In shipbuilding, the steel frame of a vessel is designed to last for decades.
When individual components need modernization, the structure itself is not replaced. Instead, retrofitting is used as a targeted and efficient approach. The same principle applies to MYTEX Retrofit for municipal wastewater treatment plants with plate and frame systems. The existing frame remains in place, while modernization is achieved through custom designed retrofit blocks and modules that precisely match the existing footprint.
Growing pressure on operators as aging modules become a limiting factor
Municipal wastewater operators across Europe and internationally face similar challenges. Inflow volumes continue to increase, discharge limits become more stringent, and operating costs rise steadily. As membrane modules age, operators are often confronted with an unattractive choice between costly spare parts and complete module replacement. Both options involve significant expense, downtime, and operational risk. MYTEX Retrofit offers an alternative approach by upgrading performance while making use of existing structures rather than replacing them.
MYTEX customized blocks for existing frames
The core of the MYTEX Retrofit concept is the use of custom designed membrane blocks that are engineered for existing frames. This approach preserves the original module construction and concentrates modernization on filtration performance and membrane technology.
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Your operational benefits:
- Replacement outfitting blocks or modules, custom-fit to the existing footprint
- Suitable for any plate-and-frame system (retrofit approach for existing frame constructions)
- Original construction remains intact: less intervention, lower project risk
- A predictable upgrade path instead of a full rebuild
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Drop in upgrade without impact on control systems
MYTEX Retrofit is designed as a drop in solution for plate and frame modules, enabling step by step upgrades with limited time and cost effort. The retrofit blocks are engineered to fit into existing frames without requiring structural modifications. This makes the approach particularly suitable for plants where changes to tanks, peripheral equipment, or control systems are not desired or not feasible.
Case study: cruise ships retrofitting existing frames to meet stricter IMO requirements
Since the introduction of stricter international regulations, the maritime industry has faced increasing compliance pressure. The IMO Resolution MEPC.227(64), in force since June 1, 2021, introduced tighter effluent standards for onboard wastewater treatment, particularly in Special Areas such as the Baltic Sea. As a result, many existing systems risk noncompliance if they are not upgraded.
Five cruise ships required an upgrade of their membrane bioreactor systems because the previously installed modules no longer met expectations regarding performance and durability. At the same time, the new solution had to integrate seamlessly into the existing module frames to avoid costly structural modifications.
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The MYTEX Retrofit solution:
- Custom-fit solution: Membrane blocks were designed to be installed directly into the existing frames using a precise drop in approach.
- Easy handling: The modular blocks can be handled by two people and do not require tank modifications.
- Durability: The expected operating lifetime is approximately five years, with no need for tank access during maintenance.
The retrofit projects were implemented across five ships between 2022 and 2023. Each vessel was equipped with approximately 4,950 square meters of MYTEX membrane area.
The upgraded systems were designed to comply with IMO MARPOL MEPC.227(64) requirements. The retrofit resulted in improved effluent quality, simplified maintenance procedures, reduced operational interruptions, and cost savings through the continued use of existing frames. With MYTEX, the requested effluent limits of TSS < 35 mg per liter, BOD < 25 mg per liter, COD < 125 mg per liter, total nitrogen < 20 mg per liter, and total phosphorus < 1.0 mg per liter were easily achieved.
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Retrofit that expands options rather than limiting
For European and international operators, flexibility and long-term planning security are essential. MYTEX Retrofit addresses these requirements by offering a PFAS free solution, freedom in membrane selection, more than 80,000 possible configurations, and a retrofit strategy that can be aligned with existing maintenance schedules and budget cycles.
Your next step
If you operate a municipal wastewater treatment plant and are looking to increase capacity or improve performance without changing the existing footprint or control systems, WTA UNISOL offers a pragmatic and technically sound option. To discuss your specific application and retrofit potential, please contact Andreas Bareth as your direct point of contact.
WTA UNISOL will also be present at IFAT Munich 2026. We look forward to welcoming you to booth A2 534 to discuss retrofit strategies and practical implementation approaches in person.
Further technical details and background information will be available here:
Discover MYTEX Retrofit
