- Title: “The Effect of Organic Matter on Mineral Weathering.” His final report and poster were titled “Water Retention and Mineral Weathering in a Forest Catchment.”
- Sponsored by: DWRC
- Advisor: Dr. Paul Imhoff of the UD’s Department of Civil and Environmental Engineering
Abstract: The contact time between water and the mineral surface will affect the rate at which minerals are weathered within the soil. This study looks at a series of measurements that were taken at four depths over a nine-month period. The parameters of interest are precipitation, matric potential, soil moisture, temperature, and infiltration rate. The parameters were first examined graphically and qualitatively. A precipitation event was then examined in detail to look at the effect on each parameter over time. For the matric potential, soil moisture, and temperature it can be seen that the layer closest to the ground soil has a more extreme response to the precipitation event compared to the deeper layers. It is both a quicker response and a higher variability from the average. This shows variation in contact time with depth.
- Title: Developing a Resource Guide for Funding Community Resilience in Delaware.” Her final report and poster were titled “Delaware Database for Funding Resilient Communities (DDFRC)."
- Sponsored by: DWRC
- Advisor: Philip Barnes of the UD’s Institute for Public Administration
Abstract: The goal of our project is to create an easily accessible and navigable database which houses important information on funding and assistance resources available to government officials to help them improve community resiliency. By providing a single database with information on various available resources, our hope is that local and municipal governments are able to locate and take advantage of resources without the added burden of conducting long searches for relevant assistance programs. Additionally, by creating an instructional video to teach users how to use the database and the filtering functions, we further reduce the amount of time government officials will spend searching for funding and assistance opportunities.
In order to meet our goal, we conducted an exhaustive internet search of possible grants, loans, and technical assistance programs which aim to increase community resiliency. We compiled all of the information into one document, which supplies information such as providing agency, program description, eligible project activities, typical funding amount, eligible applicants, important dates, information on how to obtain assistance, links to external sources, application or project examples, and contact information for the specific contact person for the program.
Our next major step in the project was determining how our filtering functions would work. We first decided what information would be the most important for users in choosing assistance programs. Then, based on these categories, we decided upon tags to use which help in filtering the resources based on the community’s specific needs. Once we completed the tagging process, we populated the database with the assistance programs and filtering functions. The final step of our research was to create the instructional video and publicize it, teaching users how to navigate the database and use the tagging system.
In this research project, I discovered that the information required to help government officials address community resiliency is available but not very well organized. Various agencies and national foundations have resources available, but they are difficult to find unless one checks each source independently. Because of the lack of existing policy research in this area, local and municipal governments face great challenges in improving community resiliency and decreasing the effects of climate change. Our project, however, directly addresses this issue by organizing all relevant information in one location and making the database adaptable as new opportunities arise.
By compiling all of our findings in one database, we will significantly reduce the amount of time dedicated to searching for assistance programs. Because our data are specifically for Delaware local and municipal governments, they will only have to look through programs that apply to their area and not worry about opportunities outside of the region. By organizing all of this information in one location, we will effectively ease the process of searching for grants and assistance. The instructional video will also assist users in using the database quickly and efficiently. As such, the implications of our project will ultimately increase community resiliency and make it easier for government officials to reduce the effects of global climate change.
