Stockholm (Nordsip) – Following the launch of the third Exponential Climate Action Summit organised by ‘We Don’t Have Time’, a series of six in-depth table talks about circularity will take place. NordSIP tunes into the second one to hear sector experts explore the potential of turning wastewater into a valuable resource and find out about some innovative projects. Low and behold, our own bodies – or what seeps out of them – are an integral part of the circular economy of wastewater, according to the enthusiastic experts.
“Today’s sewage is tomorrow’s resources. Today’s treatment plants are tomorrow’s resource plants, with production of biogas and nutrients such as phosphorus and nitrogen,” says Pär Dalhielm, CEO for the Swedish Water and Wastewater Association, kicking off the conversation. If we could harness the resources, such as phosphorus and nitrogen, contained in the wastewater produced each year, we could offset 13% of the global fertilizer requirement, incur environmental gains by eliminating eutrophication, and fuel wastewater treatment plants, according to Manzoor Qadir, Assistant Director, Water and Human Development Programme at the UN.
Qadir’s comments eloquently segue into the focal point of this table talk, ‘pee and poo’ or phosphorus recycling. Nutrients like phosphor and nitrogen are key since we need them to allow our fields to yield enough food and these essentials are extracted from sewage sludge, to be returned to our fields as fertilizer, according to Anna Lundbom, Marketing and Products Sales Manager at Easymining.
It is “circularity in action,” explains Caroline Whalley, expert on Water Industries and Pollution at the European Environmental Agency. Yet only half of it goes back to land use in Europe, instead the sludge is incinerated, or land filled, according to Whalley.
“Wastewater treatment plants put great effort into getting rid of sludge, despite the fact that it is rich in phosphorus,” says Lundbom. “Phosphorus, listed by the European union as a critical raw material, can be recovered from the sludge and brought back into the loop, securing an endless supply. What if we could realise that wastewater treatment plants are factories too, producing the nitrogen and phosphorus needed to grow our foods but doing it from the waste streams instead. With this approach, the wastewater treatment plants of today will be the resource plants of tomorrow,” she continues. EasyMining, alongside other technological initiatives, are spearheading phosphorus recycling technology by extracting all kinds of minerals from sewage sludge ash, according to her.
“We are far from achieving the full potential of phosphor recycling,” claims Qadir and the other panellists agree with him. According to him, large volumes of wastewater are disposed of in freshwater bodies and groundwater worldwide, leading to further environmental damages, health risks and algae growth. Chris Thornton, from the European Sustainable Phosphorus Platform (ESPP), adds that out of the 20 million tonnes of phosphorus dug up annually, most end up in the fresh water, contributing to eutrophication.
Discussing the effects of climate change, Thornton draws the attention to a known paradox. “Eutrophication actually contributes to climate change. When the algae grow, they take up some C02 from the atmosphere, which is nice, but then they die, sink to the bottom of the lake or river, decompose, and emit methane,” he explains. Therefore, phosphorus recycling is essential even from a climate change perspective, according to him.
A major concern is that of contaminants in sewage sludge, such as PFAS, pharmaceuticals, and microplastics. “We are worried about pollutants in the sludge, so the sludge is incinerated, or land filled,” explains Whalley. A reasonable solution until technological solutions are more capable of reducing the concentration of nutrients to avoid further eutrophication, she continues.
‘We need legislation that actually makes wastewater valuable and sellable,” argues Jan Svärd, CEO of EasyMining. According to him, if the quality is the same, or better, it is unreasonable not to use it simply because it stems from wastewater. “I call for legislators to really start to legislate and facilitate the transition to circular economy,” he concludes.
“Regulators, at least in the EU, are improving the legislation,” says Thornton. He points out that phosphor recovery from wastewater is included in the EU green taxonomy and mentions the EU fertilizing products regulation (FPR), which is part of the EU’s Circular Economy Package.
In defiance of colloquial terminology, we appear to be up shit creek with a paddle. Despite phosphorus recycling being far from achieving its full potential, businesses, institutional investors, and policy makers are now taking steps to encourage the circular momentum characterising wastewater management.