We are excited to kick off a special three-part blog series leading up to InterAqua 2026, held at Tokyo Big Sight from January 28th to 30th. Over the next few days, we will introduce the three innovative water treatment systems we’ll be showcasing at our booth.

In this first installment, we are featuring our High-Efficiency Filtration System, powered by NAGASEP Silicone Hollow Fiber Membrane technology.

Advanced Solid-Liquid Separation

Traditional filtration often struggles with fine particulate matter or requires heavy chemical usage. This exhibit demonstrates a physical separation process that leverages the unique structural advantages of our silicone hollow fiber membranes to achieve high-clarity water recovery without the need for complex pre-treatments.

Key Features of the System

This demonstration unit showcases the practical application of NAGASEP modules in industrial and environmental water treatment, offering several distinct advantages:

• Superior Durability: The silicone material provides excellent chemical resistance and thermal stability compared to standard polymer membranes.
• High Permeability: The hollow fiber design maximizes surface area, allowing for high flow rates within a compact footprint.
• Low Maintenance: The flexible nature of the fibers minimizes clogging (fouling) and allows for easier cleaning cycles, extending the lifespan of the module.
• Versatile Application: Ideal for removing suspended solids, turbidity, and specific contaminants from industrial process water or wastewater.

Experience the Technology

At our booth, you can see the compact integration of the NAGASEP module and observe the clarity of the treated water in real-time. Our technical team will be on-site to discuss how this membrane technology can be customized to meet your specific filtration requirements.

We look forward to seeing you at Tokyo Big Sight!

Visit Us at InterAqua 2026

• Dates: January 28–30, 2026
• Venue: Tokyo Big Sight
• Booth: 2S-T14

The post What to Expect at InterAqua 2026: Featured Exhibits (Part 3) appeared first on NAGASEP.

In this second installment, we’re featuring our Degassing and Aeration System, demonstrated using the NAGASEP Test Module.

Controlled Oxygen Management for Water Treatment

Water in contact with the atmosphere typically contains around 8 ppm of dissolved oxygen under saturated conditions. In many water treatment processes, precise control of dissolved gases—both removal and reintroduction—is essential.

This system demonstrates how dissolved oxygen can be efficiently removed and reintroduced using silicone hollow fiber membrane technology.

How the System Works

The system consists of a degassing module, an aeration module, and an oxygen enrichment process working together in a continuous flow:

• Green tank on the left: Water containing approximately 8 ppm of dissolved oxygen is pumped into the degassing module (Model: M40-A).
• Blue tank on the right: inside the module, pressure is reduced by a vacuum pump. As the water passes through the silicone hollow fiber membranes, dissolved oxygen is removed, reducing the concentration to 1 ppm).
• The degassed water is then pumped into the aeration module (Model: M40-B), where oxygen-enriched air (30% O₂) is supplied. Oxygen permeates through the membrane, increasing the dissolved oxygen level back to 8 ppm.

At the same time, ambient air (21% O₂) is fed into the oxygen enrichment module. Under reduced pressure, oxygen selectively permeates through the hollow fiber membranes, producing oxygen-enriched air. The oxygen concentration is monitored by the oxygen analyzer located at the center of the system, and the enriched air is then supplied to the aeration module.

See the System in Action

This exhibit highlights how membrane-based degassing and aeration can provide precise, energy-efficient dissolved gas control for water treatment applications.

We invite you to visit our booth and see the system operating live at the exhibition.

Visit Us at InterAqua 2026

Dates: January 28–30, 2026
Venue: Tokyo Big Sight
Booth: 2S-T14

The post What to Expect at InterAqua 2026: Featured Exhibits (Part 2) appeared first on NAGASEP.

In the 21st century, water scarcity has become a worldwide problem due to factors such as global population growth, increased water use, and climate change. 2.1 billion people worldwide lacked access to safe water in 2017, and 844 million of them are reported to lack access to even drinking water.

In response to the serious water shortage problem, the water shortage problem can be solved if seawater, which accounts for about 97% of the water present on the earth, can be converted into fresh water necessary for human activities. Desalination of seawater is one of the most promising solutions to the water shortage problem, especially for drinking water.

2. Seawater Desalination

Desalination methods can be broadly classified into evaporation, which utilizes the phase change from liquid to vapor, and reverse osmosis (RO), which does not utilize the phase change while the water remains in the liquid phase. The evaporation method is further classified into the multi-stage flash method (MSF), multiple-effect method (MED), and vapor compression method (MVC). The electrodialysis (ED) method, which does not use phase change, also exists as a desalination technology, although it is less proven.