- Title: “Impact of Climate Change on Water Quality: Effect of Temperature and Particle Size on the Kinetics and Thermodynamics of Mineral Solubility”
- Sponsored by: DWRC
- Advisor: Dr. Chin-Pao Huang of the UD’s Department of Civil and Environmental Engineering
Abstract: Climate change is of increasing concern since temperature increase is a major factor in chemical and biological processes, specifically in kinetics. The kinetics of mineral solubility have a direct impact on ion concentrations in water, which in turn affect the water quality. The appropriate concentrations of cations, such as calcium, sodium, potassium, aluminum, and iron must be maintained for optimal water quality for both aquatic and human life. In these experiments, synthetic rainwater and common soils found in the mid-Atlantic region, Matapeake and Evesboro, were used to determine the effects of increasing temperature on mineral solubility. Various particle sizes and temperatures were tested. ICP-OES technology was used to determine the ion concentration with time of aluminum, iron, manganese, magnesium, potassium, sodium, and calcium. We found that with decreasing particle size, ion concentrations generally increased. We found similar results with increasing temperature. However, we also saw decreasing ion concentration with time, leading us to conclude some ions were adsorbing onto soil surface particles. From desorption results only, we were able to find a rate constant k and an activation energy Ea, using both the Thomas graphical method and the Arrhenius equation. From this information, we were able to determine the rate-limiting step for the dissolution process of both soils into rainwater.
- Title: “Integrating Biochar Amendments in Green Stormwater Management Systems for Enhanced Nitrogen Treatment of Stormwater Runoff”
- Sponsored by: DWRC
- Advisor: Dr. Paul Imhoff of the UD’s Department of Civil and Environmental Engineering.
A major cause for decreased water quality in Delaware is nutrient loading of natural waters, due to not only fertilizer and manures but also urban sources such as road runoff. With rising population, this pollution is only expected to increase. To combat this, the Delaware Department of Transportation is required to comply with Total Maximum Daily Load regulations. While necessary, adhering to these standards is quite costly, so any new technology might be helpful in reducing the financial burden on taxpayers.
A recent solution to runoff pollution has been the implementation of bioretention areas. These are good at removing suspended solids, oil, grease, bacteria, heavy metals, and other nutrients, but not nitrogen. However, recent experiments show biochar can absorb a significant amount of ammonium and increase water retention in the unsaturated zone, which in turn will increase nitrogen uptake in plants and conversion of ammonium to nitrogen gas.
This past summer, laboratory and field experiments were performed to observe the effects of the amendment of biochar and zero-valent iron (ZVI). In the lab, column experiments were executed to measure the hydraulic conductivities of white sand and ZVI samples. Dried samples were packed into 20-inch long columns and saturated using de-aired distilled water. The head difference was measured by comparing water levels in tubes attached to the top and bottom of the column, the effluent volume was recorded with a small graduated cylinder, and the time elapsed was logged using a stopwatch. After numerous trials at different pump rates, the hydraulic conductivities were calculated using the following formula K= [(V*L)/(A*H*t)]. The white sand trials resulted in an average hydraulic conductivity of 166.006 inch/hour, while the average hydraulic conductivity of ZVI was 57.517 inch/hour, almost three times lower than that of white sand. These data show that ZVI would have better water retention than white sand, supporting the use of ZVI in bioretention media in order to reduce the effluent flow of stormwater runoff.
Additionally, a 36-hour field experiment took place on the University of Delaware’s Laird Campus, where the effects of biochar-amended media on stormwater runoff were tested using a representative artificial rainfall event. A pilot-scale test facility had been constructed in 2014 containing side-by-side treatment cells, with one cell filled with biochar-amended media and the second containing a standard bioinfiltraton mixture without biochar. During the experiment, water was pumped at equal rates through showerheads above each cell. Water samples were taken from multiple locations in the cells during the experiment, and were filtered before being analyzed for different chemicals by graduate students. After examination, it was seen that the amendment of biochar and zero-valent iron increased the residence time by 10%, and nitrate removal was amplified by 300%. While further research is needed, it appears that biochar and ZVI are promising solutions to increase both nitrate removal and retention time of stormwater runoff. If added to bioretention sites along roadways, biochar and ZVI should help unload runoff of its artificial nutrients, and in turn improve the quality of surrounding water.
- Title: “Nutrient Loading and Ecosystem Response in the Murderkill River.” His final report and poster were titled “Rates of Net Primary Production from Continuous High-frequency Monitoring of Coursey Pond, Delaware.”
- Sponsored By: DWRC
- Advisor: Mr. A. Scott Andres of the Delaware Geological Survey.
