抄録
The 20th century society applied one–pass type urban water system, which brought some issues; the decrease of river water flow owing to massive water intake, centralization of urban wastewater discharge into the receiving waters, high energy requirement for water transport, and adverse effects on human health and aquatic organisms derived from trace chemicals and pathogens in discharge from centralized wastewater system etc. Meanwhile, the quantity of water that is available and accessible can become scarce in the future. Sustainable urban water cycles with reduced carbon footprint is also now becoming a primary goal of water supply and sewage works. Municipal sewage has shifted from a waste to a resource that can recover water, energy, biomass, nutrients and other valuable constituents. We need to seek for more cascaded water system in the 21st century, which will be realized by developing new water treatment technology. Combinations of unit processes using membranes and oxidation technology can make various water applications from various water resources including wastewater. In this research project we evaluated the processes in terms of removal of pathogens, chemicals, toxicity and energy consumption. In addition application of the developed processes to the fields including Okinawa, south China and Vietnam were discussed.
