![\"\"](\"https:\/\/www.nutrientplatform.org\/wp-content\/uploads\/2025\/04\/Screenshot-2025-04-30-at-11.47.27-1400x436.png\")
<\/figure>\n<\/div><\/div>\n\n\n\nWithin the KNAP project, 46 partners are working together to return valuable nutrients from residual streams back to agriculture. In doing so, we close the loop \u2013 safely, responsibly, and effectively.<\/p>\n\n\n\n
From wastewater treatment to circular fertilizer<\/strong> ICL uses this ash in the production of Puraloop \u2013 a circular phosphate fertilizer that is completely safe, effective, and certified. In this way, a residual product from the water purification chain gets a second life on the land. And it contributes sustainably to a fertile soil for the potato \u2013 and thus also for the fries.<\/p>\n\n\n\n Field trial: circular and effective<\/strong> The results from these fouteen test fields are promising: healthy potato plants with a strong harvest, and a proven contribution to circular agriculture.<\/p>\n\n\n\n We are therefore happy to share both the results and the fries made from potatoes grown in the trial field fertilized with Puraloop. This demonstrates that high-quality recycling is not only possible \u2013 it also pays off.<\/p>\n\n\n\n Why not all residual streams are being used yet<\/strong> One example of an untapped stream is the nutrients found in process water from the agri-food industry \u2013 such as the potato processor that makes your fries, as well as breweries and dairy factories. This process water, used during food production, is rich in valuable nutrients and minerals. When it can no longer be used, it ends up in water treatment. While cleaner than domestic wastewater, it still contains too many nutrients to be discharged and thus needs purification. During purification, the nutrients are consumed by bacteria, which clean the water. The nutrients remain in what is called \u2018aerobic biomass\u2019. Currently, this nutrient rich biomass is also incinerated, just like sludge. But wouldn\u2019t direct use be more efficient?<\/p>\n\n\n\n Within the KNAP project, we are also exploring how this biomass can be used as a source for safe, circular, and natural fertilizers. This way, we bring the hidden value of the agri-food industry back to the land \u2013 and close the loop.<\/p>\n\n\n\n Together, we complete the cycle<\/strong> This collaboration between HVC<\/a>, SNB<\/a>, Lamb Weston<\/a>, ICL<\/a><\/strong><\/em>, and the Nutrient Platform shows that it can<\/em> be done: using residual streams to grow new, healthy crops. From ash from water treatment to nutrients for potato plants \u2013 from waste to valuable, sustainable fertilizer. Together, we are building an agriculture that makes smarter use of our resources \u2013 and is ready for the future.<\/p>\n","protected":false},"excerpt":{"rendered":" To make fries from potatoes, you need large-sized potatoes that have grown well thanks to a healthy soil. Typically, farmers use synthetic fertilizers containing N-P-K: nitrogen (N), phosphate (P), and potassium (K). Plants need these nutrients to grow and produce fruit. However, producing synthetic fertilizers requires a lot of energy and results in high CO\u2082 …<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":4501,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-4536","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/pages\/4536","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/comments?post=4536"}],"version-history":[{"count":14,"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/pages\/4536\/revisions"}],"predecessor-version":[{"id":4606,"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/pages\/4536\/revisions\/4606"}],"up":[{"embeddable":true,"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/pages\/4501"}],"wp:attachment":[{"href":"https:\/\/www.nutrientplatform.org\/en\/wp-json\/wp\/v2\/media?parent=4536"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Currently, phosphate and many other nutrients end up in wastewater. After the treatment of this wastewater by water authorities, sewage sludge remains \u2013 rich in natural nutrients, but not yet clean enough for direct reuse. Sludge processors such as HVC and SNB already extract heat and energy from this sludge by drying and incineration. The incineration process also destroys and removes pollutants like pathogens, microplastics, and pharmaceutical residues. What remains is a mineral ash full of usable raw materials, from which nutrients are recovered.<\/p>\n\n\n\n
Together with our partners, KNAP carried out a field trial with potato cultivation. Fourteen innovative recovered fertilizers were applied, including one already approved for the market: Puraloop.<\/p>\n\n\n\n
Although more and more circular fertilizers are becoming available, many nutrient streams remain unused. Why? Technical challenges, legislation, and the need for up-scaling.<\/p>\n\n\n\n
At KNAP, we work on solutions \u2013 from innovation to policy \u2013 so that more and more of these residual streams, such as aerobic biomass, can safely return to the land.<\/p>\n\n\n\n