Traditionally, the function and health of ecosystems has been assessed using infrequent “grab samples” and minimum or maximum water quality criteria for targeted uses. With increasing availability of automated and continuous water-quality monitoring devices, it is now possible to assess rates of biogeochemical processes and responses to physical forcing, as a better indicator of ecosystem health and function. Continuous sensors were deployed on the Murderkill River at the outflow of Coursey Pond, Delaware to monitor Total Maximum Daily Loads (TMDLs) of bioreactive contaminants and other water quality parameters. Temperature and dissolved O2, together with wind speeds determined at a nearby station, were used to determine daily gross primary production and respiration, O2 gas exchange, and net primary production. These calculations are potentially automatable and can be used by managers to assess ecosystem behavior and health on ecologically relevant time scales.
- Title: “Biogeochemical Controls on Metal and Nutrient Fluxes in a Protected Estuary in Delaware.” Her final report and poster were titled “Comparison of Greenhouse Gas Fluxes from Two Flooded, Vegetated Environments.”
- Sponsored By: DWRC
- Advisor: Angelia Seyfferth of the UD’s Department of Plant and Soil Sciences
This project compared two different flooded, vegetated systems for their greenhouse gas contributions during a seasonal timeframe, and was analyzed with water data such as redox potential, iron (II) concentration, and dissolved organic carbon concentration, in order to gain a better understanding of biogeochemical processes occurring within these flooded areas and their contributions to macroscopic greenhouse gas emissions. One of the sites is a protected estuary located in Dover, DE, and the other site includes a rice paddy cultivation plot located on the University of Delaware agricultural campus, constructed in order to represent global rice cultivation practices. The sites are similar because they are both flooded systems with high-silicacontaining plants, but the estuary site is a naturally occurring system while the rice paddies are constructed to maintain flooding. An ultimate goal of the Seyfferth lab group is to determine a cost-efficient modification to rice cultivation soils that will minimize arsenic uptake, maximize rice plant quality and rice yield while minimizing greenhouse gas emissions that can result from the addition of an organic amendment. Four different treatments were considered: a rice huskamended treatment, a rice husk ash-amended treatment, a calcium silicate-amended treatment, and a control soil without an amendment. The husk-amended soil showed a consistent peak in methane flux after about 20 to 30 days of sampling, while the other three treatments and the estuary grass site were relatively unchanging with time. Water data collected for the rice paddy cultivation soils during the same time period also showed a shift after 20 to 30 days, noticeable with all four treatments. In addition, carbon dioxide was noticed to gradually decrease with time for all four rice paddy treatments, and remained relatively constant with time for the estuary site. The results of this work will be used to compare with future data collection, and to allow researchers to gain a better understanding of the biogeochemical processes occurring in these two separate systems and their macroscopic effects on greenhouse gas production and consumption.
- Title: “Development of a Fungal Biocell Reactor for Treatment of a Food Processing Wastewater”
- Co-Sponsored By: DWRC and the UD’s College of Agriculture and Natural Resources
- Advisor: Dr. Anastasia Chirnside of the UD’s Department of Entomology and Wildlife Ecology
Currently, a soybean processing plant located in western Maryland has high concentrations of pollutants in its effluent wastewater. As a result, the facility managers have implemented a sophisticated treatment system consisting of an anaerobic lagoon, aeration basin, and two facultative lagoons. Still, effluent concentrations are too high. For example, the treated wastewater has a Total Kjeldahl Nitrogen (TKN) concentration that averages between 300 and 500 mg/L, a chemical oxygen demand (COD) concentration that averages between 4,000 and 5,000 mg/L, and a pH that is greater than 8. Despite high concentrations of wastewater pollutants, the processing plant still possesses a NPDES permit to discharge into surface waters. It has been argued that the high levels of complex nitrogen molecules in this wastewater are not an environmental concern because they are difficult for most nitrogen-degrading organisms to break down. Regardless, there is always a possibility that the complex nitrogen molecules get broken down into simpler compounds at some time and in some place. It is much safer to eliminate, or at least minimize, these harmful chemicals on the premises rather than take the risk of having them get naturally broken down and released to the environment. Therefore, the purpose of this study was to evaluate the ability of white rot fungi, grown on two types of support materials in a solid-state biocell reactor, to reduce high concentrations of TKN and COD in a food processing wastewater.
