Implementation of Phosphorus Recovery from the wastewater stream – The European FP7 project P-REX
Being one of the key nutrients, there is no doubt about the importance of phosphorus for all life on Earth. This element is even considered “life’s bottleneck”, as Isaac Asimov, one of the brilliant minds of the last century already stated in 1959 in his essay of the same title. Its importance as plant nutrient is emphasized by the huge amount of about one million metric tons of mineral phosphorus annually imported into Europe to sustain good harvests. Since phosphorus is a limited fossil element and given the strong dependency of Europe on phosphorus imports, its extensive recovery from “secondary deposits” is of paramount importance and follows the principles of the European Roadmap for Resource Efficiency. No matter, if there would be a phosphorus peak in the future or even physical scarcity, pure reason alone should force us to secure this vital resource not only for ourselves but also for future generations. Scarcity itself is not a problem of the future, but an actual thread to many people’s life whose cannot effort fertilizers to grow enough food for themselves. They know the essential or real demand of phosphorus humans need to survive, whereas in Europe we can afford luxury uptake. The availability of phosphorus is dramatically dependent on economical drivers. Looking at the current supply-chain efficiency of phosphorus, only about 20% of mined phosphate rock is finally consumed in form of food (Schröder et al. 2010). Most of the precious element is lost on its way from mine to fork. However, phosphorus does not disappear and can, unlike oil, be recycled once used. In developed countries with proper sanitation and wastewater treatment, the wastewater stream represents a relevant phosphorus reserve. In Germany, more than 50% of the annually imported mineral phosphorus destined to be used as fertilizer (about 120,000 metric tons) could be substituted by recovered phosphorus from the wastewater stream if it were recycled completely. Various technologies have been developed in recent years to tap into this secondary resource. They might also be applicable for other material flows like manure and digestate. The traditional application of sewage sludge in agriculture was the dominating recycling path in the past, but is increasingly refused due to concerns about pollutants being harmful for the environment and public health. Technological alternatives are about to contribute to close the phosphorus cycle again (Kabbe 2013). Although some of these techniques are already feasible, they still need to be implemented onto the market. Three waste material flows, sewage sludge, manure and digestate are all alternatives to industrial fertilizers and compete for the same limited land area. Thus, only solutions that safeguard human health and the environment are viable resulting in a driver for wide-spread application of innovative alternatives when direct valorization on arable land falls short. For successful market implementation, new technologies and their resulting products need to be proven capable and feasible. Within the European project P-REX, novel and available technical solutions for phosphorus recovery and recycling will be demonstrated in full-scale. Their performance and feasibility will be systematically assessed and validated, as well as the quality of obtained recycling products with focus on plant-availability and eco-toxicity. Environmental impacts (LCA) and costs (LCC) will be calculated based on these data. Together with the analysis of the legal framework and existing market barriers and market potentials for novel recycling technologies and their products, strategies and recommendations will be developed for efficient and wide-spread implementation of phosphorus recovery with regards to specific regional conditions. A first overview of legal, societal and market aspects has been elaborated within the first project year and was discussed in the stakeholder workshop “Recycled Phosphorus Fertilizer- Market Chances and Requirements” in Podebrady (CZ) in September 2013. The finalized report (A. Nättorp et al, 2013) is available for download at the project’s website: www.p-rex.eu. Stakeholder workshops in different European regions will be organized in 2014 to ensure the involvement of all relevant stakeholder perspectives and regional conditions and needs. Especially the end-user perspectives (plant operators, fertilizer industry, crop farmers) need to be considered more in the overall discussion in the future. P-REX is aiming to increase the European phosphorus recycling rate from municipal wastewater by closing gaps between science, policy and practice, as it was a key message of the First European Sustainable Phosphorus Conference in March 2013: waste less, recycle more and cooperate smart (www.phosphorusplatform.eu). Besides wastewater and sewage sludge, manure and digestate bear substantial quantities of phosphorus for recovery and possible synergies just wait to be applied.