Transcript Lysbilde 1

Welcome to
Bekkelaget Wastewater Treatment Plant
Gas holder and
Upgrading plant
Admin building
Rock caverns
FACTS:
•
35-40% of all wastewater from
Oslo, treated at Bekkelaget
WWTP
•
Plant put in operation in 2000
•
Owned by the City of Oslo,
operated by the private
company Bekkelaget Water inc.
(BEVAS)
•
Approximate 280.000 pe
•
Average daily flow ~100.000
m3/d
•
Outlet demands:
P-removal > 90%
N-removal > 70%
(including overflow)
•
Sludge production ~5.500 tons
DS/year
•
Gas production: 3.700.000 Nm3
Concession
•
New demands from 01.01.2009:
– Nitrogen
70% of all nitrogen must be removed
– Phosphorus:
90% of all phosphorus must be removed
– Organic matters: 70% of organic matters as BOD5,must be
removed
– And the total amount of overflow must be less than 2% of
the total loads of nitrogen, phosphorus and organic matters
These new demands together we increasing load to the plant will
cause some challenges in the future
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Phosphorus and Nitrogen loads to
Inner Oslofjord 1910-2004
Water capacities
•
Dry weather flow 1450 l/s -125.000 m3/d biologically
treated (max capacity 1900 l/s)
•
Water flow rates between 1900-4000 l/s is treated
chemically
•
Water flow rates between 4000 - 6000 l/s is treated
through 3 mm screens
Water and sludge treatment process
PAX-18
Primary
Precipitation
1900 l/s<Q< 4000 l/s
Q<1900 l/s
Magasin~35.000m3
Primary
Clarifier
Filter
Activated
sludge
Q=1900 l/s
Sand, grit and
screenings
FeSO4
Biogasupgrading
4000 l/s < Q < 6000 l/s
Biogas
Bio sludge
Thickener
Buffertank
Primary sludge
Digester
Silo
Dewatering
Silo
Overflow
PAX-18
Buffer
Digester
Overview
Water treatment
1. Inlet tunnel
2. Screens, sand and grit
removal
3. Primary settling/ direct
precipitation
4. Bio step, activated
sludge
5. Clarifiers
6. Extra space(not in use)
7. Sand filters
Sludge treatment
8. Digesters
9. Sludge treatment
10. Sludge treatment
11. Ventilated air
treatment – odor
control
12. Biogas, upgrading
212 m
12
Sludge – heating system - existing
Thickener
Primary
sludge
Sludge
buffertank
Biosludge
Sludge
buffertank
Biogas
Thickener
Heating – buildings and plan
Ventilation + adm in building
Boiler (gas/oil)
Digesters
De watering
Silo
RSL 1
Silo
RSL 2
9
Sludge – heatingsystem
Thickener
Primary
sludge
Excess heat from upgrading plant
Upgrading
biogas
Sludge
buffertank
Biosludge
Sludge
buffertank
Thickener
Biogas to upgrading
Pellets
Heating – buildings and plan
Ventilation + adm in building
Boiler (Gas/oil)
Digesters
Heat pump
Without heatpump in operation
Cooling of sludge
De watering
Silo
RSL 1
Silo
RSL 2
1
0
Use of biogas
• The plant produces large amounts of biogas
• It is similar to f.ex Propan and has a high heating value
• Until 2006 – gas used for sludge drying and heating of sludge and
buildings
• From 2006-2010, only 50% of produced energy from gas used
• Different solutions discussed
– Electricity production
– Fuel production, two different options – gas production similar to
2,2 million liters of diesel pr year
– Heat to district heating system
Bærekraftig drift
Optimalisering energibruk - BRA

BRA nå og fremtiden:
Til nå
– Anlegget satt i drift 2000, relativt moderne anlegg
– Lys og ventilasjonsstyring
– Frekvensomformere
– Stort overskudd biogass
Fremover
– Varmepumper
– Oppgradere/frigjøre biogass til drivstoff
– Pellets som støttevarme
– Fokus på O2 regulering, godt nok
– Bruk av lavverdig energi
•
I forbindelse med vurdering av alternativ fremtidig bruk av biogassen
på BRA ble det utarbeidet et miljøregnskap - 
1
2
Upgraded biogas (biomethane)
• Upgraded biogas (biomethane) as fuel is almost CO2 neutral and is
the most environmental friendly of fuels commercially available
• In 2009 the biogas production was 3.600.000 m3 (60% methane),
equivalent of 24 million kWh/year or 2.2 mil liter diesel. The
production can keep 80 busses running on biomethane, every day
• The plant for upgrading of biogas to biomethane was put in
operation early in 2010
• The investment costs for this plant was 32 mill NOK. Including
necessary investments rebuilding the heating system and the sludge
treatment process the total cost was 55 mil NOK
COOAB ® process – CO2 absorption
CO2 absorption
Gas drier
gassholder
High pressure
compressor
Activated coal - filter
200 bar
CO2
0,5 bar
2 bar
Odorizer
CO2 removal/
COOAB recovery
Water quality 2010
440,6 mill m3
39,98 mill m3
0,67 mil. m3
Total flow:
Treated volume:
Overflow:
Phosphorus
in
(tons)
161,4
out
(tons)
12,48
Nitrogen
1 328
408
69,3
10,0
70%
BOD
7 313
129
97,5
3,1
70%
COD
16 965
-
-
-
-
*Concession numbers are incl. overflow.
**Results from 2010 incl. overflow
Removed Concentration Concession
(%)**
(mg/l)
(tons)*
92,3
0,31
90%
Sludge
•
•
Sludge production: 17.700 tons sludge, or 5.400 ton TS / year
90% of sludge are being used as a fertilizer for grain production
Limit
(mg/kg TS)
2002
2009
Pb (mg/kg TS)
80
36,8
18,8
Cd (mg/kg TS)
2
1,48
0,68
Hg (mg/kg TS)
3
1,04
0,65
Cr (mg/kg TS)
100
34,3
19,8
Ni (mg/kg TS)
50
26,3
17,1
Cu (mg/kg TS)
650
703
277
Zn (mg/kg TS)
800
398
410
Bekkelaget Water inc.(BEVAS)
• The Municipality of Oslo has signed an operation contract for
Bekkelaget WWTP (BRA) with BEVAS for 15 years
• Operation contract stared in October 2001
• BEVAS is owned by Läckeby Water Group (Sweden)
• Läckeby also have interests in Purac AB, and offer services within,
construction, design, building, equipment and operation.
• The company has 180 employees, has a turnover on 600 mil. SEK,
and runs businesses in 10 countries