Project Proposals for 2011-2012 DWRC Undergraduate Internships

SEVENTEEN as of 3/15/2011

1. Controlling greenhouse gas emissions from landfills with biologically active soils (posted 2/27/08)
2. Fresh water possibilities using a membrane distillation process (posted
2/11/08)

3. Zero valent iron and additives to enhance biofiltration of water (posted 2/11/08)

4. Patterns and processes for controlling intertidal groundwater discharge to the Delaware Bay at Roosevelt Inlet (posted 3/9/07)

5. Sustainable mosquito control for stormwater ponds (posted 2/23/07)

6. Lewes Citizen Monitoring Program, Broadkill Watershed Tributary Team, and Delaware NEMO Program (posted 3/10/06)

7. Hormones in runoff from agricultural lands receiving application of poultry litter (posted 2/6/09)

8. Identifying sources, flow paths, and fate of dissolved organic carbon (DOC) and nitrogen (DON) in forested watersheds (posted 2/6/09)

9. Wetland conservation and comparison on the University of Delaware campus (posted revised 3/25/10)

10. Influence on the Delaware River and Bay system from varying inputs from the watershed (posted 2/20/07)

11. Interactions between soil chemistry, exotic plants invasions, and stream biodiversity in forested riparian corridors of varying width (posted 3/16/07)

12. Education and outreach internship to improve public perception of wetlands throughout Delaware

(posted revised 3/8/10)

13. Hydrogeologic data visualization and delivery for the web (posted revised 3/19/10)

14. How dam construction and removal influences alluvial sedimentation in the Christina River Basin (posted 3/4/11)

15. Analysis of herbicides in soil and water samples from field studies on fate and transport (posted 3/15/11)

16. Development of an assay to monitor the activity of fungal enzymes in soil (posted 3/15/11)

17. The use of recycled water for irrigation of turf and landscape plants (posted 3/15/11)

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1. Controlling greenhouse gas emissions from landfills with biologically active soils (posted 2/27/08)

Interested in this internship? 

Contact Dr. Paul T. Imhoff imhoff@udel.edu, (302) 831-0541

University of Delaware (UD) College of Civil and Environmental Engineering  Web: www.ce.udel.edu/~imhoff


There is growing concern that the buildup of greenhouse gases (GHG) in the atmosphere is leading to global climate change with undetermined consequences. Most of the attention to date has focused on controlling emissions of carbon dioxide (CO 2), the most common GHG. However, interest in controlling other GHGs, particularly methane, is increasing. Methane is of concern because it is more than 20 times more effective in trapping heat in the atmosphere than CO 2. Landfills are the largest source of anthropogenic methane, accounting for approximately 30 percent of emissions.

One means of mitigating methane emissions from landfills is by constructing biologically active soils on the landfill surface. Microorganisms in these soils may then oxidize methane, converting it to less potent CO 2 and water. With support from the US Department of Energy, we are evaluating the ability of different compost/soil/woodchip mixtures to oxidize fugitive methane, particularly under different climatic conditions.

This project involves field work in California, laboratory studies in Delaware, and mathematical modeling. Students participating in this project would assist in the laboratory measurements and possibly some field studies. If you are interested in either microbiology, water and gas flow in natural systems, or environmental chemistry you should enjoy this project.

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2. Fresh water possibilities using a membrane distillation process (posted 2/11/08)

Interested in this internship? 

Contact Dr. Steven Dentel dentel@udel.edu, (302) 831-8120

University of Delaware (UD) College of Civil and Environmental Engineering  Web: www.ce.udel.edu/~dentel

 

Fresh water sources are becoming more limited in Delaware, and many other locations nationally and worldwide. In some areas of this country, desalination processes are now being employed to convert sea water and brackish water to fresh water. Unfortunately, these processes (flash distillation, reverse osmosis, and electrodialysis) are energy intensive, which makes them costly.

