Meyer, Roland; Luthin, Anna

Phosphorus is an elementary raw material that is essential for life on this planet and that is widely used as fertilizer. In the context of the EU’s strategy towards an effective circular economy (CE), recovering phosphorus e.g. from sewage sludge from wastewater treatment plants as a secondary product is crucial. Several new technologies for recovering phosphorous developed in recent years – mainly on labor scale. To scale up and to compare the environmental impacts of these technologies, the German Ministry of Education and Research (BMBF) started the project RePhoR. Each of the seven subprojects within RePhoR is asked to conduct a Life Cycle Assessment (LCA). This is coordinated by the authors of this abstract to ensure the comparability of the assessments, e.g. by setting the same functional unit (FU) and the same assumptions according to ISO 14040/14044. The aim is thus to develop a catalog of criteria that serves as a basis for tackling the highly complex problem of ensuring comparability of the different technologies. In particular, it is to be highlighted how the CE-aspect can be considered and emphasized in LCA, since higher phosphorus recovery rates are often also associated with higher environmental impacts. Complexity of the problem is related to different qualities of the recycled fertilizer (e.g. plant availability, harmful accompanying substances). Though being in an early stage of the project, it is to be expected that the plant availability will play a significant role in defining the FU as the different products have different approaches (e.g. long- or short-term fertilizers or specialized on specific plants). Hence, a simple comparison on a weight-scale is not applicable. Furthermore, the calculation of credits, e.g. for chemical byproducts, marks an important influence to be considered. Preliminary findings from the research will be presented at the conference.