A collaborative study led by environmental scientists from Rutgers University, NJIT, and the Meadowlands Research and Restoration Institute (MRRI) sheds light on the presence and behavior of airborne Per- and Polyfluoroalkyl Substances (PFAS) in Northern New Jersey’s urban atmosphere.
Dr. Wen Zhang and his former Ph.D. student, Dr. Fangzhou Liu, alongside researchers (Cheryl Yao, Xinting Wang, Dr. Francisco J. Artigas and Dr. Gao Yuan) from multiple institutions, has co-authored a groundbreaking study investigating the distribution and partitioning of PFAS in the region’s air. The research, published in Science of the Total Environment, provides crucial data on the presence of these persistent and potentially harmful pollutants, which have been widely used in industrial applications and consumer products. PFAS are known for their resistance to degradation and have been linked to adverse health effects. While much research has focused on their presence in water and soil, this study highlights the importance of monitoring airborne PFAS, which can contribute to long-range transport and human inhalation exposure. The findings underscore the need for improved air quality monitoring and regulatory measures to address this emerging concern.
This study exemplifies the power of interdisciplinary collaboration, combining expertise from environmental science, atmospheric chemistry, and engineering to enhance our understanding of PFAS pollution. The research team hopes their findings will inform policy decisions and inspire further studies on the environmental fate and human exposure risks associated with airborne PFAS.
For more details, the full study can be accessed here.
Dr. Zhang’s former postdoc, Dr. Jiahui Hu, published a paper in Chemical Engineering Journal and elucidating the regulation mechanism of cellulose hydrothermal valorization via non-corrosive Lewis acids and bases. Cellulose, the most abundant component of biomass, is an essential renewable and carbon–neutral resource that can be converted into valuable products through hydrothermal treatment. However, the industrial application of hydrothermal technology for cellulose valorization is hindered by the formation of complex products which are challenging to separate. This study introduces a novel strategy for regulating product formation in cellulose hydrothermal conversion using non-corrosive Lewis acids and bases, integrating density functional theory calculations with experimental investigations. Frontier molecular orbital analysis reveals that peroxodisulfate, with strong electrophilicity, acts as a Lewis acid, directing the reaction toward the formation of levulinic acid. Conversely, peroxymonosulfate and thiourea, as nucleophilic Lewis bases, promote the accumulation of hydroxymethylfurfural by preventing its further degradation to levulinic acid and polymerization to carbon microspheres. Thiosulfate, with excessively strong nucleophilicity, inhibits the conversion of cellulose into sugars, thereby altering the whole hydrothermal decomposition pathways. Focusing on thiourea as a model additive, the study identified optimal conditions for hydroxymethylfurfural accumulation: a thiourea-to-cellulose ratio of 0.05:1, a reaction temperature of 220 °C, and a reaction time of 2 h. Additionally, increasing the initial reaction pressure from 0.1 MPa to 1.5 MPa resulted in a 92 % increase in hydroxymethylfurfural yield. This study provides a theoretical foundation for regulating cellulose hydrothermal processing via Lewis acids and bases, offering new insights into selective product formation and advancing biomass valorization technologies.
Dr. Wen Zhang and Dr. Kamalesh K. Sirkar, along with their research team (e.g., Fangzhou Liu, Dr. Weihua Qing, Dr. John Chau, Dr. Qingquan Ma, and Guangyu Zhu) at the New Jersey Institute of Technology (NJIT), have published a groundbreaking study in Desalination on an innovative air gap membrane distillation (AGMD) module that significantly enhances water treatment performance.
The study introduces a novel two-hollow-fiber-set membrane module, where a poly(etheretherketone) (PEEK) hollow fiber membrane (HFM) is placed inside a hydrophobic polyvinylidene fluoride (PVDF) HFM, creating an ultra-thin air gap of just 121 μm. This design achieves high thermal efficiency and improved water vapor flux, reaching 9.05 kg/m²∙h under optimal conditions (85°C brine, 5°C coolant).
