Grantee Research Project Results
Nanobubble-enabled foam fractionation: Characterization and application for PFAS removal in complex water matrixes
EPA Grant Number: SU841126Title: Nanobubble-enabled foam fractionation: Characterization and application for PFAS removal in complex water matrixes
Investigators: Zhang, Wen
Institution: New Jersey Institute of Technology
EPA Project Officer: Page, Angela
Phase: I
Project Period: March 1, 2025 through February 28, 2027
Project Amount: $75,000
RFA: 21st Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity, and the Planet Phase I (2024) RFA Text
Research Category: P3 Awards , Drinking Water , Clean Water , Waste Reduction and Pollution Prevention , Groundwater, Contaminant Fate and Transport , Groundwater, Contaminants, Treatment , Aquatic Ecosystems , Health Effects , Water Quality , Human Health , Water , Land and Waste Management , PFAS Treatment , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Chemical Safety , Environment , Water Treatment , PFAS Detection
Description:
Nanobubbles in water exhibit unique physicochemical and fluid dynamic properties than ordinary macrobubbles. For example, nanobubbles have a long residence time in water due to their low buoyancy and high stability against coalesces, collapse or burst, and the formation of bulk bubbles. Nanobubbles have a higher efficiency of mass transfer compared to bulk scale bubbles due to the high specific surface areas. The high specific surface also facilitates physical adsorption and chemical reactions in the gas liquid interface. The collapse of nanobubbles creates shock waves, which in tum, promotes the formation of hydroxyl radicals (•OH), which may promote degradation of organic matters or disinfection. With respect to foam fractionation, the high surface areas and hydrophobicity of nanobubbles could effectively adsorb and immobilize hydrophobic organic contaminants such as PFAS. This project embarks on nanobubbles to establish foams in water and remove PFAS via a green fractionation separation process that appear to have low energy footprints and leave no chemical residuals. Besides research efforts, new course modules and hands-on experiments will be developed to integrate the research activities into student engagement and education. Undergraduates and graduates in different STEM disciplines (e.g., civil, chemical and environmental engineering) will be recruited to participate in the research project tasks under PI's team's mentorship.
Objective:
Perfluoroalkyl and polyfluoroalkyl substances (PFAS), with their omnipresent presence in the environment and toxicity, have recently drawn substantial attention. Without proper treatment, PFAS in wastewater may pollute the subterranean ecosystems, causing pollution to surface water and groundwater. To mitigate PFAS pollution and health impact, different water treatment processes or technologies have been demonstrated including adsorption by powdered activated carbon (PAC) or granulated activated carbon (GAC), anionic ion exchange, nanofiltration (NF), and reverse osmosis (RO). However, they either suffer from high operational cost or insufficient removal ability for PFAS in wastewater with complex water matrixes. This project aims to develop a nanobubble-enabled foam fractionation process to remove PFAS from wastewater. The project will examine (1) the colloidal properties of nanobubble foam under variations of water chemical properties such as pH changes, salinity and presence of co-existing natural organic matters and synthetic surfactants, (2) the removal efficiency of PFASs with different carbon chain lengths in synthetic water and real water that may simulate contaminated ground water, landfill leachate and brine wastewater from regenerate backwash processes in reverse osmosis membrane filtration and ion exchange, (3) comparison of PFAS removal performances of foam fractionation using nanobubbles, microbubbles and macro bubbles that may yield different foaming ability and structures. The project findings will provide an insight for novel low-cost and sustainable water purifying technologies for complex wastewater. The scientific merits from this project include: (1) increasing the removal efficiency of the recently most concerned contaminant PFAS under exposure to nanobubble ebullition, and thus to evaluate the possibility of practical application on the field for the economic feasibility; (2) unraveling the intriguing interaction mechanisms between nanobubbles, water, and contaminants.
Expected Results:
The anticipated research outputs include peer-reviewed journal articles, conference presentations, novel PFAS removal technique, patent applications and project reports. Moreover, research seminars will be run collaboratively with industrial partners and collaborators such as landfill leachate treatment facilities in New Jersey. The potential project outcome includes transformative knowledge to alleviate water contamination in different affected small, rural, tribal and/or underserved communities or areas. The effective means to mitigate PFAS and other emerging co-existing contamination such as heavy metals, solvents or chemical additives and pharmaceutical residuals from impaired water bodies can improve human health and well-being and also boost environmental quality, aesthetic values, economic competitiveness. The measure of success is the numbers of peer-reviewed journal publications or presentations, feedback from our industrial partners or collaborations and community engagement via seminars and presentations during or after the project period.
Supplemental Keywords:
nanobubbles, PFAS, foam fractionation, restorationThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.