A newer process for desalination is called membrane distillation. This process uses waste heat to remove salt from water. Its main advantage is that heat sources such as waste heat from industrial processes, or even solar heat, may be usable to drive the desalination process.

Current work is with a major industry which has provided our lab with a pilot scale unit. We are analyzing the feasibility of this process for industrial applications where it may be the most profitable. As the process evolves, it may become a viable method of providing fresh water in developing countries or in warmer climates. A student working on this project would work with current researchers until familiar with the industrial applications and then, on a more independent basis, explore these other applications. You should enjoy this project if you’re interested in one or more of the following: water supply, water chemistry, water treatment, heat transfer, computer programming, economics,
practical experimental design and analysis.

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3. Zero valent iron and other additives to enhance biofilitration of water (posted 2/11/08)

Interested in this internship? 

Contact Dr. Pei Chiu pei@udel.edu, (302) 831-3104

University of Delaware (UD) College of Civil and Environmental Engineering  Web: www.ce.udel.edu/~pei

 

Both locally and in third-world countries, methods for the treatment of well water often rely on filtration though a bed of sand. The removal of both bacterial and chemical constituents from the water is accomplished mainly by a bacterial film that forms on the upper layers of the sand. However, there is recent evidence that viruses are not efficiently removed, even though these can carry water-borne diseases.
 
A new method of removing (or, more accurately, inactivating) viruses in water has recently been developed at UD. It uses metallic iron, known as zero-valent iron (ZVI), which provides a chemical process shown to remove some contaminants and to inactivate viruses in water. The next
step is to determine whether this ZVI can be added to a conventional sand filter to improve the removal of viruses and other contaminants. To apply the method in third-world countries, the method should also remove chemical constituents that impart undesirable tastes to water.

This project will assess the combination of biofiltration with the ZVI additive. To be successful, the modification should not impair the
removal of bacteria as already achieved by the sand filter, and this will be assessed. The removal of viruses will be determined, and the
removal of organic and inorganic substances contributing to poor taste will be evaluated. Different filter configurations must also be
compared in order to optimize the process.

 

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4. Patterns and processes controlling intertidal groundwater discharge to Delaware Bay at Roosevelt Inlet (posted 3/9/07)

Interested in this internship? 

Contact Dr. Bill Ullman ullman@udel.edu, (302) 645-4302

or Doug Miller dmiller@udel.edu or Tom McKenna mckennat@udel.edu for more information.

University of Delaware (UD) College of Marine and Earth Studies, Lewes, DE and Delaware Geological Survey  Web: www.ocean.udel.edu and www.udel.edu/dgs/

 

Project description:

A significant fraction of water and associated nutrients from coastal watersheds in southern Delaware are transported to Delaware Bay through groundwater pathways. Groundwater discharge is spatially patchy, but where it occurs, there is evidence of discharge at all times except during the highest high tides. The intern will use multiple field techniques to estimate groundwater flow at a known discharge site near Roosevelt Inlet at the UD campus in Lewes, Delaware. The first approach will estimate groundwater flow rates from the upland to the Bay using upland water levels, estimates of hydraulic conductivity based on the propagation of the tidal signal into the aquifer, and Darcy’s law. The second approach will estimate groundwater flow rates perpendicular to the shoreline as a function of tidal height using data from in situ temperature sensors and simple analytical models. Lastly, discharge per unit area at the discharge site will be directly measured using seepage meters deployed in an array perpendicular to the shoreline. These techniques will allow the student researcher to estimate aquifer characteristics and determine the magnitude and distribution of fresh, salty, and total groundwater discharge as a function of tidal height and other factors. There also is potential to estimate associated nutrient loads to the intertidal and subtidal zones. This work builds on research conducted by a previous DWRC undergraduate intern (Garrett Peters, Summer 2006). Summer dormitory housing is available (shared bedroom, bathroom, and kitchen; $545/ten weeks) at the Hugh R. Sharp Campus of the University of Delaware in Lewes. This project is ideal for a student with interests in developing their field and analytical skills in hydrology, hydrogeology, and/or coastal processes. 

