Dialogue to the Future: Interviews with a New Generation of Researchers in the AJI

The 11^th Interview

Interview with Dr. NGUYEN Thi Thuong

――First, could you tell me what led you to decide on a career as a researcher?

Thuong: Since childhood, I have been deeply curious about the world and passionate about teaching. This innate curiosity led me to discover the unique opportunities that research offers—exploring unanswered questions and developing innovative solutions. For me, research is not only a path to continuous learning but also a way to address critical challenges while inspiring and guiding others to explore new possibilities. During my undergraduate studies, I worked on projects that sparked my interest in tackling environmental issues, particularly water protection and wastewater treatment. This passion grew stronger during my PhD, under the mentorship of Professor Soda Satoshi. His guidance and the opportunity to work on real-world problems solidified my decision to pursue a career in research. It is a field where I can combine my love for learning, problem-solving, and teaching to make meaningful contributions.

――I can see how you developed such a great interest in your current research field, wastewater treatment. Regarding your research life in Japan, you mentioned about Professor Soda, your supervisor, and you have been doing research at Ritsumeikan University since receiving your Ph.D. So, what motivated you to pursue your studies in Japan?

Thuong: The turning point in my decision to study in Japan came at the end of 2018 when I had the opportunity to complete a one-month internship at Ritsumeikan University as a first-year master's student at Vietnam-Japan University, Vietnam National University. During this internship, I was deeply impressed by Japan's advanced environmental technologies and innovative solutions. While I had always been aware of Japan’s leadership in these areas, experiencing them firsthand had a lasting impact on me. For example, I was amazed by the excellent water treatment systems that allow people to drink tap water directly, and I was also impressed by the punctuality of the trains and the careful waste separation practices, evidenced by the eight trash bins on a single floor. This experience inspired me to explore Japan further and solidified my desire to study here.

――What do you think about the characteristics of Ritsumeikan University in your research field?

Thuong: Ritsumeikan University is an excellent institution for conducting research in my field, particularly in sustainable wastewater treatment and environmental technologies. The university fosters interdisciplinary research, which is crucial for addressing complex environmental challenges like wastewater management, with the Department of Civil and Environmental Engineering being especially prominent in this area. Ritsumeikan actively supports cutting-edge research and international collaboration with many institutes and universities, including my former university, Vietnam-Japan University. This provides ample opportunities to network with scholars and practitioners worldwide. Moreover, the university is well-equipped with advanced laboratory facilities and offers strong support for experimental research. This has been instrumental in my studies, particularly in developing innovative wastewater treatment technologies. The collaborative environment and mentorship from experienced professors, such as Professor Satoshi Soda and Professor Jun Nakajima, have significantly enhanced my ability to conduct high-quality research and present my findings effectively. Overall, the academic support, funding opportunities, and global perspective at Ritsumeikan University create a highly conducive environment for advancing my research and fostering my career development.

――By the way, why did you choose to come to Japan in the first place?

Thuong: In addition to my admiration for Japanese culture and the positive impression I gained of Japan during my 1-month internship, as well as the excellent learning environment at Ritsumeikan University that I mentioned earlier, there is also a personal reason that motivated my decision. My grandmother, who has had a significant influence on my life, has always been fascinated by Japan. Although she has never had the chance to visit, she has long dreamed of experiencing the country. I saw this as the perfect opportunity to not only pursue my academic goals but also fulfill my grandmother’s wish by taking her on a trip to Japan. These personal motivations, combined with my academic aspirations, led me to prepare my application immediately after my internship, ultimately setting me on the path toward my doctoral journey in Japan.

―― So you have been interested in Japan since your childhood, because of your grandmother. That’s a wonderful story. Now, let me ask a question about your life in Japan. How was your life studying abroad when you first came to Japan?

Thuong: As I mentioned in my previous response, before officially starting my PhD journey in Japan, I had a one-month internship here. However, my true academic journey in Japan began in late 2019 when I arrived to pursue my PhD, just as the COVID-19 pandemic began.

――Ah, yes, you arrived in the middle of the pandemic period. That must have been hard.

Thuong: Yes, indeed. During that time, most students, including myself, were studying online, which limited my interactions with others. Unfortunately, a planned experiment at a mine in Kyoto Prefecture was canceled, and all domestic and international conferences were also canceled due to the pandemic. To make matters more difficult, my grandmother passed away from a stroke during this period.

