2025 Activity Report vol.6:Nagasaki University

The Nagasaki University (Water Environment Science program of the Graduate School of Integrated Science and Technology) welcomed eight participants to Nagasaki from November 2 (Sun) to 7 (Fri), 2025: three undergraduate students and one lecturer from the Faculty of Industrial Technology, Bandung Institute of Technology, Indonesia; two undergraduate students from the Faculty of Chemistry, University of Science, Vietnam National University, Hanoi; and two undergraduate students from the Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Thailand.

This science and technology exchange program (science and technology training course) was titled "Membrane Separation Technology Training for Safe Water Production from Contaminated Water Sources." This program, conducted through collaboration between industry, academia, and government (water treatment companies, Nagasaki University, and the Nagasaki Prefectural Waterworks Bureau), provided training on Japan's advanced water treatment technology, with the goal of enhancing the participants' membrane separation technology skills and preparing them for a return to Japan as researchers or engineers. The training focused on reverse osmosis membranes (pore size <1 nm) and nanofiltration membranes (pore size 1-2 nm), which are suitable for purifying contaminated water sources to produce safe tap water. The participants had attended on-demand lectures and completed assignments prior to their arrival, allowing them to discuss technical terms immediately after arriving and to smoothly complete the laboratory exercises.

During the exercises, the participants changed the filtration conditions (membrane permeation flux) of reverse osmosis and nanofiltration membranes, recorded the changes in salt removal, and submitted experimental reports in groups. Through comments and advice on the submitted experimental reports, the participants seemed to have had their first opportunity to learn how to write research reports. They actively asked questions to the graduate students from Nagasaki University who supervised them, deepening their interactions with each other. Their practical experience of applying what they had learned theoretically appeared to deepen their understanding of membrane separation.

For the membrane treatment plant design, the students utilized software they had used at their alma mater to create detailed plant flow diagrams, which appeared to be at the same level as those drawn by actual engineers. Furthermore, by using the reverse osmosis membrane software they had learned after arriving in Japan, they learned how to determine the type, number, and operating conditions of membrane elements to meet target water quality targets, providing a more practical design experience.

Additionally, a tour of the Sasebo City Water Bureau's Yamanota Water Purification Plant provided participants with an opportunity to learn not only about ceramic membrane filtration equipment but also about the importance of pre-treatment by experiencing actual membrane treatment equipment and water sources. At the final day's symposium, the invitees, divided into three groups, gave presentations on their universities, summarized their practical training, and presented the results of their group assignments.

Despite the short duration of the training, this exchange program demonstrated the strong interest and growth of the invitees in the technology. Their proactive attitude was conveyed to our graduate students, who were also inspired by it, making it a highly meaningful program.