1. P-Recovery from Wastewater – A Beneficial Strategy for Utilities?
2018 Danube Water Conference
May 2 – 3, 2018
Arabel Amann

2. Wastewater Treatment First and foremost tasks:
protection of the aquatic environment (reduction standard parameters COD, P, N, ...)
safe disposal of sewage sludge
Recent years - discussions on multiple additional functions/goals:
improvement of treatment for micropollutants, antibiotic resistance, microplastics,…
resource efficiency: reduction energy demand, improved heat reuse
resource recovery: conversion biomass to energy, nitrogen, phosphorus, …

3. Phosphorus – A critical raw material
white phosphorus (P4)
since 2017
Supply Risk
phosphate rock
since 2014
Source: European Commission (2017)
Economic Importance

4. Phosphorus losses in the EU 27
Source: van Dijk. et al. (2016)

5. Recovery points and potentials
sludge liquor
sewage sludge
sewage sludge ash
Source: modified from Montag, D. (2008)

6. Costs Comparison of Technologies
Reference: Conventional WWTP with enhanced P removal and co-incineration of sludge
Result: Beneficial recovery possible, high uncertainties
10 % are for monoincineration
Source: Egle et al. (2016)
Reference system has decisive impacts on cost evaluation!!!

7. Factors influencing costs and benefits
P-removal type (biological, chemical, filter,…)
Sludge stabilisation (aerobic, anaerobic,…)
Sludge dewatering efficiency
Current sewage sludge transport distances
Sewage sludge disposal costs
Product quality and market price (for P and other secondary products)
System boundaries!

8. Example System I WWTP with enhanced biological P removal (EBPR) and sludge digester

9. Struvite from Sludge Supernatant
Precipitation of struvite (NH4MgPO4·6H2O) with pH-adjustment and Mg dosing
Operational and Financial Benefits:
Reduction of pipe clogging
Reduction of nutrient backflow to WWTP-influent
+ Revenue for product
Example:
Ostara WASSTRIP® and PEARL®
Source Picture: OSTARA (2017)

10. Struvite after Sludge Digester
Precipitation of struvite (NH4MgPO4·6H2O) with pH-adjustment and Mg dosing
Operational and Financial Benefits:
Reduction of pipe clogging
Reduction of nutrient backflow to WWTP-influent
Improvement of sludge dewatering
Reduction of polymer demand
+ Revenue for product
Example:
AirPrex®
Source Picture: CNP (2015)

11. Struvite Processes around the world
Véolia Struvia®
Helsingor (DK): EW
Suez Phosphogreen®
Aarhus (DK): EW
Marselisborg (DK): EW
AirPrex®
Berlin (DE): 1 Million EW
Amsterdam (NL)
Ostara Pearl®
Chicago (USA): 4,5 Millionen EW
Slough (UK): EW
© Christian Kabbe 2017
YES!
(with Bio-P and Digestion)
Limited!
Business Case?
Recovery?

12. Example System II Wastewater treatment with sewage sludge mono-incineration and disposal of ash

13. Example: P-acid production from ash
Leaching of phosphorus from ash + cleaning of resulting acid-solution -> H3PO4
Financial Benefits:
Reduction of ash for disposal (who exploits cost reduction?)
+ Revenue for product
+/- Revenue for additional products (valorisation uncertain)
Example:
Remondis TetraPhos®
Source Picture: Remondis

14. Example: Fertilizer production from ash
Conversion of phosphorus in ash to plant available form by mixing with acids + granulation of product (only high quality ashes = low heavy metal content)
Financial Benefits:
No ash for disposal
+ Revenue for fertilizer
Example:
Seraplant® or
Conventional Fertilizer Industry
(ICL Fertilizer)
Source Pictures: Klärschlamm-Kooperation M-V (2017)

15. Ash Processes Pilot Plants in Europe
Fertilizer Production
ICL Fertiliser: Amsterdam, full-scale/ Ludwigshafen, planned
Ash2Phos® (Helsingborg, pilot)
P-acid Production
EcoPhos® (Varna, Demo/Dürnkirchen),
TetraPhos® (Hamburg, full-scale planned)
PARFORCE® (Freiberg DE, Demo)
Phos4Life (Spain/Zurich, laboratory scale)
P4 Production
ICL Fertilizers – RecoPhos InduCarb (Patent acquired)
© Christian Kabbe 2017
POSSIBLE
(uncertainties)
High!
Business Case?
Recovery?