――Oh, I’m sorry to hear that. She was dreaming of coming to Japan, wasn’t she?

Thuong: That’s right. It was heartbreaking knowing that I wouldn’t be able to help her to fulfill her dream of visiting Japan. This combination of challenges left me feeling uncertain, but with the encouragement of my supervisor and the support of the Department of Science and Engineering, I was able to stay focused on my research and complete my experiments successfully. I also found solace in participating in an online Vietnamese language class for students at Ritsumeikan University, and I enjoyed connecting with members of the volunteer club in Kusatsu City. These interactions provided a much-needed sense of community and gave me the motivation to continue pursuing my academic career.

――That news gives me a sense of relief. In spite of being quarantined in Japan, you could get some social connections even in that situation, right?

Thuong: Yes, the quarantine period also allowed me to explore online learning in more depth, which proved valuable for my studies. As the pandemic began to subside in early 2022, my student life truly flourished. I had the opportunity to engage in cultural experiences, such as enjoying wearing a kimono while viewing the cherry blossoms, watching fireworks, and experiencing a traditional New Year celebration with a Japanese friend’s family. I also began a part-time job related to my research at a Japanese company. What made me happiest though, was my continued involvement in volunteering and participating in activities for foreigners in Kusatsu City, Shiga. These experiences allowed me to meet and engage with not only Japanese people but also individuals from various countries, enriching my understanding of different cultures.
Looking back on these three years of my PhD journey in Japan, I realize that it has been a beautiful and unforgettable chapter of my life. Despite the challenges, this experience has deepened my love for my career and strengthened my belief in the path I have chosen.

――Thank you for telling us about these experiences. It sounds like you are having a meaningful social life and enjoying Japanese culture. How about your research? For doing your experiments you needed a specific setting. It must have been difficult at first. How did you overcome the obstacles you encountered during the quarantine?

Thuong: Thank you for your thoughtful question. During the quarantine, it was indeed challenging to conduct experiments, especially with the specific settings required for my research. However, I adapted by focusing on theoretical aspects, analyzing existing data, and reviewing literature to refine my research approach. I also used the time to plan and prepare for future experiments by optimizing methods and reviewing potential setups. Additionally, I stayed in touch with my mentors and colleagues, discussing ideas and solutions to overcome the limitations. Once restrictions eased, I was able to resume experiments with the adjusted plans and settings.

——And what do you think of daily life in Japan?

Thuong: Living in Japan has been a wonderful experience, and there are many aspects of daily life here that I truly appreciate. I love the sense of safety and convenience in Japan. The public transportation system is incredibly efficient, making it easy to explore different places. I also admire the cleanliness and organization everywhere, from the streets to public spaces, which creates a pleasant environment. Another aspect I enjoy is experiencing the four seasons so vividly. For instance, I often take walks in nearby parks to admire the cherry blossoms in spring or the vibrant autumn leaves, go skiing in winter, and enjoy fireworks in summer. Additionally, people’s natural politeness and respect in everyday interactions, both at my university and outside, make me feel welcomed and comfortable. Also, I was particularly impressed by the many elderly people who actively support and teach Japanese to foreigners. This inspired me to contribute more through volunteer work and participate in social activities.

——It’s good to know that you enjoy the natural and social environment in Japan. Let me ask a question about learning Japanese language. How do you often use Japanese in your daily life?

Thuong: Actually, I primarily use English at work. However, learning Japanese has been an important part of my experience in Japan, both academically and in daily life. I try to learn and use Japanese in various ways, such as communicating with locals in shops, restaurants, and during my travels. Academically, I sometimes use Japanese to interact with students and professors, as well as to read research papers related to my field.
My motivation for learning Japanese stems from both personal and professional goals. On a personal level, I aim to connect more deeply with Japanese culture and people. Professionally, Japanese proficiency is valuable for collaborating with Japanese researchers and participating in academic discussions. Honestly, my Japanese is still not good, but I’m continuing to learn and practice it little by little in my daily life. I hope that someday I’ll be able to use Japanese confidently in interviews.

――Let me go back to your research specialty, environmental engineering and wastewater treatment. What led you to choose these fields of research? What kind of differences did you find between Vietnam and Japan?

