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Ashok Gadgil

Water Disinfecting Device

Patent No. 5,780,860

Physicist Ashok Gadgil has helped 100 million people across four continents by making water safe to drink and by increasing the energy efficiency of stoves.

Millions of people die annually from waterborne diseases, and Gadgil’s UV Waterworks is a water disinfection system that uses UV light to kill disease-causing pathogens. Using only 60 watts provided by a battery or solar panel, it provides safe drinking water for 2,000 people at a rate of four gallons per minute.  The system has deployed in communities from India to the Philippines to Ghana. Another of Gadgil’s inventions, the Berkeley-Darfur Stove, was created to reduce the fuel demand of those in displacement camps in Darfur. His stoves have been distributed across Sudan and Ethiopia, benefiting hundreds of thousands of people.

Today, at the Gadgil Lab at UC Berkeley and the Lawrence Berkeley National Lab, Gadgil continues to research ways to improve the water and energy supply of people in need. A graduate of the University of Bombay, the Indian Institute of Technology, and the University of California, Berkeley, he has received numerous awards, including the Lemelson-MIT Awards for Global Innovation.

Ashok Gadgil. (nd), retrieved April 9, 2014 from Lawrence Berkeley National Laboratory Web Site:

Ashok Gadgil. (nd), retrieved April 9, 2014 from Environmental Energy Technologies Division (EETD) Web Site:

Ashok Gadgil. (nd), retrieved April 9, 2014 from Lawrence Berkeley National Laboratory Institute for Globally Transformative Technologies Web Site:

Ashok Gadgil. (nd), retrieved April 9, 2014 from The Lemelson Foundation Web Site:

Arsenic Removal. (nd), from Gadgil Lab for Energy and Water Research Web Site:

Brown, Steven (2014, March 5). Berkeley Lab licenses arsenic-cleaning technology to Indian Company, retrieved April 9, 2014 from San Francisco Business Times Web Site:

Davidson, Martha (1999, Feb. 26). UV Waterworks: Ashok Gadgil, retrieved April 9, 2014 from The Lemelson Center for the Study of Invention & Innovation Web Site:

Inspirational Innovators: Dr. Ashok Gadgil (2005, January), retrieved April 9, 2014 from World Intellectual Property Organization (WIPO) Magazine:

Lemelson MIT. Inventor Honored for Bridging Innovation and Humanitarianism to Help Millions Globally Live Safer Lives, retrieved April 9, 2014 from Business Wire:

Gadgil knew from an early age that he wanted to become a scientist and find solutions for new problems. By the time he was in fourth grade, he had finished reading all the general science books required at the high school level.

Feeding his interest in science, his parents would get for him Popular Science, Popular Mechanics and Scientific American from a local library so he could read them at home. It was his curiosity about how things worked that led him to pursue a degree in physics from the University of Bombay. His continued interest in research prompted him to pursue a master’s degree and a Ph.D. from UC Berkeley. And his interest in the practical applications of physics led him to work on solving environmental issues.

It was in 1993, after learning of the tens of thousands of deaths from the Bengal Cholera in his home country, that Gadgil began envisioning an affordable device to disinfect drinking water. Using ultraviolet light’s ability to kill the disease-causing bacteria and viruses, Gadgil designed the inexpensive and non-polluting technology used in UV Waterworks.

In attempts to establish an efficient water disinfecting method, Gadgil had earlier reached out to contacts in India proposing the UV disinfecting technique, which damages the DNA of bacteria and viruses so they can’t reproduce and therefore die. Gadgil had no success in pitching the idea to colleagues in India so he decided to assemble a small team and take on the project himself.

While others had already attempted to disinfect water by immersing UV lamps into the water, biofilms would still grow on the surfaces in contact with water, and the bio-fouling would rapidly make the UV lamps ineffective in killing pathogens. Gadgil and his team found that if they kept the lamp out of the water, with a polished aluminum reflector above the lamp to reflect UV light into the water, it would facilitate disinfection and without any risk of biofouling the lamp surfaces.

The device allows clean, filtered, disinfected drinking water to be sold for profit at about two cents per 10 liters. The water is sold in community-scale installations by WaterHealth International, providing safe-to-drink water in India, Ghana, Nigeria, Liberia, Bangladesh and the Philippines. Each device is powered by 60 watts of electricity.  Water is disinfected using 20,000 times less primary energy compared to disinfection using firewood for boiling, and therefore very little carbon dioxide is released into the air.

Gadgil initially considered using the Internet to share his design with anyone wishing to reproduce the device. Eventually he realized the benefits of patenting it, which would allow for protection against ill-manufactured copies.

In 2005, Gadgil told the World Intellectual Property Organization’s publication, WIPO Magazine, that when designing the perfect device, he looked for a simple design with no moving parts that would remain easy and cheap to make, maintain, and repair. It was based on his experience living in India that he determined several specifications for the device, including the idea that it should not be dependent on pressurizing devices and should operate at a high flow rate so users didn’t have to wait long for treated water.