In order to address the purpose of this study, two growth support media were used: cornstalks, which are nutrient rich, and an inert support made of fibrous plastic. For each media, 6 reactors were used, 3 of which contained killed fungus and support materials. Once good growth was present, wastewater was pumped through all reactors and samples of each reactor, as well as the influent, were collected on days 0, 1, 2, 3, 4, 7, 10, 14, 21, 28, 35, 42, 49, and 56. For each sample, pH, COD, and TKN were measured, plotted, and analyzed.
The pH steadily increased between days 0 and 28. The greatest increase occurred between days 28 and 35, where pH increased by about 0.4 for all samples. After this increase, the pH remained relatively steady for the treatments and influent. In general, T1 and T3 (both with the inert support) had larger pH values than the influent. The pH of T4 was generally close to that of the influent, and the pH of T2 generally remained below that of the influent.
The COD of the influent increased by 1738.5 mg O2/L over the 56-day testing period. The influent experienced the greatest increase in COD between days 21 and 28, where it increased by 1686 mg O2/L. In general, T2 and T4 (lignocellulosic supports) had COD values larger than that of the influent. T1 and T3 generally had COD values smaller than that of the influent.
The TKN of all samples, including the influent, was generally between 100 and 200 mg/L. A few values lie outside of this range, but are most likely outliers as they do not follow the trend of the data. Generally, the TKN values for T2 and T4 were found to be greater than that of the influent. The TKN values for T1 and T3 were found to be less than that of the influent.
Overall, the inert support material did not increase the concentrations of TKN or COD in the effluent while increases were seen when the fungus was grown on the cornstalks. More work is needed to evaluate the influence of the inert support on the pH of the effluent and to develop better methods for inoculating the fungus on the inert support material.
- Title: “The Isotopic Composition of Throughfall in Relation to Drop Size Diameter Distribution”
- Sponsored By: DWRC
- Advisor: Dr. Delphis Levia of the UD’s Department of Geography
Considering throughfall constitutes a large proportion of the rainfall that makes it to the forest floor, the throughfall drop size distribution of a rain event could potentially have large implications for the water and elemental cycling within temperate forests. The preliminary results of this study imply that (1) throughfall drop size distribution and drop diameter vary on an event basis; and (2) factors such as air temperature, wind speed, and canopy state could have an effect on drop size diameter. In order to better understand the relationship between drop size diameter and throughfall composition, future research will be directed at analyzing the isotopic signature of throughfall in relation to drop size diameter.
- Title: “Pulse of the Watershed: Studying Rapid (Sub-hourly) Changes in Stream Water Quality Using High-frequency, in situ Sensors.” Her final report and poster were titled “Diel Patterns in Dissolved Organic Matter in a Forested Headwater Catchment in Maryland.”
- Sponsored By: DWRC
- Advisor: Dr. Shreeram Inamdar of the UD’s Department of Plant and Soil Sciences
Patterns of water quality parameters such as dissolved organic carbon (DOC) and nitrate-N caused by biotic and abiotic processes in a watershed are important to understanding underlying biological and hydrological controls within a stream. This study investigates the nature of the short-term patterns of dissolved organic matter (DOM) that occur over a 24-hour period, and the potential variables that influence the concentration and composition of organic matter in a forested watershed. Closely analyzing these trends may allow us to predict how streams will respond to changing conditions, such as climate change.
- Title: “Breathable Membrane Enclosures for Fecal Sludge Stabilization: Application in Eco-vapor Toilets.”
