In my previous blog post, we discussed nitrogen (N) and phosphorus (P) as essential nutrients, their role in agriculture, and why recovering them from waste is not just a good idea but almost a necessity; today, we’re going to take it a step further.
Because, of course, none of what we’ve been discussing comes out of nowhere. It’s not just a matter of research, nor is it solely about sustainability—it’s also a matter of regulation. And this is where the new European Urban Wastewater Treatment Directive (UWWTD) comes into play.
But before we dive into the regulatory details, let’s do a quick “refresher”—but I promise there won’t be a test at the end 🙂
In the previous post, we saw how traditional fertilizers rely heavily on non-renewable resources, how Europe is highly dependent on imports, and how their intensive use can also lead to significant environmental problems such as eutrophication. Given this situation, we discussed nutrient recovery as a key solution within the Circular Economy: recovering N and P from agricultural and livestock waste and wastewater to produce sustainable fertilizers, such as struvite.
And not only that, but we also mentioned that at CARTIF we have been working in this area for years. A clear example is the European WalNUT project, a project under the Horizon 2020 program that we at CARTIF have coordinated and which just concluded last February after more than four years of work. During this time, technologies have been developed and validated for nutrient recovery from various sources: municipal wastewater, industrial wastewater, and even brine from desalination plant effluent.
As a grand finale, an event was held in Brussels where the consortium members presented the main results achieved during the project. But it wasn’t just a technical presentation; it also provided an interesting forum for discussion, where industry experts analyzed the importance and implications of the new wastewater directive. And this is where all the pieces begin to fall into place.
Because what used to be innovation is now becoming a necessity.
The New European Wastewater Directive: Background and Objectives
The new Directive (EU) 2024/3019 on urban wastewater treatment is precisely about that: changing the game. The previous regulation, from 1991, focused heavily on something basic but fundamental: collecting and treating wastewater to prevent direct impacts on rivers, lakes, and coastal areas. And hey, it worked pretty well. But 30 years later, the context has changed radically.
But today, the socioeconomic context is very different from that of the early 1990s, and it is no longer enough simply to “treat” wastewater. Now we must do it better, on a larger scale… and with a different mindset. One of the most significant changes is that the new directive broadens its scope. More small towns will have to properly treat their wastewater, which means bringing solutions to rural or scattered areas as well—where this has traditionally been more challenging.
But what’s really interesting is what we might call a “shift in philosophy.” Among other things, the directive introduces the treatment of micropollutants, such as emerging pollutants, which include pharmaceuticals and cosmetics. Yes, those very compounds we use every day and which, until now, went largely unnoticed at wastewater treatment plants. To remove them, it will be necessary to incorporate advanced treatment methods, which represents a significant technological leap.
“The directive introduces, among other things, the treatment of micropollutants, such as emerging pollutants, which include pharmaceuticals and cosmetics.”
In addition, the “polluter pays” principle is being strongly emphasized, shifting part of the cost of these treatments to the industries responsible for those pollutants. This change, beyond its economic implications, sends a clear message: water management is everyone’s responsibility.
And now we come to one of the aspects that ties most closely to what we discussed in the previous post. The new UWWTD no longer views wastewater treatment plants merely as treatment facilities, but as true resource recovery plants—or what are commonly known today as urban biofactories or biorefineries.
These are true technological hubs for transformation, focused on wastewater treatment, but also on the generation of energy, reusable water, and, yes, nutrients as well. In fact, the directive explicitly promotes the recovery of phosphorus and other resources, fully aligning with the principles of the circular economy. In other words, what was once considered waste that needed to be managed is now understood as a raw material that must be utilized.
Opportunities for Innovation: From the WalNUT Project to the Future of the Industry
Does that ring a bell? Exactly.
Everything we’ve discussed regarding nutrient recovery, struvite, or technologies like those developed by WalNUT fits perfectly into this new framework. And that’s not all. The directive also sets energy neutrality targets for wastewater treatment plants, promoting the production of renewable energy. In other words, it’s not just about recovering nutrients, but also about closing the energy cycle.
In short, we are moving from wastewater treatment plants to urban biorefineries or biofactories.
So, without making much of a fuss, but with a pretty powerful paradigm shift.
The challenge? Enormous. Adapting infrastructure, adopting new technologies, financing investments, training staff, and so on.
The opportunity? That’s huge, too.
Because this entire regulatory framework only serves to reinforce an idea that we had already been observing in research (and also in projects like WalNUT): the future of water management lies in waste recovery, resource recovery, and integration into circular economy models. And along that path, what seemed innovative just a few years ago… is now becoming essential.
At the Circular Economy and Biotechnology Division of the CARTIF Technology Center, we continue to work toward this very goal, researching and developing innovative solutions that will drive all these advancements through the R&D&I projects in which we participate.
But as you know, it doesn’t end here 😉
More about nutrient recovery…
