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In the plan for its project development, IWAMA has several objectives, one of which includes launching a series of investments in the local wastewater treatment plants. These investments allow piloting innovative solutions in smart energy and sludge management that could be afterwards widely used in the Baltic Sea Region. Over the course of the project, we will highlight investment-related activities as they are being developed.

One of the pilots supporting the smart energy management is a combined anammox-constructed wetland pilot-plant in Gdańsk, Poland. As the plant has almost finished installing the purchased equipment and soon will be ready to start testing, we are sharing their pilot solution.

Pilot concept

The concept proposed for the Wschód WWTP in Gdańsk combines low energy consumption with cost-effective processes to achieve more effective wastewater treatment and maximal recovery of organic compounds present in the wastewater for increased biogas production. The process involves three stages:

  • Primary treatment consist of coagulation-flocculation-sedimentation process, followed by filtration for enhanced carbon extraction and phosphorus removal.
  • Secondary treatment incorporates autotrophic deammonification by partial nitritation-anammox process in integrated fixed film activated sludge (IFAS) system that features the benefits of both fixed film and conventional suspended growth activated sludge systems.
  • Final post-treatment is demonstrated by the two-stage constructed wetland that provides low cost removal of the remaining organics and nutrients.

The performance of the wastewater treatment will be monitored with inline probes measuring solids, pH, oxygen, conductivity, ammonia, nitrite and nitrate. The IFAS bioreactor will be equipped with the automatic regulation of the process temperature and oxygen concentration using PLC control system.

The piloted concept allows the possibility of recovering a high fraction of organic carbon and removing nitrogen with the nitritation-anammox process. Increased carbon extraction leads to a higher production of biogas that can be utilized in a combined heat and power plant (CHP) to generate surplus renewable power. The anammox-based process allows a shortcut in the nitrogen cycle since anammox bacteria convert ammonium and nitrite directly into nitrogen gas. This enables nitrogen removal at 60% lower oxygen consumption compared to conventional nitrification-denitrification systems.

Why waste energy on wastewater?

The innovative combined technology considerably improves the energy balance and allows making a plant cost-effective and energy-positive. Moreover, recovering energy from the wastewater treatment brings many environmental and health benefits.

The plant starts its pilot operation already this autumn launching the primary treatment process in September, with the secondary treatment process to begin in October.