16. System Perspective Example – Canton of Zurich, Switzerland
Disposal cost in canton in 2014 before operation of mono-incineration
Calculated costs with mono-incineration and phosphor recovery from ash
Source Picture: modified from Adam (2017)
Digestion
Dewatering
Transport
Thermal Treatment
Phosphor Mining

17. Summary (I) P recovery is no core task of wastewater utilities (yet)
P-recovery = beneficial for utilities?
Yes, under specific circumstances…
General reference point = treatment costs + sewage sludge disposal price
2 examples were benefits can be exploited:
WWTP with enhanced biological P-removal
WWTP with high disposal costs for sewage sludge

18. Summary (II)
Under different WWTP and disposal schemes tendency to a cost increase, e.g.
chemical P-removal
agricultural application or co-incineration of sludge (low disposal costs)
no mono-incineration plants (investment needed)
Still, other benefits could arise e.g. higher independency from disposal market (municipal incineration)
P-recovery an integral part of sewage sludge disposal concepts

19. THANK YOU!
Management Perspective Egle, L., Zoboli, O., Thaler, S., Rechberger, H., Zessner, M. (2014) The Austrian P budget as a basis for resource optimization. Resources, Conservation and Recycling 83, 152– Zoboli, O., Laner, D., Zessner, M., Rechberger, H. (2016) Added Values of Time Series in Material Flow Analysis: The Austrian Phosphorus Budget from 1990 to Journal of Industrial Ecology 20, 1334– Zoboli, O., Zessner, M., Rechberger, H. (2016) Supporting phosphorus management in Austria: Potential, priorities and limitations. Science of The Total Environment 565, 313– Technology Perspective Egle, L., Rechberger, H., Zessner, M. (2015) Overview and description of technologies for recovering phosphorus from municipal wastewater. Resources, Conservation and Recycling 105, 325– Egle, L., Rechberger, H., Krampe, J., Zessner, M. (2016) Phosphorus recovery from municipal wastewater: An integrated comparative technological, environmental and economic assessment of P recovery technologies. Science of The Total Environment 571, 522– Amann, A., Zoboli, O., Krampe, J., Rechberger, H., Zessner, M., Egle, L. (2018) Environmental impacts of phosphorus recovery from municipal wastewater. Resources, Conservation and Recycling 130, 127–139.

20. Sources
Adam (2017). Ziel und Strategie bei der Klärschlammverwertung und Phosphorrückgewinnung im Kanton Zürich Dreiländertreffen, Schweiz.
CNP (2015). AirPrex™: Biosolids Treatment Optimization Process with the option of Phosphate Recovery. MWEA - Annual Biosolids Conference, March 2nd 2015.
European Commission (2017). Communication on the list of critical raw materials 2017.
Egle, L., Rechberger, H., Krampe, J., Zessner, M. (2016) Phosphorus recovery from municipal wastewater: An integrated comparative technological, environmental and economic assessment of P recovery technologies. Science of The Total Environment 571, 522–542.
Klärschlamm-Kooperation M-V (2017). Die Klärschlamm-Kooperation Mecklenburg-Vorpommern. Aktueller Stand
OSTARA (2017). Ostara Process Flow Diagram Handout.
Remondis (2018). TetraPhos Process Scheme Handout.
van Dijk, K.C., Lesschen, J.P., Oenema, O., Phosphorus flows and balances of the European Union Member States. Science of The Total Environment, Special Issue on Sustainable Phosphorus Taking stock: Phosphorus supply from natural and anthropogenic pools in the 21st Century 542, 1078–