The number of desalination plants under planning and construction around the world has been particularly high in recent years, with desalination plants currently in operation in more than 120 countries. Reverse osmosis accounts for 65% of the world’s desalination plant capacity, a significant share.

3. water vapor permeation membrane method

Apart from the methods mentioned above, there is the water vapor permeable membrane method, which uses a gas separation membrane to separate water vapor.

Polydimethylsiloxane has high gas permeability among polymer membrane materials due to its high molecular mobility and extremely large molecular chain spacing. Among these materials, polydimethylsiloxane has extremely high water vapor permeability, making it possible to selectively permeate water vapor from seawater to obtain fresh water.

By supplying seawater to the housing side of the silicone hollow fiber membrane module NAGASEP and passing dry air through the hollow fiber membrane, water vapor is permeated from the liquid phase to the vapor phase. Since water vapor moves several hundred times faster than oxygen, the gas phase is quickly saturated with vapor and water can be recovered. By reducing the air flow rate as much as possible, this desalination method consumes less energy.

  At present, adsorption with activated carbon is the most mainstream separation method for recovering organic vapors from exhaust gas. However, adsorption has some problems, such as the need for regeneration system and the large size of the equipment. As the development of simpler and more energy-efficient organic vapor recovery and recycling technology is expected, the recovery method using membrane separation operation has become an attracting choice.

  By supplying ambient air to the silicone hollow fiber membrane module NAGASEP and depressurizing the permeate side, VOCs in the environment can be concentrated and recovered. As an actual application, NAGASEP has been put to practical use in a metering device that collects gasoline vapor leaked at gas stations when refueling. Gasoline vapor leaked into the atmosphere is suctioned through a double-tube refueling nozzle, then concentrated by a hollow fiber membrane, and finally collected as liquid gasoline. The system is also being considered for practical use in the recovery of organic vapors such as hexane discharged into the environment from factories and as a monitor of odors (VOC) in the ambient air. If you wonder whether NAGASEP could be a solution for your problem, feel free to contact us and have a discussion.

The post Water Recovery with Silicone Hollow Fiber Membranes appeared first on NAGASEP.

This is a separation method that has been attracting attention in recent years, replacing the distillation method. The inner side of the silicone membrane module is in contact with a liquid containing the target substance to be separated, while the outer side is vacuumed, or gas is supplied to vaporize and permeate the liquid.

It is a membrane separation technology mainly used to collect solvents in organic solvents because it can separate and concentrate mixed components at the molecular level by using a pore-free polymer membrane or a porous membrane with ultra-fine pores.

The selectivity of the membrane increases the vapor concentration of the target material on the permeate side, which can then be cooled, condensed, and recovered as a concentrated liquid.

For example, let’s see how to use silicone membrane to turn 10% ethanol solution into a 60% one.

When a 10% low-concentration ethanol solution is passed through the membrane, ethanol (vapor) preferentially permeates the membrane, and a 60% ethanol solution can be acquired and concentrated on the permeation side.

This separation method has significant advantages over other separation methods because it does not require large facilities like distillation methods and can effectively separate azeotropic mixtures.

The post What is pervaporation method for separation? appeared first on NAGASEP.

Air humidity needs to be controlled, no matter in homes or factories. Examples include dehumidifying spaces where moisture-sensitive precision equipment is installed to prevent breakdowns, dehumidifying gases in pipes to prevent rust formation, removing water vapour that becomes noise when analyzing gas components to obtain highly accurate analysis results, dehumidifying air in rooms to prevent condensation and fogging of glass, and many other situations.

There are three main methods of dehumidification: refrigeration, adsorption and membrane separation, each with its own characteristics.

The refrigeration method cools the gas and condenses the water vapour to dehumidify it. It is often used in situations where there is a large amount of processing, but the equipment can be large in size due to the treatment of condensed water, which can be a problem in terms of installation space.

Adsorption methods use adsorbent materials that take up moisture well to dehumidify, and are the best for drying out gases. On the other hand, for continuous use, it requires the use of heat or other energy to remove moisture from the adsorbent material. When used in factories, the structure becomes more complex because two pieces of equipment are required, one for dehumidification and the other for moisture removal, and this also has the problem of increasing the size of the equipment.

The membrane separation method is used for dehumidification of analysis gases, whereby moisture is permeated from one side of the membrane to the other. In gas analysis using gas chromatography and other methods, dehumidification is necessary as a pre-treatment for analysis. Otherwise, the accuracy of analysis results is reduced if moisture is present in the gas. Pre-treatment by dehumidification is particularly necessary for the analysis of gases with high moisture content, such as exhaust gases and breathing gas. Membrane separation systems are also used in applications where contamination is not permitted, such as in analyzers. Using membrane for dehumidification makes the equipment clean and smaller in size.

