Post

NAWI Executive Director, Dr. Peter Fiske, recently engaged in a compelling conversation with Jeanne Destro, the Morning News Anchor for WAKR Radio’s “This Week in Tech.” Broadcasting on the esteemed “Soft Hits 93.5 FM,” the commercial radio station is dedicated to serving Akron, Ohio.

In a timely alignment with Akron’s recent announcement of an impending water rate hike, Jeanne Destro’s focus on water-related issues struck a chord. The City of Akron revealed plans to raise water rates for residents by a minimum of $10.00 per month, commencing in January. As local concerns mount about the financial implications of this decision, the global perspective remains poignant, with millions worldwide yearning for access to clean water—a stark reminder of the privilege many take for granted.

The conversation delved into the broader implications of water scarcity and its intersection with climate change. Against the backdrop of 2023 being declared the hottest year on record, Fiske illuminated the cascading effects of rising temperatures on natural disasters. From intensified storms and floods to rampant wildfires and debilitating droughts, these calamities wreak havoc on essential systems, particularly the aging infrastructure responsible for water supply.

Beyond the global challenge of water scarcity, Fiske spotlighted innovative solutions pursued by Fontus Blue, an Akron-based clean water technology company where he serves as a consultant. Amidst the escalating demand for water, Fontus Blue endeavors to explore unconventional avenues to source, treat, and reclaim water previously dismissed as “undrinkable.”

The interview underscored the vital role of technology in addressing water-related crises. Fiske’s insights, grounded in his connection to the Akron area, shed light on Fontus Blue’s ongoing initiatives to revolutionize water treatment and recovery. In the face of natural disasters or man-made catastrophes, such as the recent train derailment in East Palestine, Ohio, the discussion explored the potential of water desalination and purification technologies to mitigate the impact of contaminated water sources.

For those keen on understanding the intersection of technology, water, and sustainability, the full podcast and interview with Dr. Peter Fiske are available for listening [here](link). This enlightening conversation transcends local water rate concerns, urging listeners to contemplate the broader implications of water access, climate change, and the imperative for innovative solutions in safeguarding this precious resource. Listen to the interview and podcast.

The first World Water Day was held on March 22, 1993, when the United Nations General Assembly decided to celebrate the importance of freshwater. This year’s theme is ‘groundwater, making the invisible visible’.
Most people imagine the ocean when they think about desalination. However, the first reverse osmosis (RO) water treatment plant—built in Coalinga, California in 1965—was designed to desalinate brackish groundwater. There is a LOT of brackish groundwater across the United States, especially in locations that have limited freshwater supplies. The U.S. Geological Survey estimates that total brackish groundwater resources in the U.S. are 800 times the total amount of fresh groundwater pumped from all other sources every year. In line with this, NAWI Research Consortium Member Massachusetts Institute of Technology published an excellent assessment of the potential of brackish groundwater desalination in the country. Ocean desalination plants around the world currently produce more than 10 billion gallons of freshwater daily. In contrast, the total water production from brackish groundwater desalination facilities around the world is 2.3 billion gallons per day. 

Brackish groundwater desalination has a number of advantages over ocean desalination:

• Brackish groundwater is often far less saline than ocean water, thus requiring less energy to remove the salt and enabling higher water recovery rates. 
• It is geographically widespread and available as a resource for diverse communities (not just for those along the coast).

However, brackish groundwater is a challenging non-traditional water source to treat. Water is the “universal solvent”, and water that has remained underground for a long time can become saturated not only with highly soluble constituents (like salts) but also sparingly soluble constituents (such as silica and gypsum) that can precipitate out during the desalination process, “scaling” the interior surfaces of pipes and membranes. And, far from the seacoast, there are few options for economically disposing of the brine waste from the desalination process. Read more below as NAWI’s Research Director Dr. Meagan Mauter discusses the detailed baseline study conducted by NAWI researchers to assess the current technology approaches to treating this vast but challenging water supply.

NAWI has a number of research projects underway to tackle the many technical challenges that prevent wider use of brackish groundwater desalination. 

Colorado State University (CSU) researchers are embarking on two groundbreaking projects with the aim of significantly reducing the energy costs associated with water desalination and purification. These initiatives, funded through grants from the U.S. Department of Energy’s National Alliance for Water Innovation (NAWI), align with the program’s overarching goal of revolutionizing the cost and energy landscape of desalination over the next five years, addressing the growing global need for drinkable saltwater.

The most effective method for desalination currently involves reverse osmosis filtration systems, which exert substantial pressure over extended periods to force saltwater through tiny membrane passages. However, the energy intensity of this process, especially on a large scale, remains a significant challenge.
Led by Steven Conrad, associate professor of systems engineering, the first project aims to enhance energy grid efficiency by identifying opportunities for energy conservation and management between filtration desalination plants and their connected power grids. The team, in collaboration with partners such as the Electric Power Research Institute, the National Renewable Energy Laboratory, The Salt River Project (AZ), and the Water Replenishment District (CA), will model and select optimal ways to integrate existing water treatment plants with modern electric grids. The objective is to leverage new technology and sustainable energy processes to reduce overall system costs, with a total project value of approximately $900,000.

Co-led by Tiezheng Tong, associate professor of civil and environmental engineering, and Jason Quinn, professor of mechanical engineering, the second project focuses on lowering the cost and energy requirements for achieving zero-liquid discharge in desalination. Addressing the energy-intensive brine crystallization step, the team, in collaboration with Washington University in St. Louis, Clarkson University, Argonne National Laboratory, and OLI Systems, Inc., will explore sustainable approaches to improve efficiency and reduce carbon intensity. This project carries a total award of $1.3 million, with CSU receiving $295,000.

Both projects, set to commence in December 2023 and lasting at least two years, anticipate contributing to the development of better desalination technology. By lowering energy costs, these initiatives aim to mitigate the environmental impact of traditional water transportation and make clean drinking water more accessible, particularly in regions like the U.S. Pacific Southwest. With a commitment to creating water treatment systems with minimal negative impacts, CSU endeavors to provide a valuable tool for meeting global water needs.

The projects also underscore CSU’s dedication to advancing water technology and fostering interdisciplinary collaboration to address societal challenges at a profound level. As these endeavors unfold, they are expected to not only benefit graduate students involved in the research but also offer broader value to the global community.

Read about this research.

This article highlights the work of NAWI Research Consortium researchers Kurban Sitterley, a water treatment expert at NREL, and Alexander Dudchenko, an associate staff scientist at the Stanford Linear Accelerator Center, who worked together to build a new ion exchange model that can be used to guide utilities in identifying the best ion exchange systems. Read the article.

This article is published by WateReuse Association in collaboration with National Alliance for Water Innovation (NAWI). Lauren Nicole Core is water specialist consultant with the World Bank Group and communications lead with Lawrence Berkeley National Laboratory, Berkeley, CA;  and .

Artificial Intelligence (AI) grabs headlines for its ability to mimic, in its own distinctive way, human expression, from writing to artwork. However, its most important applications venture beyond generative AI to address challenges that have confronted humankind since the dawn of civilization. Secure and sustainable access to freshwater, for instance. Our most important natural resource has never been more severely threatened, and the global need for new sources of usable freshwater has never been as great.

As such, nations, regions, and communities around the world are actively pursuing alternative water supplies such as brackish water or potable reuse of municipal reclaimed water. However, purifying these sources means increases in energy, chemical use, and the need for talented, highly trained advanced water treatment operators.

It is therefore important to find ways to drive down the costs of energy and chemicals associated with water treatment, and to support operators.

In an effort to address such challenges, research supported by the United States Department of Energy’s National Alliance for Water Innovation (NAWI) is using AI and machine learning (ML) to reduce energy and chemical use, improve operational support, increase treatment system uptime, and improve confidence in purified water quality. The research aims to lower the cost of Reverse Osmosis (RO)-based advanced treatment (RBAT) by developing new—and improving existing—technological solutions to make treatment of nontraditional waters competitive with conventional water sources for specific end-use applications.
“The researchers are part of the NAWI Alliance, which focuses on making desalination and water treatment technologies more efficient, effective, and reliable,” explains Peter Fiske, Executive Director of NAWI. “These technologies will enable 90% of our current non-traditional water sources to achieve pipe parity – when the levelized cost for treating and reusing nontraditional water sources are equal to the cost of today’s marginal water supplies.”

