The United Nations Framework for the Classification of Resources (UNFC) is a generic tool that can be used for all types of resources, including anthropogenic resources. Compared to the primary raw material sector, the classification of resources is not common in the recycling sector. Therefore, we are working on a conceptual approach with seven stages to define, evaluate and classify a project and to summarize the results in a report. At the same time, we are working on a concept of how the UNFC can be used at national level.
The principle how the results can be combined will be shown by the case studies on the recovery of phosphorous from sewage sludge. Statistical data was used for a mass flow analysis (MFA), looking at the amount of sewage sludge produced, processed and treated for phosphorous recovery. The result of the MFA is visualized in a Sankey diagram. This approach helps to identify the viable projects in terms of circular economy and those that meet the criteria for phosphorous recovery. Based on that, it can be shown how much of the phosphorous is currently being recovered. In addition, specific projects along the recycling value chain were selected to apply the conceptual approach. This provides information on the level of confidence of the produced materials, the technical feasibility as well as the economic viability and environmental and social impact of the project. Overall, the results can be used to compare the projects and highlight the potentials and obstacles of the project.