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theses

Polychlorinated Biphenyls (PCBs) are chlorinated organic compounds that are classified as toxic, bioaccumulative, and persistent in the environment. Although the commercial production and use of PCBs was banned in the late 1970s, PCBs are ubiquitous in the environment as they cycle through air, water, soil, and sediment at levels that often exceed applicable environmental standards. The purpose of this dissertation was to identify PCB sources to the sediments of the Delaware River and the air of the New Jersey/Delaware River basin region. This was accomplished in part by analyzed existing data sets via a source apportionment tool called positive matrix factorization (PMF). In Delaware River sediment (Chapter 2), PMF resolved seven factors. Three were unweathered Aroclors, two were non-Aroclor sources related to pigment use and production, and the remaining two were probably originally related to Aroclors but were highly weathered. PMF was also applied to data from the Delaware Atmospheric Deposition Network (DADN) collected in Camden (1999-2011) and New Brunswick (1997-2011) (Chapter 3). PMF resolved four factors at each site. The factors that dominate PCB burden in the atmosphere at both sites resemble unaltered Aroclor 1242 and vaporized Aroclor 1248. During 2004-2011, only one of the eight factors was declining. All others were unchanged or increasing. This suggests natural attenuation alone will not control atmospheric PCB concentrations, and additional efforts are needed to control PCB emissions. Moreover, the Total Maximum Daily Loads promulgated for PCBs in the tidal Delaware River are not achievable in the foreseeable future due to continuing atmospheric deposition. In Chapter 4, PCBs 4 and PCB 11 were measured by reanalyzing the original gas-phase DADN samples from Camden, New Brunswick, and Lums Pond. To ensure that these dichlorobiphenyl congeners can be accurately quantified in these samples, a careful study of the breakthrough of PCBs when using polyurethane foam (PUF) as a sorbent for high-volume air sampling was performed. Gas-phase concentrations of PCB 11 ranged from non-detect to 146 pg m-3 and did not display a strong urban to rural gradient. PCB 4 concentrations ranged from 0.18 to 168 pg m-3 and were highest at Camden.

ETD_5433

Ph.D.

Includes bibliographical references

by Pornsawai Praipipat

doi:10.7282/T37D2SFH

ETD doctoral

The author owns the copyright to this work.