NAWI is the largest federal investment in water treatment, desalination, and water reuse since the 1960s. The innovative national research program and public-private partnership brings together industry, academic, national laboratory, and other stakeholders across the country to advance next-generation desalination and water recycling technologies.

Reverse Osmosis to Reverse Water Insecurity

RO is a long-proven water treatment process that lies at the heart of most potable reuse systems. RO-based facilities can render water from nontraditional sources safe for use in a wide range of applications, lessening our reliance on groundwater and other often overtaxed freshwater supplies.

But the effectiveness of RO comes at a cost. The RBAT approach consumes a great deal of energy. This limits its scalability, especially for less affluent communities, and leads to questions about more environmentally sustainable alternatives.

Nevertheless, “the adoption of water reuse is gaining momentum. Studies like this that help improve the energy efficiency of water reuse keep that momentum strong, improving the health and resilience of communities across the United States,” said WateReuse Association Executive Director Patricia Sinicropi.

Sampling Wastewater…Without Samples

Researchers use AI to deliver more efficient testing and assessment of wastewater and to eliminate contaminants more adaptively and cost-effectively than traditional control methods allow. Take N-nitrosodimethylamine (NDMA) for example. NDMA once played a key role in the production of rocket fuel, but these days is mainly present in water as a disinfection byproduct. It is considered extraordinarily carcinogenic based on a study linking it to liver tumors in mice.

Because it is a very small molecule, NDMA can partially pass through RO. So, RBAT uses ultraviolet (UV) radiation to destroy NDMA, among other water quality benefits. This method destroys certain chemicals found in water through photolysis, which uses intense UV light to shatter the chemical bonds characteristic of targeted contaminants. UV also inactivates many pathogens, and in combination with certain chemicals like hydrogen peroxide, can further break down unwanted contaminants. Like RO, this process consumes a great deal of energy.

Traditionally, water treatment engineers have sampled wastewater from the multiple treatment processes that make up an RBAT array and sent them to be tested for NDMA and other dangerous contaminants. This process can take up to one month. These samples contribute to a database reaching back months or years, and the updated series is analyzed to identify the highest concentration of NDMA across all samples.  Since NDMA is an important contaminant and measuring it at a lab is slow and expensive, engineers and operators assume the worst. The intensity of UV light is set based on the highest or near-highest NDMA levels ever measured, and not changed.

The research team proposes to address the energy inefficiency typical of traditional RBAT-based treatment solutions by using an AI- and ML-based approach. It goes beyond direct sampling in favor of analyzing enormous datasets to train “soft sensors.” Soft sensors are AI models that use faster, cheaper data sources to predict the concentrations of slower, more challenging contaminants like NDMA. The result is a real-time estimate of key contaminants in a water source, including its most elusive. Researchers have demonstrated that AI can predict NDMA concentrations within ±3 parts per trillion of their actual value. This analysis informs the treatment process, reducing unnecessary UV treatments by roughly 50% while still reducing NDMA levels far below regulatory limits. Further AI research in the same NAWI project is modeling microfiltration and RO with AI to detect faults or optimize energy and chemical use within those steps of RBAT systems.

“The development and implementation of advanced controls for optimization, such as ML and AI, is an area that is ripe for innovation,” said Andrew Salveson, Project Lead and Water Reuse Chief Technologist, Disinfection Chief Technologist, and Project Manager at Carollo Engineering. “In some cases, advanced controls are built into individual processes, but the controls are not integrated across the entire system and don’t account for impacts on upstream or downstream processes. To the best of our knowledge, no studies have applied ML or AI to the operation of integrated RBAT trains in potable water reuse.”

Advanced Fault Detection for Better Reliability

This research organizes AI to support RBAT systems under two umbrellas: process control and fault detection. A pilot scheduled for 2024 will test the team’s efforts to provide better fault detection through real-time AI analysis. Adaptive process control and intelligent monitoring of treated-water supplies will allow water-treatment facilities to address fluctuations in water quality before they threaten to impact the delivery of usable freshwater.

This approach will also save energy and lower costs to water consumers, and researchers have hope that it will increase public confidence in its water supply. Those pilots will be conducted at Las Virgenes Municipal Water District (LVMWD) in Calabasas, California – an early adopter and innovator of such technological interventions – and Orange County Water District (OCWD) in Fountain Valley, California.

In advance of the pilot, researchers are currently conducting a series of simulations against historical data collected from high-frequency online sensors used by water utilities partnering with the project. These simulations encompass five different fault-detection and process-control methods, the results of which will be assessed at the end of this phase of the project. Researchers expect that more than one method will achieve their target of 10% energy savings, 20% cost savings, or 50% improved reliability. The most promising set of controls will be tested more rigorously at two demonstration-scale RO-based water-reuse facilities designed to produce potable water.

These are still early days for AI in general, and especially for its use as a facilitator of water reuse and as treatment of nontraditional water sources. But this research has already demonstrated significant advantages in water-testing methods, and researchers expect similar results in their efforts to inform fault detection and process controls with AI. Full implementation of the research team’s findings for commercial and municipal purposes will only be possible after a thorough real-life trial mirroring large-scale water treatment and reuse. For now, AI holds immense promise for a new generation of more efficient, steadier water treatment facilities capable of safely delivering freshwater from a wider variety of nontraditional sources than current technology allows.

Author’s note: The views expressed in this column do not necessarily represent the views of the US Department of Energy or the US government.

NAWI is a public-private partnership that brings together a world-class team of industry and academic partners to examine the critical technical barriers and research needed to radically lower the cost and energy of desalination. NAWI is led by DOE’s Lawrence Berkeley National Laboratory in collaboration with National Energy Technology Laboratory, National Renewable Energy Laboratory, and Oak Ridge National Laboratory, and is funded by the Office of Energy Efficiency and Renewable Energy’s Industrial Efficiency and Decarbonization Office.

There are many more NAWI-supported research projects and innovators leading the charge for a circular economy through desalination and water supply research. NAWI provides several opportunities for participation, from applying for Alliance membership to volunteering to advise a project team as a Project Support Group member. Through relentless dedication to enhancing water accessibility, purity, and affordability, NAWI’s visionary research instills optimism for a future where access to clean water becomes a reality for all.

Research Partners: Baylor University: Amanda Hering; Carollo: Amos Branch, Andrew Salveson, Charlie He, Wen Zhao, Daniel Hutton, Kyle Thompson; Las Virgenes Municipal Water District: Burt Bril, Darrell Johnson, John Zhao, Steve Jackson; National Water Research Institute: Kevin Hardy; Orange County Water District: Han Gu, Jana Safarik, Megan Plumlee; United States Military Academy: Katheryn Newhart; West Basin Municipal Water District: Alejandra Cano-Alvarado, Margaret Moggia, Uzi Daniel, Veronica Govea; Yokogawa Corporation: Steve Hayden, Yasuhiro Matsui.

This article describes how a new NAWI-supported materials-screening platform is advancing breakthroughs in water treatment technologies. The full article was published in the September 2023 Journal AWWA. A free, flipbook version is available here.

If you drink tap water, you can probably thank Abhishek Roy.

A good amount of the world’s drinking water gets purified through something called a reverse osmosis membrane, which filters out salt and other contaminants. And if your water squeezes through this kind of filter, it is likely that Roy helped build it. But even if you cannot thank Roy for that particular membrane, there is a good chance you will benefit from at least one of his many others. He currently holds 75 patents worldwide.

“Membranes are an enabling technology,” said Roy, a senior staff scientist at the National Renewable Energy Laboratory (NREL). “Membranes play a very, I would say, behind the screens—or scenes—role to provide one of the most crucial parts of today’s life: clean water.” (“Screens” was not a slip of Roy’s tongue; it’s a membrane pun!)