At a request by the United States Agency for International Development’s (USAID) Office of Foreign Disaster Assistance to decrease the fuel demand in displacement camps in Darfur, the Berkeley-Darfur Stove was developed at Lawrence Berkeley National Laboratory.  The stoves are now distributed in Darfur by the nonprofit organization Potential Energy (formerly The Darfur Stoves Project), in partnership with other non-profits such as Oxfam America, and Plan Canada.

First produced in partnership with CHF International and eventually Oxfam America, the stove is assembled in North Darfur by a Sudanese nonprofit (Sustainable Action Group) and primarily benefits women and girls. It was designed by Gadgil along with his colleagues, students and local Darfur women. Compared to the local traditional wood stoves, the Berkeley-Darfur Stove allows users to save up to 55 percent of fuel (and proportional costs for fuel).  In a 2010 survey in North Darfur camps, the local partner SAG found that households were spending about 33% of their family budget to fuelwood purchases – because by then there was no fuelwood left within walking distance from the camps.

Not only does Gadgil’s invention allow for large monetary savings, it also increases the personal safety of women and children.  Some women may walk up to seven hours a day, three to five times a week, in search for firewood, which makes them vulnerable to assault every time they leave their displacement camps.

Recently, the stoves have been modified for use in Ethiopia where approximately 80 percent of houses use firewood for cooking.  The stoves are valuable as the country’s wooded land has dramatically decreased over the past decades.

As a professor at UC Berkeley, Gadgil encourages students to explore the social-economic component of innovation and promotes the importance of research that finds solutions to societal problems that impact the world.

Recently, Gadgil and researchers at the Gadgil Lab for Energy and Water Research had been working on ways to inexpensively remove naturally occurring arsenic from drinking water in Bangladesh and India and surrounding regions. The Lawrence Berkeley National Laboratory licensed the Electrochemical Arsenic Remediation (ECAR) technology in 2014 to Luminous Water Technologies.

Another technology developed by the Lab is the Arsenic Removal Using Bottom Ash (ARUBA). The method also removes arsenic form contaminated drinking water in an inexpensive, safe and efficient manner.

Gadgil has co-authored more than 95 published journal papers and more than 100 conference papers. His areas of expertise include drinking water treatment, energy efficiency, computational fluid dynamics of indoor air and pollutant transport, and simulation methods for complex non-linear systems. In 2001, he was named one of the top U.S. inventors by the book Inventing Modern America.

He serves on several national and international advisory committees focusing on energy efficiency, invention and innovation, and issues related to development and the environment. He is an elected Fellow of the American Physical Society and a member of the National Academy of Engineering.

Ph. D., Physics, 1979, University of California, Berkeley

Master of Science, Physics, 1973, Indian Institute of Technology, Kanpur, India

Bachelor of Science, Physics, 1971, University of Bombay, India

Senior Scientist and Director for the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory

Andrew and Virginia Rudd Family Foundation Professor of Safe Water and Sanitation in the Department of Civil and Environmental Engineering at the University of California Berkeley Campus

Dare to dream, and aim high. At the same time, keep your feet on the ground regarding protection of your intellectual property and turning it into a good business – As told to WIPO Magazine

I hope we find ways to unleash and nurture the creative genius of hundreds of thousands of individuals around the world who have good ideas but don’t know what to do with them, or are not able to turn them into products that benefit humanity – As told to WIPO Magazine

A physicist by training, Gadgil uses his expertise to benefit disadvantaged communities around the world by integrating science and cultural needs. His invention of the UV Waterworks provides affordable safe drinking water that is delivered with financially viability.  The Berkeley-Darfur Stove reduced the need for fuel, saved household expenses, and increased safety for women in Darfur, who often have to walk alone up to seven hours a day in search for firewood, all for a one time outlay of $20 per stove.  His inventions have helped millions of people around the globe. Gadgil also works with community stakeholders to support and expand the adoption of his devices.

Alumni Leadership Award, by the IIT Kanpur Alumni Association of Silicon Valley, 2013

The 5th Prince Sultan Bin Abdulaziz International Prize for Water, Creativity Prize, 2013

Lemelson-MIT Award for Global Innovation, 2012

Zayed Future Energy Prize, 2012

European Inventor Award, 2012

Heinz Award, 2009

Popular Mechanics Magazine’s Breakthrough Award, 2007

Tech Laureate Award, 2004

World Technology Award for Energy, 2002

Popular Science Magazine’s Best of What’s New Award, 1996

Discover Magazine’s Award for Technological Innovation, 1996

Pew Fellowship in Conservation and the Environment, 1991

Patent Number

UV Water Disinfector
Vikas Garud
Gas Flow Means for Improving Efficiency of Exhaust Hoods
Apparatus and Method to Detect an Impending Failure of a circuit Caused by Deposits of Aerosol
Apparatus for Treating Environmental Tobacco Smoke (ETS) Particle and Gas-Phase Contaminants
Apparatus for Low Cost Water Disinfection
Portable Water Treatment Unit
Method for Low Cost Water Disinfection

Occupation: Senior Scientist and Director for the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory

Born: November 15, 1950 in Bombay, India

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