Biology Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/2749

Browse

Filters

2011 - 201912020 - 20211

Settings

Subject: search.filters.subject.mass spectrometry

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    CHARACTERIZATION OF SEPTIC SYSTEM WASTEWATER AND MUNICIPAL SOLID WASTE LANDFILL LEACHATE
    (2021) Martin, Katherine; Gonsior, Michael; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The growing United States population means increasing waste production and a corresponding increase in the use and release of contaminants of emerging concern (CECs). The increasing volume and changing composition of waste poses new challenges for waste management and the protection of ecosystem, surface water, and groundwater resources. In the U.S., most domestic solid waste is disposed of in landfills, and domestic wastewater is treated by wastewater treatment plants (WWTPs) or onsite wastewater treatment systems (OWTSs). While OWTSs, the majority of which are conventional septic systems, account for the minority of wastewater treatment in the U.S., they present a significant pollution risk because they are not subject to the same treatment level or discharge regulatory standards as municipal WWTPs. Landfill leachate is also an important source of environmental contamination because most existing landfills in the U.S. are closed, unlined landfills that lack engineered systems to enhance refuse degradation or collect leachate. To mitigate the pollution risks of these effluents, it is important to understand initial wastewater composition and how to identify and trace environmental contamination.In this study, I generated background molecular composition data for landfill leachate and domestic wastewater effluents and developed chemical tracers for septic system impacted streams. I used ultrahigh resolution, Fourier-transform ion cyclotron resonance mass spectrometry, to molecularly characterize the dissolved organic matter (DOM) of septic system wastewater and septic system wastewater-impacted surface waters. I also analyzed traditional water quality markers such as CECs, chloride, nitrate isotopic signatures, and nutrients. Additionally, I molecularly characterized landfill leachate DOM and analyzed similar chemical markers to those used in the septic system study to understand composition. The goals in the main septic system study were to better understand the composition and natural processing of septic system wastewater and to develop new chemical wastewater tracers while assessing traditionally used tracers. The landfill leachate study addressed the lack of nontargeted leachate composition data. Determining initial molecular composition is necessary to understand the consequences of discharge to the environment and to design leachate treatments.
  • Thumbnail Image
    Item
    IDENTIFYING AND TRACKING MARINE PROTEIN AND ITS IMPORTANCE IN THE NITROGEN CYCLE USING PROTEOMICS
    (2011) Moore, Eli Kelly; Harvey, H. Rodger; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Protein comprises the largest compartment of organic nitrogen in the ocean, and makes up a major portion of organic carbon in phytoplankton. Protein has long been thought to be highly labile in the environment and rapidly lost during diagenesis. However, the analysis of dissolved and particulate organic matter with NMR has revealed that much of dissolved and particulate marine organic nitrogen is linked by amide bonds, the very bonds that join amino acids in proteins. Throughout the global ocean, total hydrolysable amino acids (THAAs, the building blocks of proteins) can be measured in the water column and sediments, yet their biosynthetic source has remained elusive. Here, analytical techniques were developed combining protein solubilizing buffer extractions, gel electrophoresis, and proteomic mass spectrometry in order to investigate the biogeochemical significance of marine protein from primary production during transport and incorporation in sediments. These techniques enabled the detection and classification of previously unidentified marine sedimentary proteins. Specific proteins were tracked through the water column to continental shelf and deeper basin (3490 m) sediments of the Bering Sea, one of the world's most productive ecosystems. Diatoms were observed to be the principal source of identifiable protein in sediments. In situ shipboard phytoplankton degradation experiments were conducted to follow protein degradation, and it was observed that individual proteins remained identifiable even after 53 days of microbial recycling. These studies show that proteins can be identified from complex environmental matrices, and the methods developed here can be applied to investigate and identify proteins in degraded organic matter from a broad range of sources. The longevity of some fraction of algal proteins indicates that carbon and nitrogen sources can be tracked down the marine water column to sediments in diatom dominated systems as well as other types of phytoplankton. Using proteomic techniques to understand the marine carbon and nitrogen cycles will become increasingly important as climate change influences the timing, location, and phylogeny of those organisms responsible for oceanic primary production.