The water coming out of your faucet is safe to drink, but that doesn’t mean it’s completely clean. Chlorine has long been the standard for water treatment, but it often contains trace levels of disinfection byproducts and unknown contaminants. Georgia Institute of Technology researchers developed the minus approach to handle these harmful byproducts.

Instead of relying on traditional chemical addition (known as the plus approach), the minus approach avoids disinfectants, chemical coagulants, and advanced oxidation processes typical to water treatment processes. It uses a unique mix of filtration methods to remove byproducts and pathogens, enabling water treatment centers to use ultraviolet light and much smaller doses of chemical disinfectants to minimize future bacterial growth down the distribution system.

“The minus approach is a groundbreaking philosophical concept in water treatment,” said Yongsheng Chen, the Bonnie W. and Charles W. Moorman IV Professor in the School of Civil and Environmental Engineering. “Its primary objective is to achieve these outcomes while minimizing the reliance on chemical treatments, which can give rise to various issues in the main water treatment stream.”

Chen and his student Elliot Reid, the primary author, presented the minus approach in the paper, “The Minus Approach Can Redefine the Standard of Practice of Drinking Water Treatment,” in The American Chemical Society.

The minus approach physically separates emerging contaminants and disinfection byproducts from the main water treatment process using these already proven processes:

• Bank filtration withdraws water from naturally occurring or constructed banks like rivers or lakes. As the water travels through the layers of soil and gravel, it naturally filters out impurities, suspended particles, and certain microorganisms.
• Biofiltration uses biological processes to treat water by passing it through filter beds made of sand, gravel, or activated carbon that can support the growth of beneficial microorganisms, which in turn can remove contaminants.  
• Adsorption occurs when an adsorbent material like activated carbon is used to trap contaminants.
• Membrane filtration uses a semi-permeable membrane to separate particles and impurities from the main treatment process.

 

The minus approach is intended to engage the water community in designing safer, more sustainable, and more intelligent systems. Because its technologies are already available and proven, the minus approach can be implemented immediately.

It can also integrate with artificial intelligence (AI) to improve filtration’s effectiveness. AI can aid process optimization, predictive maintenance, faulty detection and diagnosis, energy optimization, and decision-support systems. AI models have also been able to reliably predict the origin of different types of pollution in source water, and models have also successfully detected pipeline damage and microbial contamination, allowing for quick and efficient maintenance.

 

“This innovative philosophy seeks to revolutionize traditional water treatment practices by providing a more sustainable and environmentally friendly solution,” Chen said. “By reducing the reliance on chemical treatments, the minus approach mitigates the potential risks associated with the use of such chemicals, promoting a safer water supply for both human consumption and environmental protection.”

CITATION: Elliot Reid, Thomas Igou, Yangying Zhao, John Crittenden, Ching-Hua Huang, Paul Westerhoff, Bruce Rittmann, Jörg E. Drewes, and Yongsheng Chen

Environmental Science & Technology 2023 57 (18), 7150-7161

DOI: 10.1021/acs.est.2c09389

The Strategic Energy Institute (SEI) of the Georgia Institute of Technology is excited to welcome Laura Taylor as the interim director of the Energy, Policy, and Innovation Center (EPICenter).

Taylor is currently serving as chair of the School of Economics in the Ivan Allen College of Liberal Arts at Georgia Tech. Prior to joining the faculty in 2018, she was the director of the Center for Environmental and Resource Economic Policy at North Carolina State University and associate director of the Environmental Policy Program at Georgia State University (2001 – 2015).

Taylor has extensive experience measuring the broader economic benefits associated with improved air, water, and ecosystem quality and is an elected fellow and past president of the Association of Environmental and Resource Economists. She has held numerous advisory board positions, including the environmental economics subcommittee of the U.S. Environmental Protection Agency’s science advisory board and the legislative research commission advisory subcommittee on offshore energy exploration for the North Carolina General Assembly.

