Wastewater as a resource: Strategies to recover resources from Amsterdam’s wastewater

Resources are becoming scarce. Therefore, reuse of resources is becoming more and more attractive. Wastewater can be used as a resource, since it contains many resources like organic matter, phosphorus, nitrogen, heavy metals, thermal energy, etc. This study focused on the reuse of organic matter and phosphorus from Amsterdam’s wastewater. There is a wide variety of possible alternatives, and the technical options are growing. The problem is not the availability of technology for resource recovery, but the lack of a planning and design methodology to identify and deploy the most sustainable solutions in a given context. To explore alternative, coherent and viable strategies regarding resource recovery from Amsterdam’s wastewater chain, the development process of dynamic adaptive policy pathways was used. In the first phase a material flow analysis was made for Amsterdam’s wastewater chain and analyzed for water, organic matter and phosphorus. In the second phase measures were identified and characterized. The characterization was based on criteria focusing on changes in material flows, recovered products and implementation horizon. For the Amsterdam case recovered products concerned alginic acid, bioplastic, cellulose, phosphorus and biogas. In the third phase the measures were combined into strategies, which are combinations of measures that focus on a specific goal of resource recovery. For the Amsterdam case this resulted in four strategies: a strategy focusing on production of alginic acid, a strategy focusing on production of bioplastics, a strategy focusing on recovery of cellulose, and a strategy focusing on recovery of phosphorus. Adaptive policymaking showed to be a good approach to deal with the wide variety of possibilities and uncertainties. It resulted in a coherent policy as the resource recovery goals became clear, a flexible policy as the lock-in, no-regret and win–win measures could be identified, and an up-to-date policy as a periodic update is possible that will reveal new chances and risks.