Research on water purification that uses ultraviolet LEDs that can be saved in "3mm horns"

[AFP = current affairs] The contaminated water has produced many victims through infectious diseases such as cholera, but the 3 mm angle light source may improve this situation.Research is conducted by Japan and Southeast Asia, which use a small UV-emitting diode (UV-LED) device to disinfect water, which is required anywhere in the world.

"I think I was drawn to a clean image that handles water with light," said Associate Professor, Kumiko Oguma, the Graduate School of Engineering, the University of Tokyo.The heart of the test machine is a 3mm square LED element.General chlorine disinfection in purification affects the taste and smell of water.Ultraviolet rays do not use chemicals, and there is no toxic disinfecting side product.Furthermore, UV-LED has no risk of leakage of harmful substances in the event of damage, such as mercury ultraviolet lamps.

　There are 408 water purification plants nationwide (as of the end of March 2020) that have introduced ultraviolet disinfection in addition to chlorine disinfection.These are devices that use conventional mercury ultraviolet lamps as light sources, but there is only one public water purification plant that has already implemented UV-LED devices.It is Nagashima Town in Kagoshima Prefecture.This is a pioneering initiative in the world.Ultraviolet rays damage the genes of microorganisms such as underwater viruses and bacteria, and the infection can be stopped by suppressing growth.

　There are various health hazards caused by water.For example, groundwater contamination derived from soil such as arsenic or fluorine, but its effects are local.On the other hand, pollution of drinking water in water is the most primitive and universal task, and about 830,000 diarrhea diseases caused by drinking contaminated water are about 830,000.In particular, there are many deaths of infants under 5 years old in developing countries.Oguma said that the problem was needed to solve the problem, and he wanted to deliver the device here.

■ Combination that makes sense

　Oguma has been conducting a survey of safe access to safe water in Southeast Asian countries.Among them, the Philippine survey is impressive.On a remote island without commercial power supply, a demonstration test of a water purification device combined with solar cells was conducted.

　While the current that reaches the ordinary household is an AC current, the LED is driven by a DC current, and the solar cell creates a DC current.In other words, driving UV-LED in solar cells is direct and small.

"Because the low latitude area with high solar radiation is more troubled with water, it makes sense to combine solar power and water treatment."

　For the practical use of the equipment, he says, "I want to make money falling down to the site," such as creating employment."Donations of good intentions will not continue," pointed out that the key to sustainability in the Sustainable Development Goals (SDGs) of the United Nations (UN) is the key to business.

■ It has passed the time limit

　The United Nations is the SDGs target 6 and has provided safe and affordable drinks by 2030.Mr. Oguma says that a large -scale aggregation -type distribution system, such as a conventional infrastructure, is "passing the time limit" to distribute safe water.

　UV-LED allows small-scale distributed water treatment.Oguma regards this as one of the social infrastructure and says that it can be achieved for the first time in combination with large -scale integration.

　Among the devices involved by Oguma, the faucet is used for tens of thousands of yen per set.UV-LED elements are expected to continue, and in the future they can expect more cheaper devices.For example, 2 liters of 2 liters per minute in the faucet 99.It is also possible to be inactive 999 %.

　In Japan, the Water Week will be reached from August 1st.It is easy to imagine a developing country when it comes to water problems, but Oguma points out that "there are people who can be left behind in Japan."It is a mountain depopulated area where the water pipe is not reached.Japan's public water supply is about 98%, but the remaining 2%of the people have to rely on village water supply and private wells.I believe that it is more reasonable to use small -scale distributed water treatments to realize a society where all people can use safe water, rather than aiming for a 100%penetration rate here.

■ Connected edge

　Oguma's lab also has a student who came to Japan on the edge of a field survey.Achilles Espaldon (42) from the Philippines worked as a teacher at the University of San Agstin (UNIVERSITY OF SAN AGUSTIN) in his home country.He participated in Oguma's remote island survey, and he chose a doctoral course in Japan.After his graduation, he returned to the university and wants to stand on the podium while cherishing his research activities.

　Vu Duc Canh (33) was also a connection that Oguma met in a Vietnamese survey.Currently, he is conducting research that distinguishes the infectious of the virus in drinking water.Indonesian Indrastuti (34) studies microorganisms in groundwater in rural villages.After his graduation, he wants to resume his duties in the public and national Ministry of Housing.

　In the future, Oguma will aim to commercialize UV-LED devices in both domestic and overseas, while accumulating empirical research.[Translation Edit] AFPBB NEWS | Usage conditions