UV-LED Water Treatment Device for Better Access to Safe Water

Some developing countries have limited access to piped water supply and people in such countries are using contaminated groundwater and river water. In emerging countries, their water supply systems cannot keep up with urbanization and rapid population concentration; depopulated settlements in mountainous areas suffer aging water supply facilities that are unsustainable; and evacuation centers and temporary housing also have a problem with water supply in the event of large-scale disasters. In these circumstances, where securing water is a pressing concern and huge costs and long periods of maintenance, renovation, and restoration are required, alternative water supply systems can function effectively.

As one measure, we are developing a water purification device equipped with compact, mercury-free ultraviolet light emitting diode (UV-LED), intending to disinfect water at the point of water use (Point-of-Use). While aiming to optimize the equipment design through laboratory performance evaluation and outdoor demonstration tests, we also conduct on-site surveys on the actual water use in developing countries and the quality of everyday water, trying to grasp their needs for water purification equipment.

We are exploring stand-alone water supply systems that can be used even in off-the-grid areas and in the blackout after disasters. These systems are to be powered by renewable energy.

Through this research and development, it is possible to supply safe drinking water to people who are "left behind" in the conventional infrastructure systems. We aim to reduce the inequality between developing countries and developed countries in water access, narrow the gap between urban areas and rural parts, and lessen the disparity between the rich and the poor.

- Surapong Rattanakul and Kumiko Oguma. Analysis of Hydroxyl Radicals and Inactivation Mechanisms of Bacteriophage MS2 in Response to a Simultaneous Application of UV and Chlorine, Environmental Science and Technology 51(1), pp.455-462, 2017.
- Bibas Guragai, Satoshi Takizawa, Takashi Hashimoto, Kumiko Oguma. Effects of inequality of supply hours on consumers' coping strategies and perceptions of intermittent water supply in Kathmandu Valley, Nepal. Science of the Total Environment 599-600, pp.431-441. 2017.
- Kumiko Oguma,Mika Koshio, Jenyuk Lohwacharin and Satoshi Takizawa, Effects of Suspended Particles in Water on Efficiency of UV Disinfection Journal of Japan Society on Water Environment Vol.40, No.2, pp.59-65, 2017 in Japanese
- Kumiko Oguma, Ryo Kita and Satoshi Takizawa, Effects of Arrangement of UV Light-Emitting Diodes on the Inactivation Efficiency of Microorganisms in Water, Photochemistry and Photobiology 92, pp.314-317, 2016.
- Kumiko Oguma; Surapong Rattanakul; and James R. Bolton, Application of UV Light Emitting Diodes to Adenovirus in Water, Journal of Environmental Engineering, ASCE 142(3), 04015082, 2016.
- Kumiko Oguma, Mitsuru Okasa, Nga Tran Thi Viet, Satoshi Takizawa, Water quality deterioration in drinking water supply systems in Hanoi, Vietnam. Water and Wastewater.Vol.57, No.10, pp.741-749, 2015 in Japanese
- Kumiko Oguma and Madjid Mohseni. UV Treatment: A Solution for Small Community Water Supplies? IUVA News, Fall 2015, pp.25-27, International Ultraviolet Association.
- Kumiko Oguma, Jatuwat Sangsanont and Hiroyuki Katayama, Comparison between chlorination and UV disinfection of untreated wastewater after disasters, Journal of Water and Environment Technology, 12(3), pp.154-161, 2014.
- An Thuan Do, Keisuke Kuroda, Takeshi Hayashi, Tran Thi Viet Nga, Kumiko Oguma, Satoshi Takizawa, Household Survey of Installation and Treatment Efficiency of Point-of-Use Water Treatment Systems in Hanoi, Vietnam. Journal of Water Supply: Research and Technology-AQUA 63(2), pp.154-161, 2014.

- Patent application 2013-245606