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.
The advantages of struvite plants include the fact that they are comparatively easy to implement in existing plant technology, while at the same time they offer the option of producing a high-quality fertilizer directly at the wastewater treatment plant site, which has high plant availability with low water solubility and also has a low trace substance and heavy metal load. Last but not least, current studies show that such wet-chemical processes for P recovery generally require less energy than conventional P fertilizer production, or significantly less energy than the mono-incineration route. So far, however, it has not been possible to establish a consistent marketing channel for the P recyclates produced in the struvite plants. Against this background, the following goals were defined in the concept phase of “P-Net”:
Establish a regional cluster for P-recycling that focuses on P-recyclates that are already being produced today but have not yet found their way onto the market.
Optimize existing struvite plants for P-recovery to such an extent that they will meet the requirements of the amended Sewage Sludge Ordinance in the future and are operated economically.
Establish the promising processes and measures developed and optimized in the P-Net project on the national and international market.