As greenhouse gases like carbon dioxide trap heat in our atmosphere and a warming climate strains our water supplies, these little enablers are becoming even more valuable. Roy’s most prolific membrane not only improves water quality by 40%, but it also uses 30% less energy than its predecessors. Those energy cuts could help reduce global carbon emissions and slow climate change—and so could Roy’s hydrogen-powered fuel cells, which need membranes to generate clean energy for things like power plants, cars, or even laptops.

But Roy is not only preventing new emissions; his inventions could also help remove carbon that has already escaped into our atmosphere or our oceans.

“There is now a global need for decarbonization, right?” Roy said. “And we are trying to help in every possible way.”

In short, Roy is an enabler for the enablers.

Roy first encountered membranes during his doctoral studies at Virginia Tech. His background was in polymers—the molecular chains behind synthetic materials, like plastics, but also natural structures, like DNA. But his advisor, James McGrath, was “a very forward-looking person,” Roy said. And McGrath wanted to find a way for polymers to boost the green technology movement.

“I got my Ph.D.,” Roy said, “but also a doctorate in understanding membranes and how they can solve world problems.” (He got something else, too: a prestigious R. A. Glenn Award from the fuel division of the American Chemical Society for his doctoral thesis, which led to a breakthrough in fuel cell research).

Membranes require energy—sometimes a whole lot of energy—to push substances through their selective layers. So, if researchers could build more energy-efficient membranes, those energy savings could significantly reduce global carbon emissions (and costs), too.

Roy’s inventions do exactly that. His favorite invention, the water purification membrane that cut energy use by 30%, earned him the Gordon E. Moore Medal, one of the most highly esteemed awards available for members of the chemical industry. Now, he is working to realize yet another of McGrath’s antipollution plans.

“Thirty years back, fuel cells were a dream,” Roy said. “Now, they’re no longer a dream; they’re a reality.”

That reality runs on membranes. In fuel cells, membranes separate hydrogen to generate energy while emitting nothing but water. Roy also helped invent more energy-efficient membranes for petrochemical industries, which produce products like plastics, medical equipment, fertilizers, and even clothing. With Roy’s membranes, those industries could both reduce their overall energy consumption (and therefore their carbon emissions) and capture carbon, too.

Now, at NREL, Roy is working to make fuel cells, water-purification devices, and carbon-capture technologies more efficient and cost effective. “That’s my goal—to establish the lab as a national hub and help to address those challenges,” Roy said.

Before Roy joined NREL in 2021, he spent about 15 years at Dow Chemical. Throughout that time (and even in the two years since he joined the laboratory), Roy has earned many high-profile awards, especially for his water purification technologies. Most recently, he and Mou Paul, a materials scientist at NREL, won the 2023 Polymer Science and Engineering Cooperative Research Award for their work in global water sustainability. Roy also earned the 2014 Virginia Tech Outstanding Recent Alumni Award and Dow Chemical’s coveted Sustainability Innovator Award (as of 2014, Roy was one of just five recipients). And he was recently elected to the board of directors for the North American Membrane Society.

In May 2023, the membrane magician was awarded funding from the National Alliance for Water Innovation (NAWI), whose mission is to make water more affordable, energy efficient, and accessible. With his award, Roy, a member of the NAWI Alliance and research consortium, is crafting yet another multipurpose membrane.

“As you purify water, you leave behind salt. What happens to this salt? That’s a big question,” Roy said. “And salt water will also contain water, right? Every drop of water counts.”

Typically, that salty byproduct is tossed away or left to evaporate. But Roy’s latest membrane can extract those precious drops of pure water, as well as salts needed for chemical processes. This kind of purification often demands huge amounts of energy (the more stuff that is in the water, the harder it is to push it through a membrane). But Roy’s solution, which he is working on with collaborators at the University of Texas and Lawrence Berkeley National Laboratory, will reduce both energy use and costs.

“That’s the major goal—reducing the overall cost of water,” Roy said. (He is also adapting that membrane to remove carbon from seawater thanks to a grant from the Office of Naval Research). “But if you want to develop this decarbonization technology,” Roy continued, “it’s very important that you engage not only the top leaders but also people who are emerging.”

About five years ago, Roy was chosen to join the National Academies of Sciences, Engineering and Medicine’s New Voices project, which aims to expand diversity in the sciences and encourage early-career scientists to tackle national and global challenges. With the group, he helped author an opinion piece, published in Scientific American, that argued for increasing diversity across all scientific disciplines. When more women became cardiologists, the article argued, that led to better outcomes for women with heart disease.

“Of course, technology is the key, right?” Roy said. “But engaging the young scientific community into the whole process—that’s so critical.”

Now, Roy is not only an enabler for his mini membrane enablers but also for the next generation of scientists who will take up the fight against climate change, one polymer, fuel cell, water droplet, or carbon molecule at a time.

The National Alliance for Water Innovation is a public–private partnership that brings together a world-class team of industry and academic partners to examine the critical technical barriers and research needed to radically lower the cost and energy of desalination. The alliance is led by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory in collaboration with DOE’s National Energy Technology Laboratory, National Renewable Energy Laboratory, and Oak Ridge National Laboratory and is funded by DOE’s Industrial Efficiency and Decarbonization Office.

Researchers at the Department of Energy’s Oak Ridge National Laboratory are developing advanced automation techniques for desalination and water treatment plants, enabling them to save energy while providing affordable drinking water to small, parched communities without high-quality water supplies.

Climate change and growing populations are straining the lakes, rivers and aquifers that traditionally provide clean water. Today, more towns need to be able to treat brackish, salty or biologically-polluted water to drinking water standards. But operating this more complex treatment often requires expensive technical expertise.

Through DOE’s National Alliance for Water Innovation research program, ORNL, universities and private companies are working together to develop and demonstrate fully-automated, multi-stage treatment systems that are effective at making nontraditional water sources clean and healthy for drinking or irrigation.

Co-founded by ORNL and the National Renewable Energy Laboratory, NAWI is a research initiative that also seeks to make this treatment affordable, decentralized and energy-efficient even for water sources that vary daily in content and quality.

“Fully treating and reusing water creates a circular water economy,” said ORNL lead researcher Kris Villez. “We want to make a nontraditional water source economically competitive against a traditional, mostly pure water source, something we call ‘pipe parity.’ These nontraditional sources vary a lot in quality and availability. This means that they can only achieve pipe parity through automated controls,” allowing cost-efficient water treatment even for historically underserved or rural communities without a large tax base.

A team led by Villez is developing software based on machine learning that can make decisions about the best actions to maintain a high quality of treatment in the most efficient way, saving energy, money and water. Choices can be influenced by daily weather, drought conditions, real-time energy and water prices, plant maintenance and changes in the composition of the untreated water.

Villez said this type of water treatment automation could eventually be vital not only for municipal water systems in thirsty areas like the Colorado River Basin but also in water-intensive industrial facilities, such as food and beverage processors or utilities with water-based cooling systems.

“The central concept of NAWI has always been to increase water availability,” said Yarom Polsky, a NAWI topic area lead for process innovation and intensification. “Advanced automation is a critical element.” It enables optimization of the performance of water treatment systems, with benefits such as cost reduction and efficient adaptation to changes in the composition of source water.

“Making advanced automation accessible to small water utilities and small stand-alone systems is essential for widespread adoption,” said Polsky, who is also director of ORNL’s Manufacturing Sciences Division. “Small and medium-size system providers typically have fewer resources for hiring technical experts to implement advanced controls.”

Villez’s team already demonstrated similar but smaller-scale automated controls on a single-unit treatment system established in Aurora, Colorado, by the Colorado School of Mines. The city of Aurora, Baylor University and several software vendors are also partners in the project, which uses reverse osmosis to remove salt from water.

Researchers are currently pursuing the next step, developing controls for plant-wide optimization. This will be tested for the first time on a treatment train of six units that can flexibly switch between various levels and types of water treatment. Doing so enables an automated choice between using all units to produce municipal drinking water or only using a few to supply irrigation, depending on markets, costs and other changing conditions.

“We want to deliberately introduce changes to see if our model is accurate, so we have the ability to respond to adversarial events, inadvertent errors or gradual changes in the bacterial treatment process that you might not notice if you don’t compare,” Villez said. “We’re balancing economic performance with resiliency.”

