Date of Award

3-2022

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Systems Engineering and Management

First Advisor

Eric G. Mbonimpa, PhD

Abstract

The persistence, fate, and transport of per- and poly-fluoroalkyl substances, which have been shown to have adverse effects on human health, have been previously studied in environmental media such as soils and groundwater. This study investigates concrete, a medium that is rarely studied but frequently present in instances where PFAS originating from AFFF releases and spills have occurred. Used heavily throughout aviation firefighting, AFFF poses environmental hazards due to the length of PFAS degradation and toxicological implications, thus its classification as a forever chemical. From the very limited reports to date, studies have suggested very slow release from concrete, potentially serving as a long-term source, prolonging its environmental persistence. This work discusses the development of a fate and transport model that can be applied to PFAS contaminated concrete including stormwater channels that may drain from AFFF release points. This study consisted of three phases: (1) saturation and contamination, (2) desorption and flushing, and (3) sampling and analysis. The study used AFFF to investigate retention of PFAS by the concrete, as well as the ability of chemical dyes to trace the hydraulics of flowing water through small mock channels and its permeation in the concrete. A desorption model developed from this data incorporates properties of the concrete and simulated hydrological runoff, along with mechanistic terms for both diffusion and adsorption kinetics. This model can be used to estimate the length of time PFAS may remain above a given action level and provide a model that can be easily adapted to DoD and civilian installations to better manage and mitigate PFAS.

AFIT Designator

AFIT-ENV-MS-22-M-234

DTIC Accession Number

AD1174065

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