Abstract
While Japan's inherent water resources are relatively abundant, the country is nevertheless faced with a variety of water-related problems. These include local water shortages and insufficient water supplies due to urban redevelopment, as well as multi-level government restrictions on water usage. Membrane technology is considered to be a promising means of solving these problems. In Japan, the application of membrane technology to water supply treatment began in 1991 with the launch of the MAC21 project. At present, water purification using membranes is being performed at a rate of 130, 000 m3/d.
The application of membranes to the reclamation of sewage has been lagging. In this regard, the membrane bioreactor is expected to be an effective technology not only for water reclamation but also for reducing the risk of pathogenic microorganisms and viruses in environmental water supplies.
