| dc.identifier.uri | http://hdl.handle.net/11401/77796 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | Quaternary ammonium compounds (QACs) are high production volume classes of chemicals used as surfactants and disinfectants that have been found at high levels in urban marine sediments. As sewage is the main source of QACs to such environments, they have been suggested as tracers of sewage-affected particles. Despite relatively high sediment concentrations and their unique potential to be used as sewage tracers, research on their behavior in the environment is lacking. The primary objective of this thesis was to gain new insight into the distribution and fate of QACs in sewage impacted marine environments. Additional objectives included the application of QACs to provide information about the sources and geochemical fate of metals and diethylhexyl phthalate (DEHP) in these environments. The studies in this thesis are primarily focused in Hempstead Bay, with additional studies in Long Island Sound (LIS) and Jamaica Bay. A study of the occurrence and fate of QACs in LIS and Hempstead Bay provided the first studies of QACs with distance from a dominant sewage source. Results from LIS indicate that larger more hydrophobic QACs are extremely persistent and can be measured at great distances (>70km) from New York City sewage sources. These largest QACs were used to determine that sewage contaminated western LIS sediments serve as a source of Ag, Cu, Pb and Zn, but that other sources (e.g., atmospheric deposition) are also important. While Cd and Mo also had significant correlations with QACs, these relationships are thought to be a function of sediment redox conditions. The concentrations of QACs also decreased with distance from the major sewage outfall (Bay Park sewage treatment plant) located in Hempstead Bay. Sewage outfalls in Hempstead Bay are located in the high current Reynolds Channel situated between two ocean inlets. Other recent studies have indicated that much of this sewage is not immediately flushed out of these inlets, but retained in Hempstead Bay, likely contributing to eutrophication and hypoxia. Concentrations of QACs in surface sediments within about 5 km of the outfall were very similar to those measured in highly sewage impacted Jamaica Bay. Total organic carbon was also enriched in the same areas of Hempstead Bay, most likely due to sewage derived organic matter. This provides greater evidence that particulate organic matter from the sewage discharges is also retained to a significant degree in the Bay. Comparison of QAC tracers with metals suggest significant contributions from sewage but that the contribution from sewage was only appreciable for Ag, with much smaller inputs for Cu, Zn, and Pb. In contrast, comparisons of DEHP with DTDMAC 18:18 suggests that sewage is the dominant source of this compound to Hempstead Bay and that DEHP may be similarly persistent in this environment Changes in the composition of smaller QACs were noted in LIS, and together with data from Hempstead Bay, inform a new conceptual model about the fate of QACs once released from a sewage source. In this model, QACs in the environment are comprised of a labile pool available for desorption and degradation as well as a resistant portion that persists during transport from a source. The size of the labile pool is thought to be proportional to QAC size and chain length, and the rate at which this labile pool is decreased during long range transport is thought to decrease with these measures of hydrophobicity. Additional factors may be contributing to the compositional changes observed in LIS and Hempstead Bay, including changes in the history of release of different QACs. Similar compositions of all QACs across both basins were found, especially at distances farther from point sources. This is likely a combination of similar urban sources and may also be related to similar resistant phase pools of sorbed QACs across multiple basins. Geochronologies of QACs from dated sediment cores from environments with known histories of sewage treatment provide a clearer picture of the history of QAC inputs. The inputs of dioctadecyl dimethyl ammonium (DTDMAC 18:18) to both Hempstead Bay and Jamaica Bay were found to be relatively stable over the last twenty years, providing additional support for their use as sewage tracers. Cores from both basins indicate that the relative compositions of dialkyldimethyl ammonium compounds (DADMACs), smaller benzylalkyl dimethyl ammonium compounds (BACs), alkyltrimethyl ammonium compounds C20 and C22 (ATMACs) and the smallest ditallowdimethyl ammonium compounds (DTDMACs) have increased relative to DTDMAC 18:18 over the last 20 years, and these increases are thought to be due to increases in use. Matched cores taken over 20 years in the same location provide more evidence for in-situ stability of QACs in reducing marine sediments. The first lab incubations testing biodegradation of field aged QACs in sediment taken proximal to the major sewage outfall in Hempstead Bay were conducted under oxic and anoxic conditions, indicating no significant degradation for all but the smallest QACs. | |
| dcterms.available | 2017-09-20T16:53:37Z | |
| dcterms.contributor | Cochran, J. Kirk | en_US |
| dcterms.contributor | Brownawell, Bruce J | en_US |
| dcterms.contributor | Aller, Robert | en_US |
| dcterms.contributor | Ferguson, P. Lee | en_US |
| dcterms.contributor | Stapleton, Heather. | en_US |
| dcterms.creator | Doherty, Anne Cooper | |
| dcterms.dateAccepted | 2017-09-20T16:53:37Z | |
| dcterms.dateSubmitted | 2017-09-20T16:53:37Z | |
| dcterms.description | Department of Marine and Atmospheric Science. | en_US |
| dcterms.extent | 288 pg. | en_US |
| dcterms.format | Monograph | |
| dcterms.format | Application/PDF | en_US |
| dcterms.identifier | http://hdl.handle.net/11401/77796 | |
| dcterms.issued | 2013-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:53:37Z (GMT). No. of bitstreams: 1
Doherty_grad.sunysb_0771E_11434.pdf: 4635964 bytes, checksum: 09c53d78db54cc14975155daee3eb1cc (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Chemical oceanography | |
| dcterms.subject | environmental distribution, environmental fate, quaternary ammonium compounds, sewage tracers, source allocation, surfactants | |
| dcterms.title | The distribution, fate and application as tracers of quaternary ammonium compounds (QACs) in sewage impacted estuaries. | |
| dcterms.type | Dissertation | |
