Navajo Pottery-Inspired Ceramic Water Filter

Billions of people around the world lack access to clean, drinkable water. A research team led by engineers at The University of Texas at Austin has developed a new water filtration system using locally sourced materials for members of the Navajo Nation in the Southwest.

The team is using a simple method of lining clay pots with pine tree resin collected from the Navajo Nation and incorporating tiny, silver-based particles that can be used to purify water to make it drinkable. “A small amount of resin can provide control over nanoscale silver release and thus reduce unnecessary loss of the active component, while preserving the silver surface from getting passivated,” said Navid Saleh, Professor in the Fariborz Maseeh Department of Civil, Architectural, and Environmental Engineering and one of the leaders on the project.

“Ceramic water filters are produced commercially in many parts of the world. The use of locally sourced materials, low-cost of the device, and the promise of pottery to bridge the trust gap of the Navajo hold tremendous promise,” said Saleh.

Inspired by Judy Pasternak’s book Yellow Dirt, Saleh brought his students on a field trip to the Navajo Nation in 2012. They learned about the consequences of Uranium mining during the ‘40s-‘80s from this area, particularly those related to contamination of water with heavy metals and radionuclides. They also were exposed to the Navajo cultural norms and ethos and realized how pottery is central to their physical and spiritual world. One of the students in that field trip, Stetson Rowles III, who also happens to be a potter, became the lead researcher in this project.

Rowles and Saleh together came up with the idea to utilize pottery as the gateway in earning trust of the Navajos while addressing a part of the water contamination challenge with nanomaterials. They worked with a third-generation Navajo potter, Deanna Tso, gathered a pinyon pine tree resin from the region, used their centuries-old technique of using the resin in pottery, and infused nano-scale silver to disinfect water. All they have to do is pour water through the clay pots, and the coated pottery removes bacteria from water and generates clean, drinkable water.

This Navajo pottery-inspired ceramic water filter can cheaply disinfect water, while bridging the trust gap between Navajos and the non-Native world. “Making water filtration technology cheap doesn’t solve all the problems and making it effective doesn’t solve everything either. You have to think about the people you are making it for,” said Saleh.

According to the researchers, the Navajo Nation has a history of mistrust of outsiders, and that makes it less likely that people there would adopt a new technology made entirely by others. Using pottery, working with the community, and relying on local materials were important to the effectiveness of this project.

Using silver particles for water filtration is not the main innovation. Others have used this technology in the past. The key is controlling the release of nanoparticles, which can reduce the usable life of the filters. And the silver particles mix at high volume with some of the chemicals, such as chloride and sulfide, in the untreated water, leading to a “poison layer” that can reduce the disinfection efficacy of the silver particles on the clay lining.

The materials used by the researchers are abundant in the environment. These include the pine-tree resin that mitigates the uncontrolled release of the silver particles during the water-purifying process. The materials and construction process for the pots cost less than $10, making for a potentially low-cost solution.

“People” or consumers are usually left out during the conception of a technical idea or design of a technology, said Saleh, adding that “The norm is to reside in the realm of science and engineering, develop a solution to obtain efficiency as the only output, and eventually bring consumers into the fold by rolling out beta versions of the technology.”

Saleh believes that water technologies should follow a different path, since these impact lives on a day-to-day basis and are central to human life. “A technology is good if people use it. Ignoring local knowledge, not knowing what drives decisions in a community can cause a technology to die in the engineering trenches,” he said.

“This is just the beginning of trying to solve a local problem for a specific group of people,” Saleh said. “But the technical breakthrough we’ve made can be used all over the world to help other communities.”

This article was written by Chitra Sethi, Editorial Director, SAE Media Group. For more information, visit here .

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