Thuong: I have always been passionate about protecting the environment, especially water resources, which are essential for life but increasingly threatened by pollution and overuse. I grew up in a small village in Vietnam, where water contamination was a visible problem. Growing up in such an environment, I witnessed firsthand the critical need for sustainable solutions in water and wastewater management. Environmental engineering appealed to me as it combines science, technology, and innovation to solve real-world problems. My interest in wastewater treatment grew during my studies, as I recognized its potential to protect water quality and recover valuable resources. This interest deepened when I was accepted as a Master’s and PhD student under the guidance of Associate Professor Nguyen Thi An Hang and Professor Soda, who introduced me to green technologies like constructed wetlands (CWs), an eco-friendly approach to wastewater treatment.
In comparing Vietnam and Japan, I noticed a gap in adopting advanced wastewater treatment methods. Japan has led in implementing environmentally friendly technologies, while many areas in Vietnam, particularly rural and industrial ones, still lack effective systems. This inspired me to focus my research on green technologies like CWs, which could provide sustainable, cost-effective solutions for both countries. By bridging this gap, I hope to improve wastewater management in Vietnam while learning from Japan’s achievements.

――Your research involves conducting experiments. Could you provide more details about the process?

Thuong: In my research, the process of conducting experiments typically follows a series of systematic steps. For example, in my study of wastewater treatment using CWs, the process begins with defining the research objectives, such as investigating the removal of heavy metals from mine drainage.

—— By the way, how does pollution with heavy metals influence our lives, if we are exposed to it?

Thuong: Heavy metal pollution can have significant impacts on human health if someone is exposed to it. When heavy metals like lead, mercury, arsenic, or cadmium accumulate in the body, they can cause a range of health problems. For example, lead exposure can severely affect the nervous system, leading to developmental issues in children and cognitive decline in adults. Mercury poisoning can damage the kidneys and nervous system, causing tremors, memory loss, and other neurological symptoms. Arsenic is linked to an increased risk of cancer and can also cause skin lesions and cardiovascular problems. Cadmium exposure can lead to kidney damage and bone health issues. As you may know, Japan is home to two well-known diseases: Minamata disease, caused by mercury pollution, and Itai-Itai disease, caused by cadmium pollution.
In addition, heavy metals can also harm ecosystems, affecting plants and animals and disrupting food chains. Therefore, addressing the sources of heavy metal contamination, such as industrial and mine wastewater, is very important.

—— I see, we must find a way to prevent such pollution. So, what about the experimental process...?

Thuong: First, I carefully design the experimental setup. For this, I select the types of filter materials and plants to use in the CWs, considering their known roles in water purification. For example, I often use materials like clamshells and plants such as common reed or cattail. Once the materials are selected, I prepare the experimental systems and set them up in a controlled environment. Synthetic wastewater is carefully designed to mimic the conditions of real wastewater, including factors such as pH and the presence of heavy metals. Specific parameters, such as hydraulic retention time, are also set to simulate real-world conditions.
With the setup complete, I begin the experiment by introducing the contaminated water into the CWs, ensuring that they operate in continuous flow mode. I then monitor the water quality at regular intervals, collecting samples from both the influent and effluent. These samples are analyzed to measure contaminants, assess plant health, and evaluate microbial activity. Other water parameters like pH, dissolved oxygen, temperature, and contaminant concentrations are also recorded throughout the experiment. As the experiment progresses, I analyze the data using statistical methods to assess the efficiency of the CWs in removing contaminants. The analysis helps identify the most effective combinations of plants and filter materials for specific contaminant removal, as well as the roles each component plays in the purification process. Throughout the experiment, I adjusted parameters as needed to optimize the system’s performance. Multiple trials are conducted to ensure the reliability and repeatability of the results. At the end of the experiment, I summarize the findings and compare them with existing research. The conclusions drawn from the study contribute to enhancing the efficiency of CWs in wastewater treatment and highlight the environmental benefits of using green technology for sustainable water purification.

Figure 1: A series of lab-scale CWs for acid mine drainage treatment in BKC campus, Ritsumeikan University: a) hybrid clamshell-based CWs; b) a combination of neutralization and floating CWs; c) CWs filled with corncob biochar.

Figure 2: Clamshell-based CWs planted with Ubon paspalum for the treatment of anaerobically digested swine wastewater in Hanoi, Vietnam

Figure 3: Pilot-scale CWs planted with cattail for neutral mine drainage treatment in Kyoto prefecture.

Figure 4: Setup of a trickling filter combined with CWs planted with water spinach for greywater treatment.

