[in Japanese]

View full abstract

Bio-toilet, a dry toilet using sawdust as artificial soil matrix was introduced. The principle and method to decompose and extinguish human waste (excreta) without odor formation were described. Mechanism of odor formation from a conventional septic tank in anaerobic condition was demonstrated and maintenance of aerobic conditions in sawdust matrix was critically important to suppress the odor formation in the dry toilet. Then effective evaporation of water from the matrix was an important factor to keep the matrix aerobic. The characteristics of sawdust such as (1) high porosity, (2) moderate water retention, (3) high evaporation rate of water, (4) low density, (5) anti-abrasive, (6) bacteria tolerance, and (7) biodegradability were important for a longer operation of the toilet system without odor formation and for changing the sawdust matrix into multi-functional recyclables.

View full abstract

It was the 1970’s when we noticed the problem relating to human waste treatment in mountain districts by occurrence of eutrophication of the Oze District. Then in the 1990s, there was a rising concern about the human waste treatment again when Escherichia coli was detected in rivers which issue from the mountain districts including the Southern Alps. Backed by these problems, development and introduction of non-discharge human-waste treatment equipment which was usable even at sites where the infrastructure was not constructed were promoted. As diverse techniques of human waste treatment were required depending on the condition of a location, the Ministry of the Environment established in 2003 the division of treatment technologies for human waste in mountain district in “The Pilot Project of Environmental Technology Verification of Japan” to verify objectively the performance of the technologies by third parties. Thus, the Ministry has exerted their efforts for dissemination of these technologies.
Five years have passed since this verification project was introduced, and it will be a full-fledged operation in 2008. Hitherto, verification methods of technologies and improvement of the verification system were mainly examined. It would be a mature time to make the project beneficial to users as well.

View full abstract

As toilets for mountain areas are usually installed under a severe environment, night soil treatment by the toilets are not enough and few information are available for the reality of the status. In this study, current status on the toilets was revealed through a series of investigation on toilets in Mount Fuji. In order to conserve natural environment and offer more comfortable toilets for users, new technologies have been introduced and verified, and classified based the results. It was found that it is necessary to set up a verification system for technologies of toilets for mountain areas for both visitors and owners of mountain lodges. It is also expected that there will be more such technologies for the toilets available in natural environment areas

View full abstract

Workshop through Lavatory Cleaning in Kyoto (commonly called “Benkyo-kai”) is one of educational/research communities in Kyoto. Its main activities include the monthly cleaning of school lavatories, which is conducted on the second Saturday of each month. A questionnaire survey was conducted at 2 elementary schools after the monthly lavatory cleaning, and it was found that there are significant differences in the questions “Are you the first to say Hello?” and “Do you use school lavatories cleanly?” between the children who participated in the “monthly cleaning” and the children who did not participate, for both schools. In addition, it was found, from the analysis of feelings of children after the cleaning, that among 45 children who participated in the cleaning involuntarily, 42 children (93.3%) came to recognize lavatory cleaning affirmatively, and it was inferred that they came to have feelings of satisfaction and achievement. These results indicate that the practice of monthly cleaning of school lavatories may lead to the mental and physical growth of children.

View full abstract

The situations in the public toilets in Japan have been developed since around 1985. We have been supplying the functions of the sanitation, safety, which are mostly based on the human factors engineering, and the relaxations. In result, it is said that Japan provides one of the most comfortable public toilets now.
I myself have been mainly involved in designing of public toilets for 20 years at the commercial buildings, the stations, the parks, the schools and so on. Through these trends, it has been getting more important to catch the characteristic of the public toilets which comes from the idea of universal design. In addition, nowadays these play roles as the spaces for not only discharge, but also supply the energy and relax. These ideas and works are well received, however there still have some problems left, which is mainly about the smell. To solve these, it is necessary to look at the progress after the completions, and relate them to the next proposal and works.

View full abstract