The aim of the measure „Regional Phosphorus Recycling“ (RePhoR) supported by the Federal Ministry of Education and Research (BMBF) is to contribute to the implementation of the amended Sewage Sludge Ordinance by providing innovative economic solutions for regional P-recycling. The new Sewage Sludge Ordinance requires P recovery from sewage sludge and prohibits agricultural reuse of sewage sludge for all WWTP >50.000 PE. After a transition period (ending between 2029 to 2032 depending on WWTP size) at least 50% P must be recovered from sewage sludge and at least 80 % from sewage sludge ashes. The resulting increased use of secondary phosphorus from the circular economy should significantly reduce the loss of phosphorus and Germany’s dependence on phosphorus imports.
Together with partners from science and industry, a concept for regional P recycling was developed for the Harz and Heide region in the "P-Net" project. The selected region has a high density of process technologies for wet-chemical P recovery in the form of struvite, which is unique in Germany.
In recent years, processes that produce crystalline phosphorus products by means of precipitation and crystallization have become established in the large-scale implementation of phosphorus recovery. P-Net is researching the unresolved issues relating to this technology in order to adapt it to the requirements of the amended Sewage Sludge Ordinance. Thus, the advantages of these plants for fertilizer production will be preserved and made more widely usable. The focus here is on establishing a regional network for the recycling of phosphorus thus strengthening this technology. Following the successful completion of the concept phase, the following objectives were defined for the implementation phase of "P-Net":
Addressing and working on the problems and open questions of the production of P recyclates in the form of struvite.
Converting the impetus provided by the amendment to the Sewage Sludge Ordinance into a driver for struvite plants in particular.
Establishment of a regional cluster for P recycling, based on the P recyclates already produced today that have not yet found their way back into the market.
Optimization of existing struvite plants so that in the future they will also meet the requirements of the amended Sewage Sludge Ordinance in an economical mode of operation.
Further development and optimization of the promising processes and measures investigated within the framework of P-Net in order to establish them on the national and international market.