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5. Sustainable mosquito control for stormwater ponds

Interested in this internship? 

Contact Dr. Jack B. Gingrich gingrich@udel.edu, (302) 831-1308

University of Delaware (UD) Dept. of Entomology and Wildlife Ecology


Introduction

 

Stormwater ponds (BMPs) have been shown to be an important breeding habitat for mosquitoes, including both nuisance species and West Nile virus (WNV) vectors. Over the past four years, Gingrich et al.(J. Amer. Mosq. Cont. Assoc., 2006) have developed new evaluation methods that distinguish among types of ponds that produce mosquitoes in large numbers and those that do not. Detention ponds, especially extended detention ponds, often do not drain within the 72-hour period that they were designed for. Instead they often take 10-14 days or longer to dry out, which is more than ample time for a brood of mosquitoes to complete its life cycle. When they do dry out, wet mud around the periphery of these ponds become the target for oviposition by floodwater mosquitoes of the Aedes group of mosquitoes, which include several potential WNV vector species. Also, certain categories of retention ponds, especially shaded ponds with shallow perimeters, become breeding sites for numerous mosquito species, including Culex and Aedes group members. We have also studied these same characteristics for bioswales and bioretention strips. Certain common features that lead to problems in all these BMPs are improper design, poor drainage, silting in, or excessive riprap areas that provide protection and food for mosquito larvae.

 

Over the past two years, we have determined a non-pesticidal pond treatment method that provides multiple benefits to stormwater ponds. Using aluminum sulfate treatment once per month in the summers, we found that we can not only reduce larval abundance of the worst groups of mosquito vectors for West Nile virus, but also we can reduce phosphorus concentrations and bacterial loads. Although these preliminary findings look promising, more work is needed in quantifying these benefits, and in determining if there are long term issues in using this treatment. An additional possible benefit might be reducing nitrogen concentrations, which would also need further study. Looking at possible adverse impacts, are invertebrate predators affected, are applications needed too frequently, and are there undesirable effects on pH?

 

Proposed Field Tests

 

The field tests would involve selecting 24-48 comparable retention ponds previously studied in 2004-2006. Ponds that would be picked would be known to produce fairly high mosquito numbers (mean = 0.6 larvae per dip or greater). We will use only one treatment group (alum) and one control group. Twelve to 14 ponds will be placed in each group, being careful to select ponds in pairs so that high abundance and low abundance selections will be evenly dispersed among the two groups.

 

Starting in later May, we will do three pre-treatment collections. By late June, we will start treating the treatment group with alum, and continue the treatments once a month thereafter. We will collect all larvae from 100 dips from each pond for every two-week cycle (total of eight collections from June to September), and perform all the environmental measures concurrently as well. We will be identifying larval mosquitoes in the lab, as well as counting them. We will also be analyzing chlorophyll, phosphates, nitrates and pH, as well as making slides for bacterial counts. These will be done under oil immersion magnification in an epifluorescence microscope.

 

In addition to these field experiments, we would be conducting lab studies to evaluate the relative development of larvae given algae or bacteria as food. These experiments will be designed to determine which of these foods is most essential for selected groups of mosquito larvae, and they should help to corroborate our field findings.

Data would be entered into an automated database, with all the information from site collections plus all field site characteristics included. Controls and treatment groups would be analyzed by stepwise multiple regression and paired t-

Success of the treatment method would be evaluated based on mosquito abundance reduction, ease of treatment, and overall cost to implement each treatment. Results will be presented in both tables and graphs. We will link these field results to results obtained in the laboratory studies.

Expected Results

Our expectation is that the treatment group will show reduced larval abundance compared to the control group, and this difference will be statistically valid. We expect to see improved water quality (N and P reductions), reduced bacteria counts, and minimal adverse impacts. We also expect to have more definitive data, based on lab results, on why the treatment works. This will be important im making adjustments to treatments, and finding out when and how often treatments should be applied in order to maximize treatement benefits.

