From the beginning of 2019 approximately one third of the nutrients used by UPM Kaukas mill integrate’s biological wastewater treatment plant has been replaced by Kekkilä Recycling Joutseno composting plant’s side stream: reject water rich in nitrogen.
The co-operation is another exciting step towards the 2030 target of using only recycled nutrients for wastewater treatment at all UPM sites around the world. Using recycled nutrients is the third commitment UPM has made to the Baltic Sea Action Group, an organisation devoted to protecting the Baltic Sea. UPM Kaukas uses all the nutrients available at the Joutseno composting plant replacing around 4,5 tonnes of nitrogen each month.
The use of recycled nutrients in water purification is good common sense: the industrial production of nutrients is energy intensive. Phosphorus, often used in nutrients, is a depleting natural resource that is in better use as a fertiliser in agriculture. The wastewater generated in many industrial processes is rich in nutrients, not nutrient-poor, as in the forest industry. That nutrient-rich wastewater could often be utilised as such for the nutrient-poor wastewater treatment bacteria in circular economy co-operation between companies. If these side streams are not utilised, they will increase the wastewater load to treatment plants and cause additional costs for the companies.
After the idea of recycling side-stream nutrients at UPM Kaukas was presented to Kekkilä in the spring of 2018, things started moving quickly. Taru Päiväläinen, researcher at UPM Northern Europe Research Center, was responsible for the project at UPM. Päiväläinen has since moved over to UPM’s Responsibility team.
“In the summer we ran a two-week laboratory simulation on how Kekkilä’s wastewater works as a nutrient in our wastewater treatment plant. The results were promising, so we quickly moved on to a mill scale test run. The test continued until Christmas, after which we decided to continue the same way. In the reject water generated by Kekkilä, nitrogen is in the form of ammonium, which is the most preferred form of nitrogen for our diligent organisms in the waste water treatment plant,” says Päiväläinen, who spent lonely hours working hard on the tests on Midsummer, an important summer festivity in Finland.
The Kekkilä composting plant produces reject water when damp exhaust air is discharged from its’ thirteen composting tunnels, through the ammonia scrubber and the biofilter. Moisture condenses into reject water and is directed into a tank. Once filled, the tank is transported to Kaukas.
”Before the cooperation we ran the reject water into the municipal wastewater treatment. This collaboration makes the entire process more sustainable. In the last few years we have taken many steps forward in handling our wastewater. This is another good example of our efforts and works well for the environment and for us financially as well. It also has a local employment effect. Everyone benefits from both the project and the bigger idea behind it,” says Vesa Kaipia, the facility manager at Joutseno composting plant.
Kekkilä Recycling’s composting services are available to anyone. Typical clients are municipalities, food companies and forest industry operators. The majority of the compost produced at Joutseno is used as a base for producing garden soil for Kekkilä’s garden soil pickup stations.
much more at: https://www.upm.com/news-and-stories/articles/2019/03/a-delicious-meal-cooking-in-the-composting-plant-of-kekkila-for-the-micro-organisms-of-upm-kaukas-water-treatment-plant/