In a related NAWI project, ORNL researchers are also building a digital twin of a real-world desalination plant owned by Orange County, California. This digital twin is a dynamic model of the plant, which allows testing diverse designs and controls in a virtual laboratory without affecting customers. Ultimately, the digital twin will enable a real-time response to changes in electricity pricing, avoiding water production at times when energy is most expensive.

Polsky points out that water treatment is both an energy-intensive process and an energy necessity. Clean water heats and cools today’s power plants and industrial processes. “As we proceed through our energy transition, water treatment is also likely to be critical for energy applications of the future,” such as producing green hydrogen for industry, transportation or long-term energy storage, he said.

Other researchers who contributed to these water treatment automation projects include ORNL’s Alexander Melin and Sally Ghanem, along with former ORNL postdoctoral researcher Dhrubajit Chowdhury. Funding was provided by NAWI and the DOE’s Advanced Materials and Manufacturing Technologies Office.

UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

Innovative water treatment and desalination technologies hold promise for building climate resilience, realizing a circular water economy, and bolstering water security. However, more research and development is critical not only to radically lower the cost and energy of such technologies, but to effectively treat unconventional water sources. Conventional water supplies, such as fresh water and groundwater, are typically used once and thrown away, rendering this valuable and finite resource inaccessible for further use. Since its launch in 2019, the National Alliance for Water Innovation (NAWI) has made strides in developing new technologies to economically treat, use, and recycle unconventional waters (such as brackish groundwater, municipal and industrial wastewater, and agricultural run-off), which could point to a future where water equity and security is accessible to all.

Led by Lawrence Berkeley National Laboratory  (Berkeley Lab) and supported by the United States Department of Energy, NAWI is a five-year, $110 million research program and public-private partnership. NAWI brings together over 1670 individual NAWI Alliance members, over 400 partnering organizations, and numerous water research facilities.

“NAWI is driving breakthrough research to reduce the price, energy costs, and greenhouse gas emissions of new water technologies,” said Peter Fiske, executive director of NAWI. “Our work also bridges cutting-edge research with real people and places, such as producing secure, reliable, and affordable water for communities that are most in need.”

NAWI’s robust research portfolio spans analysis for water-energy grid integration to development of algorithms, models, and adaptive process controls for resilient operations. Now in its third year of operation, NAWI is supporting pilot projects that will treat unconventional water sources to provide usable water in real-world environments. Many of the pilot projects partner directly with communities and groups that have historically been underserved by existing water supplies. Each project will also generate a range of data sets usable by other researchers seeking to advance the field of data analysis and automation, and fault detection in water treatment systems.

These 5 NAWI pilot projects are transforming water treatment and desalination technologies.

Removing Arsenic from California Well Water for Rural Communities

Arsenic, a naturally-occurring carcinogenic contaminant, is widely present in groundwater. In both California and around the world, many wells are contaminated with arsenic levels surpassing safety thresholds. This compels communities to either set up costly and intricate purification setups or cease using their local wells, resulting in the inconvenience of traveling long distances to procure water for domestic purposes. This initiative will demonstrate a new simple, dependable, and highly automated electrochemical arsenic-removal process employing iron and electrical currents. This method ensures the secure elimination of arsenic from well water while requiring minimal human intervention. Collaborating with the residents of Allensworth, California – a rural community whose residents travel significant distances to pay for retail water from a kiosk – is central to this project.

Turning Waste to a Valuable Resource for a Circular Economy

Desalination methods commonly recover a portion of pure water while generating a byproduct known as brine or concentrate, which contains high levels of salt and poses challenges for economical and environmentally friendly disposal, particularly at onshore desalination plants. This project centers on creating and implementing an innovative approach to intensify the concentration of brine through electrodialysis. This technique not only increases water yield but also converts the dissolved salts into valuable industrial chemicals. The initial testing of this system will take place at the Kay Bailey Hutcheson Desalination Plant situated in El Paso, Texas.

Enhancing Water Treatment Efficiency to Minimize Waste and Maximize Sustainability

The concept of desalination and repurposing of municipal, industrial, and agricultural wastewater presents an appealing strategy to enhance the dependability and resilience of water resources. However, the existence of dissolved minerals capable of obstructing reverse osmosis membranes and components, a phenomenon known as scaling, imposes constraints on the volume of water that membrane processes like reverse osmosis can restore. This project seeks to incorporate an innovative, exceptionally efficient technique for extracting scale-forming ions from concentrated brine solutions, thereby enabling significantly elevated water recovery rates and reducing waste brine volume. Through a mobile testbed, this advancement will help ensure high-recovery desalination across five locations in California.

Advancing Membrane Technology for Greater Resource Recovery

Electrodialysis Metathesis (EDM) is a desalination process that employs specialized membranes and chemical processes to generate fresh water. It also converts residual brine into two distinct streams: one rich in calcium and the other rich in sulfate. These streams hold the potential for further refinement into valuable industrial chemicals, thereby creating an additional revenue stream from the desalination process. This approach also aids in diminishing the volume of waste brine generated. Historically, EDM has necessitated the addition of sodium chloride (NaCl) to provide the essential ions for forming these distinct solutions. This NAWI-supported project implements a novel ion-selective membrane technology to eliminate the requirement for supplementary NaCl, potentially leading to a reduction of up to 50% in the energy demands of conventional EDM. The effectiveness of this system will undergo rigorous testing at the Brackish Groundwater National Desalination Research Facility, situated in Alamogordo, New Mexico, under the oversight of the U.S. Bureau of Reclamation.

Transforming Municipal Wastewater to Drinking Water to Improve Water Security

Municipal wastewater can be reprocessed into drinking quality water. Reverse osmosis has traditionally been a final treatment step that can provide the high purity required to satisfy drinking water quality regulations, but reverse osmosis generates a brine waste stream and drives up the cost and energy required for direct potable reuse. This project will perform a side-by-side demonstration at Silicon Valley Clean Water’s treatment plant in Redwood City, California, of both a reverse osmosis-based treatment train and a novel treatment train that achieves nearly the same purity without using reverse osmosis. The team will also investigate how different types of wastewater treatment technologies produce effluents that are either easier or harder to transform into drinking quality water.

NAWI is led by DOE’s Lawrence Berkeley National Laboratory in collaboration with National Energy Technology Laboratory, National Renewable Energy Laboratory, and Oak Ridge National Laboratory, and is funded by the Office of Energy Efficiency and Renewable Energy’s Industrial Efficiency and Decarbonization Office.

# # #

Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 16 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

As climate change flames a megadrought in the U.S. Southwest, the country is hitting some worrisome records. The water level of Lake Mead, which provides water for millions of people, is hovering near its lowest ever. And in some places, the shrinking Colorado River, which irrigates about 5 million acres of farmland and quenches the thirst of over 40 million people, is just desert and dust.

Meanwhile, as of 2018, about 80% of the country’s wastewater—including water used in agriculture, power plants, and mines—gets dumped back into the world, untreated and unusable, a wasted opportunity. And although today’s go-to purification technologies, which use a process called reverse osmosis, are still the most cost-effective and energy-efficient way to treat seawater and briny groundwater, conventional reverse osmosis cannot handle super-salty waters—those containing double the salt content of the ocean. As U.S. water supplies shrink (and get saltier), the country can no longer afford to dump even the saltiest sources back into the world.

Now, in a new study published in Desalination, members of the National Alliance for Water Innovation (NAWI) research consortium analyzed an emerging form of reverse osmosis, called low-salt-rejection reverse osmosis. These novel systems could treat even highly salty water. But the design is so new it is still theoretical.

So, to learn how these technologies might compete with other water treatment options, the NAWI research team developed a mathematical model that could, with help from a supercomputer, quickly evaluate the cost, clean water output, and energy consumption of more than 130,000 potential system designs. Their results show that, in many cases, low-salt-rejection reverse osmosis could be the most cost-effective choice, potentially reducing the overall cost of producing clean water by up to 63%.

“The ultimate goal of this research is to conduct a thorough techno-economic evaluation of a new technology that hasn’t been tested in the real world yet but has the potential to enable high-water-recovery desalination,” said Adam Atia, a senior engineer at the National Energy Technology Laboratory and the paper’s lead author.