References

 

Gingrich, J.B., R.D. Anderson, G.M. Williams, L.L. O’Connor, and K.H. Harkins. 2006.  Stormwater ponds, constructed wetlands, and other best management practices as potential breeding sites for West Nile virus vectors in Delaware during 2004.  J. Amer. Mosq. Cont. Assoc. 22: 282-291.

 

Peck, G.W. and W.E. Walton.  2006. Effect of bacterial quality and density on growth and whole body stoichiometry on Culex quinquefasciatus and Cx. tarsalis (Diptera: Culicidae). J. Med. Entomol. 43:25-33.

 

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6. Lewes Citizen Monitoring Program, Broadkill Watershed Tributary Team, and Delaware NEMO Program (posted 3/10/06)

 

We have opportunities for internships with our Citizen Monitoring Program, Broadkill Watershed Tributary Team, and Delaware NEMO Program for students having interest in outreach education and some applied research while living down at the beach. We could probably find them student housing in a UD dorm.

 

Contact Joe Farrell jfarrell@udel.edu (302) 645-4250

University of Delaware (UD) Sea Grant Program, Lewes

 

  

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7. Hormones in runoff from agricultural lands receiving application of poultry litter, Newark, Delaware (posted 2/6/09)

 

Interested in this internship? 

Contact Dr. Shreeram Inamdar inamdar@udel.edu  (302) 831- 8877

University of Delaware (UD) Department of Bioresources Engineering

Sex hormones are produced naturally by poultry and cattle and excreted in their urine and feces. Large numbers or cattle or poultry (on animal production facilities or farms) can result in significant amounts of hormones to be discharged with runoff. Land application of manure or poultry can also be an important source of hormones. These hormones are also referred to as endocrine disrupting chemicals (EDCs) since they cause physiological and reproductive disorders in aquatic and wildlife species that are exposed to these hormones. Thus, these hormones are of environmental concern and are now being regarded as emerging contaminants.

We are currently evaluating the concentration, fate, and transport of hormones from plots receiving poultry litters. Samples of surface runoff and soil water are collected following rainfall events. These samples are then analyzed in the laboratory using state-of-the-art ELISA techniques. Students will be involved in collection of runoff samples, analysis of samples in the laboratory, and synthesis of results. Students interested in the project should have some background in environmental or agricultural sciences and preferably courses in chemistry, water quality, hydrology, soils, or watershed management.

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8. Identifying sources, flow paths, and fate of dissolved organic carbon (DOC) and nitrogen (DON) in forested watersheds (posted 2/6/09)

 

Interested in this internship? 

Contact Dr. Shreeram Inamdar inamdar@udel.edu  (302) 831- 8877

University of Delaware (UD) Department of Bioresources Engineering

DOC and DON have important environmental implications. DOC plays an important role in the acid-base chemistry of acid sensitive freshwater systems; affects the complexation, solubility and mobility of metals such as aluminum and mercury; influences the adsorption of pesticides in soils; is linked to the formation of potentially carcinogenic trihalomethanes when surface water is chlorinated for drinking; attenuates UV radiation and thus provides protection to aquatic biota; and connects the C and N cycles of terrestrial and marine ecosystems.

DON constitutes a significant portion of the total N flux for some ecosystems; a large portion of DON can become bioavailable for estuarine plankton; and recent research suggests that DON in drinking water sources can contribute to formation of toxic nitrogen disinfection by-products.

We are currently evaluating the sources, flowpaths, and fate of DOC and DON in runoff waters from a forested watershed near the campus of UD. This study has been funded by a grant from the National Science Foundation. Water samples are collected routinely from rainfall, throughfall, soil water, groundwater, and streams during storm events and non-storm periods. The samples are then analyzed for DOC, DON and other parameters in the laboratory. Students will be involved in watershed instrumentation, collection of runoff samples, analysis of samples in the laboratory, and evaluation of the data to determine the quality and quantity of DOC and DON in various runoff sources. Students interested in this project should have a strong background in environmental sciences and preferably courses in chemistry, water quality, hydrology, soils, or watershed management.