Key contributions of the study include: ✅ High packing density of 1297 m²/m³, enabling efficient mass transfer ✅ 98.7% salt rejection, ensuring desalination effectiveness ✅ Finite element analysis using COMSOL Multiphysics to predict water flux and temperature profiles ✅ Principal component analysis (PCA) to assess performance factors, highlighting the critical role of air gap thickness in temperature polarization
This innovative approach could lead to more efficient and scalable membrane distillation systems for water purification, desalination, and resource recovery.
On 01/26/2025, we held a family party at Professor Zhang’s home to say goodbye to our three group members, Dr. Ge, Hongmei, Dr. Jiahui Hu and Lili Li.
Dr. Ge is a lecturer at Hubei University of Technology and her research areas include emerging contaminants removal by microalgae, and microalgal removal and harvesting. She has been here with Dr. Zhang’s group as a visiting scholar from 02/2024 to 02/2025.
Dr. Jiahui Hu is a postdoctoral researcher who joined Zhang’s group in February 2025 and conducts research on microplastics/PFAS detection in food waste and membrane distillation. After leaving Zhang’s group this spring, she will begin a postdoctoral position at the U.S. Salinity Laboratory (USDA-ARS) in Riverside, California, focusing on PFAS in agricultural systems.
Lili Li is a doctoral student from the Institute of Hydrobiology, Chinese Academy of Sciences, and has been conducting research in algae-laden water separation technologies and their engineering application. She stayed in Zhang’s group as a visiting student from 02/2023 to 02/2025 and conducted research in magnetic separation of algae and CO2 nanobubbles for enhanced algal growth.
A heart-felt wishes to these scholars for their prosperous future and careers!
Meanwhile, we recently accepted three new visiting scholars this spring:
Dr. Mu Hui, professor from Jinan University, will start her visiting scholarship in Zhang’s group for one year and will focus on resource recovery for environmental applications.
Dr. Mubarshar Mubashar is a postdoctoral fellow at the Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China. His research focuses on mixotrophy-based nutrient recovery from wastewater, carbon neutrality, and carbon capture and utilization using microalgae. Mubashar will stay in Zhang’s group as a visiting scholar, where he will conduct research in CO2 nanobubble-driven mixotrophy-based carbon capture and nutrient recovery.
Haodong Jia, a Ph.D. student from Shanxi University, will work on PMS activation for wastewater treatment, electrochemistry analysis of catalysts, and membrane distillation for desalination and pollution removal. His visiting scholar will start from January to June 2025.
Dr. Shan Xue, a former Ph.D. student and postdoc of Prof. Zhang’s group, now a research scientist at PureNanoTech Inc., recently published her postdoctoral research in Langmuir (https://doi.org/10.1021/acs.langmuir.4c04781), which evaluated the interfacial processes of nanobubble evolution and production across a porous membrane surface. Many operational factors and membrane properties can significantly influence nanobubble production and characteristics. This study examined how membrane pore size, surface hydrophobicity, and gas/water flow conditions affect nanobubble size and concentration. Findings reveal that reducing the ceramic membrane pore size from 200 nm to 10 nm slightly decreased the mean nanobubble diameter, from 115 nm to 89 nm. Furthermore, membranes with a hydrophilic outer surface and hydrophobic pore surface generated smaller nanobubbles with higher concentrations in water. Additionally, a high water cross-flow rate (e.g., >1 L·min⁻¹) increased the nanobubble concentration, though bubble size remained unaffected. In contrast, the gas flow rate had a more pronounced effect. Increasing the gas flow rate from 0.5 to 12 L·min⁻¹ significantly raised the nanobubble concentration from 3.09 × 10⁸ to 1.24 × 10⁹ bubbles·mL⁻¹ while reducing the mean bubble diameter from 100 nm to 79 nm. An interfacial force model was applied to analyze bubble detachment at the membrane pore outlet, considering factors such as gas flow/pressure, surface tension, and shear forces from water flow. These findings offer valuable insights into the mechanisms governing nanobubble generation via gas injection through porous membranes.