Although a few studies have evaluated the potential cost and efficiency of low-salt-rejection reverse osmosis systems, this study offers a more comprehensive analysis of their design, operation, and performance. To better understand the potential promise of these theoretical systems, the team used a supercomputer to hone in on the most optimal, cost-effective designs. They then explored how those designs might function in hundreds of thousands of scenarios (as opposed to just a handful).

Because low-salt-rejection reverse osmosis systems allow more salt to pass through each membrane, they require less force—and therefore less energy—to push the water through. But, if more salt can squeeze through, the resulting water is, not surprisingly, still too salty to drink. To produce potable water, this still-too-salty water gets recycled back into the previous membrane stages. Once the salt content is low enough, standard reverse osmosis can take care of the rest, generating high-quality drinking water.

All that recycling adds to the system’s complexity. So, the team needed to find out: How many membrane stages are optimal? How many recycling loops are needed? And how much cost and energy do those loops add? To answer these questions, researchers could calculate, individually, how much clean water each design could produce from waters with different concentrations of salt.

“That would potentially take a really, really, really long time for them to solve,” said Ethan Young, a researcher at the National Renewable Energy Laboratory (NREL) and an author on the study. “We were able to do it in a few minutes with high-performance computing.”

And, in those few minutes, they examined not one but hundreds of thousands of potential scenarios.

“The novelty of our study is the computational force power we brought to bear on this analysis,” added Bernard (Ben) Knueven, a fellow NREL researcher and author.

Without a supercomputer, all those calculations would take about 88 days instead of one hour or even a few minutes, Young said. Of course, the supercomputer also needed Knueven and Young’s mathematical magic to solve these complex design problems both quickly and accurately.

With all that speedy math, the team discovered that low-salt-rejection reverse osmosis could outperform its competitors in both cost and energy use—at least for water containing less than 125 grams of salt per liter. But the team’s model could also help other research teams identify, build, and test the most promising system designs.

“The hope is, by doing these computational analyses, we can give the experimentalists information to say, ‘Oh, here’s an interesting thing to study,’ or, ‘No, this is probably completely ruled out,’” Knueven said.

The model could be expanded, too, to help experimentalists hone in on the best designs for reverse osmosis systems, generally. Their study is the first to both use and add to NAWI’s Water treatment Technoeconomic Assessment Platform (WaterTAP). A publicly available software tool, WaterTAP gives users the power to model and simulate various water treatment technologies and evaluate their cost, energy, and environmental trade-offs.

“I think it’s so cool. We’re building a tool that can help us and other researchers assess the potential of new and exciting technologies,” Knueven said of WaterTAP, which was built through a collaboration between NREL, Lawrence Berkeley National Laboratory, the National Energy Technology Laboratory, Oak Ridge National Laboratory, and the Regents of the University of California.

Next, the researchers hope to partner with experimental teams to build and evaluate how low-salt-rejection reverse osmosis systems function in the real world. Mineral buildup, for example, could slow the system down and should be accounted for in future evaluations.

Even so, Atia said, this emerging form of reverse osmosis could be a valuable tool to maximize water recovery from high-salinity sources. “And our model can play a key role in supporting the technology’s deployment,” he said.

“To me,” Knueven said, “it’s a demonstration of what we can do with a little bit of computation and a little bit of optimization.”

Learn more about NAWI and its members’ efforts to secure an affordable, energy-efficient, and resilient water supply for the United States.

The National Alliance for Water Innovation is a public-private partnership that brings together a world-class team of industry and academic partners to examine the critical technical barriers and research needed to radically lower the cost and energy of desalination. The alliance is led by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory in collaboration with the National Energy Technology Laboratory, the National Renewable Energy Laboratory, and Oak Ridge National Laboratory and is funded by the U.S. Department of Energy’s Industrial Efficiency and Decarbonization Office.

Republished with permission from the University of Illinois Urbana Champaign.

The nitrate runoff problem, a source of carcinogens and a cause of suffocating algal blooms in U.S. waterways, may not be all gloom and doom. A new study led by the University of Illinois Urbana-Champaign demonstrates an approach for the integrated capture and conversion of nitrate-contaminated waters into valuable ammonia within a single electrochemical cell.

The study, directed by chemical and biomolecular engineering professor Xiao Su, demonstrates a device capable of an eightfold concentration of nitrate, a 24-times enhancement of ammonium production rate and a greater than tenfold enhancement in energy efficiency compared with previous nitrate-to-ammonia electrocatalysis methods.

“By combining separation with reaction, we overcame previously existing limitations of producing ammonia directly from groundwater, where the concentrations of nitrate are very low, and thus make the conversion step inefficient,” Su said.

The findings are published in the journal Nature Communications.

“The goal of this study was to use as little energy as possible to remove nitrate from agricultural runoff before it hits our waterways, and transform it back to a fertilizer or sell it as a chemical feedstock,” Su said. “Our technology can thus have an impact on waste treatment, sustainable chemical production and advance decarbonization. We are hoping to bring greater circularity into the nitrogen cycle.”

The team developed a unique, bifunctional electrode that can separate and up-concentrate nitrate from a water stream, while converting to ammonia in a single unit using purely electrochemical control. “The bifunctional electrode combines a redox-polymer adsorbent, which captures the nitrate, with cobalt-based catalysts that drive the electrocatalytic conversion to ammonium,” Su said.

The system was tested in the lab using agricultural runoff collected from drain tiles around the U. of I. research farmlands to evaluate the potential of the technology for real-world conditions, the researchers said.

“This is a very efficient capture and conversion platform with a low footprint,” Su said. “We don’t need separate electrochemical cells for the water treatment and ammonium production or adding extra chemicals or solvents. Instead, we envision a module installed directly onto farmland and run using the power generated from the electrocatalytic process and a small solar panel.”

The team said its next goal is to develop even more selective materials used in the device to achieve higher nitrate removal and accelerate the conversion to ammonia – while engineering larger scale systems for practical deployment in the field.

Kwiyong Kim is the first author of the study, with contributions from Jaeyoung Hong and Jing Lian Ng, from the Su group. The work was carried out in collaboration with Tuan Anh Pham, from the Lawrence Livermore National Laboratory, and Alexandra Zagalskaya and Vitaly Alexandrov, from the University of Nebraska.

Su also is affiliated with the Beckman Institute for Advanced Science and Technology and also is a professor of civil and environmental engineering at Illinois.

The National Alliance for Water Innovation, funded by the U.S. Department of Energy and the Institute for Sustainability, Energy, and Environment at Illinois supported this study.

Editor’s notes:

To reach Xiao Su, call 217-300-0134; email .

The paper “Coupling nitrate capture with ammonia production through bifunctional redox-electrodes” is available online.

DOI: 10.1038/s41467-023-36318-1

In April 2022, a team of engineers hiked into California’s Sierra Nevada mountains to hunt for snow. Instead, they found mostly bare, dry dirt and only a few of the snow patches that provide one-third of California’s water supply.

In the coming decades, water scarcity and insecurity are likely to intensify across much of the United States. In California, the Sierra Nevadas are expected to lose a staggering 65% of their snowpack over the next century, said Hariswaran (Hari) Sitaraman, a researcher at the National Renewable Energy Laboratory. That loss, plus political, economic, and other challenges, is making it essential for drought-prone states, like California, to tap alternative water sources such as brackish (or salty) waters and agricultural runoff.

And yet, the most common way to treat and reuse nontraditional water supplies is through a process called reverse osmosis, which can be both expensive and energy intensive.

Now, Sitaraman and Ilenia Battiato, two members of the National Alliance for Water Innovation (NAWI) research consortium, have used supercomputers to study reverse osmosis systems as a whole—a first for both the type and scale of reverse osmosis research. With their new technique, the duo also discovered a new system design that could make these technologies about 40% more energy efficient—and therefore more cost-effective—while producing the same amount and quality of clean drinking water.

“Until now, people have been looking at a tiny piece of the entire reverse osmosis module and drawing conclusions from that,” Sitaraman said. “But we looked at the entire thing.”