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9. Wetland conservation and comparison on the University of Delaware campus (posted revised 3/25/10)

 

Interested in this internship? 

Contact Dr. Greg Shriver gshriver@udel.edu (302) 831-1300

University of Delaware (UD) Department of Entomology and Wildlife Ecology

 

We propose to estimate vegetation diversity and the bird use of the wetland habitats on the UD Farm. This project will provide the first year of sampling to monitor the avian response to the restoration. Wetlands are often underappreciated by those who do not understand their importance within an ecosystem, however, they provide significant wildlife habitat and ecological services. Gathering data on the wetlands on campus will increase our understanding of this habitat and help determine if the wetlands are healthy and functioning properly. This project has three objectives; 1) to estimate plant species richness and diversity, 2) to monitor the bird nesting activity and abundance, and 3) to design and implement the first year of monitoring vegetation and avian changes on the three UD Farm wetlands.

To sample vegetation we will use line transects in each of the three wetlands on the UD Farm and record the species and percent cover of each species detected within 1 m of either side of the line transect. We will use point count sampling to estimate avian species richness and diversity in each wetland during the course of the breeding season (June - August). We will search for and locate as many nests from all breeding bird species as possible to estimate nest density and I will monitor each active nest to estimate nest survival. We will use these data to compare the vegetation species richness and diversity, avian species richness and diversity, nest density, and nest survival among the three wetlands on the UD Farm.

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10. Influence on the Delaware River and Bay system from varying inputs from the watershed (posted 2/20/07)

 

Interested in this internship? 

Contact Dr. Jonathan Sharp jsharp@udel.edu (302) 645-4259

University of Delaware (UD) College of Marine Studies, Lewes, DE  Web: www.ocean.udel.edu

The Delaware River and Bay system is one of the largest and most important estuarine systems in the United States. Housing the sixth largest urban region in the country, it provides drinking water to over 10 million people in New York City and Philadelphia urban areas. It serves as one of the largest port complexes in the country and one of the largest fresh water ports in the world. By most standards, it was the first and, at one time, the most polluted estuary in the US; yet it has had one of the most dramatic water quality improvements in the world. The Delaware Estuary is home of many valuable living resources: it used to be the major fishery site in the country for shad and sturgeon, and it currently supports the largest horseshoe crab population in the country. Consequently it is invaluable to migratory shorebirds that feed on the horseshoe crab eggs.

Professor Sharp’s laboratory group has been studying the microbial biogeochemistry of the Delaware Estuary for almost three decades. We define microbial biogeochemistry as the study of inputs, and biological and geochemical reactions of the major elements, such as carbon, nitrogen, phosphorus, oxygen, and silicon. Natural inputs come into the estuary from the watershed, while anthropogenic (man-made) inputs come from industrial and municipal activities primarily in the greater Philadelphia area. The upper watershed inputs can vary depending on weather and climate conditions. For example, major storm events will introduce higher levels of natural inputs, but will also dilute urban inputs. The anthropogenic inputs have changed considerably over the last 4 decades. We have a number of long-term databases (with time scales ranging from about 25 to 100 years) that allow us to understand changes in time. With this project, we will further extract information from these databases and interpret the impact from long-term improvement in anthropogenic activities and inputs on the Delaware River and Bay system. We will also evaluate the impact from recent changes from periodic storm activities, possibly associated with climate change.

Professor Sharp’s laboratory is on the Lewes campus. This project could include residence in Lewes in the summer and/or work from Newark with periodic visits to Lewes. It may also include participation on research cruises on the Delaware Estuary.

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11. Interactions between soil chemistry, exotic plants invasions, and stream biodiversity in forested riparian corridors of varying width (posted 3/16/07)

Interested in this internship? 

