Research

Our lab is interested in studying the occurrence, fate, and treatment of contaminants of emerging concern (CEC) in the natural and built environment.  We apply novel analytical and monitoring techniques to assess both human and environmental health risks associated with toxic and harmful substances. We also develop and test novel treatment technologies to reduce exposures to toxic contaminants and improve water quality.

Ongoing and completed Projects

1. ERASE-PFAS: Understanding the surface-active properties of PFAS for enhanced removal by bubbling-assisted water treatment processes (2020 - 2025)

Role: PI; Funding source: National Science Foundation; Collaborators: Dr. Ben Hsiao (Co-PI); Dr. Ben Ocko (BNL)

Poly- and perfluoroalkyl substances (PFAS) are a group of manmade chemicals that have been used since the 1950s in more than thousand different applications due to their unique properties. One of their most important and life-saving applications is in the production of firefighting foams. Extreme stability and strength featured by PFAS makes them highly persistent in the environment, and hence are often referred to as ‘forever’ chemicals. PFAS are detected in almost every single person’s blood in the U.S. and are associated with a very long list of health problems in both humans and animals. PFAS are also widely detected in drinking water across the U.S. Unfortunately, commonly used water treatment processes do not remove PFAS efficiently. The goal of this project is to understand their unique detergent-like properties and use that information to develop a simple and cost-effective treatment process. PFAS are surfactants and hence can accumulate at the surface of air-bubbles. The proposed work will use air bubbles of different sizes to capture PFAS and enrich them at the water surface. The enriched PFAS layer at the water surface can then be removed leaving behind PFAS-free treated water. The first aim of this project is to characterize the accumulation pattern of PFAS at the surface of air bubbles and to identify conditions leading to increased accumulation of PFAS on the bubble surface. The second aim is to use the ideal condition identified in aim 1 to develop an optimized bench-scale air bubble reactor to treat contaminated water using different bubble sizes and in the presence of commonly used water treatment chemicals to enhance PFAS removal. The simplicity of the proposed approach allows it to be employed in combination with conventional treatment processes like coagulation-flocculation systems to efficiently remove PFAS from contaminated water. 

 2. Enhancing the removal of hydrophilic per- and polyfluoroalkyl substances by Granular Activated Carbon using hydrophobic ion-pairing as pre-treatment  (2023 - 2025)

Role: PI; Funding source: US Bureau of Reclamation; Collaborator: Suffolk County Water Authority

In this project, we will be pilot testing a novel approach called "hydrophobic ion-pairing" (HIP) to improve the removal of PFAS using Granular Activated Carbon (GAC) filters. The specific research objectives are to: (i) optimize the HIP dosing for pretreatment to achieve ideal treatment of PFASs mixtures, (ii) evaluate the breakthrough of the HIP reagent from GAC columns in field conditions, (iii) evaluate the impact of dissolved organic matter (DOM) on HIP performance, and (iv) perform a preliminary cost assessment of the process and savings based on the decreased changeout frequency of the carbon.

3. Extraction and Removal of PFAS from Impacted Water and Soil using Air Bubbles (2021 - 2024)

Role: PI; Funding source: Strategic Environmental Research and Development Program (SERDP)

Similar to the concept described above for the ERASE:PFAS program funded by NSF, this project will utilize air bubbles for the remediation of PFAS-contaminated water and soil. The project will focus on treating higher levels of PFAS typically found in AFFF-impacted regions. In addition to testing the removal of targeted PFAS from impacted water and soil, the study will also assess the performance to remove unknown precursors and transformation products by employing a combination of total oxidizable precursor assay (TOP) and non-target screening. 

4. PFAS Release for Spent Granular Activate Carbons in Solid Waste Management Facilities (2023 - 2024)

Role: Co-I; Funding source: Strategic Environmental Research and Development Program (SERDP); Collaborators: University of Maine, Orono (lead); University of Texas at Austin

The objectives of this project are to: (i) evaluate commercially available and well-characterized PFAS-laden GACs in terms of PFAS release potential while deciphering release mechanisms; (ii) unravel the effects of PFAS types and molecular properties on PFAS release in single- and multi-solute systems; and (iii) demonstrate the effect of pertinent background chemistry elements on PFAS release. The knowledge generated here will be complementary to the ongoing regulatory and practical efforts of waste management facilities relaying to the handling of PFAS-laden solid wastes. 

