Rutgers New Jersey Agricultural Experiment Station [The New Jersey Water Resources Research Institute]

Past Graduate Student Research

 

Fiscal Year 2010
Fiscal Year 2009
Fiscal Year 2008
Fiscal Year 2007

To view current graduate research visit our Recent Research page.

To view all previously funded research, please visit our Annual Report Archive


Fiscal Year 2010

Comparative toxicological assessment of the gasoline oxygenates MTBE, ETBE and TAME, and their metabolites, in the zebrafish cardiovascular system

Josephine Bonventre1 with Professor Keith Cooper2
1Joint Graduate Program in Toxicology, Rutgers, The State University of NJ/UMDNJ
2Dept. of Biochemistry and Microbiology, Rutgers, The State University of New Jersey

This project compared the toxicological effects of common gasoline oxygenates, methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) on developing zebrafish (Danio rerio), using morphological and molecular endpoints. The developing cardiovascular system is often a target for chemical toxicants and the pathways affected are conserved across species (Heideman et al., 2005). Our preliminary studies on MTBE, ETBE and TAME toxicity to developing zebrafish demonstrated that acute low dose exposure of zebrafish embryos to nominal concentrations of the individual gasoline oxygenates (0.625mM to 10mM) yielded a dose-response relationship for various lesions associated with vascular development, dose response vial studyincluding pooled blood in the common cardinal vein, cranial hemorrhages, abnormal intersegmental vessels, and pericardial edema. The preliminary studies also suggested that though ETBE and TAME induced lesions in embryos similar to those that occurred with MTBE, lesions occurred at lower doses, were more severe and were less targeted to the developing vasculature. We hypothesized that MTBE-targeted toxicity to developing vasculature resulted from a disruption in the vascular endothelial growth factor (VEGF) pathway, a mediator of blood vessel development. Angiogenesis, the development of blood vessels from preexisting blood vessels, is a conserved developmental process and important to proper growth and development of all species. In addition, we hypothesized that ETBE and TAME would significantly alter expression of other non-vascular specific genes that were not affected by MTBE.

Table 1: Structurally similar gasoline oxygenates MTBE, ETBE and TAME

chemical and structural information on the gasoline oxygenates MTBE, ETBE and TAME

The addition of a methyl group does not drastically alter the chemical characteristics between MTBE, ETBE and TAME. However, the results of this research show that the toxicity of the three oxygenates on developing zebrafish is different. While MTBE, ETBE and TAME elicit some of the same vascular lesions, the addition and placement of a methyl group in ETBE and TAME results in more toxic compounds with less specific target organ systems.

Reference:
Heideman, W., Antkiewicz, D.S., Carney, S.A., and Peterson, R.E., 2005. Zebrafish and cardiac toxicology. Cardiovas Toxicol 5, 203-214.

Contact Information:

Josephine Bonventre
Joint Graduate Program in Toxicology
E-mail: jbonvent@eden.rutgers.edu

Professor Keith Cooper
Rutgers University
Telephone: (848) 932-5614
E-mail: cooper@aesop.rutgers.edu

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Investigation into the Role of Arsenic Reducing Bacteria in the Mobilization of Arsenic into Groundwater in New Jersey

Adam Mumford with Professor Lily Young
Department of Environmental Sciences
Rutgers, The State University of New Jersey

The interplay of physical, geochemical and biological factors must be studied in
order to understand the release of arsenic to the groundwater. In this study, we propose to examine the role of microbial activity on the mobilization of arsenic from subsurface sediments into the groundwater. Towards this end, we will analyze groundwater and sediment samples from high-arsenic sites on Crosswicks Creek and the Millstone River for the presence of the arsenic respiratory reductase gene, arrA, as well as the presence of arsenic reducing bacteria. Earlier studies in New Jersey have been focused on the geochemical factors involved in arsenic mobilization, and it is hoped that this study addressing the microbiology of arsenic transformations will provide a more complete understanding of how arsenic is released into the groundwater.

Major Findings:
• Microbial arsenic reduction was observed in microcosms inoculated with material from sites with elevated arsenic, while no arsenic reduction was observed in microcosms from a site lacking elevated arsenic. This suggests the potential for microbial involvement in arsenic mobility in groundwater.
• Different microbial communities were found at each site. However, some microorganisms were common between sites.
• Microbially reduced As(III) persisted in sediment microcosms after all As(V) was bound. This indicates that microbially reduced arsenic may be more mobile in groundwater.
• Despite the presence of arrA, Pike Run groundwater microcosms did not reduce As(V). This underlines the importance of culture studies to confirm activity.