- Sponsored By: DWRC
- Advisor: Daniel Cha of the UD’s Department of Civil and Environmental Engineering.
The main focus of this research was to determine if components of an Auto-Thermal Aerobic Digestion (ATAD) system could be replicated on a laboratory scale. The next step would be to determine if these components could be incorporated into a current breathable membrane toilet design created by the late Dr. Steven Dentel. These toilets feature a breathable plastic membrane that has hydrophobic properties. These hydrophobic properties mean that while water molecules cannot pass through the membrane, the water vapor molecules can pass through the membrane due to even miniscule differences in temperature. Miniature reactors were created under laboratory conditions utilizing a synthetic sludge that was made in lab. This sludge was seeded with both compost and actual fecal matter to introduce microbes into the system in the hopes that they would increase temperature and subsequently the drying rate of the fecal matter. These reactors were well mixed using mechanical stirring rods and aerated through the use of air stones. Various measurements including pH, dissolved oxygen (DO), and temperature were taken daily to monitor the conditions within the reactor. The results indicated that it was feasible to generate small scale ATAD reactors using a laboratory system setup. Temperature levels were initially held constant but did show a slight increase after a period of time. Additionally, DO levels in each reactor dropped significantly throughout the experiment and there was a gradual increase in pH, indicating the presence of microbial activity within the reactors. With further consideration it was determined that the ATAD components may not be feasible to incorporate into the membrane toilet design. In order to be successful the ATAD system needs a constant heat, aeration, and mixing source. Each of these components would be difficult to incorporate into a cost efficient system that could be easily deployed and managed in a developing country to replace waterless pits. Additionally, the incorporation of these components would require an external energy source, another factor that makes incorporating these components difficult. Moving forward perhaps there is another method that can easily raise the temperature within the reactors to encourage evaporation of water vapor across the membrane.
- Title: “Application of the DESEU to Water Resources.” His final report and poster were titled “Potential for the Delaware Sustainable Energy Utility to Invest in Clean Water.”
- Sponsored By: DWRC
- Advisor: Dr. Lawrence Agbemabiese of the UD’s Center for Energy and Environmental Policy
The State of Delaware has several water issues affecting current and future water security. Agricultural and industrial pollution has polluted the vast majority of Delaware’s water supply and the effects of global warming will only exacerbate these problems especially due to sea level rise along Delaware’s coast. I examined the major water issues facing the State of Delaware, assessed the State’s official goals for improving water security, and investigated whether the Delaware Sustainable Energy Utility can play a role in aiding the State to achieve its goals. I found that the Delaware Sustainable Energy Utility could begin collecting and making public information on the extent of Delaware’s water problems, which are not sufficiently researched, as well as investing in pollution reducing technology.
- Title: “Assessing the Impact of Severe Storm Events on Exported Sediment, Particulate Organic Matter, and Nutrients and Stream Water Quality.” Her final report and poster were titled “Relating Rainfall Intensity to Sediment Mobilization at Fair Hill.”
- Co-Sponsored By: DWRC and the UD’s College of Agriculture and Natural Resources
- Advisor: Shreeram Inamdar of the UD’s Department of Plant and Soil Sciences.
Precipitation has increased by about 5% in the United States over the past 50 years, with this increasing trend being most predominant in the Northeast. Among the effects of increased rainfall is increased sedimentation in streams. This study aimed to correlate increased rainfall with increased sediment mobilization in a small watershed located in the Fair Hill Natural Resource Management Area in Cecil County, Maryland. We used automated ISCO samplers to take water samples in response to rainfall, sediment concentration was calculated, and sediment was dried for further analysis. Hourly rainfall totals from DEOS (Delaware Environmental Observing System) data were compared to corresponding sediment values. Sediment concentrations were positively correlated with rainfall intensity.