5. Treatment of Poly- and Perfluoroalkyl Substances in Drinking Water (2019 - 2024)

Role: Co-I; Funding source: NYS Department of Health; Collaborators: Gobler (PI)

Perfluoroalkyl substances (PFAS) are a large group of man-made compounds that are widely used in commercial products for more than 60 years. PFAS feature unique properties to resist heat, oil, stains, grease and water, and hence, are used as coatings on clothing, carpets, furnishing, non-stick cookware, take-out fast food containers, and in fire-fighting foam. PFAS are very stable and persist in the environment for a very long time. Due to the increasing evidence of human health concerns and environmental toxicity associated with these compounds and a lack federal regulation, several U.S. states are adopting a maximum contamination level (MCL) to protect public health. 

In this project our group will closely work with state, county, and local agencies to:

• evaluate the efficiency of existing treatment approaches (GAC, ion-exchange treatment, and advanced oxidation processes) in removing PFAS; 

• research and develop novel or refined treatment technologies (novel sorbents and/or combination of technologies) to enhance the removal of PFASs from drinking water; and,

•  scale-up, build and test the feasibility of using select novel/refined treatment technologies for pilot-scale treatment (point-of-use and point-of-entry) of contaminated drinking water.

6. Bioavailability, Bioaccumulation, and Toxicity of PFASs in Benthic Biota Exposed to Impacted Marine Sediments (2022 - 2025)

Role: Co-I; Funding source: SERDP; Collaborators: McDonough (PI); Gobler, Volkenborn, McElroy

The objectives of this project are to: (i) describe the effects of key variables (sediment characteristics; PFAS molecular structure; PFASs mixture complexity) on surface water quality, bioavailability, bioaccumulation, and elimination of AFFF-associated PFAS in major groups of benthic organisms, (ii) evaluate the importance of diet as a PFASs exposure route for benthic consumers, and (iii) determine the relative potency of individual PFAS and PFAS mixtures with respect to fish larvae mortality. 

7. Measurement of PFAS isotherm on regenerated granular activated carbon at environmentally relevant concentrations (2019 -)

Role: PI; Funding source: Industry

Although treatment using GAC is effective in removing PFAS from waters, effective regeneration techniques to remove adsorbed PFAS from GAC are required to re-use the carbon and to make the treatment process more cost-efficient. In this project, we are partnering with a company that employs an effective chemical regeneration approach to remove PFAS from exhausted GAC. The objectives of this project are to (i) evaluate the efficiency of the regeneration process; (ii) characterize the GAC after regeneration; and (iii) determine adsorption capacity of GAC after multiple regeneration cycles.

8. Pilot Data for NIH $8.75 Million Stony Brook Superfund Research Center Grant: Spread of Environmental Contaminants from Storms Impacted by Climate Change (2022 -)

Role: Co-I; Funding source: Provost Venture Fund, Stony Brook University; Collaborators: Meliker (PI), McDonough, Reed, Gobler

The objectives of this project are to (1) generate baseline data on historical and emerging high-risk contaminants including chlorinated solvents, 1,4-dioxane, and heavy metals in groundwater, surface water, and in people nearby superfund sites; and (2) establish a quick-response monitoring team to quantify local contamination of homes and communities after storms.

9. Method development and validation for wastewater surveillance of opioids (2022 -)

Role: Principle Investigator; Funding source: NYS Department of Health, Center for Disease Control

The goal of this seed project is to develop a standardized approach to measure opioids in wastewater to support its surveillance by wastewater-based epidemiology on a larger scale. 

11. Treatment of 1,4-Dioxane Using Advanced Oxidation Processes (2017 - 2020)

Role: Co-Investigator; Funding source: NYS Department of Environmental Facilities & NYS Department of Health; Collaborators: Gobler (PI)

1,4-Dioxane is a widely used solvent in a variety of industrial and commercial applications, such as in the manufacture of chlorinated solvents (e.g. 1,1,1-trichloroethane), in products such as adhesives, sealants, paint strippers, dyes, greases, varnishes, waxes, and in the manufacture of pharmaceuticals. Wastewater discharges, unintended spills, and historical disposal practices have been identified as some of the important sources of 1,4-dioxane in drinking water sources.  1,4-Dioxane is classified as a probable human carcinogen based on sufficient evidence of carcinogenicity from animal studies. The chemical is highly persistent, soluble in water, resistant to (bio)degradation, non-volatile and has a low sorption coefficient, making it extremely difficult to remove from water using conventional water treatment processes (e.g. by activated carbon, air stripping etc.).

Our research is focused on developing and evaluating various configurations of advanced oxidation processes (AOP) to remove 1,4-dioxane from drinking water. Though AOP technology has been widely studied under laboratory conditions, very few reports are available that evaluate their performances on larger scales (pilot- and full-scale systems).