At Stanford, Wastewater Won’t Be Wasted
A new research facility will test processes for recovering clean water, energy and valuable materials.
When construction begins on Stanford’s unique water reclamation research facility this spring, it will culminate years of study and planning by university faculty who see exciting possibilities in what others dismiss as waste.
The William and Cloy Codiga Resource Recovery Center, named after the Stanford alumnus and his wife who committed funding that will allow the project to move forward, will test innovative technologies for the recovery of clean water, energy and valuable materials from wastewater. The goal is to accelerate commercial development of promising ideas for resource recovery by testing and optimizing new wastewater treatment processes at a scale that is credible for investment.
The center is due to begin operation in 2015. Initially, it will demonstrate that nonpotable water (suitable for watering grounds and washing vehicles) can be recovered from wastewater, using systems that are essentially self-powered from materials in the wastewater. After additional testing and optimization, the system could become a key component of a recycled water plant serving the Stanford campus. The water must meet very high standards before it can be used for landscaping.
In a novel twist, the center will take a decentralized approach to water recycling. Instead of pumping recycled water uphill from a traditional treatment plant located near the water, which is expensive and inefficient, the Resource Recovery Center will develop mobile units with sensors and systems that allow them to be monitored and controlled remotely. These units may be used on campus or deployed at other locations for testing under real-world conditions. Their use may transform traditional thinking that wastewater treatment plants must be built at the water’s edge, and usher in systems that can operate wherever water can be captured for local reuse.
A team effort
Three Stanford visionaries worked together for four years to make the project happen: Craig Criddle, a professor of civil and environmental engineering; Dick Luthy, the Silas H. Palmer Professor of Civil Engineering; and Tom Zigterman, associate director of Water Services and Civil Infrastructure at Stanford. Criddle and Luthy, who are senior fellows with Stanford Woods Institute for the Environment, contributed technical expertise, while Zigterman was instrumental in winning university approval for the project and guiding it through the planning process.
The Stanford-led National Science Foundation Engineering Research Center, called Re-inventing the Nation’s Urban Water Infrastructure (ReNUWIt), is providing research support for Ph.D. students and postdoctoral scholars to test new approaches to wastewater management. Additional funds for sponsored pilot-scale research projects at the site are anticipated from local utilities, private donors, industrial partners and government agencies.
A confluence of ideas
Multiple streams of research flowed together to make the center a reality. Environmental Venture Project (EVP) seed grants by the Stanford Woods Institute and “Uncommon Dialogues” – conversations among a diverse group of experts – paved the way, and many Stanford faculty members and outside partners contributed research and expertise. The first EVP grant in 2004, awarded to Criddle and Christopher Francis, associate professor of environmental earth systems science, fostered use of DNA-based methods to diagnose instabilities at the City of Palo Alto’s wastewater treatment plant. This collaboration spawned broader interests in local water issues and formation of the Stanford-Palo Alto Water Team, which was composed of Stanford researchers, Stanford water utilities staff and personnel from Palo Alto.
In a second EVP award in 2009, Criddle joined forces with Brian Cantwell, a professor of aeronautics and astronautics. Their EVP developed a low-cost technique that extracted nitrogen from wastewater and converted it into nitrous oxide, the same fuel used to power rockets. The nitrous oxide subsequently broke down into pure nitrogen and oxygen – gases that could be used to power a treatment plant.
Working with The Bill Lane Center for the American West, the Stanford Woods Institute sponsored three “Uncommon Dialogues” that stimulated thinking about a test bed for an energy-efficient water reclamation on the Stanford campus. They also laid the groundwork for Water in the West (a joint program between Woods and the Lane Center) and the ReNUWIt initiative.
The first two workshops in November 2008 and March 2009, led by Luthy and Stanford History Professor David Kennedy, brought together Stanford faculty with dozens of regional water officials, engineers, regulators and environmentalists and jump-started the race to create innovative solutions to urban water supply and management issues.
The third dialogue in May 2010, organized by the Stanford-Palo Alto Water Team, sparked collaboration between Stanford researchers and San Francisco Bay Area utility leaders and consultants in water and wastewater treatment. ”These Uncommon Dialogues were very timely,” said Luthy. “The call from the National Science Foundation for proposals for new Engineering Research Centers came just as we concluded the second Uncommon Dialogue.”
A well-timed breakthrough
At the third dialogue, Perry McCarty, the Silas H. Palmer Professor of Civil Engineering, Emeritus, described a new anaerobic (no-oxygen) technology for wastewater treatment that he had recently worked on with colleagues at a university in South Korea. The method showed great potential but had only been tested at laboratory scale. At that meeting, Criddle described energy recovery from nitrogen, another promising laboratory-scale technology. The need for scale-up was clear. Motivated by this event, Criddle, Zigterman and the Stanford-Palo Alto Water Team developed a proposal for a test facility at Stanford, later approved by Provost John Etchemendy, while Luthy included test beds as a centerpiece of the Engineering Research Center proposal.
As plans developed for the Resource Recovery Center, a breakthrough in Korea shaped the final stages of planning: Professor McCarty and his colleagues succeeded in a pilot-scale test of the new anaerobic technology. “The timing was perfect . We decided to incorporate this exciting technology as a core element of the center. This would give us the chance to carry out the first U.S. testing and to investigate its ability to produce both clean water and energy from campus wastewater,” said Criddle.
In the future, the center could focus on advanced treatment technologies that recover energy and high-value materials from waste. Stanford scientists have other research projects in progress that may one day be incorporated into the new center.
Stanford postdoctoral scholar Yaniv Scherson is already moving technology for energy recovery from nitrogen, initiated by the 2009 EVP award to Criddle and Cantwell, to pilot scale with testing at the Delta Diablo Sanitation District in Antioch, Calif. Funding has been provided by a National Science Foundation award and the Stanford TomKat Center for Sustainable Energy. This technology may be developed further at the Resource Recovery Center.
Another good candidate for scale-up at the center is the microbial battery developed by Stanford doctoral student Xing Xie, a co-advisee of Criddle and Yi Cui, associate professor of materials science and engineering. The battery generates energy from wastewater using naturally occurring “wired microbes” that produce electricity as they digest dissolved organics.
Experts at the workshop in 2010 knew that many treatment plants throughout the U.S. needed to be upgraded or replaced. Most were built in the 1970s, when Congress passed the Clean Water Act and provided generous federal funding for wastewater infrastructure. The workshop participants wanted the next generation of plants to harvest energy and recover clean water.
Criddle feels even more urgency today. The drought in California has upped the ante. “The country needs this quickly. We need to do this fast,” he stressed.
If all goes well, the center will optimize energy recovery processes in portable units that can begin to be tested by municipal systems in two years and the entire project will be ready for testing on a larger scale in four years. “It usually takes 10 years in this field to do something like this,” Criddle said. “We need to work faster.”
Stanford ecologist and climate scientist Chris Field looks to the 28th UN Climate Change Conference for a roadmap on what he considers solvable challenges.
Visiting Scholar Lily Hsueh on why California's new climate disclosure laws could be a gamechanger.
Josheena Naggea of the Center for Ocean Solutions discusses how people in the tropics, or the 'tropical majority,' have invaluable expertise and knowledge of the ocean that is key to helping protect the high seas.