“I’m excited about Laura Taylor’s experience and her vision for deepening engagement of EPICenter with the academic units and faculty on campus,” said Tim Lieuwen, professor and David S. Lewis Jr. Chair in the Daniel Guggenheim School of Aerospace Engineering and executive director of SEI. “EPICenter exists to connect the deep expertise and convening power of Georgia Tech to real-world problems faced by regional decision-makers, and she has a wealth of experience in this applied mission.”

Taylor’s research has received funding from a variety of sources, including the U.S. Environmental Protection Agency, U.S. Department of Agriculture, U.S. Department of Interior, and the National Science Foundation. Her current research focuses on the economics of environmental management and includes topics at the intersection of energy systems and human health, exploration of household responses to water conservation policies, and benefits of hazardous waste site cleanup for neighboring communities.

“I am thrilled to lead the Energy, Policy, and Innovation Center,” Taylor said. “With the rapid advances in clean energy in the Southeast and across the nation, I look forward to engaging the research faculty across Georgia Tech and amplifying the strong energy policy research that’s happening here.”

About EPICenter

Operating as a division of the Strategic Energy Institute, EPICenter was created to provide an unbiased and interdisciplinary framework for stimulating innovation in energy policy and technology for the Southeast. Based out of the campus of Georgia Tech, the center draws upon regional and national expertise within academia, businesses, non-governmental organizations, and research facilities.

Researchers from Georgia Tech's School of Civil and Environmental Engineering received a $2.1 million grant from the U.S. Environmental Protection Agency (EPA) to investigate contaminants in drinking water.

The EPA is funding the research on the occurrence and concentration of pathogens and disinfection by-products and the environmental conditions favorable to their growth in drinking water distribution systems.

Carlton S. Wilder Associate Professor Ameet Pinto, the project's principal investigator, said disinfection is used to kill microorganisms to make drinking water safe for consumption.  Yet, disinfecting to kill microorganisms can also result in formation of harmful disinfection by-products.

“Our key project goal is to shine a light on when, where, and why pathogens and disinfection by-products occur and co-occur in drinking water systems across the country,” Pinto said. “This will help water utilities better navigate the tradeoff of managing microbiological and chemical risks in drinking water and thus enhance the reliability of safe drinking water supply to their consumers.”

According to the EPA, opportunistic pathogens such as Legionella pneumophila, nontuberculous mycobacteria, and Pseudomonas aeruginosa can grow in drinking water systems and pose potential risks to public health. The occurrence of these and other microbial pathogens is also associated with contaminated storage facilities and other problems in water distribution systems such as backflow and low-pressure incidents.

If left untreated, these contamination events can lead to outbreaks of gastrointestinal, respiratory, and other waterborne illnesses. The disinfectants used to control these pathogens can cause additional problems by reacting with natural organic matter, bromide, and other contaminants to form disinfectant by-products, which also have the potential to be harmful to human health.

Georgia Tech is one of four institutions selected by the EPA to receive nearly $8.5 million in grant funding, along with the University of Minnesota, Michigan State University, and the University of Texas. The Georgia Tech team includes Turnipseed Family Chair & Professor Ching-Hua Huang and Assistant Professor Katy Graham.

The Georgia Tech Strategic Energy Institute (SEI) hosted the third annual Energy Storage Grand Challenge Summit this summer. The three-day event was sponsored by the Department of Energy’s (DOE) Office of Electricity and organized by the Oak Ridge National Laboratory (ORNL). The summit engaged a diverse set of energy storage stakeholders to discuss how the DOE continues to formulate strategies and pathways to accelerate energy storage innovation and deployment over the next decade and beyond.

In his keynote address, Gene Rodrigues, assistant secretary for Electricity at the DOE, shared the agency’s strategic priorities and invited stakeholders and participants to own the challenge together by focusing on partnerships and practical, cost-effective solutions for energy storage. The event consisted of tours of the local “living labs,” including the Georgia Power microgrid in midtown Atlanta and the Georgia Power Smart Neighborhood, presentations from DOE’s national labs, and panel discussions with industry experts. Discussion topics included the science underpinning energy storage, storage innovation deep dives, accelerating long-duration energy storage with public-private partnerships, and more. The event was attended by more than 200 people.