The results are published in a new paper in Separation and Purification Technology.

Along with Battiato, an assistant professor of energy science and engineering at Stanford University, Sitaraman created a fluid dynamics solver—a numerical tool that can analyze how fluids, like salty water, flow into a reverse osmosis system, pass through several membrane filters, and come out clean on the other side.

With their solver, Sitaraman and Battiato studied reverse osmosis systems with high precision, enabling them to uncover any snags or inefficiencies. For example, to filter brackish waters, reverse osmosis systems use high pressure to push the water through several membranes, which, like sophisticated coffee filters, block salts and other minerals from passing through. That process cleans the water, but it also creates thin layers of salty buildup on the membranes. And that buildup can affect how well the water flows, potentially reducing the system’s efficiency.

“That thin layer needs to be measured correctly to understand how much pure water you get out of salt water,” Sitaraman said. “If you don’t capture that right, you cannot understand how much it costs to run a reverse osmosis plant.”

A more efficient reverse osmosis system is more cost-effective, too.

Yet, most reverse osmosis plant owners do not have a high-performance computer to replicate Sitaraman and Battiato’s high-fidelity simulations—which so accurately mimic real-life reverse osmosis technologies—to uncover snags in their own systems. So, Sitaraman performed the complex work of creating a simpler model equation that can predict a system’s mass transfer, estimating how much pure water can be filtered out of brackish water. With his model, engineers can now discover how to improve the efficiency (and cost) of their own systems.

“If the economics improve,” Sitaraman said, “then of course reverse osmosis systems will be more widely used. And if they’re more energy efficient, they will contribute less to greenhouse gas emissions and climate change.”

That is a huge win, but Sitaraman and Battiato’s tools can benefit far more than reverse osmosis plant owners. Other researchers can build on their work to study the efficiency and cost of all kinds of reverse osmosis filtration technologies beyond those used to treat unconventional water sources. The food industry uses these filters to create highly concentrated fruit juices, more flavorful cheeses, and much more. Aquariums need them to remove harmful chemicals from their waters. And reverse osmosis systems can even extract valuable minerals and other substances that could be used to make cheap fertilizer or fuel.

One huge advantage of high-fidelity simulations, Battiato said, is the ability to study a vast range of reverse osmosis system configurations without investing the time and money required to build and experiment with real-life systems.

“We want the system to correctly capture the physics,” Battiato said, “but we are theoretically not constrained by manufacturing.”

With simulations, the team can quickly explore far more potential designs and home in on the best. That is how Battiato and Sitaraman identified their potentially more effective arrangement of spacers (which are bits within the reverse osmosis system that create turbulence and keep channels open to help water flow through). Their new spacer arrangement not only improves the system’s energy efficiency by 40%, but it also produces the same amount of equally pure water.

Although the duo’s simulations accurately replicate real-life systems, they are still theoretical. Sitaraman hopes another research team will build their design and evaluate how closely the real system matches their models. In the meantime, their higher-resolution (or more precise and comprehensive) simulations could help researchers avoid making inaccurate assumptions about how reverse osmosis systems work and, in so doing, learn how to improve the technologies.

Today, most engineers use trial and error to discover how to improve their reverse osmosis systems. But that process is slow, and water shortages are coming fast. With Battiato and Sitaraman’s simulations, engineers could speed up the development of more efficient and cost-effective technologies, so the country can access unconventional water sources when communities—like drought-stricken western towns—desperately need them.

“Water is a scarce resource,” Battiato said. “I don’t think we can afford to do coarse optimization anymore. We need to save every drop of water that we can.”

Learn more about the National Alliance of Water Innovation and their efforts to secure an affordable, energy-efficient, and resilient water supply for the United States.

The National Alliance of Water Innovation is a public–private partnership that brings together a world-class team of industry and academic partners to examine the critical technical barriers and research needed to radically lower the cost and energy of desalination. The alliance is led by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory in collaboration with the National Energy Technology Laboratory, the National Renewable Energy Laboratory, and Oak Ridge National Laboratory and is funded by the U.S. Department of Energy’s Industrial Efficiency and Decarbonization Office.

After a summer of COVID restrictions, travel and (hopefully) a bit of vacation, many of us are heading back into the office or classroom.  While we might not spend a great deal of time thinking about the implications for our water use at work, NAWI friends at Phoenix Process Equipment Co. and Aquacell Water Recycling Ltd. certainly do.  Over the past month, they have graciously hosted NAWI members on tours of the Salesforce Tower in San Francisco and Meta corporate campus in Menlo Park, CA (yes, that Meta) where they designed and installed onsite “blackwater” reuse facilities. They shared some important lessons in operating small-scale water treatment systems.

First the stats.  Both facilities were designed to accommodate large office populations and treat between 40 to 90 thousand gallons per day of rainwater, toilet, and sink wastewater to a quality safe for additional toilet flushing and/or irrigation (of salinity sensitive redwoods!). Both facilities used roughly the same process train consisting of belt filter (with solids discharged to sewer), aerobic membrane bioreactor system (MBR), RO, ultraviolet (UV), and remineralization. While the Salesforce system was idle at the time of our visit, Meta’s system was just getting restarted after a long COVID hiatus, and will be resuming water delivery in the coming weeks. 

Next the insights:  

1. COVID threw onsite systems a major curveball. Meta’s campus was fully populated before the 2.5 year-long COVID shutdown; the new “normal” office population (about one-third of pre-pandemic numbers) is sufficient to sustain the MBR, but is far below the original design capacity. We had some great discussions about resilient designs, including what it would take for systems to operate at a mere 10% of their design capacity for an extended period of time.  
2. Tanks, tanks, tanks! Water treatment and reuse systems require a LOT of water storage. This is often overlooked in academic studies. Not only are tanks expensive ($2-$10 per stored gallon) but they also have a significant footprint — not cheap when it means displacing coveted parking spots and valuable Silicon Valley real estate. Ideally, below-grade storage tanks are integrated into the original building design. Researchers probably need to do a better job of factoring storage into the total cost projections for on-site systems. 
3. Insensitivity (indifference?) to electricity consumption. During both of our tours, we had a hard time even finding the electrical meter and system designers often have no information about the actual system energy use once its installed and operating.
4. Odor and color control is essential. Office building tenants do NOT want to smell even a whiff of typical wastewater treatment plant “fragrance”, and tenants don’t want to flush their toilets with yellow water. A lot of our process designs for onsite blackwater reuse are dictated by odor and color rather than by safety concerns. We wondered aloud where NAWI technologies could make an impact in these two important aesthetic areas. 
5. Permitting blackwater recycling systems remains a regulatory challenge. While greywater recycling has become significantly easier to permit over the past decade, blackwater systems are really first-of-a-kind demonstration sites in most regions. They are often held to the same standards for daily monitoring, sample collection, and thus demand frequent sensor monitoring and calibration. Technology and regulations are going to have to evolve together for building-scale reuse to really take hold.
6. These systems are far too complex to be managed by a typical property manager or site engineer. Both sites we visited had real-time remote monitoring. The (operational) Meta facility had a dedicated Level 2 operator onsite, as well as a contract with a local laboratory for daily sampling collection/analysis. Additional facilities operation support and maintenance was a phone call away. 

Katie Weitzel and her team were awarded for their research poster titled Treatment and Reuse of Agricultural Drainage Water: Challenges and Opportunities. Weitzel, a Ph.D. student at the University of Cincinnati, attended the 2022 Association of Environmental Engineering and Science Professors (AEESP) Research and Education Conference to represent her work. 

“There were a lot of people interested in this work and I had a lot of interaction with people during the poster session,” said Weitzel. “It was nice to see so many people interested in this and starting discussions about treatment of non-traditional water sources.”

Weitzel and her team’s research focuses on water innovation surrounding agricultural drainage, and their poster presented information from the agricultural baseline work they’ve been investigating as part of the NAWI research consortium. The poster content complemented the conference theme, “Environmental Engineering at the Confluence,” which covered the full breadth of environmental engineering. The conference explored emerging developments in the field and focused four areas of convergence: convergence of education and research, convergence of research in air, water, and soil, convergence of research and action, and convergence of research, practice, and entrepreneurship.