Neel Ahuja, a senior at Millburn High School in New Jersey, has been selected as a Regeneron Science Talent Search (STS) Top 300 Semifinalist, earning a $2,000 scholarship for his groundbreaking research on mitigating PFAS water contamination. His work, conducted under the mentorship of Dr. Wen Zhang at New Jersey Institute of Technology, focuses on the innovative application of mycorrhizal hydroponic plants to reduce per-and polyfluoroalkyl substances (PFAS) in water systems.
Neel’s journey with the Zhang Research Group began in June 2023 as part of the Partners in Science Program. Initially, he contributed to the project titled “Effects of Surfactants, Ion Valency, and Solution Temperature on PFAS Rejection in Commercial Reverse Osmosis (RO) and Nanofiltration (NF) Processes.” With Dr. Zhang’s mentorship, Neel honed his research skills, mastered experimental design, and gained experience analyzing complex data.
Building on this foundation, Neel independently designed and executed his own project, which explored the use of plants to remediate PFAS contamination. Dr. Zhang supported him throughout the process, providing critical guidance and lab resources. Neel’s dedication to environmental sustainability and innovative solutions led him to present his findings at the National Junior Science and Humanities Symposium (JSHS) and the International Science and Engineering Fair (ISEF). At both prestigious competitions, Neel secured second place, earning scholarships of $10,000 and $2,000, respectively.
Reflecting on his achievements, Neel shared, “I am incredibly grateful for the opportunity to work under Dr. Zhang’s guidance. His mentorship not only expanded my understanding of environmental science but also empowered me to pursue my passion for sustainable solutions. This journey has been an unforgettable experience, and I am deeply appreciative of the support I’ve received along the way.”
On January 24, 2025, the New Jersey Institute of Technology (NJIT) hosted the workshop “Nanobubbles for Sustainability: Transforming Agriculture and Environmental Management” at the Weston Hall 220 Gallery Conference Room. Organized by Dr. Wen Zhang, the event brought together leading researchers, industry professionals, students, and policymakers from across the globe to explore the transformative applications of nanobubble technology in sustainable agriculture and environmental management.
The workshop highlighted nanobubbles’ potential in areas such as pollution mitigation, soil health improvement, water efficiency, and agricultural productivity. Discussions also delved into innovative strategies for pollutant degradation, carbon sequestration, and improving water use in controlled environment agriculture. Attendees gained valuable insights into the science behind nanobubbles and their practical applications in addressing pressing global challenges.
The event featured an impressive lineup of speakers, including international experts such as Prof. Pan Li (Tongji University), Prof. Yoshikatsu Ueda (Kyoto University), and Prof. Yongsheng Chen (Georgia Institute of Technology), who discussed topics ranging from nutrient utilization in aquatic vegetation to the role of nanobubbles in urban sustainability. Industry leaders also contributed, with presentations from Dr. Michael Radicone (I2 Air Fluid Innovation) and Dr. Jeff Bodycomb (HORIBA), highlighting advancements in nanobubble characterization and real-world applications.
Dr. Wen Zhang’s group collaborated with Professor Yang Li from Beijing Normal University and Jae-Hong Kim at Yale University and published a paper in Nature Communications in 2025 with the title of Silver single atoms and nanoparticles on floatable monolithic photocatalysts for synergistic solar water disinfection (https://doi.org/10.1038/s41467-025-56339-2).
This study presented a floatable monolithic photocatalyst with ZIF-8-NH2 loaded Ag single atoms and nanoparticles (AgSA+NP/ZIF) and explored photocatalytic water disinfection under sunlight. Atomically dispersed Ag sites form an Ag−N charge bridge and extend the lifetime of charge carriers and thereby promoting reactive oxygen species (ROS) generation. The results promoted the practical use of powdered photocatalysts that is often impeded by limited recovery and inefficient inactivation of stress-resistant bacteria in oligotrophic surface water. The results shown that the photothermal effect of the plasmonic Ag nanoparticles reduces the bacterial resistance to ROS and impairs DNA repair capabilities. Under sunlight irradiation, the synergistic effect of Ag single atoms and nanoparticles enables 4.0 cm2 AgSA+NP/ZIF to achieve over 6.0 log inactivation (99.9999%) for the stress-resistant Escherichia coli (E. coli) in oligotrophic surface water within 30 min. Furthermore, 36 cm2 AgSA+NP/ZIF is capable of disinfecting at least 10.0 L of surface water, which meets the World Health Organization (WHO) recommended daily per capita drinking water allocation (8.0 L). This study presents a decentralized and sustainable approach for water disinfection in off-grid areas.