With the expansion of battery and electric vehicle manufacturers in Georgia and neighboring states, Georgia Tech is playing an integral role in developing the technologies that enable equitable, lower-cost, and cleaner generation, storage, distribution, and utilization of energy. By hosting events like this, SEI continues to strengthen partnerships with industry, national labs, government decision makers, and local communities.

“Georgia Tech has longstanding expertise in energy storage research and commercialization, with researchers working across the battery value chain from solid state batteries to new battery chemistries, polymer electrolytes, flow batteries, and much more,” said Tim Lieuwen, executive director of SEI, Regents’ Professor, and David S. Lewis Jr. Chair in the Daniel Guggenheim School of Aerospace Engineering. “This is substantiated with the formation of the Georgia Tech Advanced Battery Center at Georgia Tech this fall.”

The newly formed Center acts as the focal point at Georgia Tech to enhance interactions between industry, researchers, and students in the area of energy storage. It is led by co-directors Matthew McDowell, professor, Woodruff Faculty Fellow, and initiative lead for energy storage at SEI and Georgia Tech's Institute of Materials; and Gleb Yushin, professor in the School of Materials Science and Engineering. A key goal of the Center is to construct a battery manufacturing facility at Georgia Tech that will serve as a research and development and workforce training resource for the region.

“Georgia Tech has a wealth of talent in energy storage R&D, and we are excited to further engage with companies and government to develop and deploy advanced battery technologies,” said McDowell. “We are accelerating our research, education, and training to help achieve massive electrification of our society.”  

A new cybersecurity technology that relies on the unique digital fingerprint of individual semiconductor chips could help protect the equipment of electrical utilities from malicious attacks that exploit software updates on devices controlling the critical infrastructure.

The GridTrust project, which has been successfully tested in a real substation of a U.S. municipal power system, combines the digital fingerprint with cryptographic technology to provide enhanced security for the utilities and other critical industrial systems that must update control device software or firmware.

Led by researchers at the Georgia Institute of Technology (Georgia Tech) in collaboration with the City of Marietta, Georgia, the project was supported by the U.S. Department of Energy's Office of Cybersecurity, Energy Security, and Emergency Response (CESER). GridTrust also included researchers from Sandia National Laboratories and Protect Our Power, a security-focused not-for-profit organization. The three-year, $3 million project began in 2021.

GridTrust Improves Security for Device Updates

“The security of updates applied to equipment is critical to maintaining operation of the nation’s electricity grid,” said Santiago Grijalva, the project’s principal investigator and Southern Company Distinguished Professor in Georgia Tech’s School of Electrical and Computer Engineering. “We have demonstrated that GridTrust can block direct cyber-attacks through the equipment supply chain in multiple configurations and scenarios, while also preventing a whole array of potential errors. What we have developed and demonstrated will provide multiple layers of additional security to the existing electricity grid.”

The project focused on power system controllers, including sensors, actuators, and protection relays that are normally located in power substations distributed throughout a utility’s service area. Malicious actors may attempt to alter the software controlling the devices to, for instance, turn off power or damage the equipment. The attacks could take place if technicians attempt to use corrupted software to make updates at utility substations or other facilities.

Authentication Uses Semiconductor PUFs, Cryptography

Installed as part of the substation equipment, GridTrust would verify the authenticity of the software before any updates were installed, and it would ensure that the software was being applied to the correct device – by a person authorized to do so. In addition to cryptographic technologies, the system uses a new form of security based on unique physically unclonable functions (PUFs) that exist in certain semiconductor chips. PUFs are a set of unique characteristics created by minor variations that occur during chip fabrication.

“The PUF relies on random behavior based on variations in the manufacturing process, and they cannot be changed after fabrication,” said Vincent Mooney, an associate professor in Georgia Tech’s School of Electrical and Computer Engineering. “During an update, the GridTrust interfacing device first proves its identity using the PUF, then it verifies both utility and vendor signatures using their public RSA keys. Only if all these checks are passed will the firmware update be successfully installed. If the update isn’t installed, the device will continue to operate with its previous firmware version, and the utility’s network operations center will be notified to investigate.”

