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  • Undergraduate Poster Abstracts
  • Environmental Engineering

    FRI-730 THE EFFECTIVENESS OF GEOBACTERACEAE AS A BIOREMEDIATION TECHNIQUE FOR URANIUM-CONTAMINATED GROUNDWATER

    • Enrique Rodriguez ;
    • Charles Werth ;

    FRI-730

    THE EFFECTIVENESS OF GEOBACTERACEAE AS A BIOREMEDIATION TECHNIQUE FOR URANIUM-CONTAMINATED GROUNDWATER

    Enrique Rodriguez, Charles Werth.

    The University of Texas at Austin, Austin, TX.

    The aim of this research is to analyze the kinetics of Geobacteraceae reacting with acetate in order to reduce uranium in contaminated groundwater. This study will provide insight on how to optimize the reduction process for uranium in groundwater. Geobacteraceae, when exposed to proper conditions, has the ability to safely remove uranium from groundwater and presents a cleaner, more efficient alternative to existing pump and treat remediation processes. Manganese oxide (MnO2) was used in place of uranium as it is safer to use. Nine anaerobic batch reactors were created and consisted of acetate, sulfide, Geobacteraceae, and MnO2. Three mass concentration groups were created by coating glass slides and had the following initial MnO2 masses: 1.12 x 10-4 ± 5.37 x 10-6 moles; 6.75 x 10-5 ± 2.57 x 10-7 moles; and 5.46 x 10-6 ± 1.44 x 10-6 moles. The experiment was run for 9 days with samples of solution being taken every 12 hours. The final mass concentrations were used to calculate a mass balance for each reactor, and the groups had the following results: 48.25 ± 6.54%; 48.05 ± 4.63%; and 59.19 ± 2.11%. The results suggest that the lower initial concentrations of uranium would yield more effective reduction of the contaminant. Further experimentation would be required to determine suitable ranges of uranium concentrations. For future works, other parameters such as acetate or Geobacteraceae concentration could be varied in order to determine the most effective kinetics for the bioremediation of uranium contaminated groundwater.

    FRI-731 BIODEGRADATION INHIBITION OF FIVE HYDRAULIC FRACTURING ORGANIC COMPOUNDS BY GLUTARALDEHYDE IN GROUNDWATER MICROCOSMS

    • Shantal Tummings ;
    • Jessica Rogers ;
    • Joseph Ryan ;

    FRI-731

    BIODEGRADATION INHIBITION OF FIVE HYDRAULIC FRACTURING ORGANIC COMPOUNDS BY GLUTARALDEHYDE IN GROUNDWATER MICROCOSMS

    Shantal Tummings1, Jessica Rogers2, Joseph Ryan2.

    1University of Central Florida, Orlando, FL, 2University of Colorado Boulder, Boulder, CO.

    Horizontal drilling and hydraulic fracturing are used to extract natural gas and crude oil from shale formations in many regions in the U.S. Low permeability shale formations were previously not considered for energy recovery; however, horizontal drilling and hydraulic fracturing technologies have revitalized the natural gas industry by allowing economic extraction from these formations. Unconventional oil and gas development, while being financially beneficial to the economy, is potentially detrimental to groundwater sources. In addition to water and sand, fracturing fluids contain a number of chemical additives such as emulsifiers, corrosion, scale inhibitors, and biocides. In the event of a surface spill or casing leak, fracturing fluids may contaminate subsurface groundwater. Biocide in the fracturing fluids may affect the way in which other organic compounds in the fracturing fluids biodegrade in the environment. In this study, we will investigate how the most commonly used biocide glutaraldehyde inhibits the biodegradation of other organic compounds found in fracturing fluids in groundwater. Our hypothesis is that higher concentrations of glutaraldehyde will inhibit the biodegradation of cocontaminants. Aerobic groundwater microcosms will be used to measure the biodegradation of 5 frequently used hydraulic fracturing fluid organic compounds under varying concentrations of glutaraldehyde. Preliminary results show the presence of glutaraldehyde retards the degradation of organic compounds. At high concentrations, biodegradation is inhibited.