The silicone rubber used in NAGASEP separation membranes is one of the most permeable to moisture in the air of all the various separation membrane materials, such as polysulphone and polyimide. NAGASEP can be used in a variety of situations to optimize air conditions. 

The post Air humidity control by silicone membrane appeared first on NAGASEP.

  At present, adsorption with activated carbon is the most mainstream separation method for recovering organic vapors from exhaust gas. However, adsorption has some problems, such as the need for regeneration system and the large size of the equipment. As the development of simpler and more energy-efficient organic vapor recovery and recycling technology is expected, the recovery method using membrane separation operation has become an attracting choice.

  By supplying ambient air to the silicone hollow fiber membrane module “NAGASEP” and depressurizing the permeate side, VOCs in the environment can be concentrated and recovered. As an actual application, NAGASEP has been put to practical use in a metering device that collects gasoline vapor leaked at gas stations when refueling. Gasoline vapor leaked into the atmosphere is suctioned through a double-tube refueling nozzle, then concentrated by a hollow fiber membrane, and finally collected as liquid gasoline. The system is also being considered for practical use in the recovery of organic vapors such as hexane discharged into the environment from factories and as a monitor of odors (VOC) in the ambient air. If you wonder whether NAGASEP could be a solution for your problem, feel free to contact us and have a discussion.

The post VOC (Volatile Organic Vapor) Recovery with Silicone Hollow Fiber Membranes appeared first on NAGASEP.

 

When talking about hollow fiber membranes, it is important to know that they are thin, tube-like membranes with a hollow center. They are lightweight and compact. They also offer a very large surface area for their size. Because of this, hollow fiber modules can be made smaller and more cost-efficient. This makes them highly versatile in many industries.

How are they used? Hollow fiber membranes are applied in many different fields. In water filtration, they are common in household water purifiers. They remove contaminants and improve the quality of drinking water. In the food and beverage industry, they are used to filter and clarify alcoholic drinks and water. In industry, they are part of activated sludge treatment systems at wastewater plants. In medicine, they could be key components in ECMO systems.

Technically, a hollow fiber module is made of bundles of membranes fixed with resin and placed inside a casing. There are two main types. One filters from the inside out, called internal perfusion. The other filters from the outside in, called external perfusion. External perfusion modules usually have lower pressure drop. This means they are more energy-efficient.

Maintenance and cleaning are very important. Contaminants can be removed in two ways. The first is physical cleaning, by using back-pressure from the clean side to push out debris. The second is chemical cleaning. Different chemicals are used for different types of fouling. Hot water or sodium hypochlorite for microorganisms. Sodium hydroxide for proteins. Surfactants for oils. Acid for minerals.

What are the benefits of hollow fibers? They are light, compact, cost-effective, and easy to clean in different ways. This makes them economical and durable for continuous use.

Finally, we would like to introduce the NAGASEP product. Most hollow fiber membranes are porous. NAGASEP’s silicone hollow fiber membrane is different. It is solid and non-porous. This stops clogging from happening. It also means there is no need for back-pressure cleaning. The surface can be cleaned easily with hypochlorous acid, surfactants, or acids. This gives a very efficient, low-maintenance solution.

The post Features of Hollow Fiber Membrane Modules and how to clean them appeared first on NAGASEP.

NAGASEP is a homogeneous membrane separation module filled up with silicone rubber hollow fibers.

Porous membranes are permeable. They separate various components by sorting them according to the size of the pores in the membrane. Therefore, membrane fouling, a phenomenon in which membrane performance deteriorates during operation due to clogging of the pores, is likely to occur and requiremaintenance.

Homogeneous membranes, on the other hand, have no pores, so there is no need to worry about membrane fouling. Gase moleculars have a  diameter of only a few Å (10-10 m), so small that they can permeate through a homogeneous membrane without pores by the thermal motion of the polymer chains.

Permeation through a homogeneous membrane happenrs in three steps:

①dissolution of molecules at the high pressure side of the membrane

② diffusion of molecules within the membrane

③ desorption of molecules at the low pressure side of the membrane.

Solubility in the membrane increases in proportion to the size of the molecule. Thus, the larger the molecule, the greater its condensability, and this effect makes it easier to dissolve into the membrane.

Conversely, diffusivity in the membrane is generally smaller because the larger the molecules, the greater the resistance. However, silicone rubber membranes have large gaps in the polymer chains, so even gases with large molecules are not affected by diffusion velocity. The permeation rate is determined by the difference in solubility. 

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