From treatment plants to resource recovery plants

Untreated wastewater is a major threat to our health and the environment. But managed sustainably, our sewers are a rich source of valuable raw materials. It is time to turn our wastewater treatment plants into resource recovery plants.

02 Jun 2025

Today, the discharge of untreated wastewater into waterways is a growing health and environmental threat. But managed sustainably, our sewers can be a rich source of valuable resources, including clean water, energy, and nutrients.

– Left untreated, wastewater poses a significant risk to people and the environment. But as well as removing the bad stuff from wastewater, we need to recover as much of the good stuff as possible. So, the concept of a resource recovery plant is not so much a new label as it is a shift in mindset, says Pär Larshans, Chief Sustainability Officer at Ragn-Sells Group.

One of the most important resources found in wastewater is phosphorus. Used in animal feed and fertilisers, this nutrient is so vital to our ability to produce food that the European Union has included it in its list of critical raw materials. With very limited production from domestic phosphate mines, Europe is heavily dependent on imports from highly problematic sources outside the EU.

"As well as removing the bad stuff from wastewater, we need to recover as much of the good stuff as possible.”

Pär Larshans, Chief Sustainability Officer at Ragn-Sells Group

The same is true for many other essential materials. Today, Europe consumes about 25%–30% of the world’s raw materials but produces only 2–3%. To increase self sufficiency, the EU has identified increased recycling of critical raw materials as a key strategy. Through the Ash2Phos technology, developed by Ragn-Sells innovation company EasyMining, we can contribute to this aim by extracting clean, high-quality phosphorus from sewage sludge.

– To feed a growing planet in a sustainable way, we simply must break our dependence on virgin phosphorus. With the Ash2Phos technology, we offer a circular solution to reduce Europe’s phosphorus supply challenge. That is, if the EU allows it, says Anders Kihl, Chief Strategy Officer and R&D Director at Ragn-Sells Group.

Currently, the EU bans the use of phosphorus recovered from waste in animal feed, even though the Ash2Phos product is of higher quality and purity than virgin phosphorus. Like much waste legislation, the ban reflects the so-called waste hierarchy, a principle that sees waste as a problem to be minimised rather than a valuable resource.

– The waste hierarchy belongs in the dustbin of history. If we are to find circular solutions to Europe’s critical raw material needs, Europe must replace the waste hierarchy with a sustainable resource supply strategy. Transforming wastewater treatment plants into resource plants should be a cornerstone of such a strategy, says Pär Larshans.

This article was published in Ragn-Sells’ 2024 Sustainability Report, which offers insights into our sustainability efforts, progress on seven key goals, and our vision for a circular and sustainable society. Download report here