Life-cycle assessment for resource recovery facilities in the wastewater sector

The concept of wastewater treatment is evolving under the circular economy perspective with the focus on resource recovery of water, nutrients, and energy. In this context, decentralized wastewater schemes can be a good solution as they are alternatives that release pressure on treatment plants that may be at the limit of their treatment capacity and could minimize the costs of wastewater pumping. On the other hand, the possibility of resource recovery in the management scheme is much simpler, as reclaimed water or biofertilizer flows could be applied for irrigation and fertilization of surrounding areas. This chapter aims to determine the environmental profile through the life-cycle assessment (LCA) methodology of P-recovery technologies implemented in decentralized and hybrid treatment processes at different scales. Wastewater segregation, lower energy consumption and sludge recovery as fertilizer significantly improve the environmental score. However, special attention needs to be paid to the technologies chosen. The results obtained show how the treatment facilities with greater resource recovery efficiency and lower energy consumption are rewarded with lower environmental burdens. When comparing P-recovery, the decentralized configuration of the Recovery and Utilization of Nutrients 4 Low Impact FErtiliser (Run4Life) project located in Sneek presented the best environmental results. The AshDec® process attained better results in P-recovery from the sludge of decentralized Japanese facilities installed in households with 18.2% of P in contrast to the recovery efficiencies of the other facilities (<4% for the centralized sludge treatment in the facilities of Lingen and Senboku integrated with the decentralized Japanese treatment).