 I was recently introduced to Prof. R. S. Silver’s 1979 history of desalination, slyly titled For want of a nail (Desalination Volume 31, Issues 1–3, October 1979, Pages 39-44). Silver summarizes his career in desalination research, noting that it is often the small things in desalination that end up mattering the most. 

This cautionary tale weighed on my mind when I recently toured the Advanced Water Treatment Plant (AWTP) located in Cambria, California. Prior to the development of the plant, Cambria had relied on groundwater from a nearby creek. The Central Californian local community knew it was time for a water-supply related change after years of low rainfall and over-reliance on a single water supply.  

Cambria’s AWTP⁠—a secondary water supply based on reuse of treated wastewater⁠—was thus built in 2015 during the height of California’s most recent multi-year drought. 

The picturesque town’s treated wastewater is first diverted to a percolation basin where it seeps into the subsurface. It then interacts with freshwater percolating from the mountains to the East and seawater seeping inland from the West. The mixed groundwater is then pumped out of the basin, filtered, and desalinated with a 2-stage Reverse Osmosis (RO) system. This RO system recovers 92% of the fresh water, which is then reintroduced into the town’s groundwater well-field further upslope. The MF-RO-UV-H2O2 unit processes of the packaged desalination facility are elegantly housed in a set of cargo containers, cleverly laid out so that the entire system resembles a set of large tan Legos.

Unfortunately, R. S. Silver’s admonition became particularly apparent once the system was up and running. The small amount of brine generated from the facility was disposed of by pumping it into an evaporation basin nearby. The evaporation basin itself was rigorously engineered to prevent leaks but… the cool foggy weather common for the central coast resulted in very low evaporation rates. And, when a winter storm caused runoff to overtop the basin, the entire water project was put on indefinite hold.

The entire “kingdom” of brackish desalination has been waiting for a brine disposal nail.

On a related note, NAWI has begun to review Concept Papers submitted in response to our recent call for proposals for piloting novel small-scale desalination systems (read the Pilot Program FAQ for more information). I am very hopeful that the desalination community will come forward with breakthrough approaches to further treating and reducing (or even eliminating?) the liquid brine waste stream that has bedeviled brackish desalination for so long.

NAWI’s theory of action is based on the belief that technical innovation is most impactful when it is performed in context. Materials are contextualized within a process; processes are contextualized within treatment trains; treatment trains are contextualized within water systems. While pandemic shut-downs have had minimal effect on our materials and process development projects, we have sorely missed the opportunity to visit water system operators. Pre-pandemic visits to Carlsbad West Basin Water District in LA and the Kay Bailey Hutchison Desalination Plant in El Paso, Texas allowed us to learn about non-traditional source water treatment trains designs, operational challenges, and economic benefits for water users.  

So it was tremendously exciting when federal travel restrictions were eased in March and we were finally able to resume NAWI field trips. Our first three visits were to Trevi Systems, a NAWI project performer working on concentrate management in Petaluma, CA; Red Rocks community college, the site of a USBR pilot facility for reusing cooling water blowdown; and Dr. Tzahi Cath’s Direct Potable Reuse (DPR) trailer, then located in Colorado Springs. Visits to each site provided an opportunity to see NAWI technologies (or related unit processes) in action, hear directly from operators about the challenges and opportunities for low TRL research to make a difference in the cost and energy intensity of their treatment trains, and brainstorm creative new ideas for future collaboration.  

The NAWI technical program looks forward to facilitating and hosting many similar site-visits in the months to come. If you are an Alliance Member operating a small scale facility that would like to host NAWI performers, please reach out to Zach Stoll, our Research Program Manager, who will gladly work with you and our project performers to facilitate future visits. Similarly, if you are a NAWI performer interested in attending a site with the NAWI team, please stay tuned for future emails about opportunities to join.

Aurora Kuras is a graduate student in Environmental Engineering at the Colorado School of Mines, a NAWI Consortium Member. She defended her thesis on Functional Data Analysis for Detecting Faults in Water and Wastewater Treatment on Wednesday, March 30th. This research is important because early and effective fault detection in water and wastewater treatment plants is important to maintain water quality and prevent process disruptions. Her work applies a method in functional data analysis (FDA) for fault detection to drift faults observed in a sequencing batch membrane bioreactor and closed-circuit reverse osmosis system. Her research is advised by Profs. Tzahi Cath and Amanda Hering.

Colorado Springs Utilities, Colorado School of Mines (Mines), and Carollo Engineers partnered in 2020 to create a mobile direct potable reuse (DPR) demonstration system (7,000 gpd) that purifies municipal wastewater for potable use. On March 8, the project team won the 2022 WateReuse Award for Excellence in Education and Outreach. Award recipients include Colorado Springs Utilities (Kirk Olds, Donene Dillow, Birgit Landin, Shaun Thompson, Jennifer Kemp, Lisa Halcomb), Colorado School of Mines (Tzahi Cath, Mike Veres, James Rosenblum, Tani Cath, Mason Manross, Chris Bellona), and Carollo Engineers (Jason Assouline, Andrew Salveson, Tasie Kade, John Rehring). Read the article.

Countries and communities require sustainable sources of water for economic growth, sociopolitical stability, and quality of life. However, water scarcity and insecurity are pervasive problems around much of the world. As such, it is important to urgently develop technologies for advanced water reuse that are cost efficient and effective – that may even change the way we use and reuse water.

Nature uses water over and over again, in an endless long cycle of evaporation and precipitation, powered by the sun. Humans, in contrast, tend to use water only once – drawing fresh water from a local source, using it for various purposes, and then discarding the wastewater back into the environment after minimal treatment, often exhausting their limited water resources.

For decades, scientists have been working on new technologies to enable treatment and direct potable reuse of water, but the applications have been largely limited to “out-of-this-world” environments such as water supply systems on the International Space Station.

Colorado Springs Utilities, Colorado School of Mines (Mines), and Carollo Engineers partnered in 2020 to create a “down-to-Earth” version of this technology: a mobile direct potable reuse (DPR) demonstration system (7,000 gpd) that purifies municipal wastewater for potable use. The system is now being tested and demonstrated at the Colorado Springs Utilities’ JD Phillips water reclamation plant, but is due to travel to several other locations in Colorado later this year.

The DPR demonstration lab is the vision of Dr. Tzahi Cath, a Professor of Civil and Environmental Engineering at Mines. “If we can take the water, and instead of just wasting it we could recover it and reuse it again for potable purposes, it will save money and energy, and it will save many problems during drought years” says Cath, “[…] communities must have a wider portfolio of sources of water to make sure that we have drinkable water under any circumstances.”

While there have been previous examples of  DPR technology, including units packaged in mobile systems, most of these have relied on reverse osmosis, which leaves behind a waste stream of concentrated contaminants that must be managed and disposed of, also limiting the percent water recovery of the system. In contrast, the Mines mobile DPR lab utilizes advanced treatment technologies such as ozonation, biologically active filtration, ceramic microfiltration, ultraviolet disinfection with advanced oxidation, and granular activated carbon to efficiently destroy pathogens and trap and remove contaminants of emerging concern, purifying close to 100% of the water. The mobile system also has a range of advanced sensors and automated fault detection technologies to ensure that all processes are operating properly and synchronously, and that the water meets drinking water regulations at all times.

The DPR system was recently put to the test, and it passed with flying colors — close to a million gallons of water were successfully treated over the first 6 months of operation. The water met all Colorado’s drinking water quality limits, and a few batches of water from the mobile lab were used to produce beer by several local breweries and soft drinks that were served in public outreach events. Specifically, all emerging contaminants of concern and disinfection by products such as PFAS, 1,4-dioxane, TCEP, TCPP, and NDMA were reduced to much below the regulatory or advisory levels, and microorganisms such as coliforms were completely eliminated from the product water. 

Seeing (and Tasting) is Believing

Mines embarked on this technology demonstration project, anticipating that some residents would be nervous about the concept of drinking recycled water. The system is designed to allow visitors to observe the water treatment process directly, and taste the high-quality water produced. 