Contact Information:

Adam Mumford
Rutgers University
E-mail: amumford@eden.rutgers.edu

Professor Lily Young
Rutgers University
Telephone: (848) 932-5710
E-mail: lyoung@aesop.rutgers.edu

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Hydrogeophysical investigation of subsurface controls on persistent canopy gaps in the New Jersey Pinelands

Andrew Parsekian with Professor Lee Slater
Department of Earth and Environmental Science
Rutgers University - Newark

The objectives of this study are three-fold: 1) estimate properties of the nearsurface
geology (i.e. clay content, particle texture) which may influence local hydrology within individual canopy gaps, 2) make comparisons of the physical properties of the subsurface between vernal pond canopy gaps and peat-filled “spungs” and 3) assess the potential of paleo-channels to impact local and regional ground water flow.

Summary Remarks:
Geophysical methods have been highly successful at characterizing the subsurface in and around isolated wetlands in the New Jersey Pinelands. This study effectively identified clay layers located beneath vernal pools and peat-filled spungs. These subsurface units may control surface hydrology and, as a result, vegetation patterns. Evidence suggests that the wetlands were initiated in conjunction with existing low permeability strata perhaps corresponding with a dramatic climatic shift in the time period since the Wisconsin glaciation.

GPR Interp_2

Ground-penetrating radar profile across Spung 1 (top) showing the peat thickness as a curved reflection near the center of the image.  The resistivity distribution below the same area is presented in the lower panel.

Contact Information:

Andrew Parsekian
Rutgers University-Newark
E-mail: parsekia@pegasus.rutgers.edu

Professor Lee Slater
Rutgers University-Newark
Telephone: (973) 353-5100
E-mail: lslater@andromeda.rutgers.edu

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Green Remediation of Tetracycline in Soil-Water Systems

Pravin Punamiya with Professor Dibyendu Sarkar
Department of Earth and Environmental Studies
Montclair State University

The central hypothesis is that the nanoparticles of Fe/Al-oxides and organic C in drinking water treatment residuals (WTRs), with their high specific surface area, pH-dependent surface chemistry and high reactivity have high adsorptive capacity for oxytetracycline (OTC). We expect to answer the following research questions:
• Is it possible to bind OTC and its metabolites by amending manure with Fe- and Al-WTR thereby reducing potential availability/mobility?
• What is the geochemical fate of OTC and its degradation products/metabolites?
• What is the specific mechanism of retention of these various species?
• What are the effects of relevant environmental factors on the retention process?
• What is the possibility of the bound OTC undergoing desorption with time?
Answering these basic questions will let us evaluate if it is possible to model/extrapolate the bench-scale laboratory data to a larger scale to design an effectively implement a field-scale OTC removal technology. The hypothesis will be evaluated, and the research questions will be answered by pursuing the following objective:
Objective: Determine the retention-release mechanism and characteristics of OTC and its metabolites on WTRs as a function of environmental factors.

Conclusions:
• Both Al- and Fe-based WTRs exhibited high OTC sorption affinity, exhibiting minimal
OTC desorption.
• Sorption of OTC by the WTRs was rapid and equilibrium was reached within 5h
regardless of the initial OTC concentration.
• pH-dependent sorption behavior of both Al- and Fe-WTR was observed for all solid:solution ratios and initial OTC concentrations tested.
• No significant effect (p>0.05) of ionic strength on sorption of TCs was observed between 0.1-1 mM. However at higher initial concentration of OTC (1 and 2 mM), ionic strength dependence was observed.
• Results from the current sorption study suggest that both Al- and Fe-WTR can be used as an excellent low-cost and green sorbent for OTC removal from aqueous medium.
• The research will also provide a cost-effective medium for OTC immobilization in
wastewater treatment facilities as well as in lagoons at concentrated animal feeding
operations.
• The current research finding will also help us to develop a “green remediation” technique to immobilize and stabilize OTC in lagoons, storage at concentrated animal feeding operations, and manure and manure-amended soils rich in OTC.