Contact Dr. Chris Williams ckwillia@udel.edu (302) 831-4592

University of Delaware (UD) Dept. of Entomology and Wildlife Ecology


Forested strips along streams often remain after an area has been developed for anthropogenic use. Although prior research suggests these buffers can be effective at protecting water quality, their potential value as a source of suburban biodiversity has remained unexplored. The primary objective of this study is to understand the factors governing the ability of riparian forest corridors to preserve native biodiversity in agricultural landscapes and suburbia. To this end, we intend to meet four research goals, each focusing on one aspect of riparian corridor function: 1) we will determine the width of forest buffer needed to protect a stream from nitrogen, phosphorus, and pesticide runoff, based on local conditions, 2) we will determine the width of buffer needed to maximize the native plant biodiversity of the corridor and to discourage exotic plant invasion, 3) we will determine the nature of the relationship between corridor width and stream macroinvertebrate community health, and 4) we will investigate the relationship between patterns of riparian corridor presence and patterns of fish assemblage composition across the landscape. Meeting these research goals will allow the building of a comprehensive model of how riparian forest corridors can best be utilized to protect native biodiversity when the connectivity of natural habitats is at odds with necessary human land use.

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12. Education and outreach internship to improve public perception of wetlands throughout Delaware (posted revised 3/8/10)

 

Interested in this internship? 

Contact Dr. Katherine Bunting-Howarth katherine.howarth@state.de.us (302) 739-9949

Division of Water Resources, Delaware Dept. of Natural Resources and Environmental Control

 

The need to improve the understanding of wetland functions and benefits among the public of Delaware is imperative to the protection and sustainable use of our natural resources. This internship will focus on improving access to education and outreach materials by public and private organizations. There are multiple venues that can be utilized and this project can be tailored to the interests of the intern. Product options include one or more of the following: 1.) Add content to the existing website that functions as a clearinghouse for educational material and DNREC wetland progrmas: 2.) Create graphical illustrations relating to wetland health, wetland habitats and functions, wetlands on a watershed context to inform the public of wetland services, functions, and vulnerability; 3.) Design ads that could be utilized in free or paid media promoting wetland services. These ads could be in rotation on the Delaware Wetlands website, printed for distribution, printed as posters or run as paid ads if funds are available; 4.) Develop a series of articles on current wetland projects and/or issues that will be featured on the Delaware Wetlands website and provided to other organizations to include in their newsletters. Examples include recently completed restoration projects, wetland research, and wetland functions of significance; and 5.) Design and write literature/brochures for different audiences including realtors, consultants, builders, landowners, the general public and decision makers.

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13. Hydrogeologic data visualization and delivery for the web (posted 3/19/10)

Interested in this internship?
Contact John Callahan john.callahan@udel.edu (302) 831-3584
Delaware Geological Survey (DGS)

DGS data, reports, and map products are increasingly being used by State agencies (DNREC, DelDOT, DDA) and local governments to support land-use planning and resource management decisions. Several existing and proposed regulations and ordinances cite these DGS resources and encourage and require the use these resources for preparation of development plans and permit applications. This information is currently scattered across multiple locations and in disparate formats. Provision of DGS resources through a web-based data delivery application would standardize the availability and means of access for these resources for governmental agencies, development community, consultants, and the public, creating more efficient access to information and capability for more thorough analysis of all applicable data.

The student will participate in a joint project between the Delaware Geological Survey (DGS) and the Delaware Department of Natural Resources and Environmental Control (DNREC) to make DGS hydrogeologic data available through the web. These data include current and historical groundwater levels for numerous wells throughout the state, subsurface aquifers and geologic units, groundwater recharge areas, and potentially other chemistry and hydraulic data. In addition to working directly with the data, such GIS mapping and time-series plotting, the student will work with researchers on the usability and functional needs of a web-based display and delivery mechanism.

Objectives are: To gain practical experience in working with raw and processed observational data and the pitfalls that accompanies its standardization; to understand how this data is used in research-based funded projects; and to identify patterns or problems in these datasets when integrated into a common environment.