Tourists can visit the PureWater Colorado Mobile Demonstration in Colorado Springs and watch the entire water treatment process in action. Funded by a Colorado Water Conservation Board Grant, with additional support from the National Science Foundation (NSF), and other industry partners, the interactive exhibit shows a scaled model of the carbon-based DPR process. 

The mobile DPR demonstrates that advanced water reuse technologies are not as far off as we think, and that you don’t have to be an astronaut to use one. DPR and other advanced water reuse technologies could help communities facing water insecurity and shortages by diversifying water supply and hedging against water risk. DPR could also  help to provide clean water quickly and cost-efficiently to people displaced by natural disasters and drought. 

On March 8, the project team won the 2022 WateReuse Award for Excellence in Education and Outreach. Award recipients include Colorado Springs Utilities (Kirk Olds, Donene Dillow, Birgit Landin, Shaun Thompson, Jennifer Kemp, Lisa Halcomb), Colorado School of Mines (Tzahi Cath, Mike Veres, James Rosenblum, Tani Cath, Mason Manross, Chris Bellona), and Carollo Engineers (Jason Assouline, Andrew Salveson, Tasie Kade, John Rehring).

DPR, Desalination, and More

Mines is part of the National Alliance for Water Innovation (NAWI), the U.S. Department of Energy’s 5-year research program to lower the cost and energy of desalination and water reuse technologies. NAWI is working to revolutionize the US water supply by enabling the affordable treatment and reuse of non-traditional sources such as wastewater. The operating data generated by the mobile lab will help researchers to develop new control sensors and algorithms to allow such systems to autonomously operate safely, reliably, and inexpensively. The mobile DPR lab is one more step in the shift toward a circular water economy.

Trevi Systems, Inc., a NAWI Alliance organization, recently licensed a pair of new switchable solvent water extraction technologies that were developed by a team of researchers at Idaho National Laboratory (INL). The research team is led by NAWI Alliance member and INL researcher, Aaron Wilson.

“Trevi Systems is excited to be partnering with NAWI and INL on this promising technology,” said John Webley, Founding Chairman and CEO of Trevi Systems. “With INL providing the theoretical framework underpinning the desalination mechanism and NAWI the funding and strong project management oversight, Trevi is uniquely positioned to rapidly advance the technology to commercial deployment.”

The newly licensed technologies use a closed loop condensable gas solvent process to enable low-energy desalination and contaminant precipitation from aqueous feed streams. Researchers expect that these technologies will be able to produce fresh water from brines (and other high salinity sources, including sea water) using substantially less energy. NAWI plans to help further develop the technologies as part of the “Solvent-Driven Zero Liquid Discharge for Production of Synthetic Gypsum” task.

Read the in-depth journal article to learn more about the fundamentals of the aqueous separation technologies.

In a rapidly evolving landscape of water treatment and resource management, innovative tools are paving the way for cutting-edge research and sustainable practices. The world of desalination, water reuse, and water treatment technology has witnessed a transformative leap, and three exceptional tools stand at the forefront of this progress. Meet “River Runner,” a creation by data scientist Sam Learner, offering a remarkable journey alongside a drop of water, connecting you to its destination on a global scale. Delve into the “Aquifer Risk Map,” recently unveiled by the California State Water Resources Control Board, revealing the vulnerability of water systems to contaminants. Finally, explore the “Regulations and End-Use Specifications Explorer (REUSExplorer),” a pivotal resource from the EPA’s Water Reuse Action Plan, unveiling state regulations, treatment requirements, and more. These tools not only empower water treatment researchers but also open doors to a world of context, compliance, and opportunity for NAWI’s research program. Welcome to the future of water innovation.

1. Explore: River Runner. Data scientist Sam Learner created this marvelous tool so that anyone can follow the pathway of a drop of water anywhere in the world. This interactive tool, based on topographic and hydrological data from the United States Geological Service, enables you to follow the path of water all the way to the ocean or into a landlocked basin. As desalination enthusiasts, we are always concerned about where solutes contained in water will end up; this tool also demonstrates what parts of the U.S. are accumulating salts.
2. Explore: Aquifer Risk Map. The California State Water Resources Control Board (SWRCB) just released the Aquifer Risk Map through its Safe and Affordable Funding for Equity and Resilience (SAFER) Program. This interactive tool shows which small water systems and private wells are at risk of producing water with contaminants above the maximum contamination limit (MCL). The map enables you to explore specific localities and also to select specific contaminants such as nitrate, arsenic, and/or uranium. For NAWI teams that are considering starting pilot projects in California, this interactive map may help you identify which communities and areas may be interested in hosting your pilot. 
3. Explore: Regulations and End-Use Specifications Explorer (REUSExplorer). As part of its Water Reuse Action Plan (WRAP), the EPA just released a database of all state regulations governing water reuse. This website allows you to select a specific state, a source of water, and/or a reuse application of interest using the available drop-down menus. The results do not include laws and policies under development. It is valuable for water treatment researchers to understand what contaminant levels and treatment requirements exist in different states. The database also includes a summary of the technical basis for the regulatory framework, as well as specific information related to which waters are permitted for reuse.

Each of these tools can help the water treatment research community better understand the context, regulatory requirements, and opportunities for NAWI’s research program.

Eden Tech recently licensed two aqueous separation technologies developed by researchers at Idaho National Laboratory (INL), one of which is supported by NAWI. NAWI Alliance member and INL researcher, Aaron Wilson, is leading the vital NAWI project, which pioneers the use of dimethyl ether (DME) as a solvent to concentrate brines for zero-liquid discharge (ZLD).

The second technology, which was supported by DOE’s Critical Materials Institute, also leverages a condensable gas solvent to drive low-cost dewatering and selective precipitation of target products from aqueous feed streams. Eden plans to deploy both technologies in solution mining applications related to the Circular Water project in Saudi Arabia, and is marketing the technology under the CircularH2O brand.

Let’s talk about an aspect of desalination that is truly spooky: magnetic effects on scaling and water softening.

Claims that fixed or variable magnetic fields can reduce mineral scaling and improve water softening have been around since the 1890’s. Today you can find a dizzying variety of devices on Amazon that claim to be able to reduce mineral scaling in pipes and soften water (“Remove dissolved Ca and Mg! Without chemicals!”). The scientific literature, however, is not nearly so positive. Some reputable researchers have reported measurable effects while others report no such effects, using seemingly similar experimental approaches. Spooky!

Into this dark and haunted field of water treatment, our intrepid colleague Prof. Pei Xu of New Mexico State University and her team will try to get to the bottom of this mystery. Like the brave characters in the long-running animated children’s show Scooby-Doo, Where Are You?, Pei and her team (which includes Huiyao Wang, Fanjun Shu, Yanxing Wang, and Lambis Papelis at NMSU and Lawrence Anovitz at Oak Ridge National Lab) intend to bravely enter the haunted house of past studies of magnetic water treatment and shine a bright light to better understand what may be the source of the mystery. That bright flashlight? Small-angle X-ray and neutron scattering to resolve the atomic-level structure of nano-clusters of scaling ions in solution.

“Like the blind people feeling parts of the elephant, many researchers have touched an aspect of this phenomenon”, Pei told me recently. “We intend to develop a complete picture of the phenomenon including examining the effects of field strength, gradient strength, and the impact of dissolved organics.”

Pei and her team will also attempt to unify the range of past observations and the various theories that have been proposed to explain the strange effects observed. “For example,” notes Pei, “surface tension is observed to increase under strong magnetic fields, but surface tension is also observed to go in the opposite direction under weaker fields.” Spooky!

I asked Pei if she grew up watching the TV show Scooby-Doo, Where Are You? “Unfortunately, I did not,” Pei replied. I explained that there were 5 teen characters and a Great Dane named Scooby Doo who drove around in a van called the Mystery Machine solving crimes and debunking stories of ghosts and paranormal activities (and uncovering the nefarious adults who were perpetrating each hoax). “That’s very interesting”, Pei patiently replied.

We look forward to learning what NAWI’s version of “the Mystery Gang” uncovers as they investigate this strange phenomenon. Don’t change that dial!