The GridTrust technology can operate as a standalone device with existing utility equipment or be built into new devices. Utility sensors, actuators, relays and similar control devices are currently produced by multiple manufacturers, and the Georgia Tech researchers have been in contact with an existing supplier that is interested in incorporating the technology, Grijalva said.

GridTrust Evaluated in a Real Utility Substation

Initial testing of the GridTrust system took place in Georgia Tech laboratories, then researchers worked with technical staff at the city of Marietta to evaluate the system in one of the utility’s substations. Located northwest of Atlanta, Marietta’s power network serves approximately 42,000 customers, including several critical electrical loads. The testing was done in a substation circuit isolated from the grid to ensure that the research activity would not affect customers.

“When Georgia Tech approached us about participating in an operational technology security research project, we were excited to participate, especially considering that our mayor and city manager have always supported working with state and local universities to develop new programs and technologies to solve real-world challenges,” said Ronald Barrett, Director of Information Technology for Marietta.

GTRI Cybersecurity “Red Team” Challenges the System

As part of the testing, Grijalva and Mooney involved “red team” cybersecurity researchers from the Georgia Tech Research Institute (GTRI), Georgia Tech’s applied research organization. GTRI researchers Trevor Lewis, David Huggins, Sam Litchfield, and Matt Guinn led an effort to challenge the GridTrust system with sophisticated attempts to install software that simulated the kind of potential malware that could affect utility equipment.

“They pretended to be black-hat hackers who wanted to compromise the system by pushing a malicious configuration file to one of the devices or initiating a firmware update without being authorized to do that,” said Huggins, a GTRI senior research engineer. “They had several attack methods and strategies aimed at multiple components of the system – and were not successful.”

Such third-party validation is important to a broad range of systems, noted Lewis, a senior research engineer who participates in “red team” test scenarios for many critical systems. “We are routinely contracted to perform assessments on a variety of system architectures to emulate the actions of real cyber attackers, and to test and evaluate the security of all components within an architecture under test,” he said.

Next Step: Implementation in Utility Industry

While there are multiple manufacturers of equipment for the utility industry, the devices provide similar functions and have similar needs for periodic updating. The protection system developed by Georgia Tech should be broadly applicable to devices produced by different manufacturers, and could therefore have broad application to the utility industry.

“Georgia Tech is creating technology that makes energy delivery systems safer, and protecting that critical infrastructure is important for national security,” Huggins said. “Reliable electrical power is critical to every aspect of our society today.”

In addition to ensuring the safety of device updates, the GridTrust system will also help utilities inventory the software operating on substation devices. Large utility companies can have hundreds or thousands of substations in their service areas, each with dozens of devices that may need periodic updates.

The three-year GridTrust project is now moving into the commercialization phase where it could be licensed to manufacturers or spun off into a start-up company, Grijalva said. For utilities like Marietta Power that want to be on the cutting edge of cybersecurity, that comes as welcome news.

“We believe the work that Georgia Tech has done is critical to maintaining a safe and secure electrical grid,” said Eric Patten, Marietta Power’s electrical director. “Our goal for this project was to see a system that added another layer of security from attacks, and from what we have seen, we believe this was a success.”

Writer: John Toon (john.toon@gtri.gatech.edu)
GTRI Communications
Georgia Tech Research Institute
Atlanta, Georgia USA

 

The Georgia Tech Research Institute (GTRI) is the nonprofit, applied research division of the Georgia Institute of Technology (Georgia Tech). Founded in 1934 as the Engineering Experiment Station, GTRI has grown to more than 2,800 employees supporting eight laboratories in over 20 locations around the country and performing more than $800 million of problem-solving research annually for government and industry. GTRI's renowned researchers combine science, engineering, economics, policy, and technical expertise to solve complex problems for the U.S. federal government, state, and industry.

Three of 12 projects that received funding from the U.S. National Science Foundation’s Using the Rules of Life to Address Societal Challenges are led by researchers in Georgia Tech’s School of Chemical and Biomolecular Engineering (ChBE).

