# Center for Environmental and Health Effects of PFAS

> **NIH NIH P42** · NORTH CAROLINA STATE UNIVERSITY RALEIGH · 2020 · $126,304

## Abstract

ABSTRACT
(Environmental Science and Engineering) Research Project 4
Project 4 is one of two Environmental Science and Engineering (ESE) Research Projects for the proposed
“Center for Environmental and Health Effects of PFAS” being led by North Carolina State University (NC
State). The primary goal of the proposed Center is to provide highly relevant data and information to help the
Superfund Research Program (SRP) address the growing problem of per- and polyfluoroalkyl substance
(PFAS) contamination across the US, including contamination of drinking water sources. PFAS are considered
contaminants of emerging concern, and remediation of PFAS-impacted sites is a critical and timely public
health challenge. Granular activated carbon (GAC) adsorption is the most widely employed PFAS remediation
technology. Although much is known about sorption of organic contaminants by GAC, predicting GAC
effectiveness from laboratory data or from fundamental pollutant and GAC properties remains a significant
challenge. Our long-term objective is to develop models that predict sorption of organic micropollutants,
including PFAS, in GAC treatment systems. A critical barrier to improving existing models is that accessibility
of sorption sites inside of GAC particles is not known. An important assumption of current models is that
contaminants are uniformly distributed inside of GAC particles at sorption equilibrium. However, direct
observations of sorbed contaminants suggest that sorption can occur preferentially near the external sorbent
surface. This distinction is significant because it can explain why PFAS sorption capacity increases with
decreasing GAC particle size and why laboratory experiments overestimate PFAS removal effectiveness of
GAC. Our overarching hypothesis is, therefore, that sorption of PFAS (as well as many other organic
pollutants) occurs preferentially in a shell region near the external GAC surface. The shell adsorption
hypothesis will be evaluated by (Aim 1) observing and describing intraparticle PFAS distributions at sorption
equilibrium and (Aim 2) quantifying and describing PFAS adsorption/desorption kinetics. Using innovative
approaches, such as isotope microscopy, we will begin to open the “black box” that GAC still represents and
directly observe intraparticle PFAS distributions. We will use information from direct observations in
conjunction with results from sorption equilibrium and kinetic experiments to explain our data with a shell
adsorption model. We expect that model parameters will be physically meaningful and can be predicted from
fundamental sorbent and sorbate properties. Results of this project will support the development of effective
sorbents for PFAS removal, the design of (cost-)effective GAC treatment systems for PFAS remediation, and
the evaluation of management options for spent GAC.

## Key facts

- **NIH application ID:** 9841015
- **Project number:** 1P42ES031009-01
- **Recipient organization:** NORTH CAROLINA STATE UNIVERSITY RALEIGH
- **Principal Investigator:** Detlef R Knappe
- **Activity code:** P42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $126,304
- **Award type:** 1
- **Project period:** 2020-02-28 → 2025-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9841015

## Citation

> US National Institutes of Health, RePORTER application 9841015, Center for Environmental and Health Effects of PFAS (1P42ES031009-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9841015. Licensed CC0.

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