Ministry of Education, Culture, Sports, Science and Technology (MEXT)

The New Industry Research Organization / Regional Innovation Promotion Department

Kobe University

In this program, Kobe University carries out the research and development for creation of innovative high-performance membrane and its practical application in water treatment system as well. Membrane fouling, the biggest problem in membrane process, is greatly affected by phase-interface structure and phase-interface characteristic of membrane. Therefore, we make our best endeavors to develop the innovative high-performance membrane, by which phase-interface structure and characteristic of membrane are highly controlled, through the repeating research cycle as shown in the following figure. We also develop related process technology, such as low energy water treatment process, and purification and concentration process of contaminated water. By using these technologies and membrane, we are aiming at establishing a cutting-edge innovative water treatment process.

1. Optimization of the microstructure for membrane fouling control (phase-interface structure control)

In order to avoid the membrane fouling effectively, controlling membrane microstructure is very important. Accordingly, we are aiming at establishing a theory about the structure control of porous membrane through a detailed examination of forming process of membrane structure and measurement of three-dimensional porous structure. We also produce hollow fiber membrane by the Thermally Induced Phase Separation (TIPS) method or the Non-solvent Induced Phase Separation (NIPS) method, try to find out the relationship between membrane structure and membrane fouling.

2. Modification and control of the membrane surface property for membrane fouling control (phase-interface characteristic control)

In order to control membrane fouling, membrane structure
, as well as the interaction between membrane surface and membrane fouling substances are  important factors. Accordingly, we develop advanced membrane with high anti-fouling performance by graft polymerization method, the film coating method named layer-by-layer method, and the blend of a low fouling substance to establish the surface modification control technology.

3. Development of water treatment process using forward osmosis (FO) membrane

In recent years, forward osmosis (FO) membrane filtration attracts attention as an advanced water treatment method instead of reverse osmosis (RO) membrane. FO membrane filtration requires no driving force since water can be spontaneously transmitted by osmotic pressure difference between
solutions as the driving force. In this way, there is a possibility that the power consumption of the pumps which poses a problem in RO process can be sharply reduced in FO process. Moreover, research and development activities of the osmotic pressure power generation which transforms the energy resulting from osmotic pressure difference into electrical energy have become active around the world in recent years. In this research, we are proceeding with the development of membrane for utilization in FO membrane filtration process, and the development of water treatment system which makes the best use of FO membrane process.

4. Development of energy-saving wastewater treatment process

In order to apply membrane filtration for the wastewater treatment broadly to industry, developing an energy-saving operation process which is stable and able to reduce the running cost through the development of antifouling membrane is quite important, so is the detailed study of fouling materials in wastewater. That is, from the view of the operating condition, optimization of the water treatment process should be a very important research task as well as new membrane development. Accordingly, we are now endeavoring to develop a new antifouling water treatment membrane, and to elucidate the influence of wastewater quality and filtration conditions on membrane performance.

5. Development of water treatment technique using forward osmosis

Recently, forward osmosis (FO) has attracted attention in various industries because of its low energy consumption and low fouling tendency. FO enables water transfer through a semipermeable membrane from a low-osmotic pressure solution side, i.e., the feed solution (FS), to a high-osmotic pressure solution side, i.e., the draw solution (DS), in accordance with an osmotic pressure difference. Theoretically, hydraulic pressure is not required for the selective water transportation, unlike in pressure-driven membrane processes such as reverse osmosis (RO) process. Major application fields for FO include energy-saving sea water desalination, waste water treatment and power generation. In this program, we are developing a high-performance FO membrane, an easily regenerable DS, and innovative FO system using these techniques.

6. Basic study on microstructure optimization for the development of innovative
low-fouling membrane

In this research theme, we have clarified guidelines for membrane designing to develop anti-fouling properties, based on a concept of construction of interface property and microstructure control technology for water treatment membranes. In addition, we have revealed that it is effective to suppress fouling by introducing hydrophilic groups or zwitterionic groups into the membrane surface, or by manufacturing a composite membrane with these component materials. As a next stage, we are preparing hollow fiber membranes and membrane modules in a bench scale in-house, as well as a bench scale evaluation system using model fouling substances and river water. By making use of these, we are proceeding with a comparative study between our membranes and commercial membranes under such conditions as practical use application.

7. Elucidation of the causative substances of membrane fouling and development of the control technology against membrane fouling

For controlling membrane fouling, it is extremely important to elucidate the main components of fouling substances and to understand their characteristics. In this study, we try to analyze the fouling substances which have not been elucidated until now, using the latest analysis technologies such as LC-OCD (Liquid Chromatography - Organic Carbon Detection) and EEM (Excitation Emission Matrix) which can measure a very small amount of dissolved organic matter. In addition, we examine the effect of pretreatment technology followed by membrane filtration system on membrane fouling for the development of a control method against membrane fouling in a drinking water treatment system.


The New Industry Research Organization,
Regional Innovation Promotion Department

6-1, Minatojima-Nakamachi, Chuo-ku, Chuo-ku, Kobe, 651-0046, Japan

TEL +81-(0)78-306-6804
FAX +81-(0)78-306-6812