The 12 projects received a total of $27 million in investment, supporting the use of knowledge learned from studying the Rules of Life — the complex interactions within and between a broad array of living systems across biological scales, and time and space — to tackle pressing societal challenges, including clean water, planet sustainability, carbon capture, biosecurity, and antimicrobial resistance to antibiotics. The Georgia Tech-related projects received a total of $7.7 million.

"The enormous opportunity to apply biological principles to solving the biggest problems of today is one we cannot take lightly," said Susan Marqusee, NSF assistant director for Biological Sciences. "These projects will use life to improve life, including for many underprivileged communities and groups."

The Georgia Tech-led projects include:

• Co-Producing Knowledge, Biotechnologies and Practices to Enhance Biological Nitrogen Fixation for Sustainable Agriculture. $2.67 million (Georgia Tech and Worcester Polytechnic Institute, award 2319430)

The project’s principal investigator is Lily Cheung, assistant professor of ChBE@GT, and the co-principal investigators are Shuichi Takayama, professor of biomedical engineering at Georgia Tech, and William San Martín, assistant professor of global environmental science, technology, and governance at Worcester Polytechnic Institute.

The researchers will address food security through low-cost technology based on biological principles to increase nitrogen content in soils and improve crop production on marginal lands.

• Next-Generation Biological Security and Bio-Hackathon, $2.81 million (Georgia Tech and Massachusetts Institute of Technology, award 2319231).

The project’s principal investigator is Corey Wilson, professor of ChBE@GT, and the co-principal investigators are Matthew Realff, professor of ChBE@GT, and Christopher Voigt, professor of biological engineering at Massachusetts Institute of Technology.

The researchers will create programmable, biological combination lock methods — "on and off" states — for using synthetic biology safely, containing potentially dangerous organisms and protecting valuable ones.

• Synthetic Protocell Communities to Address Critical Sensing Challenges, $2.23 million (Georgia Tech, award 2319391).

The project’s principal investigator is Mark Styczynski, professor of ChBE@GT, and the co-principal investigators are Shuichi Takayama, professor of biomedical engineering at Georgia Tech; Brian Hammer, associate professor of biological sciences at Georgia Tech, and Neha Garg, assistant professor of chemistry and biochemistry at Georgia Tech.

The researchers will create synthetic "protocells" enabling the development of a highly sensitive, field deployable analysis system that could be used for many applications such as measuring micronutrient deficiencies in undernourished populations.

The IEEE Transactions on Power Electronics (TPEL) First Place Prize Paper Award has been awarded to a team of researchers in the Georgia Tech School of Electrical and Computer Engineering (ECE) led by Professor Deepakraj M. Divan. TPEL is renowned for its influence in the power electronics field.

In addition to Divan, the researchers include:

• Lukas Graber - Associate Professor
• Maryam Saeedifard – Professor
• Rajendra Prasad Kandula – Staff Research Scientist at Oak Ridge National Laboratory (was Chief Engineer at Tech's Center for Distributed Energy)
• Xiangyu Han - Senior Electrical Design Engineer at Tesla (ECE Ph.D. '20)
• Chunmeng Xu - Research Scientist at ABB Raleigh Research Center (ECE Ph.D. '21)
• Liran Zheng - Senior Electrical Design Engineer at Tesla (ECE Ph.D. '22)

The team's prize-winning paper titled, "7.2 kV Three-Port SiC Single-Stage Current-Source Solid-State Transformer With 90 kV Lightning Protection," proposes a new type of power transformer called a multiport modular single-stage current-source solid-state transformer (SST).

Unlike traditional transformers, it operates at high voltage (up to 7.5 kV) and performs direct AC to DC or AC to AC conversion in just one stage. The design includes a buffer port for improved power management and energy storage integration. Innovative insulation and lightning protection measures ensure safety and reliability, while a soft-switching technique reduces electromagnetic interference.

These advanced transformers address the increasing prevalence of renewable energy sources and electric vehicles in power grids, offering enhanced flexibility and control over electricity flow compared to traditional transformers.

