The war in Ukraine is threatening to trigger a global world crisis and is highlighting the EU's dependence on mineral-based fertilizers, which are mainly produced by Russia. Long considered "Europe's breadbasket", the two countries involved in the conflict account for around a quarter of the world's wheat exports. But supply chain and logistical disruptions might soon have major repercussions, especially on several least developed or low-income countries. In a note issued at the end of March, the Food and Agriculture Organization of the United Nations expressed "deep concern” about the food security situation in Ukraine, and just a few days earlier the UN head Antonio Guterres warned of a possible "hurricane of hunger" and a "meltdown of the global food system".

Together with nitrogen, phosphorus is one of the main nutrients used for fertilizers. Such an international crisis, combined with the high growth rate of the world population, is expected to drive their demand and their prices to unprecedented levels. "Phosphate supply worldwide will be impacted by the fact that you can't buy it from Russia anymore and nitrogen fertilizers are strongly impacted because they're reliant on natural gas for production," says Chris Thornton, coordinator of the not-for-profit organization, The European Sustainable Phosphorus Platform. "The difficulty in Europe is that we have just one phosphate mine in Finland and that we are 90% dependent on imports." That is why phosphate rock is on the EU list of Critical Raw Materials. Much of its resources are now concentrated in Morocco, Tunisia, and some Middle East countries like Syria, which have stopped exporting. "Being reliant on these countries is a significant problem and the current war in Europe makes much more evident that recycling phosphorus is now a priority."

Recovering nutrients such as phosphorus and nitrogen from wastewaters is a key goal of the European research project WalNUT. "Since farmers often use more fertilizer than the soil can absorb, the excess phosphorus ends up in rivers and lakes, leading to eutrophication, a phenomenon consisting in an abnormal increase of algae," says Sergio Sanz Bedate, chemical engineer at Cartif, a Spanish non-profit research institution which coordinates WalNUT. Launched in September 2021, the project is now about to finalize the analysis of such "nutrient imbalances" to prevent danger to human health and the environment while increasing resource efficiency.  "The first steps consist in mapping these imbalances in Europe, determining the resources available in terms of existing treatment plants and assessing the potential to obtain nutrients from such wastewaters."

"The process is very technical but we can roughly say that to recover these nutrients, we will rely on microbiological, chemical, and physical processes," explains Francisco Corona Encinas, WalNUT's project manager. In the coming weeks, 10 to 12 different technologies will be first tested in the laboratory and then in the pot. In about one year, the 5 most promising ones will be selected for "real-life" simulations, in as many pilot plants in Spain, Belgium, Hungary, and Greece. Each of them will treat different wastewater streams: urban, industrial, food, sewage sludge, and brine from water desalinisation and demineralisation. "For each of them, we will identify the best performing technology and four of the pilots will develop different bio-fertilizers. The remaining pilot is aimed at obtaining micro-nutrients which will be integrated into the other four biofertilizers to improve their quality."

The end goal is to promote the shift from non-renewable mineral fertilizers to bio-based fertilizers, through the development of sustainable technological solutions for nutrient recovery. These solutions will mitigate the risks linked to fertilizer discharge and foster a new circular strategy. "The traditional approach has been linear so far: you produce, you use and you throw away," says Edward Someus, former Nutriman project coordinator and General Manager of 3R-BioPhosphate Ltd. "But the world's natural resources are limited and will soon be depleted. That's why without a proper paradigm shift our economy and our societies will not be sustainable anymore. I'm not speaking of a long-term process. It's something we already have before our eyes." According to a report by the European Sustainable Phosphorus Platform, the nutrient circular economy could also generate over 90 000 jobs in Europe. In addition to environmental gains, thanks to nutrient purchase and manure valorisation, it would help create more rural, decentralised jobs that would not be subject to delocalisation.

To pave the way for the change it aims to achieve, the WalNUT project is also trying to obtain a general picture of the European "readiness" to adopt such innovative solutions. "There are many actors involved in the process: the industries producing the wastewaters, the fertilizer producers, the farmers," says Corona Encinas. "At this stage, we're trying to identify all potential obstacles to the use of biofertilizers. One of the problems is that most treatment plants rely on procedures that are focused on cleaning the wastewaters but are reluctant to recover the nutrients. What we want to show them, for instance, is that our circular approach can be profitable for them." Besides this, Corona Encinas says that the status of the current legislation on wastewater treatment is being compared and scrutinized both at the national and at the European levels.

Most experts, researchers and market players agree that a substantial push will come from the Regulation (EU) 1009/2019, which will replace in a few weeks the Regulation (EC) n°2003/2003. Mr. Someus considers it "a real game-changer". "It is a very important step forward," he says. "This regulation is absolutely welcome and comes at the right time. It will create a much wider playground for different solutions at the European level". The reason for such enthusiasm is because this new text will especially harmonize the commercialization standards in the EU and remove the divergence of national rules. "For instance, if you recovered struvite from sewage in Denmark, up to now you couldn't have it authorized in France, because it is very difficult to get mutual recognition in different member states," explains Mr. Thornton. "From now on the EU market will be opened for recycled fertilizers but, more importantly, for technologies". Approved by the European Parliament and the Council of the European Union two years ago, the new EU 1009/2019 regulation will be binding and directly applicable in all member states from 16 July.