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14. How dam construction and removal influences alluvial sedimentation in the Christina River Basin (posted 3/4/11)

Interested in this internship?
Contact Dr. Jim Pizzuto pizzuto@udel.edu (302) 831-2710
University of Delaware (UD) Dept. of Geological Sciences

The Christina River Basin Critical Zone Observatory (www.udel.edu/czo) is a joint research program of the University of Delaware and the Stroud Water Research Center (www.stroudcenter.org). The research focus of the Critical Zone Observatory is to improve our understanding of how anthropogenic disturbance promotes carbon sequestration over decadal, centennial, and millennial timescales at the watershed scale. As part of this effort, Dr. Jim Pizzuto’s research group has been studying the influence of hundreds (possibly thousands) of small mill dams on alluvial sedimentation in the Christina River Basin. These mill dams were initially constructed for water power in the 18 th and 19 th centuries, and many have either fallen into disrepair or are being removed through river restoration initiatives. Our approach combines mapping deposits behind existing and former mill dams, determining the ages of these deposits using radiometric dating methods, monitoring changes induced by contemporary dam removals, GIS analysis of aerial and LiDAR imagery, and numerical modeling. We aim to better understand how mill dam construction and removal influence sediment deposition and erosion and carbon sequestration through the Christina River Basin over the last several hundred years (and into the future).

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15. Analysis of herbicides in soil and water samples from field studies on fate and transport (posted 3/15/11)

Interested in this internship?
Contact Dr. Stacey Chirnside aemc@udel.edu (302) 831-8871
University of Delaware (UD) Dept. of Bioresources Engineering

The movement of atrazine, simazine, cyanazine and metolachlor was studied for two years under conventional and no-tillage corn production. Atrazine and simazine were detected in the ground water more frequently than metolachlor or cyanazine. During the first year of the study, all 4 pesticides were leached to the ground water shortly after application when a total of 31.5 mm of rainfall occurred. The frequency of the herbicides detected in the ground water was directly related to the soil half-life of the herbicide but related to their solubility.

Soil data showed that atrazine moved more rapidly in the soil profile in the conventional tillage than the no-tillage. Simazine was shown to move faster into the soil profile under no-tillage (91-152 cm depth) than under conventional tillage (0- 152 cm depth). Conversely, metolachlor moved more rapidly under the conventional tillage than no-tillage. Cyanazine moved below the root zone shortly after application for both tillage treatments. The frequency of herbicide detection was related to the soil half-life.

Parameters that affect degradation will have a significant effect on the movement of herbicides through the soil profile and into the ground water. The complexity of interactions within the soil makes it difficult to generalize what best management practices (BMPs) would reduce leaching of pesticide to the ground water. In order to investigate management practices, a study was initiated to assess the affect of managing the ground water depth on the movement of pesticide under minimum tillage corn production. Pesticides were monitored in the soil and ground water for 4 years. Analysis of the pesticide concentration within soil and water resulted in over 1000 samples. Calculation of pesticide concentrations for the last year of the study is needed to further define the effects of BMPs on the fate and transport of the herbicides.

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16. Development of an assay to monitor the activity of fungal enzymes in soil (posted 3/15/11)

Interested in this internship?
Contact Dr. Stacey Chirnside aemc@udel.edu (302) 831-8871
University of Delaware (UD) Dept. of Bioresources Engineering

In recent years white rot fungi (WRF), specifically Phanerochaete chrysosporium, have been found to have the ability to degrade an extremely diverse range of very persistent or toxic environmental pollutants. Studies have shown that the white rot fungus is able to degrade pesticides (Bumpus and Aust, 1987; Yadav and Reddy, 1993; Kenedy et al., 1990), polyaromatic hydrocarbons (Carberry, 1990; Mileski et al., 1988; Reddy and Gold, 2000), polychlorinated biphenyls (Thomas et al., 1992), and most halogenated aromatics. The ligninolytic metabolism of the WRF is responsible for this degradative ability. The ligninolytic extracellular enzymes produces include lignin peroxidases (LiP), manganese-dependent peroxidases (MnP), lactases, laccases, a hydrogen peroxide-generating system, other enzymes and co-factors (Barr and Aust, 1994; Maloney et al., 2001; Reedy and Mathew, 2001; and Wu et al., 1996).

