

Dirty matter

Ammonia

Carbon dioxideWater■ Deodorization Facilities

These facilities collect and remove the odor from thereceiving tank, the storage tank, other equipment and theodor from various rooms such as the pump room. The
deodorization facilities are comprised of the biologicaldeodorization tower, the chemical cleansing towers and thetowers for absorbing odor using activated carbon.

Nitrogen gas
Denitrifying
bacteria
Nitric acid
Denitrifying bacteria eat dirty matterand nitric acid, and covert them into
nitrogen gas.

Nitric acid

Sewage iscleaned by goingback and forth
between thesetwo processes.
OxygenNitrifying
bacteria

Nitrifying bacteria eat
ammonia and convert it into
nitric acid.

OxygenMany other microbes decompose
dirty matter.

Flow Diagram for the Composting FacilitiesFacilities for receiving andpretreatment

Kitchen waste

Conveyer to pourmaterial into the separator

Conveyer to pour mixed
kitchen waste
Conveyer to pour
kitchen waste into thepulverizer

ReceivinghopperConveyer to transport
products

Hopper for
returncompostDamper with acutter to return
products
Conveyer to take out
material from the separator

Compost(products)

Hot water
outflow

Primary
fermentationtank No.1

Conveyer witha cutter B

Primary
fermentation tankNo. 2

Primary
fermentation tank
No. 3

Primary
fermentation tank
No. 4

Primary
fermentation tank
No. 5

Primary
fermentation tank
No. 6

Conveyer to pour material
into intermediate hoppers

Intermediatehoppers

Secondary fermentation tank
No. 1

Conveyer topour material
intosecondaryfermentation
tanks

Secondary fermentation tankNo. 2

Ozone generator forcomposting facilities
Acid cleansing tower

Transporting
conveyer

Acidcleansing
tower

Secondary fermentation tank
No. 4

Crushed bark
Hopper forreceivingcrushed bark

Conveyer to transportcrushed bark

Composting Facilities■ Facilities for Receiving and Pretreatment
Kitchen waste is received and pulverized by the kitchen waste pulverizer,
before being stored in the storage hopper for pulverized kitchen waste.
Dehydrated sludge, return compost and crushed bark (water content
adjusting material) are added to the pulverized kitchen waste and they are
mixed in the mixer. The mixed material is composted at the primary
fermentation facilities. Drained water generated from kitchen waste istreated at the water treatment facilities.
■ Bark Crushing Facilities
These facilities crush bark and produce crushed bark which will be used toadjust water content.

Deodorization
chimney

Alkalicleansingtower

Tower forabsorbing odorwith medium
concentration withactivated carbon

Properties of Compost Products

Bark crusher
Discharging
conveyer

Deodorization facilities

Soil deodorization bed
Odor with highconcentration

Secondary fermentation tankNo. 3

Bark crushing facilities
Bark
receivinghopperCompostmaturation
warehouse

Conveyer for return
compostHopper for
return compost

Secondary fermentation facilities

Mixer

Bark

Taken out fromthe facility

Scrubber
Hot water
inflow

Conveyer for
pouring

Bark

Conveyer to pourmaterial into themagnetic
separator
Magnetic
separator

ExhaustfanFan for
ventilating theroom
Heater for the
supplied air

Conveyer totransport theproduct of primary
fermentation
Conveyerwith acutter A

ReturncompostDehydrated
sludgeHopper fordehydrated
sludgeOdor with highconcentration

Aeration blower
Storage hopper
for pulverized
kitchen waste

Conveyer totransport rejected
matter

Separator

Hopper to
store rejected
matterYard for rejected
matterTransporting
conveyer

Conveyer witha cutter

Hopper forcrushed bark

Conveyer to pour mixed
kitchen waste

Dampers for pouring waste
into the primary
fermentation tanks

Conveyer totransport
pulverized
kitchen waste

Kitchen waste
pulverizer

Sorting and returning facilities

Primary fermentation facilities

Conveyer to transport
mixed kitchen waste

Water content:
30% or less
Bulk density:
400 kg/m3
C/N ratio:
25 or less
Percentage of mixed foreign matter:
1% or less■ Primary Fermentation Facilities
Kitchen waste mixed with crushed bark, etc. is poured into the primary
fermentation tanks. These facilities mainly decompose easily-decomposed
elements in the kitchen waste through fermentation. The optimum
temperature for composting is maintained in the tanks by adjusting thebalance between aeration and exhaust. Heat generated by the fermentation
process causes the water to evaporate, and the vapor is discharged together
with the odor. The generated odorous gas is washed by the scrubber andthen deodorized.
■ Secondary Fermentation Facilities
The compost which completed the process of primary fermentation ispoured into the secondary fermentation tanks. The compost is furtherfermented and its organic matter is further decomposed throughappropriate aeration in the stirrer, so that consistent quality compost can beensured.

Secondary fermentation tankNo. 5

Pump to circulate acid
Biologicaldeodorization tower forOdor withcomposting facilities
mediumconcentration

Tower for absorbing
odor with low
concentration withactivated carbon
Odor with low
concentration

Nitrification tank

Odor withmedium
concentration

Secondary fermentation tankNo.6
Suction fan

Odor with medium
concentration■ Sorting and Returning Facilities
The separator and the magnetic separator separate inappropriate composting
matter, grit and metals which are contained in compost which has completed thesecondary fermentation process. After the inappropriate matter is removed, partof the compost is sent back and the rest is stored in the compost maturation
warehouse for complete maturation, before being shipped as compost products.
■ Deodorization Facilities
These facilities collect and deodorize the odor generated by the equipment used in
the composting facilities as well as deodorizing the building.
The deodorization facilities are mainly composed of the biological deodorization
tower, chemical cleansing towers and the towers for absorbing odor with activatedcarbon. In addition, odors from the primary fermentation tanks are deodorized in
the soil deodorization bed.
Deodorant spraying devices are also installed as a countermeasure to odor andthey spray deodorant where necessary.

Tank for waste
water fromdeodorization forcomposting
facilities

Water

Water

Sulfuricacid

Sodiumhydroxide
Sodiumhypochlorite

Denitrification
tank