Date of Award

2019

Degree Type

Thesis

Degree Name

Master of Science in Oceanography

Specialization

Chemical Oceanography

Department

Oceanography

First Advisor

Rainer Lohmann

Abstract

Poly- and perfluoroalkyl substances (PFASs) are of growing concern worldwide, due to their ubiquitous presence and adverse health effects in humans and the environment. Surface waters in the northeastern United States in particular have displayed elevated concentrations of PFASs. Passive sampling devices are excellent monitoring tools, that accumulate contaminant loadings through passive diffusion and adsorption to the sampler, and provide a long-term, time-weighted average of the contaminant over large temporal and spatial scales. Here we utilize a novel integrative passive sampler—a microporous polyethylene (PE) tube filled with Hydrophilic-Lipophilic-Balanced sorbent—to gain a better understanding of its function, utility, and uptake rates in field environments. Three sampling campaigns were conducted in the fall of 2017 and summer 2018, deploying a total of seventy-two PE tube passive samplers across nine sites in a well-mixed estuary and in two wastewater treatment plant effluents for one month’s duration. Twenty-four PFASs (including carboxylic acids, sulfonates, and precursors) were measured across all sites in the passive samplers, as well as complementary water samples, using Ultra Performance Liquid Chromatography/Mass Spectrometry. In the estuary, the PE tube samplers accumulated a sum PFASs of 2 to 15 ng sampler-1, and in the waste water treatment plant effluent 60 to 70 ng sampler-1. In situ sampling rates, which are essential when needed to calculate the contaminant concentrations in water, were characterized using a first order kinetic model, yielding sampling rates of 10-50 mL day-1. Results from this study imply that these passive samplers can be successfully used to determine dissolved concentrations of PFASs in surface waters, though the sampling rate seems to vary with external water flow velocity.

Available for download on Sunday, August 16, 2020

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