Working towards P-recovery from sludge ash in Copenhagen

Dines Thornberg. PhD

Development Manager, BIOFOS

Peter Jørgensen , BIOFOS

IWA Sweden, April 11 20181

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BIOFOS catchment area

9 share holders8 utilities (customers)1,2 mill. inhabitants3 WWTPs60 km sewer transmission pipes (BIOFOS operated)

15 MUNICIPALTIES

WWTP Lynetten

WWTP Damhusåen

WWTP Avedøre5 km

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WWTP

Avedøre

Damhusåen

Design-

kapacitet PE

Spildevand

mio. m3

Energi

solgt Mwh

Fosfor

tilført tons

1.000.000 64,8 55.944 457

345.000 26,4 7.078 159

350.000 30,6 6.365 193

1.695.000 121,8 69.387 809

2014

BIOFOS total

Lynetten

Incineration

• All sewage sludge in BIOFOS have been digested and incinerated for more than 25 years

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Lynetten (Construction 2011)

Avedøre

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• Independance-use of sludge in agriculture is sensitive in the public debate

• The sludge does not meet environmental standards

• No transport through the city

Reasons for incineration

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Digestedsludge

Incineration plant. Lynetten

Ash characterization

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Stof Enhed Max Min Max Min

Arsen mg/kg ts. 20 5 20 10 25

mg/kg ts. 300 100 200 100

mg/kg tot P 3.000 1.000 2.000 1.000 10.000

mg/kg ts. 5 2 7 3

mg/kg tot P 50 20 70 30 100

Chrom mg/kg ts. 50 20 150 40 100

Fosfor mg/kg ts. 100.000 70.000 120.000 80.000

Kobber mg/kg ts. 900 500 900 500 1.000

mg/kg ts. 0,3 0,02 7 0,3

mg/kg tot P 3 0,2 70 3 200

mg/kg ts. 80 30 120 50

mg/kg tot P 800 300 1200 500 2.500

Zink mg/kg ts. 3.000 1.500 2.400 1.400 4.000

Bly

Cadmium

Kviksølv

Nikkel

Lynetten Avedøre

RenseanlægAskens

sammensætning

Slambek

endtgør

elsen

WWTP tons DM/y kg P/t DM tons P/y

Lynetten 4.600 70-100 320-460

Avedøre 3.100 80-120 250-370

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• Landfill• Use in concrete production• Use in production of insulation material• Use in road construction • Recover Phosphorus followed by one of the above

Options for ash disposal

Potential BIOFOS P recovery

BIOFOS has the largest ‘Phosphorus-bank’ in Denmark

• WWTP Lynetten: ca. 200.000 tons SSA

• WWTP Avedøre: ca. 80.000 tons SSA

• Estimated total P : ca. 18-20.000 tons

• Ready for recovery as soon as a feasible technology exists

About 800 tons P /y in the wastewater

• Recovery on a running basis

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SSA: Sewage Sludge Ash

P-recovery from ashes– some options we have looked at

1. Ecophos 2. Easy Mining – Ash2Phos

4. DTU-Byg - Elektrodialyse3. STEAG Biolite

..even more options

Remondis TetraPhos – pilot in Hamburg

Crystal-P

ICL Recophos – P4

Decision parameters

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• Technology Readiness Level

• Cost

− Capex & Opex

• Recovery and Environmental impact

− % phosphorus

− Minerals and heavy metals

• Market

− for P

− for other components

Valley of death

Technologies for P-recovery – Ult. 2017D

eger

eeo

f re

cove

ry

0 Technology Readiness Level 9

Evaporation Struvite

100%

Biolite

Struvite, sludge

EcophosEasyMi-ning

0% Concept Lab Pilot Prototype FFR Shelf

Rejectwater

Ash

EDS

Closing remarks

• P-recovery from ashes is not yet a shelf technology, but several candidates are close

• The conditions in Germany a. o. is a strong driver for the development

• Framework conditions for Danish water utilities is both encouraging and inhibiting the implementation

• P-recovery is not a part of BIOFOS’ core task, but it is one of our strategic goals to reuse / recover all products from the wastewater treatment

• With our present framework, we estimate a slightly positive business case for P-recovery – with a high degree of uncertainty

• On this background we envisage that investments for a possible plant must come from external sources

• BIOFOS would like to be an active partner in possible First Full-scale Reference trials

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Thank you for your attention

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