    THU-732 SHORT-TERM RESPONSE OF OAK RIDGE GROUNDWATER MICROBES TO DIFFERENT CARBON SOURCES

    • Shany Ben Artsy Sr. ;
    • Romy Chakraborty ;
    • Xiaoqin Wu ;

    THU-732

    SHORT-TERM RESPONSE OF OAK RIDGE GROUNDWATER MICROBES TO DIFFERENT CARBON SOURCES

    Shany Ben Artsy Sr.1, Romy Chakraborty2, Xiaoqin Wu2.

    1Los Angeles Pierce College, Woodland Hills, CA, 2Lawrence Berkeley National Laboratory, Berkeley, CA.

    The purpose of this study is to explore the effects of different carbon sources on the growth of microbial communities present in groundwater from well FW305 at the Oak Ridge Field Research Center, Tennessee. Six different carbon sources were chosen: acetate, glucose, benzoate, casamino acids, cell lysate, and FW305 sediment extracts. Microbes were isolated using 2 dilutions of 3 different media. Isolated colonies were identified using 16S rDNA gene sequencing. The results illustrated that different microbial species were enriched being highly influenced by specific carbon sources available to them. Each carbon source enriched different bacteria, and this was confirmed by the 16S sequencing. Some novel strains of bacteria were isolated, and further work needs to be done to characterize these strains.

    THU-730 PARTICLE TRACKING METHOD FOR UPSCALING REACTIONS ON MIXING FRONTS

    • Titus Garrett ;
    • Tim Ginn ;
    • Mohamed Nassar ;

    THU-730

    PARTICLE TRACKING METHOD FOR UPSCALING REACTIONS ON MIXING FRONTS

    Titus Garrett, Tim Ginn, Mohamed Nassar.

    University of California, Davis, Davis, CA.

    Many chemical reactions in the environment depend on mixing 2 solutions where one displaces another. One example involves continuous injection of a solution into contaminated groundwater for remediation. To predict and control the impact of environmental pollution where mixing rates control reactions, it is necessary to quantify the speed with which the governing reactions go to completion. The challenge in characterizing the rates is that the mixing occurs at small scales and is difficult to simulate deterministically. We outlined a new approach that focuses on the mixing front at the interface between 2 solutions moving in a heterogeneous flow field. By simulating the transport of particles placed along the initial interface, we can mathematically approximate the mixing front position and deformation at any given time. The interface segment between each pair of mathematical particles is called a lamella that is a linearized piece of the interface. We developed lamellae-based averaging methods useful for determining the overall reaction rate even in highly complicated flow fields. The reaction extents are expressed given the geometry of a given lamella, and this allows us to calculate the reaction rate of all the lamellae in order to find the overall rate of reaction.

    THU-747 CLIMATE CHANGE-ASSOCIATED SEA-LEVEL RISE IN THE MARSHALL ISLANDS

    • Thooba Samimi ;
    • Peter Swarzenski ;
    • Slawek Tulaczyk ;

    THU-747

    CLIMATE CHANGE-ASSOCIATED SEA-LEVEL RISE IN THE MARSHALL ISLANDS

    Thooba Samimi, Peter Swarzenski, Slawek Tulaczyk.

    University of California, Santa Cruz, Santa Cruz, CA.

    Fluctuations in global sea levels play an important role in the formation and viability of atoll islands. The Republic of the Marshall Islands consists of a series of low-lying carbonate atolls located near the equator in the Pacific Ocean. This research was conducted at Roi-Namur, a small, northward-facing islet located in the northern part of Kwajalein Atoll. Prolonged human settlement of these low-lying atolls is risky for several reasons, including very scarce freshwater resources with no significant surface waters (e.g., rivers, streams, or lakes). In Roi-Namur, precipitation recharges a very shallow fresh groundwater lens that floats on top of a seawater intrusion. Water table elevations on these atoll islands fluctuate in response to oceanic tides. A hydrogeological assessment of this freshwater lens was developed to investigate possible impacts caused by recent and future sea level fluctuations and strong storms. Time series surveys of groundwater elevations in a suite of shallow wells and piezometers were used to assess the vulnerability of the freshwater lens to oceanic forcings.

    THU-731 MICROBIAL FUEL CELL FOR DEGRADATION OF CRUDE OIL

    • Salimar Cordero ;
    • Nicole Fahrenfeld ;

    THU-731

    MICROBIAL FUEL CELL FOR DEGRADATION OF CRUDE OIL

    Salimar Cordero1, Nicole Fahrenfeld2.