Tiny Bubbles, Big Results: Nanobubble Technology: An interview with Dr. Zhang by Jolene Hansen. Jolene Hansen is an award-winning freelance writer and editor who has covered the horticulture, specialty ag and CEA industries for more than a decade. Reach her at [email protected]. See all author stories here.
Any time new technology comes into play in controlled environment agriculture (CEA), growers tend to balance optimism with skepticism. It’s an industry where the adage “seeing is believing” often applies. That attitude puts nanobubble technology at a distinct disadvantage.
Typically defined as measuring between 70 and 120 nanometers in diameter, nanobubbles can’t be seen with the naked eye. With one nanometer (nm) equal to just one billionth of a meter, nanobubbles are 2,500 times smaller than a grain of salt. But the visible results experienced by nanobubble researchers and CEA growers put these tiny workhorses in the limelight.
Due to their size, nanobubbles have qualities that regular bubbles can’t match. | Photo: Moleaer
Nanobubbles in CEA
Nanobubbles occur in nature, but technology has enabled nanobubble suppliers to recreate or even improve on nature’s work. Nanobubbles have made headlines in non-agricultural realms ranging from biomedical applications, such as drug delivery and cancer diagnostics, to environmental applications, including toxic algae bloom mitigation and wastewater treatment. But for CEA, and agriculture in general, the technology is still relatively new.
The CEA application at the forefront involves treating irrigation water with nano-size bubbles containing air or specific gases, such as oxygen, ozone or nitrogen. Both the gas involved and the bubble size vary, depending on the application and the nanobubble technology involved. For example, generators from U.S.-based nanobubble supplier Moleaer, who has more than 3,500 installations in 55 countries in a variety of industries, produce nanobubbles roughly 100 nm in size.
Professor and environmental engineer Wen Zhang, Ph.D., is director of New Jersey Institute of Technology’s Sustainable Environmental Nanotechnology and Nanointerfaces Laboratory. Dr. Zhang has conducted extensive nanobubble research, including CEA applications. He also holds the patent on an award-winning nanobubble generator brought to market through PureNanoTech, Inc. (PNT).
Dr. Zhang explained that, by virtue of their size, nanobubbles have qualities that regular bubbles can’t match. For example, rather than quickly rising to the surface and popping, nanobubbles remain suspended in water and stay in constant motion for as long as they persist.
Depending on the gas contained in the bubbles, nanobubbles can deliver the following benefits:
significantly enhanced germination rates
stable, increased dissolved oxygen levels
improved nutrient uptake and utilization efficiency
improved irrigation efficiency and water management
increased beneficial microbial activity
increased resilience to stress and disease
reduced biofilm and pathogen pressure
dramatically improved yields, and much more.
Justin Leavitt, Business De velopment Manager for Moleaer, shared that it’s often difficult for growers to grasp the breadth of the impact nanobubbles in irrigation water can make.
“Anytime you change your water, you change everything that that water touches,” said Leavitt, a hands-on grower himself, who has worked in horticulture for more than 15 years. “Very rarely do we get the opportunity to make a change that creates such a domino effect, that touches so many other inputs and parts of your business.”
As Leavitt noted, with so many aspects of cultivation impacted by any major change in water and water treatment, growers have a lot of checks to go through to understand how a technology like nanobubbles fits in their operation. Making use of the expertise of nanobubble researchers and industry leaders can help.
Side-by-side comparison of leafy greens grown without (L) and with (R) nanobubble technology. | Photo: Moleaer
Solving Grower Pain Points with Nanobubble Tech
In working with CEA growers, Leavitt shared that he stresses the “three p’s” — pathogens, production and profitability. As he points out, with food safety a priority, the tools CEA growers have to fight pathogens are limited compared to the chemical fungicides used in other markets. That distinction calls for a different approach, one where nanobubbles can help.
