Associate Professor, Ph.D., School Deputy Director
Krakow School of Interdisciplinary PhD Studies
Poland
Head
Division of Biogenic Raw Materials, Mineral and Energy Economy Research Institute
Polish Academy of Sciences
Poland
Vice-Chair & Member of Polish Young Academy of the Polish Academy of Sciences
Poland
smol@meeri.pl
Krakow School of Interdisciplinary PhD Studies
Poland
Head
Division of Biogenic Raw Materials, Mineral and Energy Economy Research Institute
Polish Academy of Sciences
Poland
Vice-Chair & Member of Polish Young Academy of the Polish Academy of Sciences
Poland
smol@meeri.pl
In the Baltic Sea region, water plays a crucial role as a nutrient carrier, influencing both the ecosystem and the health of marine life. The Baltic Sea, being a semi-enclosed and shallow body of water, experiences unique dynamics related to nutrient cycling. This means that sustainable nutrient management in this area is not possible without the development and implementation of integrated water resources management plans and strategies at various levels: local, regional and international.
A key concern in the Baltic Sea region is eutrophication, which occurs when excess nutrients (especially nitrogen and phosphorus) cause an overgrowth of algae. This leads to algal blooms, which consume oxygen and create dead zones where marine life cannot survive. Next to surface runoff, mainly from agricultural areas, insufficiently treated sewage is a major source of eutrophication. Wastewater treatment plants (WWTPs), where the main resource is water, especially those that are outdated or underperforming, can be a significant source of nutrient pollution if they discharge untreated or partially treated water. Therefore, WWTPs should be supported in improving management methods and implementing highly effective methods of removing pollutants, including nutrient removal agents, before municipal sewage is discharged into the environment. In addition to the increasingly stringent legal requirements, such as Regulation No. 741 of the European Commission (EU 2020/741) on minimum requirements for water reuse for agricultural irrigation purposes, it is important to create various opportunities for implementing the assumptions of the circular economy (CE) in these enterprises. One of the possibilities is to use sewage treatment methods that allow for controlling the content of nutrients in the treated sewage, which can then be directed to agricultural irrigation. Research in this area is being carried out as part of an international project “Closing local water circuits by recirculation nutrients and water and using them in nature” (ReNutriWater) that is co-financed by European Regional Development Fund (ERDF), as a part of Interreg Baltic Sea Region fund. Thanks to the controlled content of nitrogen and phosphorus in the reclaimed water, it can be treated as ‘fertiliser water’. This is a new approach to the topic of water recovery from sewage and its management. This is also in line with the CE idea in which raw materials (in this case water and fertiliser resources) are to be retained in the economy for as long as possible and the amount of waste generated is minimised. There are a number of benefits to this approach to municipal wastewater treatment, including:
- Instead of relying solely on synthetic fertilisers, controlled reclaimed water can provide a sustainable, natural source of nitrogen and phosphorus. This reduces the need for chemical fertilisers, which are energy-intensive to produce and can contribute to pollution if overused.
- By recycling nutrients from wastewater, reclaimed water helps close the nutrient loop, transforming potential waste into a valuable resource for agriculture and thus supporting CE policies in the Baltic Sea Region.
- There are also added values for farmers themselves using reclaimed water - they can benefit financially from using reclaimed water as fertiliser, since it can reduce their dependency on commercial fertilisers.
- By providing controlled levels of these nutrients through reclaimed water, crops can grow healthier and stronger. This is especially beneficial for crops that need a consistent supply of these nutrients.
- Using reclaimed water for irrigation is a way to manage water use more efficiently and in sustainable way. It helps ensure that water used for agriculture is treated and reused, contributing to overall water sustainability.
- Reclaimed water often contains organic materials, which can improve soil structure, water retention, and microbial activity. This can enhance soil fertility over time and help maintain healthy soil for future crops, which is also important topic in the Europe and Baltic Sea region.
In summary, using reclaimed water as "fertiliser water" with controlled nitrogen and phosphorus levels can offer multiple benefits, including sustainable agricultural practices, cost savings, enhanced crop growth, reduced environmental pollution, and improved water conservation. It represents a valuable tool for promoting more circular, resource-efficient systems in agriculture, supporting both economic and ecological sustainability. Therefore, it can be concluded that water is the most important nutrient carrier in the Baltic Sea Region.