AMPHORE (concept phase) – Regional Sewage-Sludge Ash Management and Phosphorus Recycling for a Metropolitan Area

The amendment of the German sewage-sludge ordinance, AbfKlärV for the short, led to the initiation of the German Ministry for Education and Research, BMBF for the short, funding initiative “Regional Phosphorus-Recycling”, RePhoR for the short, which is part of the programme “Research for Sustainable Development” , FONA³ for the short. Under the leadership of the Ruhrverband, several water boards merged to react on this amendment, with the Emschergenossenschaft/Lippeverband, Linksniederrheinische Entwässerungsgesellschaft and Wupperverband among them. The project “Regional Sewage-Sludge Ash Management and Phosphorus Recycling for a Metropolitan Area”, AMPHORE for the short, was successfully acquired. The Institute for Environmental Engineering of the RWTH Aachen University, ISA for the short, the Fraunhofer Institute for System- and Innovation-Research and the Institute for Energy- and Environmental-Research Heidelberg cover specific research tasks as equal project partners.

The project mainly focuses on sustainable and economic sewage-sludge utilization and above all on the phosphorus recovery from sewage-sludge ashes. Therefore, the following steps are planned: phosphorus recovery from sewage-sludge ash, marketing of the recyclates and the residues’ final disposal (landfill) or recycling. These are additional to the sewage-sludge’s thermal treatment, which already exists at four sites operated by the involved water boards.
Recyclates can be fertilizers, raw phosphate substitutes or phosphoric acid as secondary raw material. The aim is to reuse them on a regional scale, which is why the marketing concept should meet the demand and the quality requirements in the region.

Several phosphate recycling technologies will be evaluated technically and economically. Subsequent to that, in a second project phase the plan is to build an industrial demonstration plant which operation shall verify the chosen dimensioning and provide information for future expansions of the phosphorus recovery process. What follows, is the establishment of an innovative, integral and regional management of sewage-sludge, sewage-sludge ashes, phosphorus recovery and recycling as well as residues’ disposal.

The ISA possesses wide scientific and technical knowledge as well as project expertise in the field of sewage-sludge management and phosphorus recovery. Therefore, in AMPHORE it fulfills the following tasks:

• Market screening and evaluation of appropriate phosphorus recovery processes
• Technical possibilities to control the ash’s characteristics and their relevance for the phosphorus recovery processes
• Characterization of treated and temporarily stored ashes and other residues from phosphorus recovery processes

The used methods and procedures shall enable applicability on other regions. In case of the implementation phase’s approval by the Federal Ministry of Education and Research, the industrial demonstration plant will have an intended operation time of at least one year. On the successful completion of the test-period follows a long-term regular operation: The technology will be able to perform an up scaling or rollout for the whole region. In the case of ongoing finance, further research and development work for process optimization and balancing could be done.