Toward a decision support framework for sustainable phosphorus management: A case study of China

Phosphorus is an essential nutrient for plant growth, as well as a critical element involved with biological metabolism. Current phosphorus utilization efficiencies in most counties are below 20%, which results in significant phosphorus loss and brings severe environmental challenges. Therefore, phosphorus flow management and recovery technologies are of great importance for global sustainable development. However, there is little research available to link up phosphorus flow management and recovery technology development. This paper proposed a systematic, hierarchical framework based on fuzzy comprehensive evaluation (FCE) to identify cost-effective waste streams and suitable technologies for efficient phosphorus recovery, while China is used as a case study to demonstrate its effectiveness. Within this framework, substance flow analysis (SFA) is used to track phosphorus flows in China, and different indicators covering phosphorus quantity, process economics, product safety and their environmental impacts were considered. By using FCE, these indicators were combined into a single score for decision making. Principal component analysis (PCA) was further incorporated to identify barriers and directions for future research and development. Although the data collection was still a challenge, the preliminary insights demonstrated that phosphorus recovery from livestock urine in China is the most cost-effective solution. The framework not only supports decision-makers to formulate national and international phosphorus policies and thus improve global sustainability, but also could be applied to other resources management such as nitrogen and rare earth elements in the future.