In a groundbreaking effort to tackle the pervasive issue of PFAS
contamination in drinking water, a research team at New Jersey
Institute of Technology has received funding from the federal
Bureau of Reclamation's Desalination and Water Purification
Research program.
This highly competitive grant, awarded to only eight projects
out of over eighty applicants, supports their innovative project
titled, “Enhanced Coagulation for the Removal of Per- and
Polyfluoroalkyl Substances using Hydrophobic Ion Pairing Approach
Project.”
Arjun Venkatesan, associate professor in NJIT’s Civil and
Environmental Engineering Department and the principal investigator
of this work, is also leading a pilot study from the same program
for a project known as “Enhancing the Removal of Hydrophilic Per-
and Polyfluoroalkyl Substances by Granular Activated Carbon using
Hydrophobic Ion-pairing as Pre-treatment” that utilizes a similar
approach to tackle PFAS contamination.
Addressing the Challenges of PFAS Removal
Per- and polyfluoroalkyl substances (PFAS), often termed
“forever chemicals,” pose a significant challenge for conventional
water treatment methods. The carbon-fluorine bonds in PFAS are
among the strongest in chemistry, making these substances extremely
resistant to natural degradation processes.
This persistence means PFAS remain in the environment
indefinitely, accumulating over time and posing long-term health
risks. Traditional treatment methods, such as granular activated
carbon (GAC) filtration, struggle to effectively remove certain
types of PFAS, particularly the hydrophilic (short-chain)
variants.
“GAC is the go-to technology for PFAS treatment,” said
Venkatesan, who is also the director of NJIT’s Emerging
Contaminants Research Laboratory (ECRL). “However, it doesn't work
for all PFAS chemicals. Long-chain PFAS are removed efficiently,
but short-chain PFAS, which are also toxic and regulated, are
not.”
The primary mechanism of PFAS removal by GAC relies on
hydrophobic interactions, which are ineffective for the
water-soluble short-chain PFAS. This gap in treatment capabilities
necessitates innovative solutions to improve water safety and meet
regulatory standards set by the U.S. Environmental Protection
Agency (EPA).
Innovative Solutions and Collaboration
The team’s novel approach involves a pre-treatment process that
significantly enhances the performance of existing GAC systems. By
adding a chemical to the influent water that forms hydrophobic
complexes with PFAS molecules, both short-chain and long-chain PFAS
can be more effectively adsorbed onto the GAC surfaces. This
process not only improves removal efficiency but also offers a
cost-effective solution that can be readily implemented in existing
water treatment facilities.
The Suffolk County Water Authority (SCWA) has played a crucial
role in this project by providing access to a contaminated
groundwater site for pilot testing. SCWA also offered in-kind
support for the construction of the pilot filtration columns and
additional water testing to complement the PFAS study, exemplifying
the practical, community-focused nature of the research.
Promising Preliminary Results
While the pilot testing has just begun, laboratory tests have
shown promising results. The pre-treatment approach has
demonstrated a significant improvement in the time to breakthrough
for PFAS removal. For instance, the time to 50% breakthrough for
PFBS, a regulated short-chain PFAS, was improved by approximately
170%.
These preliminary findings suggest that the novel pre-treatment
process could lead to substantial improvements in GAC performance,
ultimately enhancing water quality and safety.
Real-World Impact and Future Research
With the new award, the team now is ready to demonstrate the
novel pre-treatment approach for another commonly employed water
treatment process called coagulation and flocculation. The
simplicity and cost-effectiveness of this approach make it a viable
option for widespread adoption.
“Our approach can be easily implemented in existing conventional
water treatment systems with minimal modifications,” said William
Pennock, assistant professor in NJIT’s Civil and Environmental
Engineering Department and collaborator on the coagulation and
flocculation treatment research. “All we need is a chemical dosing
pump to inject the HIP chemical into the untreated water.”
This straightforward integration could result in significant
operational cost savings for water treatment facilities,
potentially reducing the frequency of GAC replacement by about
50%.
Looking ahead, the research team is also exploring the potential
of the hydrophobic-ion pairing approach for other ionic organic
contaminants, indicating a broad applicability of this technology.
Future research will focus on testing biodegradable and
environmentally friendly alternatives to the HIP chemical, ensuring
the process does not introduce secondary contaminants.
This research aligns closely with the latest EPA regulations on
PFAS in drinking water. By improving GAC filter performance and
reducing operational costs, the proposed pre-treatment process
addresses a critical national need. The successful implementation
of this technology promises immediate and cost-effective
enhancements to existing water treatment systems, benefiting
communities and advancing public health protections.
This innovative research represents a significant step forward
in the fight against PFAS contamination. By enhancing existing
water treatment processes, the team is not only addressing a
pressing environmental challenge but also providing practical,
scalable solutions that can be adopted nationwide.
Looking ahead, the research team is also exploring the potential
of the hydrophobic-ion pairing approach for other ionic organic
contaminants, indicating a broad applicability of this technology.
Future research will focus on testing biodegradable and
environmentally friendly alternatives to the HIP chemical, ensuring
the process does not introduce secondary contaminants.
This research aligns closely with the latest EPA regulations on
PFAS in drinking water. By improving GAC filter performance and
reducing operational costs, the proposed pre-treatment process
addresses a critical national need. The successful implementation
of this technology promises immediate and cost-effective
enhancements to existing water treatment systems, benefiting
communities and advancing public health protections.
This innovative research represents a significant step forward
in the fight against PFAS contamination. By enhancing existing
water treatment processes, the team is not only addressing a
pressing environmental challenge but also providing practical,
scalable solutions that can be adopted nationwide.
Andrew McMains
New Jersey Institute of Technology
973 596-3433
andrew.m.mcmains@njit.edu