    1University of Puerto Rico, Mayaguez Campus, Mayaguez, PR, 2Rutgers, The State University of New Jersey, New Brunswick, NJ.

    The release of crude oil during leaks and spills introduces organic contaminants to the environment. Using microbial fuel cells (MFCs) as a bioremediation alternative can increase contaminant degradation rates while providing a way to monitor biodegradation in situ. The objective of this study is to use an MFC to compare power generation and biodegradation in 2 different sediment types: an historically oil-contaminated wetland sediment and an oil-spiked river sediment not previously contaminated. Voltage measurements were taken with a multimeter to produce polarization and density curves to help determine useful current parameters for maximum power production. Samples of the sediment were preserved for chemical and microbial community analysis. After 7 days, a maximum power of 1.1 mW/m2 (normalized to cathode area) was produced by the wetland sediment as compared to a maximum of 0.0281 mW/m2 for the river sediment. Preliminary results for these systems indicate the effects of sediment type and microbial community on power production and biodegradation potential.

    FRI-732 CARBON-BASED NANOMATERIAL AS AN ALTERNATIVE DISINFECTANT AGENT FOR WATER TREATMENT PLANTS

    • Axel Arroyo ;
    • Toa Baja ;
    • Abelardo Colon ;

    FRI-732

    CARBON-BASED NANOMATERIAL AS AN ALTERNATIVE DISINFECTANT AGENT FOR WATER TREATMENT PLANTS

    Axel Arroyo, Toa Baja, Abelardo Colon.

    University of Puerto Rico, Rio Piedras Campus, San Juan, PR.

    Current U.S. water treatment plants use chlorine to disinfect water, but improper management of this hazardous gas can cause lethal effects on water-plant workers. Furthermore, disinfection byproducts (DBPs) produced by the chlorine disinfection process have raised health concerns because they can cause cancer to the population that drinks the water. Ultradispersed nanodiamond (UDD) is an interesting carbon allotrope since it has a small particle size (4 - 5 nm) and has great biocompatibility properties. These properties make this material an interesting one for antibacterial/antiviral treatments. We have carried out studies of UDD as a bactericidal agent as an alternative disinfection process for water treatment plants. We mixed different concentrations of UDD powder with river water from an urban watershed to determine the effectiveness of UDD as a biocompatible, reusable water-treatment agent. We cleaned the UDD by thermal methods and tested them again for disinfection properties after usage. Transmission electron microscopy (TEM), energy dispersive spectronometry (EDS), and Fourier transform infrared spectroscopy (FTIR) were done for UDD surface characterization and bacteria sampling, and qualitative (normal imaging) and quantitative data (statistical analysis) were done for UDD bactericidal properties characterization. TEM results showed the presence of UDD from 4 - 10 nm size; EDS and FTIR showed no change in UDD surface composition and molecular structure. Bacteria sampling results showed strong bactericidal properties of UDD on fecal E. coli bacteria present in the river before and after UDD usage and cleaning methods. These promising results demonstrate that UDD can be used to disinfect surface water, providing a biocompatible and reusable new disinfection material for water treatment plants.

    FRI-747 STREAM RESTORATION BY REGENERATIVE STORMWATER CONVEYANCE TO IMPROVE WATER QUALITY IN THE CHESAPEAKE BAY

    • Julianne Rolf ;
    • Thomas Jordan ;
    • Carey Pelc ;
    • Max Ruehrmund ;

    FRI-747

    STREAM RESTORATION BY REGENERATIVE STORMWATER CONVEYANCE TO IMPROVE WATER QUALITY IN THE CHESAPEAKE BAY

    Julianne Rolf, Thomas Jordan, Carey Pelc, Max Ruehrmund.

    Smithsonian Environmental Research Center, Edgewater, MD.

