Compact membrane filtration plant for wastewater treatment

Decentralized membrane filtration plant

Our membrane filtration systems are compact, decentralized units that are prefabricated in our facilities. They are designed to complement wastewater treatment processes and increase the capacity of existing biological reactors.

They are an ideal solution for expanding and optimizing all types of biological reactors, including both custom-built bioreactors and compact units. They allow for increased treatment capacity without the need for construction work and ensure rapid commissioning, thanks to their compact design and easy integration with existing hydraulic, aeration, and control systems.

Membrane filtration systems are delivered fully assembled and pre-tested, ensuring operational flexibility and consistent effluent quality without the complexity of redesigning the entire treatment line.

PFAS-free membranes

The flat-plate membranes used by Sigmadaf are completely PFAS-free. Our membranes are made of CPVC, a polymer that contains no fluorine or carbon–fluorine (C–F) bonds, so they neither contain nor generate PFAS at any stage of their lifecycle.

Applications of a compact filtration plant

Our decentralized membrane filtration systems enable:

• Address capacity constraints at existing water treatment plants.
• Retrofit projects where decanters or other separation stages are the bottleneck.
• New projects involving biological reactors in civil engineering works where membrane filtration is provided as a compact system
• Treatment of industrial wastewater that requires a high and consistent effluent quality,
• Implement the membrane separation stage as a modular component in a new project.
• Scale up the performance of a water treatment plant quickly and safely.
• Water reuse projects (combined with tertiary treatment if necessary).

Scope of supply

Each membrane filtration station is configured based on plant constraints, operational objectives, and integration requirements. Typical design options include:

How the membrane filtration plant works

Our membrane filtration plants deliver excellent performance in separating suspended solids and colloidal matter, enabling the production of high-quality effluent suitable for reuse or discharge into the environment.

The treatment process consists of the following main stages:

1. Biological treatment in the existing reactor: Wastewater is treated in the bioreactor (built as a civil engineering structure or within a compact treatment plant), where organic matter and nutrients are removed.
2. Membrane separation at the filtration station: The mixed liquor is directed to the filtration station, where submerged membranes perform solid-liquid separation, producing a steady stream of permeate.
3. Permeate extraction and control: The permeate is extracted under controlled filtration conditions (flow/pressure setpoints), ensuring stable production and predictable performance.
4. Air scouring: A dedicated aeration system minimizes fouling during operation, promoting stable flow and reducing the need for manual intervention.
5. Cleaning strategy (CIP-ready design): The station is designed to accommodate chemical cleaning routines and operating sequences that align with the membrane supplier’s recommendations and site requirements.

Whether you need to expand an existing membrane bioreactor, address capacity constraints at existing plants, or modularize the membrane separation stage in a new project, our membrane filtration systems offer a reliable solution for quickly and safely scaling up capacity.

What are the advantages of a compact, modular membrane filtration system?

• Rapid capacity expansion at existing wastewater treatment plants and membrane bioreactors (concrete tanks or compact plants)
• Compact, modular design, optimized for industrial installations and retrofit projects
• Fully assembled and factory-tested, reducing installation time and on-site risks
• Easy integration with production lines, auxiliary systems, and existing automation standards
• Operational flexibility, enabling phased expansion and redundancy strategies
• Improved availability and redundancy (multiple lines; maintenance without a complete shutdown)
• Standardization of operations using a proven automation and instrumentation concept

Our filtration membranes

Our filtration systems use flat-sheet membranes arranged in parallel within modules. They are made of chlorinated polyethylene and have a nominal pore size of 0.4 μm, with an average pore size of 0.2 μm.

They remove virtually all microorganisms and solids present in the mixed liquor. The flat-plate configuration keeps the space between the membranes clear and reduces the buildup of residues.

The water that passes through the membranes—which contains salts and non-biodegradable low-molecular-weight substances—is removed from the system by a pump. This permeate can be discharged or reused, depending on the process requirements.

CIP cleaning system

Our membranes feature a CIP (Clean-In-Place) system designed to maintain optimal performance and extend the system's service life. This system enables automated chemical cleaning without the need to disassemble the modules, effectively removing scale, organic and inorganic fouling, and biological deposits that accumulate during operation.

By integrating it into the filtration station, CIP reduces downtime, minimizes manual intervention, and ensures stable operating conditions, guaranteeing a consistent supply of high-quality effluent.