Seeking sustainable solutions for the global challenge of safe drinking water

Lead is not the only danger when it comes to drinking water – harmful bacteria can also find their way into the water we consume despite treatment prior to distribution. In the face of water scarcity and aging infrastructure, there is a need for innovative, affordable, and portable solutions to sustainably provide safe drinking water across the globe.

Engineering researchers from the University of Pittsburgh will use a $500K CAREER award from the National Science Foundation to create a sustainable material design framework to mitigate pathogen exposure in this invaluable resource.

“In addition to tap water from large-scale, municipal distribution, there are many other scenarios where we may want to disinfect our water before we drink it, such as when it is sourced from private wells or nature,” said Leanne Gilbertson, lead researcher and assistant professor of civil and environmental engineering at Pitt’s Swanson School of Engineering. “There are also emerging sources of drinking water, such as water reuse where wastewater is treated to potable standards, presenting new disinfection challenges.”

In this project, Gilbertson’s team will examine graphitic carbon nitride (g-C3N4), a non-metal material that possesses antimicrobial properties when activated with visible light. It is proposed as a sustainable material because it is developed with low-cost, abundant resources.

“We will modify the chemistry of graphitic carbon nitride to improve its photocatalytic performance,” Gilbertson said. “When light is absorbed by the material, it generates reactive oxygen species that can kill microorganisms.”

The research team will integrate the enhanced materials into a drinking water treatment device, such as a filter or portable reactor, that can be used as a viable, cost-effective solution to inactivate harmful bacteria in drinking water. They will collaborate with Aquisense, an industry leader in LED-enabled disinfection, to develop a point-of-use model.

“By manipulating the structure and composition of graphitic carbon nitride at the atomic level, we have the ability to control its optical absorption and performance for photocatalytic disinfection. Using LED technology further enables us to flexibly configure the light wavelength best suited for maximum absorption of a designed material,” said Yan Wang, a postdoctoral associate at Lawrence Berkeley National Lab and former PhD student in the Gilbertson Group who started this project.

Through this research, the team will assess whether this material is indeed a sustainable alternative for treating drinking water.

“We will apply life cycle assessment (LCA) to investigate the environmental impacts associated with synthesizing graphitic carbon nitride,” said Nathalia Aquino de Carvalho, a current PhD student in the Gilbertson group and lead author of their recent paper that lays the foundation for this work. “LCA will enable us to identify hot spots in the synthesis, tradeoffs of different synthesis routes, and opportunities to reduce the environmental footprint prior to scaling production. Applying LCA while we are designing the material enables competitive, environmentally responsible development of graphitic carbon nitride.”

Gilbertson’s group ultimately hopes to create a point-of-use device that addresses the challenge of sustainably providing safe drinking water. They also plan to develop educational resources for the general public through a podcast series and a “Science Through Storytelling” program to engage elementary students in STEM.

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