Figure 5: Plant sample collection and water sample analysis at the Environmental Engineering Lab, BKC campus, Ritsumeikan University.

——Thank you for your detailed and clear explanation, and these pictures. I can see that your experiments need a specific setting close to nature and uses clamshells and plants, so I can imagine how deeply you need to understand how the natural environment formed by the interaction of these natural actors works!

Thuong: Yes, it's essential to understand the interactions within the natural environment, especially how clamshells, plants, and other elements work together in the system to achieve effective wastewater treatment.

—— Now, I want to question about your current research activities. You organized several international workshops hosted by the AJI. I heard that each one of them was very wonderful and active. How did they go from your perspective?

Thuong: Thank you for your kind words! It’s incredibly fulfilling to hear that the workshops were considered wonderful and engaging. So far, with the support of AJI members, we have successfully organized two international workshops, which aimed to foster collaboration and knowledge exchange on sustainable solutions to pressing global issues, such as wastewater management. Organizing them required considerable effort, from coordinating with guest speakers to ensuring a diverse and engaging agenda. One of the most memorable moments was seeing participants from different countries share innovative ideas and form collaborations. The active participation and insightful discussions truly brought the workshops to life. Of course, there were challenges, such as managing time zone differences and handling the technical aspects of hybrid events. But with teamwork and careful planning, we turned these into valuable learning opportunities. A highlight was seeing how the workshops fostered long-lasting collaborations and new research initiatives. After these events, I was also honored to be invited to co-investigate the research projects of some of the speakers who attended, and now I'm working on these projects. Overall, these workshops have been an incredible experience, and I’m excited to continue organizing more in the future, including one planned for next August. It’s inspiring to see how such events bring people together to make meaningful progress.

——It sounds exciting! You could meet a lot of collaboration partners through these events. Moreover, you organized them yourself, which must have been a great experience in your academic life. For my next question, I would like to ask about your recent research interests. What are you primarily interested in, and what do you most enjoy about your recent research?

Thuong: Thank you for the question. My recent research primarily focuses on the use of green technologies for sustainable wastewater treatment, with a specific emphasis on CWs. I’m particularly interested in understanding how CWs can be optimized for treating wastewater, especially in contexts like mine drainage in Japan, where I’ve been studying the role of aquatic plants, microorganisms, and filter materials in removing heavy metals such as manganese, zinc, and cadmium. What I most enjoy about my research is the opportunity to explore nature-based solutions that can offer both environmental and economic benefits. Working with CWs allows me to connect my interest in ecological systems with practical solutions to pressing global challenges, such as water pollution and resource management. I also find it rewarding to see the potential for collaboration with other researchers and the broader community, which often leads to exciting new ideas and research directions.

――Thank you for explaining. We expect that the scientific research you are conducting on mine drainage here in Japan will have a universal impact on other parts of the world that are suffering from water pollution. The last question is about your plans and goals for the future? Please tell us your future plans for your academic career.

Thuong: In the near future, my focus will remain on advancing research into the use of CWs for sustainable wastewater treatment. This includes addressing challenges in various contexts, such as mine drainage, domestic wastewater, and livestock wastewater. A key priority is optimizing substrate-plant combinations within CWs to enhance their efficiency. My current efforts involve developing funding proposals to expand this research, particularly in areas such as nitrogen removal and greenhouse gas mitigation in swine wastewater treatment. Collaboration is central to my plans. I aim to strengthen partnerships with international researchers, especially in Southeast Asia, China, and India, to foster knowledge exchange and undertake joint projects.
Looking further ahead, my long-term goal is to become a lecturer at a Japanese or Vietnamese university and establish myself as a leading researcher in my field. I aspire to contribute to the advancement of green technologies in wastewater treatment and environmental sustainability through impactful research, publications, and teaching. Additionally, I intend to organize international workshops and conferences, mentor young researchers, and influence policy and practice in wastewater management. By advocating for nature-based solutions like CWs, I hope to promote the global application of sustainable wastewater treatment technologies. Furthermore, I also aim to foster academic exchanges between Japan and Vietnam, building a bridge of friendship and collaboration between the two countries.

——Thank you for giving us your time for this interview, Dr. Thuong. I could learn the imminent significance and infinite possibilities of your research theme from our conversation. You are certainly an inspiring example for the next-generation researchers. I encourage you to continue your great work. We are looking forward to learning about further developments in your research.