Duration of the stay
June 28. 2007 – September 5. 2007 (temporarily abroad: July 14 - July 20)
Description of and results from the invitation
Prof. Asano's accommodation was arranged in Tokyo, for it was convenient for him to visit local universities, research institutes and administrative agencies which had invited him for lectures and workshops in advance as well as to meet administrators and researchers who asked for opportunities to exchange views with the professor.
Visited institutes and universities were as follows: one research institute (PWRI), five universities (e.g., the University of Tokyo and Kyushu University), three departments of MLIT and four foundations (e.g., The Japan Water Resources Association). In addition, many administrators and researchers visited Prof. Asano to exchange information.
He introduced in his lectures, referring to the State of California of tight of water resourse as an example, estimation of increasing water demand because of population growth, water resource plan for sustainable water use and placement of urban water reuse in the plan, categories of reuse (e.g., agricultural irrigation and groundwater recharge) and their examples, current quality criteria and necessary treatment process, and an argument on how safe indirect potable reuse is (e.g., health risk from chemical substance exposure, membrane treatment technology enabling high quality water, and importance of communication). Also he showed future prospect of water reuse.
It was well understood that in southern California with short age of water resource, water resource is developed in other area such as northern California by dam construction and plenty of water is transported from a distance, and that plenty of urban wastewater is considered to be a water resource and advanced reuse technology is developed the fact that. Water resource plan have total and multiple aspects, for example transfer of water rights and water demand control had a great impact compared with Japanese system.
In California, great importance is placed on technology development ensuring high quality water for sewerage treatment technology to increase utility value of the treated wastewater as water resource. On the Contrary, in Japan, efficiency of treatment process and energy saving is important. This is because in Japan main requirement of sewerage treatment technology is the efficiency of sewerage operation, but in California the one is creation of water resource. In California reclaimed water is considered to be goods in public market, which makes economic activity of related technology vigorous.
In addition, it was made clear that culture greatly influences water use. People succeeding European culture require green garden with turf and tree in California, which is the driving force for water reuse. Japanese have lived with water for a long time, but they are separated from rivers. If they remember the old day, there is possibility of new movement of the utilization of treated water.
In Japan it is comparatively easy to get clean water and river water can dilute wastewater to some extent, therefore, people are not interested in pollution by trace pollutant, and water measurement is not carried out satisfactorily. For securing higher safety, a grasp of actual situation is necessary in future.
Prof. Asano's insightful comments and advice encouraged researchers and administrators in Japan to take a closer look at the issues.
Contribution by the invitee to the host institute (e.g. inspiration to young scientists, internationalization of a host institute as a whole, etc.)
Prof. Asano enlightened students and young scientists through the lectures and discussion meetings and gave a new vision about water resources. Many of the young audience at the University of Tokyo Hokkaido University, Kyushu University, Miyazaki University or Shimane University were interested in new idea which was not discussed very much in Japan. The followings are examples of the feedbacks:
- I have learned world's water condition from Prof. Asano's lecture, or
- After listening Prof. Asano's lecture, I have taken a closer look at the issue of wastewater reuse in Japan, so I have to study the matter further.
Moreover, the faculty members (professors, associate professors and lecturers) of the visited universities reported that they were greatly impressed by the world's most advanced water-recycling techniques and the innovative approach Prof. Asano has introduced.
Young officials of sewerage department reported as follows;
- We have to think of regal position and system for promoting water reuse in Japan.
- It was a good opportunity that we learned an argument about water reuse in Europe and the United States.
Engineers reported as follows;
- We expect that water reuse for agriculture and groundwater recharge are effective in Japan, though I am worried about shortage of water by the global warming.
- I have learned importance that we inform water quality and safety to users for promoting water reuse.
Researchers and engineers of water resource asked some question (the way to manage groundwater in the United States, the cost of water resource development, the benefit of water reuse and public information about water resource). Prof. Asano reported and commented on current status in the United States and he advised on the application and investigation in Japan.
As the hosting organization, PWRI believes that Prof. Asano's contributions to the Japanese society are very promising and respected. With his advice, our research activities will be widened and diversified. Many scientists and engineers will be fostered in this research area; at the same time leading researchers will be much more motivated to pursue their research topics.
Thanks to Prof. Asano, those in top government offices and academia had precious opportunities to hold technical discussions and to directly exchange opinions with the world eminent professor; he surely exerted considerable influence, which would not be obtained from books, on their notions or attitudes toward research and practice.
PWRI thank JSPS for their generous support for this invitation project. Prof. Asano is scheduled to visit Japan again in the latter half this year and share his invaluable insights with those in government offices and academia.