    Total maximum daily load (TMDL) levels set for the Chesapeake Bay have created a sense of urgency to mitigate nutrient input into the bay. Muddy Creek, a deeply eroded tributary of the bay, will soon be restored with a regenerative stormwater conveyance (RSC) system to reconnect the stream to the floodplain. The goal is to induce infiltration to remove suspended sediments, nitrogen, and phosphorous from the stream water by diverting high flow over the floodplain. Flows of water, sediment, and nutrients will be compared before and after the restoration to determine the effectiveness in restoring stream function. Before the restoration, groundwater quality and flow rate were measured along the restoration site’s 450 m reach. The groundwater was determined to be anoxic, with dissolved oxygen ranging from 0 to about 1 mg/L, phosphate-P up to 46 µg/L, and ammonium-N up to 450 µg/L. Groundwater nitrate concentrations were below 11 µg/L, and iron concentrations exceeded 9 mg/L in some locations, suggesting denitrification and iron oxide reduction were occurring in the aquifer. Groundwater emerging along the restoration reach made up 15% of the stream flow exiting the reach, as determined on 1 date by dilution of bromide tracer added at the upstream end. Success of the RSC will be judged by measuring decreases in nutrient concentrations in stream water beyond the effects of mixture with emerging groundwater. If the RSC approach is successful, it could provide a guide to future stream restorations.

    FRI-733 TEMPORAL VARIATION OF NUTRIENTS AND CHLOROPHYLL IN HUMBOLDT BAY, CALIFORNIA: IMPLICATIONS FOR WATER QUALITY

    • Courtney Brown ;
    • Mathew Hurst ;

    FRI-733

    TEMPORAL VARIATION OF NUTRIENTS AND CHLOROPHYLL IN HUMBOLDT BAY, CALIFORNIA: IMPLICATIONS FOR WATER QUALITY

    Courtney Brown, Mathew Hurst.

    Humboldt State University, Arcata, CA.

    Humboldt Bay is the ancestral land of the Wiyot people and California’s largest producer of oysters. The relatively good water quality in Humboldt Bay provides habitat for both wildlife and aquaculture. The focus of our research was achieving a better understanding of the Humboldt Bay ecosystem, which depends on the availability of nutrients and the production of phytoplankton to support the food web. From October 2012 through February 2015, bimonthly samples were collected from 5 locations within Humboldt Bay in an attempt to understand the sources and sinks of nutrients and measure the amount of phytoplankton. Laboratory water-quality analyses were conducted and included total suspended solids (TSS), turbidity, nutrients (nitrate, phosphate, and silicate), and chlorophyll. We observed that the main source of nutrients throughout the annual cycle was from the ocean. This occurs through upwelling events in the spring and summer, which allow the phytoplankton to bloom during this period. In the summer of 2013, a massive phytoplankton bloom in the main channel of Humboldt Bay caused drawdown of nitrate and silicate to a point that they likely limited further growth. In the summer of 2014, a smaller bloom was observed, and nutrient levels stayed elevated. Although nutrients are present during the winter, reduced sunlight and lower temperatures inhibit phytoplankton growth. Runoff played a minor role in nutrient inputs. Overall, baseline levels of nutrients and phytoplankton were established for Humboldt Bay and will support future work on these waters.

    THU-733 PARTITION COEFFICIENT OF DEHP IN METHYLENE CHLORIDE

    • Nerida De Jesus ;
    • Ingrid Padilla ;

    THU-733

    PARTITION COEFFICIENT OF DEHP IN METHYLENE CHLORIDE

    Nerida De Jesus, Ingrid Padilla.

    University of Puerto Rico, Mayaguez Campus, Mayaguez, PR.

    DEHP is a compound used in PVC plastics, building materials (e.g., vinyl flooring), medical devices, packaging, and even in a variety of food products. Due to the abundance of this material in our surroundings, studies focusing on the effects of human exposure and their wide spread release into the environment have been actively researched. Understanding equilibrium partition coefficients (K) of organic chemicals is critical for environmental engineering studies and related fields since many analytical applications are strongly dependent on these organic compounds' coefficients. A distribution study between DEHP and methylene chloride (MC) is important due to the potential impact of the solvent on the solubility of the organic contaminant. Several studies have identified MC as the preferred organic solvent for the extraction of DEHP. This will help to understand and improve the analytical method's efficiency or process. Research results validate the theory that DEHP is in fact distributed between water and MC, with an average value of Ksw = 0.70. Furthermore, a statistical analysis between the 3 different studies concluded that the sample and solvent volumes have no effect on the coefficient but do have an influence on efficiency. The different test volumes for the method show higher extraction efficiencies for lower DEHP concentrations and higher extraction volumes. Recoveries higher than 100% suggest potential solvent contamination.