The Prize Paper Award distinction is a high honor and a tribute to the fine research quality, presentation, and potential impact that the research has to the field, according to TPEL. The publication’s rigorous selection process requires multiple review levels and votes. Each year, up to five first-place prize papers and ten second-place prize papers are deemed best among those published in the preceding calendar year. In 2022, 1,292 regular papers, letters, and correspondence were published from 3,186 original submissions.

The team will be honored at the TPEL Editorial Board Meeting during the 2023 IEEE Energy Conversion Conference and Expo in Nashville, Tennessee on November 1.

Stockpile stewardship — safeguarding and maintaining nuclear defense materials using modern techniques — is a critical mission of the U.S. Department of Energy’s National Nuclear Security Administration (NNSA). Maintaining and expanding the necessary physical and human capabilities to complete this mission is driving renewed investments into nuclear science and engineering. 

Georgia Tech researchers were recently awarded $11.6 million from the NNSA to address this growing need — and to study and expand on existing models of transuranic chemistry, a branch of chemistry dedicated to studying elements with atomic numbers greater than that of uranium.

Led by School of Chemistry and Biochemistry Associate Professor Henry “Pete” La Pierre, the funding will serve to establish the Transuranic Chemistry Center of Excellence. Directed by La Pierre, the Center will house a collaborative network of five other universities and six national laboratories across the United States conducting both theoretical and applied research.

“Scientifically, actinides and transuranic elements present unique challenges to existing models of chemical bonding,” explains La Pierre. These elements are man-made radioactive metals, many of which are not available in large quantities. “There are amazing open-ended questions that are fundamental to our understanding of chemical bonding and activities, that serve to transform our knowledge of how the elements form bonds across the Periodic Table.”

Joining seven other universities, this funding comes to Georgia Tech as part of NNSA’s $100 million program establishing Stewardship Science Academic Alliances Centers of Excellence. A main goal of this program is to recruit, train, and educate the next generation of researchers in nuclear science and engineering.

“These cooperative agreements will allow NNSA to train the smartest and most skilled individuals while creating a direct pathway into our workforce with a diverse group of experts that can meet the evolving needs of the nuclear security enterprise,” said Kevin Greenaugh, Chief Science and Technology Officer for Defense Programs, in a recent press release.

“The science and engineering collaboration of this center is a true synergy,” says Martha Grover, professor and associate chair for Graduate Studies in the School of Chemical and Biomolecular Engineering and one of the collaborators for the Center. Anna Erickson, Woodruff Professor and associate chair for Research in the George W. Woodruff School of Mechanical Engineering, is another Georgia Tech collaborator. “This center provides a new example of the growing prominence of Georgia Tech in the nuclear field.”

Pushing the bounds of chemistry

“We are at core a synthetic inorganic chemistry group, which means we make new molecules and characterize them,” La Pierre explained. In his research as part of the Center, La Pierre will “be handling both radioactive and chemically reactive species to make new forms of matter.”

Characterizing new forms of matter is no easy task, requiring advanced techniques that allow scientists to envision and measure the properties of chemical bonds. Exposing the molecules to X-rays or neutrons and measuring how they scatter or diffract (depending on the experimental design), gives researchers insights into the chemical bonds that are formed.

Using a combination of these advanced techniques as well as theoretical models, La Pierre and the collaborators of the Center will be creating new molecules out of actinides and lanthanides — metallic elements on the bottom of the periodic table — and studying the details of their structures and behavior during chemical reactions. As these elements are not found naturally, the structures and properties of many of these compounds have never been studied before.

“We are creating systems that challenge existing bonding models, which we then have to go back and build new theoretical techniques in order to understand what we're seeing,” La Pierre explained. “So, this does push the forefront of our understanding of basic chemical model systems.”

To push those boundaries, scientists and engineers will be working together across the country — led by Georgia Tech. 

“There are so many faculty at Georgia Tech working in nuclear science and technology,” says Grover. “This center gives me the opportunity to collaborate with Prof. La Pierre and Erickson for the first time, in the area of flow chemistry and separations.”

“I'm looking forward to working with some incredibly talented colleagues whom I don't normally get a chance to work with,” says La Pierre. “And now we have the opportunity to work together every week with fantastic students that I would never have met otherwise. That's the main draw for me.”