A patented nanotechnology for clean drinking water

Zirconium, the 21st most abundant element in the world, is a stable and chemically innocuous metal. Nanoparticles of zirconium oxide, says Arup SenGupta, have adsorption properties that make them uniquely beneficial to human beings. They can remove four major toxins—arsenic, fluoride, phosphate and lead—from water.

SenGupta, the P.C. Rossin Senior Professor in the department of civil and environmental engineering, and three of his students have used zirconium oxide nanoparticles to invent the world’s first filter capable of removing both fluoride and arsenic from groundwater.

The students are Surapol Padungthon, who received his Ph.D. in environmental engineering from Lehigh in 2013, and Mike German and Jinze Li, who are currently Ph.D. candidates in environmental engineering.

The filter materials, called HIX-NanoZr, are polymeric ion exchangers (IX) doped with zirconium oxide nanoparticles. The doping procedure, says SenGupta, plays a critical role in producing optimum hybrid particles that are robust and accessible to water while maintaining their integrity. In addition, HIX-NanoZr can be used and reused for many cycles without being wasted.

Last September, SenGupta and Padungthon were awarded a U.S. patent for the invention.

Nearly 400 million people in Asia and Africa drink groundwater that contains toxic levels of fluoride and arsenic. Exposure to excessive amounts of fluoride can cause skeletal fluorosis, which decreases the elasticity of bones, making them more prone to fracture and causing bone and joint damage. Elevated levels of arsenic can cause skin lesions, a variety of cancers and blood vessel disorders.

SenGupta, who has worked on water-purification issues for three decades, has also developed a business model that enables people who lack clean groundwater to install and operate his purification systems in an economically sustainable way.

Last month, SenGupta and German received the 2016 VentureWell-Lemelson Sustainability Award at “Open Conference,” a gathering of technical entrepreneurs in Portland, Oregon. SenGupta and German in 2013 co-founded DrinkWell, an organization that provides purification technologies and business opportunities to people who lack access to clean water.

The sustainability award recognized the “incredible work with both the technology and the business model that [SenGupta and DrinkWell’s co-founders] have developed.” The award was presented by VentureWell, a nonprofit that promotes entrepreneurship in higher education and has supported SenGupta’s previous efforts to deploy his water-purification technology.

SenGupta and his students have invented nanotechnology-based systems of removing arsenic and fluoride from groundwater and have worked with local residents to install them in communities in the United States, Asia, Africa, South America and Europe.

At the Open Conference, SenGupta, German and Todd Watkins, the Arthur F. Searing Professor of Economics at Lehigh, gave a presentation titled “From Lab and Societal-Entrepreneurial Startup to Impact on 200,000 lives: Sustainable microenterprise for village-scale arsenic removal from drinking water.”

The three said that the microenterprise business model they developed with help from VentureWell now benefits more than 200,000 people in villages in India, Nepal, Cambodia, Laos, Bangladesh and Kenya. The enterprise enables communities to make a profit while operating village-scale systems that remove arsenic from groundwater.

“Well-run microenterprise operations generate income several times the poverty line while simultaneously reducing arsenic levels in groundwater well below world health standards,” the group reported.

SenGupta and his students were attracted to zirconium because of its filtering potential. In addition to being stable and chemically innocuous, zirconium oxide nanoparticles pose no health hazard, says SenGupta, and they offer “unique properties in removing four major toxic water contaminants, namely, arsenic, fluoride, phosphate and lead.”

“This is the only material currently available that can remove both arsenic and fluoride, and it can be reused for years without being wasted,” says SenGupta, who is also a professor of chemical and biomolecular engineering at Lehigh.

The award was the latest in a long series of honors SenGupta has received for filtration systems that he and his students have invented to remove arsenic and, more recently, fluoride from groundwater.

SenGupta is a Fellow of the American Society of Civil Engineers (ASCE) and the National Academy of Inventors (NAI). In November, he was inducted as a Fellow of the American Institute of Chemical Engineers for “distinctive professional achievements and accomplishments in the field of chemical engineering.”

SenGupta holds eight U.S. patents, with two more pending. His inventions have led to the creation of three companies—the Tengore-SenGupta (T-S) Foundation, Technology with a Human Face and DrinkWell. In 2011, T-S won the 2011 Reed Elsevier Environmental Challenge, an international contest that aims to improve people’s access to safe and sustainable water.

Last year, SenGupta received the IP (Intellectual Property) Champion Award from the United States Chamber of Commerce in Washington, D.C. The Chamber cited SenGupta specifically for the economic impacts of his intellectual property through social entrepreneurship.

In 2012, SenGupta won the Intel Environmental Award from TechAwards of the Silicon Valley. That same year, he spent six months at the Center for Sustainable Technologies at the Indian Institute of Science in Bangalore, India, courtesy of a Fulbright Environmental Leadership Award.

Story by Kurt Pfitzer

Photos courtesy of Arup SenGupta