In Japan, there are many water filtration plants but one that Loop PNG recently visited is the Kawai Purification plant located in Yokohama city.
Imagine drinking water that has been purified using ceramic membrane filtration system, a filtration system that is as thin as the strand of your hair.
That is basically water filtered through microfiltration filters to purify or treat water.
That is the level of technology that is being used today at the Kawai Purification plant. It started off in 1901 using the slow sand filtration system.
That facility was upgraded in 2014 as one of the largest membrane filtration system using membrane modules made of ceramic. The upgraded project is the first case in Japan implemented under the Private Finance Initiative scheme.
The source of water at the Kawai plant is a river called Doshi. Raw water is treated using chemicals before it is pumped into the mixing tank and into the control valve of the membrane filtration system. The water goes through tiny pores that have the same thickness as a hair strand.
It is then filtered and clean drinking water is the result. Over 172,000 cubic meters of water is produced daily. The water produced is also environmentally friendly as gravity by which water flows from the river to the plant is used instead of pumps.
The system even has its own backwashing function where impurities attached in the membranes during filtration are flushed out.
Masayuki Ida, the manager Operation of Metawater, said the water product that is sold from the plant through this new system of ceramic membrane filtration produces more water and has a lower cost in production compared to the Slow sand filtration which was used in the last 50 years at the plant.
(Loop PNG pictured of the simple version of how water is filtered using ceramic membrane filtration system.)