Erica Rossetti and Samantha Serratore
- TItle: “First State National Park: Brandywine-Piedmont Watershed Plan”
- Sponsored By: DWRC
- Advisor: Dr. Gerald Kauffman of the Delaware Water Resources Center
Several chemical, nutrient, and biological indicators can help determine water quality and ecosystem health. As a newly designated national park, students at the University of Delaware found it important to monitor, record, and analyze several parameters including temperature, pH, conductivity, dissolved oxygen, turbidity, bacteria, nutrients, and metals to determine the general health of tributaries flowing through the Brandywine-Piedmont watershed in Delaware’s First State National Historic Park. Using probes and lab facilities from the City of Wilmington and the University of Delaware, data were gathered from twelve sites throughout the watershed several times over a period of nine months. Students analyzed data according to parameter, date, and statistical averages. When compared to standards, the results showed little to no nutrient and chemical impairments, but there were some indications of chemical and bacterial concern in sites adjacent to agricultural and commercialized areas, indicative of runoff pollution or other non-point sources. As a result of these conclusions, it is the researcher’s hope that the newly designated First State National Historic Park will act as a natural water quality improvement system or that the National Park Service will proceed with further investigations in order to prevent the degradation of the water quality in the watershed as indicated by this preliminary research.
- Title: “Understanding the Role of Ditch Sediments in the Transport of Phosphorus in Agricultural Drainage on the Delmarva”
- Co-Sponsored By: DWRC and the UD’s Department of Plant and Soil Sciences
- Advisor: Amy Shober of the UD’s Department of Plant and Soil Sciences
Nutrient pollution is a real concern on the Delmarva Peninsula due to the widespread presence of artificial drainage system across Delmarva and phosphorus (P) saturated soils. Accumulation of sediments in drainage ditches over time can affect nutrient transport because sediments may act as a source of P to the overlying water. However, ditch sediments may also act as a P sink, reducing the concentration of P in overlying ditch water. The objectives of this research were to determine the P sorption characteristics of ditch sediments after many years of sediment accumulation. Intact core samples were collected from the top 5-cm of sediment from five tax ditches in Delaware; sediment samples were analyzed for Mehlich 3 P and water extractable P (WEP). Sorption isotherms were also constructed to determine P sorption capacity (Smax) and equilibrium P concentrations (EPCo) of collected sediments. The sediments collected from the drainage ditches actually had lower Mehlich 3 P and WEP concentrations than the agricultural fields they drained. The Smax and EPCo of sediments ranged from 77.6 to 484 mg kg-1 and -0.064 to 0.278 mg L-1, respectively. Results suggest that ditch sediments are often acting as a sink for P, rather than a source. However, ditch water EPCo values need to be measured to confirm this finding.
- Title: “Remineralization of Organic Matter and Chesapeake Bay Hypoxia” and her final report and poster were titled “Application of Solution 31P NMR Spectroscopy to Understand Phosphorus Speciation in Wastewater.”
- Sponsored By: DWRC
- Advisor: Dr. Deb Jaisi of the UD’s Department of Plant and Soil Sciences
Microorganisms involved in the active P removal in the aeration basin in wastewater treatment plants (WWTP) undergo aerobic and anaerobic oscillations to facilitate denitrification. Microorganisms can uptake large amount of orthophosphate and transform this into polyphosphate (poly-P) and break poly-P down in an anaerobic stage to obtain energy. In this study, several samples were collected from the Kent County WWTP in Milford, Delaware, to determine the relationship between dissolved oxygen (DO) and changes in P speciation using solution P nuclear magnetic resonance spectroscopy (31P NMR). Orthophosphate and pyrophosphate were the major P species in all samples. However, their dominance varied during aerobic condition; polyphosphate was much higher but decreased as the DO decreased. Furthermore, changes in monoesters and diesters during redox cycling suggested synthesis of both of these P compounds was slightly higher during the anaerobic cycle. These results provided clear insights into P speciation during redox alternation and are useful for tapping microbial incorporation of P into macromolecules and energy storage compounds for efficient P removal from wastewater.