Yokohama's Kawai water treatment plant: an eco-friendly membrane marvel

摘要

Kawai water treatment plant, in Yokohama city, Japan resumed operation on 1 April 2014 after a reconstruction under the country's private finance initiative (PFI).This is the first time the PFI approach has been adopted for the full-scale renewal and operation of a Japanese water treatment plant. But this is not the only reason the renewed plant is of note - it is now also the nation's largest membrane filtration treatment plant, making use of ceramic membranes. Yokohama city was the first municipality in Japan to install a modern water supply system to deliver treated water via pressurised pipes, in 1887. As the city's oldest water treatment plant, put into service in 1901, the Kawai plant has helped Yokohama's economic development as a vital part of its infrastructure. In 2009, the city launched a reconstruction project in which the plant's aging facilities were to be renewed and reinforced against its structural vulnerability to earthquakes. Of particular note, a gravity-fed filtration system was adopted for the renewed plant to reduce its environmental footprint in operation.