Wen Zhang’s research group participated in the 2025 NJIT research day, held November 25 at the Campus Center, presenting five posters that highlighted the team’s latest advances in sustainable water and agricultural systems, spanning from nanobubble-assisted agriculture, microplastics monitoring, electrochemical nitrogen recovery, to advanced oxidation for high-salinity wastewater.
Guangyu Zhu showcased a Raman-based workflow for identifying and quantifying microplastics in food and agricultural wastes, combining robust spectroscopy with AFM mapping to track polymer types and particle distributions in real-world waste streams.
Jiahe Zhang reported on an integrated tunable electrochemical system for recovering ammonia from nitrate-rich wastewater, emphasizing a three-phase electrified membrane that couples nitrate removal, gas-phase ammonia extraction, and energy-efficient nitrogen upcycling.
Yining Zhang presented a study on nanobubble-enriched hydrogels for sustainable agriculture, demonstrating how nitrogen nanobubble water and hydrogels can boost plant growth and chlorophyll accumulation under limited water conditions.
Sowmya Atukuri shared work on the colloidal behavior of nanobubbles in oil–water systems and their applications in soil remediation, illustrating how nanobubble technology can enhance contaminant dispersion and provide an eco-friendly alternative to conventional soil cleanup methods.
Haodong Jia presented new results on oxygen vacancy-rich copper-based layered catalysts for peroxymonosulfate (PMS) activation under high salinity, revealing a singlet-oxygen-dominated non-radical pathway that maintains high degradation performance across broad pH and salt conditions.
Posters:
Raman-Based Identification and Quantification of Microplastics in Food and Agricultural Wastes
This poster presents a validated Raman spectroscopy workflow for detecting and quantifying microplastics (MPs) in complex food and agricultural waste matrices. The protocol combines sample digestion, density separation, membrane filtration, optical/fluorescence screening, and Raman point spectra plus micro-mapping to confirm polymer identity. Using 53 representative waste samples across five categories (including food scraps, manure, silage, sawdust, and yard waste), the study reports MP abundances of roughly 0.09–4.44 particles·g⁻¹ and surface densities of 0.34–1.03 particles·cm⁻². EVA emerged as the dominant polymer, with additional EAA, PE, VC/VAC, PS, and PA signatures. Cost and scalability analysis suggests that this workflow can support large-scale monitoring of microplastics in food and agricultural value chains.
Ammonia Recovery from Wastewater using Integrated Tunable Electrochemical Systems
This poster describes an electrochemical redesign of the nitrogen cycle that converts nitrate-rich wastewater into valuable ammonia with minimal chemical input. The core module is a three-phase electrified membrane that simultaneously enables nitrate reduction, interfacial pH modulation, and gas-phase NH₃ extraction at a single cathodic interface. The flow-cell design proceeds through three main steps: electrochemical nitrate reduction, ammonia gas diffusion through a hydrophobic layer, and subsequent ammonium ion formation in a trap chamber. Pilot-scale tests treating real industrial wastewater with ~2% nitrate achieved stable nitrate removal with an energy demand of only about 5–6 kWh·kg⁻¹ N removed and an estimated cost of $1.0–$1.6 per kilogram, demonstrating a scalable, low-carbon alternative to conventional denitrification and Haber–Bosch ammonia production.
Nanobubble-enriched hydrogels for sustainable agriculture: enhancing water and nutrient delivery to boost plant growth
This poster introduces a dual-technology irrigation strategy that integrates nitrogen nanobubble (NB)-enriched water with agricultural hydrogels to improve kale growth under controlled irrigation. The team compared tap water, nanobubble water, hydrogel, and hydrogel–nanobubble combinations, monitoring fresh weight, leaf water content, and chlorophyll a/b. Results show that nitrogen nanobubble water consistently increased biomass, while hydrogel–nanobubble treatments further enhanced chlorophyll accumulation. Although hydrogel alone reduced fresh weight under tap-water irrigation, their performance improved significantly when paired with nanobubbles. The work highlights nanobubble-infused hydrogels as a promising, resource-efficient approach for water retention, nutrient delivery, and sustainable crop production.
Colloidal Behavior of Nanobubbles and Applications in Oil Dispersion and Soil Remediation
This poster explores nanobubble water technology as an eco-friendly option for oil dispersion and soil remediation. Using both a pressurized membrane-bubble circulation mode and a direct injection mode, the study generates micro- and nanobubbles and examines how they interact with gasoline and soil matrices. Measurements of gasoline concentration in oil and water layers show that nanobubble treatment slightly decreases the oil-phase concentration while enhancing transfer of gasoline into the water phase, indicating improved dispersion at the interface. Micro-nanobubbles remained stable over time, with bubble sizes increasing from roughly 140–180 nm to about 220–230 nm in later weeks, and oil removal efficiency was sensitive to surfactant concentration and exposure duration. Overall, the work demonstrates that tuning nanobubble properties can promote contaminant mobilization and offers a promising, chemical-lean alternative to conventional soil and groundwater remediation methods.
Oxygen Vacancy-Rich Copper-Based Layered Catalysts for Efficient Phenolic Pollutant Degradation via Peroxymonosulfate (PMS) Activation under High Salinity
This poster reports the development of a copper-based layered catalyst rich in oxygen vacancies (Ov) for activating PMS to degrade refractory organics in high-salinity wastewater. Structural engineering with urea-derived reductive gases generates abundant Ov sites that favor a singlet-oxygen (¹O₂)-dominated non-radical pathway resilient to inorganic ions. In 200 mM salt solutions, the catalyst achieves >80% phenol removal and >90% degradation of multiple phenolic pollutants over a wide pH range (3–11). Quenching experiments and XPS/EPR analyses confirm the key role of Ov and Cu(I) in driving non-radical PMS activation. The material exhibits strong durability, retaining >80% activity after repeated cycles, and offers an efficient, ion-resistant strategy for treating high-salinity organic wastewater.
