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FP7

P-REX Report Summary

Project ID: 308645
Funded under: FP7-ENVIRONMENT
Country: Germany

Final Report Summary - P-REX (Sustainable sewage sludge management fostering phosphorus recovery and energy efficiency)

Executive Summary:
The P-REX project built on the outputs of previous European research projects and performed the first holistic large scale evaluation of innovative and available phosphorus recovery technologies using municipal sewage sludge or ashes from mono-incineration in comparison with traditional phosphorus recycling by land application of sewage sludge. The technical, operational and economic data as well as comprehensive eco-toxicological and plant-availability assessments provided the basis of comprehensive life cycle assessment and life cycle costing of phosphorus recovery processes and the agricultural valorisation route of the recovered materials. Complementing a market analysis, a policy brief and guidance document for policy makers and endusers shows suitable phosphorus recovery and recycling options with regards to regional conditions (structural and legislative) and illustrates selected case studies. Since recovery alone is pointless without subsequent valorisation of the material, it is very important to know the demand side perspective. Only technologies providing marketable raw materials or final products will have a chance for market penetration and replication. Technology alone is no solution, we have to learn to see them embedded in whole value chains or even in value cycles, once we have adapted our exhaustive linear economy into a sustainable and therefore well-balanced circular economy.
The project closed important knowledge gaps that had been identified over the past years. It used a practice oriented methodology to paint a broad picture of all relevant aspects of technologies and options for the sustainable use of phosphorus today, thus enabling informed decisions and accelerating the transition to a circular economy of phosphorus without the reinvention of the wheel. It will help to improve the food security not only in Europe, but also for a growing world’s population. It clearly addresses what can already be done and what has to be done to enable a circular economy for nutrients in Europe. Think forward, act circular!

Project Context and Objectives:
The Challenge
Phosphorus is one essential element of life, which can neither be produced synthetically nor substituted by any other substance. Its importance as plant nutrient is emphasized by the huge amount of more than one million tons of mineral phosphorus annually imported into Europe to sustain good harvests. While phosphorus is a limited fossil element, its extensive recovery from “secondary renewable sources” is of paramount importance and follows the principles of the European Roadmap for Resource Efficiency and the current developments towards circular economy. Municipal wastewater represents a relevant phosphorus reserve and has the potential to cover about 20% of the P demand in Europe.
Traditional recycling of around 40% of this potential is practiced by application of sewage sludge in agriculture. But this recycling route is questioned in many countries. It has to be further secured to protect the environment and human health. Transparency and fact based measures will play a key role to generate consumer confidence. Technical phosphorus recovery and recycling can complement it, thus answering remaining obstacles caused by sludge quality and nutrient logistics. Technology concepts have been developed in recent European projects to tap into this renewable domestic resource.

Project Objectives
For the implementation to market, new technologies need to be proven technically and economically feasible and suitable modules within whole value chains. The objective of P-REX was to document and describe all relevant aspects of the alternative technologies and options that exist for recovery and recycling from wastewater, thus enabling informed decisions and accelerating the transition to a circular economy of phosphorus without the reinvention of the wheel.
The overall objectives of the project can be distinguished into three categories:
1. Processes: Demonstration and validation of the performance of available technologies for phosphorus recovery from the wastewater stream. It includes also the identification of technical conditions along the sewage sludge treatment-recovery path that are favourable for phosphorus recovery.
2. Concepts: Defining strategies for wide-spread phosphorus recovery from municipal wastewater, considering regional conditions (rural vs. urban areas, local agriculture, sewage sludge treatment-recovery-recycling path etc.) and the agricultural, environmental and economic performance of the technologies applied.
3. Market: The quantification of the market potential and identification of technical, economical and institutional barriers to the market and provision of recommendations for market development.