Lang et al. (1997) examined the effect of soil on the ligninolytic activity of four strains of WRF. Enzyme activity remained high and the presence of soil microorganisms actually doubled the MnP activity. Chirnside et al. (2005) examined the degradation of atrazine (2-chloro-4-ethylamino-6-isopropylamino-S-triazine; AT) and alachlor (2-chloro-2’,6’-diethyl-N-[methoxymethyl]-acetanilide; AL) in contaminated soil utilizing an extracellular fungal enzyme solution (EES) derived from the WRF, P. chrysosporium, grown in the PBR. Thirty-two percent of AT and 54% of AL was degraded during the 7 day incubation period. The rate of degradation decreased after several days.

Recent work done by Brian Jayne, an undergraduate researcher/DWRC intern working with Dr. Chirnside, has led to the development of several enzyme soil extraction methods that were tested for their ability to extract the ligninolytic enzymes of the white rot fungus. Percent recovery of the enzymes was low for all methods tested. This work illustrated the need for the development of a cleanup procedure in order to reduce the concentration of interfering compounds that inhibit the assays that were developed for purified enzyme extracts. Improvements in the extraction procedure also need to be developed.

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17. The use of recycled water for irrigation of turf and landscape plants (posted 3/15/11)

Interested in this internship?
Contact Dr. Stacey Chirnside aemc@udel.edu (302) 831-8871
University of Delaware (UD) Dept. of Bioresources Engineering

Water scarcity and water quality issues across the country are increasing the demand and acceptance by consumers for the use of recycled water. Agricultural and landscape irrigation is the largest user of water resources. Therefore, it is no surprise that the most common type of water reuse has been for crop irrigation and landscape irrigation in urban areas. As the demand for recycled water increases, the need for regulations and recommendations to ensure human safety and to minimize adverse environmental impacts becomes apparent. At the federal level, the Environmental Protection Agency has issued voluntary guidelines that suggest the level of treatment, the minimum quality for reuse, and the type of monitoring required.

Because of the increase use of recycled water, many states have begun to develop water reuse regulations. Due to severe water shortages and the increase use of recycled water, states such as California, Florida, Texas and Arizona are leading the way in the development of water reuse regulations. California’s regulations regarding the use of recycled water are outlined in Title 22, Code of Regulations on Water Recycling Criteria of the California Administrative Code. These regulations address the quality of the reclaimed wastewater as well as the type of equipment required to produce compliant water. Ultimately, it is the end use of the recycled wastewater that determines the level of treatment.

A comprehensive water quality guideline for water reuse in irrigation of agricultural crops was developed and recently revised by a team of water resources engineers, scientists, and water reuse consultants. The revised manual, a descriptive brochure and an interactive CD was published by the American Society of Civil Engineers (ASCE Manual 71, Agricultural Salinity Assessment and Management). In order to advance the knowledge of water reuse and improve the practice, a similar manual needs to be developed that defines water quality guidelines for water reuse in irrigation of turf and landscape plants. In order to accomplish this goal, researchers need to develop a literature review that defines from a nation- wide perspective where the research is at present and outlines what areas of research are needed in order to promote the use of recycled water in the future.

A literature review developed by Stephanie Hahn, a 2010 undergraduate research scholar/DWRC intern, outlined the current state regulations for water reuse and outlined the differences in the required quality of recycled wastewater between states. Her review briefly touched on the research work that has been done assessing the use of recycled water in the irrigation of turf and landscape plants. This proposal seeks to continue in the review of the research on recycled water reuse.