how milk byproducts become clean water and fertilizer

When discussing pollutants in public policy, acid whey is rarely mentioned compared to more well-known compounds that are harmful to the environment. Nevertheless, this common byproduct of milk production is considered by experts in the field to be one of the most toxic wastewaters and is particularly difficult to dispose of.

Consider the scale: the EU dairy sector processes over 155 million tonnes of milk every year, mainly from countries such as Germany, France, Poland, the Netherlands, Italy and Ireland. Approximately 80 to 90% of the processed amount becomes either “sweet whey” from enzyme-cured cheese or “acid whey” from cream cheese, yogurt, quark and casein production.

After all, acid whey is the real problem child of this industry, particularly due to its high biological oxygen demand, which is 175 times higher than that of typical municipal wastewater. In short, when acid whey is discharged into a body of water – as has sometimes happened in the past when disposal costs were high – it can be ecologically damaging. When microbes break it down, they consume large amounts of oxygen, suffocating aquatic life.

With EU institutions now pushing for new regulatory requirements and public demand for sustainable food production growing, dairies can no longer afford to treat sour whey as single-use waste. This, in turn, makes research into resource recovery solutions more valuable than ever to the industry.

A typical example is 3R-BioPhosphate Ltd., a former Swedish company based in Hungary that is pioneering pyrolysis technology. This specific area involves the design of systems that integrate thermal and biotechnological methods to break down organic substances.

Edward Someus, inventor of 3R technology and the company's CEO, sat down with us to explain the latest aspects of this innovation – and the challenges that lie ahead.

How important is the dairy industry for Europe?

Let's put it this way: The EU itself is currently the world's leading milk producer and exporter. The dairy sector in particular is also one of the most important agricultural and food industries in Europe. It generates 55 billion euros annually and supports around 650,000 agricultural businesses across the continent. It supports rural communities, ensures food security through high-quality nutrition and embodies centuries-old European cultural heritage. So in some ways its value exceeds simple economic value.

But the pressure to reduce the environmental impact of dairy by-products is now greater than ever.

Yes, the pressure is increasing significantly. Over the last three decades, EU legislation has steadily tightened requirements for nutrient management, wastewater treatment and circular economy. And for dairies, this means that acid whey can no longer be treated as a disposable byproduct. The difference compared to the past, however, is that there is now a financial incentive to introduce innovative renovation solutions. In the past, this route was usually not very economical.

And what role does 3R-BioPhosphate Ltd. play? in this industry?

We are pioneers in converting leftover biomass from the dairy and food industries into higher-quality products. It is a process called upcycling.

How did 3R-BioPhosphate Ltd. come about? to WALNUT? Does the company already have experience with similar projects?

Well, the company has a proven track record of providing innovative solutions for the circular economy, particularly in processing agri-food by-products into phosphate-rich fertilizers, clean water and biostimulants. And before WalNUT, we have also successfully participated in several European Union funded projects including Refertil, Nutriman and PROTECTOR, to name a few. They all focused on upcycling unused by-products with a similar goal. Therefore, becoming involved in the WalNUT project was really a natural next step.

Could you explain to us the process developed by 3R?

We have developed a three-step process that combines liquid fermentation, solid fermentation and adsorption. The result is both clean water and a phosphate-rich organic fertilizer. Let's start with liquid fermentation. We use acidic whey as a substrate and inoculate it with carefully selected microbial fungal strains. In this phase, toxic organic compounds are removed, oxygen demand is reduced, and concentrated microbial biomass is created.

From there, we move on to solid-state fermentation, which combines the microbial biomass with high-temperature processed animal bone char, a porous material rich in calcium and phosphorus. At this point, we have already developed a nutrient-rich biofertilizer for plants to be introduced into the agricultural market.

Then comes the final step: adsorption. The liquid wastewater remaining after fermentation is treated again with animal bone char, which captures the remaining nutrients and pollutants. In the end, you will receive clean water that meets drainage standards.

3R pyrolysis prototype on a regional production scale

Would you consider this process to be state of the art in preventing organic pollution and allowing reuse?

I would say that, yes. Firstly, because it is a true circular economy model: the by-products themselves become raw materials for the process. It fights pollution, creates economic value and supports sustainable agriculture. Better yet, it allows smaller dairy producers to economically dispose of their by-products, which has been the real problem for them in the past.

Why was the facility in Kajászó, Hungary, chosen for this pilot project? What made it ideal for WalNUT?

The 3R-Biofarm Upcycling Center in Kajászó was chosen primarily because of its advanced infrastructure. It includes a 30-hectare agricultural industrial site with high-temperature pyrolysis, biotech facilities and laboratories. In short, it had everything needed for the project: nutrient recovery, biomass utilization and water treatment. However, future scaling of these processes for full industrial use will require investment in larger modular units as well as new testing in different industrial environments and with regulatory certifications. This is just the first step.

Could Hungary play a role in spreading this technology across Europe?

Certainly in the sense that Hungary offers a strong demonstration platform for 3R technology at a lower cost. But the country has a relatively small domestic market. The primary expansion potential lies in larger dairy markets such as Italy, Spain, France, Germany, the USA, Australia and Japan. Hungary can therefore act as an innovation center and industrial training location for this sector and not as a large-scale producer in the narrower sense.

What excites you most about the work you do here?

Certainly the fact that we are transforming an environmental challenge into a sustainable solution that benefits the European economy. But what makes it even more worthwhile for me is that we are doing this within a circular economy approach.

Photo credit: @3R-BioPhosphate