Main benefits
  • Reliable and long-lasting
  • Low pressure drops and therefore higher efficiency
  • Possibility of future increase in aeration capacity   
  • Quick and easy installation
  • Flexible layout design
  • High temperature endurance
  • Suitable for aggressive wastewater
Main applications
  • Aeration of municipal wastewater
  • Aeration of industrial wastewater, with some restrictions


Main design features
All diffusers have a built-in non-return valve which provides additional safety to the treatment process by preventing sludge infiltration into the aeration piping system when the air flow is interrupted. The KKI215, and PRK/PIK300 diffusers are interchangeable for retrofits, offering high flexibility.


Diffusers with EPDM rubber membrane discs:

PIK300 fine-bubble

  • Polypropylene main body and an antifriction ring to protect the membrane
  • Suitable for both continuous and non-continuous aeration processes

PRK300 fine-bubble

  • Strong main body, making it suitable for SBR, MBR, and MBBR processes
  • Antifriction ring protects the membrane
  • PRF300 retrofit for upgrading 215 mm diffusers to more efficient systems

KKI215 fine-bubble

  • Suitable for both continuous and non-continuous aeration processes
  • Special support for use in deep basin applications, in water up to 15 m deep

Sucoflow DS 20 fine-bubble

  • Ideal for high-density and retrievable aeration systems
  • Easy-to-fit thread connection
Key characteristics

Diffuser  diameter

PIK300, PRK300: 336 mm

KKI215: 215 mm

Sucoflow DS 20: 500 mm

Membrane surface area

KKI: 0.025 m²

PIK, PRK: 0.060 m²

Sucoflow DS 20: 0.183 m²

Operating range (+20°C; 1 013 mbar)

KKI215: 0.5–4 m³/h

PIK300, PRK300: 1.5–8 m³/h

Sucoflow DS 20: 1–15 m³/h

Max. operating temperature:

PRK300, KKI215: 80°C

PIK300, DS 20: 100°C

  • Aerobic digestion
    In aerobic digestion in wastewater treatment, microorganisms continue to break down the organic material. These microorganisms need aeration in order to function, and some level of mixing is required to keep the process efficient and reliable. The result is reduced sludge volume and the prevention of odor. Sulzer has highly suitable products such as compressors, aerators and disc diffuser systems to support the process in the aerobic digester tank.

  • Biological process
    The target of the biological process in wastewater treatment is to remove organic, biodegradable substances via the metabolism of microorganisms and related biochemical processes.

  • Industrial water and effluent treatment
    Sulzer has a deep knowledge in wastewater treatment, and with our wide product portfolio we can now offer energy-efficient and reliable solutions for your water collection, neutralization, flocculation, sedimentation, cooling, aeration, sludge storage, digestion, and dewatering processes.

  • Tertiary treatment
    Treated wastewater may occasionally require further treatment. Local discharge rules may pose strict limits that cannot be fulfilled by even the most effective process, or a higher quality of effluent may be requested for its reuse. When tertiary treatment is needed, various levels of filtration can be applied, including very fine filtration. Often, however, a final step of mixing and aeration is sufficient to achieve the target. When this is the case, Sulzer's submersible mixer types ABS XRW and RW can be used, along with submersible aerator type ABS TA–TAK and disc diffuser system types ABS PIK, DS and Sucoflow.
Case studies and articles
  • Delivering cost savings for wastewater treatment
    Air is one of the most important elements used in wastewater treatment processes. Activated sludge systems require proper aeration of the wastewater to ensure the biological decomposition of organic compounds. However, while air costs nothing, the systems required to deliver it can account for 50 to 90% of the energy consumption of a plant. Therefore, the decisions made with respect to this equipment can have a significant impact on running costs.

  • Ensuring the right mix
    Sulzer technology is playing a key role in Energiefabriek West, an innovative bio-power scheme in the Netherlands. The Rivierenland Water Authority in the Netherlands is investing in new infrastructure to improve the performance of its wastewater treatment systems while also reducing its impact on the environment. The utility is aiming to become energy neutral by 2030, and Sulzer technology is helping it to realize this goal.

  • Vienna’s climate-neutral wastewater treatment plant gets efficiency boost with Sulzer technologies
    The E_OS (Energy Optimization through Sludge Treatment) project on the edge of Vienna is a pioneering facility designed to transform the Austrian capital’s wastewater treatment plant from a major energy consumer into a net producer. Important parts of the project therefore include maximizing energy efficiency and optimizing power generation.

  • Case studies
    Wherever fluids are pumped, mixed, controlled or applied, we are there. See how our solutions create value for customers and learn how we can make your pumping and mixing processes more efficient and profitable, safeguarding your production and ensuring lasting reliability.

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