Methodology
The P-REX project built on the outputs of previous European research projects and performed the first holistic large scale evaluation of innovative and available phosphorus recovery technologies using municipal sewage sludge or ashes from mono-incineration in comparison with traditional phosphorus recycling by land application of sewage sludge. The technical, operational and economic data as well as comprehensive eco-toxicological and plant-availability assessments provided the basis of comprehensive life cycle assessment and life cycle costing of phosphorus recovery processes. Complementing a market analysis, a guidance document for policy makers and endusers shows suitable phosphorus recovery and recycling options with regards to regional conditions (structural and legislative) and illustrates selected case studies.
Within the project structure, the first two work areas were dedicated to the assessment of technical options for phosphorus recovery from sewage sludge ash and the aqueous and solid phase of sewage sludge. The third work area elaborated solutions to minimize the sludge toxicity and was about to define and validate bio-test based monitoring routines to make the valorization of biosolids on arable land as safe as possible for human health and the environment. Based on the data and results from these work areas, the quality of the obtained nutrient concentrates and their suitability as fertilizer was assessed in work area 4 by pot experiments, bio-tests and chemical analyses. Supported by Risk Assessment, LCA (Life Cycle Assessment) and LCC (Life Cycle Costing), the technical solutions were compared with the traditional valorization of sludge on arable land as well, as with the application of mineral fertilizers manufactured from imported fossil phosphate rock.
In parallel, work area 5 was dedicated to the analysis of market barriers, legal framework and specific regional conditions with respect to the implementation of wide-spread phosphorus recycling. A thorough analysis of past business models for recovery and the current fertilizer infrastructure and market provided valuable insights for potential recyclers and a solid foundation for the policy brief. Flanked by stakeholder workshops, regional strategies and recommendations were developed and published. The eMarket for recovered nutrients, implemented in the website of the European Sustainable Phosphorus Platform (http://e-market.phosphorusplatform.eu/) is about to facilitate match making and to bridge the gap between supply (recovery) and demand (recycling) of and for recovered nutrients from liquid and solid wastes. The highly recognised P-REX policy brief and the integral guidance document summarize the major outcomes of the project and are intended to trigger and support decision makers in paving the road for Europe’s circular economy.
Project Results:
As one of the key results of the project, the proof of feasibility of novel technical options for phosphorus recovery and recycling from the wastewater stream are given and factors for market success or failure were assessed. Based on solid data mainly derived from running facilities, the first real life comparison of various processes and their recovery products enabled the identification of best suitable solutions for phosphorus recovery from the wastewater stream with respect to specific regional conditions set by existing infrastructure and legal framework. For all assessed technologies, hard cases were analysed and in most cases, secondary P material has been produced to be representative for the technologies. In work area 1 the ash based technologies AshDec, MephRec and LeachPhos have been evaluated. To provide a more grounded picture, the very promising and therefore relevant Ecophos process has been invited to be included in the assessments as well. Also the fertilizer industry as recycling route for premium quality ashes has to be considered relevant.
The AshDec approach has been optimized within the project to yield a citric acid soluble material suitable as component for fertiliser production. A patent has been submitted accordingly in 2014.
In work area 2, the recovery from wet sludge has been in focus, being directly operated at WWTPs. Here the maturity of recovery technologies, especially the ones crystallizing struvite is highest and roll-out has already been started. A new design has been piloted by Veolia demonstrating their struvite recovery system works and market penetration can be launched. So, the spectrum of struvite recovery technologies from the sludge water has been broadened. Here, the highest market potential can be predicted for the technology, providing operational benefits for the WWTP operator, meaning reduced sludge quantities for disposal, improved dewaterability and lower polymer consumption and finally valid for all - the reduced return load in the sludge liquor.
Work area 3 was destined to work on the improvement and monitoring of sludge quality. So-called green polymers have been tested in lab-, pilot- and full-scale to substitute chemical polymers commonly used for sludge thickening and drying. Although the pre-trials were quite promising regarding at least partial substitution, the full-scale trials revealed the weakness of these renewable polymers as there is a lack of shear-force stability of the flocs which is extremely relevant for the sludge dewatering with centrifuges. For the monitoring, bio-tests have been selected. In combination with chemical target substance analyses, a more reliable sludge monitoring was intended. But, the bio-tests revealed to be very elaborate and costly and not sensitive for all relevant recyclates. Concluding a cost/benefit analysis, application of these tests for frequent monitoring routines cannot be recommended. Since the toxicity results have been dependent on both, contamination and the materials solubility, wrong conclusions by non-experts cannot be excluded. At least the results from these tests provide valuable input for the upcoming definition of quality criteria for recovered nutrients to be covered by the revised fertiliser regulation EC 2003/2003. The Online Soil Monitor developed by LimCo and based on their Multispecies Freshwater Biomonitor can be seen as new exploitable foreground for soil monitoring. A new test protocol and device design have been developed in the project.
The plant-availability tests conducted in work area 4 over two seasons clearly showed struvite being a very good fertilizer, whereas the ash based materials are rather likely to be used as heavy metal depleted and P concentrated components for fertiliser production.
The conducted risk assessment revealed that technical phosphorus recycling can provide an effective measure to reduce risks for the environment and human health by application of selected recyclates instead of sewage sludge. For the case of struvite crystallized from the liquid phase, the risks were even lower compared to fossil based mineral fertilisers. But the risk assessment revealed also, that atmospheric deposition is more relevant for exposition on and in soil than the land application of mineral fertilizers and technical recyclates for the organic pollutants considered in fertilizer and sewage sludge regulation. Besides the usual suspects like for instance Uranium and Cadmium, also Copper and Zinc can pose risks due to their high quantities. Especially these results are valuable for the coming revision of the European fertilizer regulation within the circular economy package of the European Commission.
Technical factsheets were prepared, summarizing reality based information relevant for future investors. The methodology for LCA has been discussed among stakeholders from science and industry with practical experience, e.g. at the 1st European Sustainable Phosphorus Conference (ESPC) in March 2013 in Brussels and can be seen as the most advanced and reality based approach developed and published so far. The LCA results clearly show, that depending on the whole system, there is a trade-off between recovery rate and energy efficiency to be coped with. Energy intensive stand-alone solutions are not favorable options.
The same accounts for the cost. Some struvite technologies provide direct benefits and are not dependent on product valorization, whereas the chemical and thermanl routes are more vulnerable in terms of sales prices for recyclates. Since there is no one fits all solution, a reasonable mix of P recovery and recycling routes is absolutely favorable to obtain both, resource and cost efficinecy. Integrative solutions are easier to justify for the society and from economic point of view. But, regarding the legal framework, we have to cope with outdated structures and there is a strong need for a paradigm shift from waste to be disposed of towards a renewable resource to be tapped. And this is exactly the current way to move from a linear economy towards the well-balanced European circular economy.
Finally, the project closed important knowledge gaps that had been identified over the past years. It used a practice oriented methodology to paint a broad picture of all relevant aspects of technologies and options for recycling of phosphorus today. It clearly addressed what can already be done and what has to be done to enable a circular economy for nutrients in Europe.

