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http://www.wenresearch.com/visiting-scholars.html

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. 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.

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.

https://doi.org/10.1016/j.watres.2024.123037

Dr. Zhang’s postdoc, Dr. Jiahui Hu, published a paper in Water Research and elucidating biodegradation mechanisms and predicting pollutant reactivities for advancing the application of biodegradation engineering to address the challenge of thousands of emerging contaminants. Molecular biology and computational chemistry are powerful tools for this purpose, enabling the investigation of biochemical reactions at both the gene and atomic levels. This study employs the biodegradation of ten sulfonamide antibiotics as a case study to demonstrate the integration of genomics and quantum chemistry approaches in exploring the biodegradation behavior of emerging contaminants. The isolated functional strain, Paenarthrobacter sp., could completely degrade all ten model sulfonamides under aerobic conditions. These compounds share a 4-aminobenzenesulfonamide core but differ in N¹-substituent rings. Despite structural variations, all sulfonamides follow a consistent degradation pathway, yielding aminated heterocycles as end products. This pathway involves key steps such as dehydrogenation activation, ipso-hydroxylation, and the cleavage of S-N and S-C bonds, with the latter being particularly influenced by the N¹-substituents. Heterocyclic structures affect biodegradation rates by altering the electronic density at the C³ and N¹ atoms of sulfonamides. Substituents with higher electron-donating potential and lower Gibbs free energy barriers for S-C and C-N bond cleavage significantly enhance biodegradation efficiency. This work not only deciphers the universal biodegradation mechanism of sulfonamides but also offers theoretical insights for predicting the biodegradation behavior and pattern of emerging contaminants. These findings contribute to the effective removal of emerging contaminants from aquatic environments, advancing the practical application of biotreatment technologies.

This study is a collaboration with her former faculty advisors, Xiaoyan Li and Bing Li, at Tsinghua university. The research was funded by the National Key R&D Program of China (no. 2022YFE0103200), the National Natural Science Foundation of China (no. 22176107), Shenzhen Science and Technology Innovation Bureau (no. SGDX20230821091559021), and the Guangdong Higher Education Institutions Innovative Research Team of Urban Water Cycle and Ecological Safety (no. 2023KCXTD053).