“Typically, when growers think about fungicides, they’re applying fungicides to the plant. So if a pathogen goes through the water and interacts with the plant, you hope that your fungicide is working well enough,” Leavitt explained. But with nanobubble technology, you can improve water quality at the source, creating an environment environment hostile to and reducing pressures from pathogens, including Pythium, before the water even touches the plant.
Production and profitability go hand in hand. For example, oxygenation and providing high amounts of dissolved oxygen through nanobubble treatments can significantly impact yields — while maintaining and/or improving other crop performance parameters and quality overall.
“Technology has unlocked this new class of science,” Leavitt said, noting that growing today is very different from a decade ago. “We’re able to transfer gas significantly more efficiently than what was possible in the past. So now we have to relook at things.”
In the past, Leavitt said, growers were happy with results when plants received 8 parts per million (ppm) dissolved oxygen. But technology — and people’s expectations — have changed. What happens when innovation enables you to provide 12, 15, 20 or even 30 ppm dissolved oxygen? “What we’re seeing is increases in yield by supplying higher levels of dissolved oxygen,” he added.
Dr. Zhang reported that CEA research revealed dramatic results with his nanobubble generation technology, which simply employed ambient air to produce nanobubbles in water for irrigation. In a trial with basil and parsley production at a commercial CEA grower in New Jersey, plants that received irrigation water with air nanobubbles for three weeks before harvest had significantly improved results.
Compared to the control plants, the dry weight of parsley increased more than 68% with nanobubble-infused water. With basil plants, dry weight increased more than 58%, along with a 34%+ increase in the number of leaves. In other research, Dr. Zhang found that germination rates increased up to 25% with water infused with air nanobubbles. With nitrogen nanobubble infusion, vegetables saw leaf and stem sizes increase up to 50%.
Exploring Nanobubble Technology and Suppliers
As results like these become more well known, entries into the nanobubble generation market are growing. Dr. Zhang worries that, because some of this technology is good and some is not, growers can become confused and miss out on the competitive advantages that nanobubbles can bring to their farm.
Dr. Wen Zhang
As a result, Dr. Zhang says, it is essential to be able to work with companies that have the research capacity to demonstrate and confirm the claims or value propositions they present to customers regarding plant yields, water quality, and other nanobubble benefits for CEA growers.
Moleaer and PNT both have sizable in-house R&D resources and work closely with third-party research firms or institutions and growers to explore new applications and validate results. Even with Moleaer as a global leader, both in agriculture and other markets, Leavitt stressed that due diligence in exploring suppliers and trialing nanobubble generators is crucial.
“Be wary of your nanobubble generator supplier, and treat this like an interview,” Leavitt said. He advised growers to ask companies for third-part validation of the equipment they offer, and ask for validation from customers who have benefited from their specific nanobubble technology. He also adds that nanobubble knowledge isn’t the only thing to consider.
“Your nanobubble supplier should not just know about nanobubbles. If you’re in horticulture — if you’re in deep water culture lettuce, if you’re growing tomatoes, if you’re growing petunias — your nanobubble generator supplier should know about those industries, “Leavitt said. “Because there’s a product and there’s a technology, and that is one half of the battle. But your nanobubble supplier should know your industry well enough to make sure that you know all the domino effects of how this will change your operation.”
Leavitt also encouraged growers to not dismiss nanobubbles because your facility is already high tech. He shared how one CEA grower questioned whether his greenhouse — already heavily invested in technologies including oxidizers, an ozone system, and climate control — could benefit from nanobubble generation. But a trial delivered significant yield increases, despite all the agtech already in place.
“I walk into high-tech greenhouses, and we see great environmental controls; we see excellent lighting. I really think that taking a look and adding oxygen nanobubbles to your water is really that next stone that you need to turn over to continuously increase yield,” Leavitt shared. He added that with advances in technology and transfer efficiency, the barriers of 10 years ago no longer exist.