Potential Impact:
Being aware of Europe’s vulnerability in terms of P imports and food security, facilitating the Commission’s circular economy package should be high on political agendas. But, following the current discussion, rare earth metals and construction materials are the materials of priority. Nutrients, especially from bio-based materials are only somehow present in the revision of the European fertilizer regulation. This indicates that there is still strong need for lifting the nutrient related issues higher on political agendas and public awareness. The case of phosphorus is and can serve as perfect template for circular economy, since it unites a strategically important, limited and non-replaceable resource all of us need.
Today, hopes are not high, that wide-spread P recovery and recycling from waste(waster) streams will be implemented without political pressure or in positive terms – motivation, if they are not providing operational benefits or competitive product sales prices. P-REX provided the holistic picture for P recovery and recycling from wastewater and helped to bring light into the shady corners of speculation and uncertainty preventing us to dare what has to be done. It clearly demonstrated what can already be done today and what barriers prevent the next logical steps for market penetration and replication.
At a first glance, the legal framework today is lacking a level playing field for primary material based products and secondary (renewable) based materials, obviously discriminating the latter. Here the recast of the fertilizer regulation (EC/2003/2003) can help to remove these barriers for the good of environment and civil society. This of course is a big challenge having in mind, that there is not only the European Commission, but also 28 Member States with national interests. Therefore nutrient platforms are needed to act on European, but also on national or even regional levels. P-REX strongly supported this kind of platform activities and co-organised various multi-stakeholder events with the two European Sustainable P Conferences as best examples for bringing together not only scientists, but all relevant stakeholders involved in nutrient management and consumption. New media, two films and numerous presentations allowed to efficiently disseminate the P-REX messages. Especially the target group events were very fruitful, even leading to direct exchange with the Commission's DGs GROW and ENV providing valuable results for the coming challenges in policy making. The P-REX eMarket for recovered nutrients, directly incorporated into the ESPP website (http://e-market.phosphorusplatform.eu/) serves as match making instrument to bridge the gap between supply (recovery) and demand (recycling). The website www.p-rex.eu provides relevant information about the project, but also the activities out there. It delivers the most relevant deliverables and materials for the public.
Reality based recovery targets for relevant waste streams combined with recycling quotas may be supportive especially in bridging the gap between supply (recovery) and demand (recycling). But here possible additional cost have to be justified.
To ensure reality based action plans and road-maps, a sound monitoring and compilation of real data is essential. Otherwise strategies can dramatically fail due to investments into the wrong direction. Where there is today uncertainty and guess, there has to be certainty and confidence tomorrow!
Since technologies are developing continuously, best available techniques should be frequently updated and benchmarked to enable decision makers to decide for the best suitable solution for their specific needs also regarding regional preferences. P-REX delivered the template for procedure and relevant data. The process factsheets can be seen as a valuable start to be further elaborated in the coming years.
The project also revealed, that the toolkit is already there, waiting to be used. It has to be clear focus for the future not to just broaden the spectrum of semi-matured or even fancy recovery technologies, but rather more to enable the next essential step for matured technologies to enter the market. Without demonstration facilities, no novel technology will be replicated. No reference, no market!
It is also of high importance to make the most out of the existing infrastructure instead of just calling for “innovation”, which is often mixed with developing new fancy and expensive high-tech. Integration of existing know-how from one sector into another is often much more effective. The term waste indicates clearly, that we waste resources and that there is huge potential to increase resource efficiency by simply avoiding waste. This can easily be achieved without technology innovation, but with individual awareness and behaviour. Use less is the simple formula!
Having said all that, it is now time to take the next step forward in implementing what we already have available today. Production of the commodity phosphoric acid out of waste looks very promising. But also enabling the production of safe sludge will remain a pillar in the P recycling scheme. Since struvite became a recognized material suitable as fertilizer, it should also be recovered where ever applicable. All together there are already three reasonable routes waiting to be valorized in value chains from recovery to recycling. Think forward, act circular!

List of Websites:
http://p-rex.eu/
http://e-market.phosphorusplatform.eu/

Related information

Documents and Publications

Contact

Christian Kabbe, (Project Manager)
Tel.: +49 30 536 53 812
E-mail
Record Number: 187939 / Last updated on: 2016-08-12
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