Why climate strategies need to include wastewater resource recovery
At the leading global summit on climate change, one seminar explored the benefits of turning wastewater treatment plants into resource recovery plants and highlighted the importance of updating regulations to support such solutions.
01 Apr 2025Most attendees probably didn’t think beforehand that wastewater would be a relevant topic for 2024’s annual United Nations Climate Change Conference. Nevertheless, it was in the spotlight at the Swedish pavilion for COP29 in Azerbaijan on November 18. The “From wastewater treatment plants to resource recovery plants – raising the ambition for NDCs 3.0” seminar was co-organised by Ragn-Sells and the UN Environment Programme (UNEP).
Traditional biological processes for treating wastewater release greenhouse gases (GHG), such as carbon dioxide and nitrous oxide. In fact, GHG emissions from wastewater treatment plants around the world are equivalent to the global aviation industry. Yet untreated wastewater inundates ecosystems with excess nutrients that create ecological imbalances and pathogens harmful to the health of biomes and humans alike.
“...to lower these emissions is to change the way we look at things, notably how we look at wastewater”
Wastewater, however, is also a potential solution. As Tobias Lorentzson, the Swedish Ambassador to Azerbaijan, explained in his welcoming remarks for the seminar, Sweden has long been home to pioneering approaches for water governance, which includes changing the narrative around wastewater.
"Today, the focus is shifting from merely treating wastewater to instead focusing on resource recovery," he said. "Recovering renewable energy nutrients like phosphorus and nitrogen, and reusing water for industry or agriculture."
Speaking after the ambassador, Deputy Director for UNEP’s Ecosystem Division Bruno Pozzi explained that reclaiming resources during wastewater treatment would mitigate much of its climate footprint. He especially noted the advantage of including wastewater resource recovery in nationally determined contributions (NDCs) – the commitments of COP-participating countries to reduce GHG emissions through government policies and measures.
"We can turn the issue of wastewater into a powerful solution to reduce greenhouse gasses and integrate them into more ambitious NDCs," said Pozzi. "We have to be ambitious and innovative. One of the pathways to lower these emissions is to change the way we look at things, notably how we look at wastewater."
The necessary technology already exists
Presentations throughout the seminar showcased just some of the possibilities for a worldwide transformation of wastewater treatment plants into resource recovery facilities. Case studies detailed the strong viability of wastewater resource recovery in both Egypt and India. And industry product presentations underscored that there won’t be any waiting for the necessary technologies to develop. They’re already here.
A major challenge in water treatment, for example, has been perfluoroalkyl and polyfluoroalkyl substances (PFAS). These ‘forever chemicals’ circulate and build up in the environment. But, as explained during the seminar, the SELPAXT system from Chromafora has demonstrated a 90% success rate for PFAS removal where they’re most concentrated, upstream from standard water treatment, in wastewater or leachate.
EasyMining’s Aqua2N technology was also highlighted for its proven success at removing ammonium nitrogen from wastewater and converting it to ammonium sulphate. This provides a circular source for nitrogen fertilisers as well as averts any nitrous oxide emissions from conventional methods for removing it.
Now is the time to act
Still, it was the seminar’s final presentation that drove home the untapped potential of sustainable wastewater management. Speaking via video call, Brennan van Dyke, Principal Advisor to the Director of the Early Warning and Assessment Division at UNEP, provided a wide range of data points that illustrated the benefits of wastewater resource recovery systems not only for meeting the needs of society and addressing climate change, but doing so in a way that’s affordable. Despite that, the data showed wastewater was significantly lacking among COP-participating countries’ NDCs, which are set to be updated to their third iteration in 2025.
"Let's tap the potential of sustainable wastewater management to reduce GHG emissions. With NDC 3.0 set to be submitted next year, the opportunity is now," van Dyke said to the audience. "Work with those responsible for developing the NDCs in your country to explore wastewater resource recovery as one measure to reduce GHGs, while realising multiple additional financial, environmental, and health benefits."
