In order to bring Japan’s advanced technologies and knowhow to the world, it is necessary to transfer operation and maintenance knowhow accumulated by

## 3 Japan's Technological Prowess

In some Asian cities, for example, large amounts of sewage sludge or food waste and other wastes are disposed by landfill without incineration, giving rise to sanitation problems. As they are sources of methane gas, projects to reduce sludge and wastes, recycle them and collect methane gas for reducing carbon dioxide emissions can earn emissions credits under the Clean Development Mechanism (CDM) of the Kyoto Protocol. Japan has the advanced bio-recycling technology that covers from water treatment to energy collection. The business model for constructing and operating a string of facilities for adequate water treatment, biomass recycling and biomass power generation can be expected to grow going forward (Figure 4-3-8). Japan ranks the world's top-tier league in water treatment technology. In particular, Japanese membrane technology for seawater desalination commands a large share of about 70 % in the world (Figure 4-3-3).

Note: Japan includes Japanese companies' group firms operating overseas. Survey method: data provided by membrane suppliers (14 companies cooperation with the Association of Membrane Separation Technology

of Japan) plus publicized materials (IDA Inventory Report 2006)

Source: Association of Membrane Separation Technology of Japan (2007)

Figure4-3-4 Trends in Membrane Shipments

Source: Toray Industries, Inc.

municipalities that have undertaken water supply services to private-sector companies. To do this, joint initiatives between the public and private sectors are essential.

Reverse osmosis (RO) membranes by a Japanese manufacturer have been adopted at a total of 100 plants in 26 countries/areas in the world by March 2009, and the combined desalination capacity of facilities using its RO membranes exceeds 15 million cubic meters a day (equivalent to the quantity of domestic water consumed by over 60 million people) (Figure 4-3-4). The manufacturer estimates that the desalination process using RO membranes consumes less than one-fifth of heat, power and other energy required by the conventional evaporation method. Assuming that the use of RO membranes spreads at the same rate as in the five years from 2010, desalination using RO membranes are estimated to reduce carbon dioxide emissions by some 100 million tons by around 2020 (Figure 4-3-5).

As a result of continued efforts to develop the RO membrane technology, energy consumption in the desalination process was reduced to about one-sixth, to less than the cost of the evaporation method. Thus, the RO membrane technology is expected to produce the cobenefit of water quality improvement and emissions reduction as a measure to cope with global warming (Figure 4-3-6).

Japan also has a broad range of technologies that can greatly contribute to water infrastructure development in the world, including the heat pump technology that focuses on the thermal potential of groundwater and Johkasou technology quite useful in wastewater treatment. The heat pump is the technology to move heat from one location at a lower temperature to another location at a higher temperature using heat media and semiconductors, etc., commonly adopted in refrigerators and air conditioners. In particular, Japanese companies excel in the heat pump technology to use groundwater, whose temperatures are stable throughout the year, as the heat source. As for Johkasou, the installation of Gappei-shori-Johkasou (which treat kitchen and toilet waste) is required when introducing flush toilets in areas