Contact Information:

Pravin Punamiya
Montclair State University
Telephone: (973) 655-3456
E-mail: punamiyap1@mail.montclair.edu

Professor Dibyendu Sarkar
Montclair State University
Telephone: (973) 655-3456
E-mail: sarkard@mail.montclair.edu

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Fiscal Year 2009

Innovative Research and Development for Environmental Protection and Sustainable Waste and Wastewater Management System Design

David Babson with Associate Professor Donna Fennell
Department of Environmental Sciences
Rutgers, The State University of New Jersey

Recovering energy from biogas generated from degrading organic substrates (biomass) is attractive because there are numerous sources of cheap biomass to use, including municipal solid waste (MSW). The ability to characterize and understand the significant biochemical pathways involved in anaerobic degradation processes will allow optimized systems to effectively recover valuable fuel products from degrading waste while minimizing and simultaneously treating associated wastewater streams

The proposed strategy focuses on maximizing methanogenesis to increase the prospect of recovering useable energy, while minimizing the energy needed to treat associated wastewater streams without compromising a commitment to clean water effluents.
The following individual hypotheses will be tested:

    • Substrate competition may occur when attempts are made to foster both methanogenesis and anammox, and could affect the quantity of respective chemical product generation (i.e., methane and nitrogen gas) from systems containing both viable communities.
    • Environmental conditions exist that select for methanogenic archaea or anammox bacteria independently, and thus strategies can be employed to control and optimize these processes simultaneously.
    • There is a system-scale desirable optimum between methanogenesis and anammox in organic waste and wastewater reactors where the overall energy output can be maximized.

    The results of this research establish the wastewater contaminant, ammonia, as an additional biofuel to be recovered from anaerobic systems.  It also begins to justify simultaneous methane and ammonia recovery from integrated systems that recover valuable fuel products from degrading biomass while minimizing and treating associated aqueous discharge streams.

    Contact Information:

    Associate Professor Donna Fennell
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-5748
    E-mail: fennell@envsci.rutgers.edu

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    Development of two in vivo fish assays to study the anti-estrogenic action of polycyclic aromatic hydrocarbons and to evaluate endrocrine activity in NJ wastewater effluents

    Sean Bugel1 with Professor Keith R. Cooper2
    1Department of Environmental Sciences
    2Department of Biochemistry & Microbiology
    Rutgers, The State University of New Jersey

    The proposed research sought to investigate the link between exposure to aryl hydrocarbon receptor (AhR) agonists and reproductive effects in killifish (Fundulus heteroclitus).  Early studies from our lab reported finding evidence for endocrine disruption in both male and female killifish inhabiting Newark Bay, NJ (Bugel, 2009; Bugel et al., 2010).  These findings included decreased gonadal weights and altered gonadal development in both genders, decreased egg-yolk precursor protein expression (vitellogenin) in the female, altered steroid signaling expression (gonadal aromatase) in the female, and a potential relationship between activity of the aryl hydrocarbon pathway and vitellogenin expression.  As a result, we sought to further investigate the contaminant related effects on reproductive processes in Newark Bay, and explore the relationship between aryl hydrocarbon exposure and these newly discovered reproductive impacts. 

    Aryl hydrocarbon receptor agonists (i.e. dioxins, furans, polycyclic aromatic hydrocarbons) are found throughout the NY-NJ Harbor Estuary and are among the highest concentrations ever reported.  These contaminants are thought to be impacting fish populations by interfering with normal endocrine signaling.  Subsequent experiments have explored contaminant impacts on the biochemical level of reproductive pathways and the potential relationship between AhR agonist exposure and endocrine disruption.  Early results indicate that exposure of naïve male killifish to the Newark Bay environment can elicit an estrogenic response evidenced by induction of the vitellogenin pathway, a female egg-yolk protein.  This biomarker response was attenuated with increased exposure time, and may explain why previous studies have found no evidence for exposure of estrogenic contaminants to aquatic species in this ecosystem, despite the presence of known estrogenic contaminants.  These findings indicate that conventional exposure biomarker studies may lead to premature conclusions that are based on biomarker responses that give false negatives.  In a separate study, when killifish from both Newark Bay and the reference population were injected with 17β-estradiol, both genders from Newark Bay exhibited vitellogenin induction, although to a much lesser degree compared to induction in the reference population.  This shifted dose-response curve for vitellogenin induction indicates a biochemical impact on the estrogen signaling pathways within Newark Bay and a decreased responsiveness to estrogen.  The doses at which the Newark Bay killifish have a significantly lower protein induction are environmentally and physiologically relevant.  Therefore, a decreased responsiveness in males may complicate using vitellogenin as a conventional biomarker in this population and may help explain why the reproductive impacts in the female that have been previously reported.  Additional laboratory studies are being performed to explore exactly how the aryl hydrocarbon pathway interacts with the estrogen pathway to elicit these effects.

    Contact Information:

    Professor Keith R. Cooper
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-5614
    E-mail: cooper@aesop.rutgers.edu

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    Application of molecular and metabolic biomarkers of anaerobic hydrocarbon degradation as evidence for natural attenuation in New Jersey groundwater samples

    Amita Oka with Professor Lily Young
    Department of Environmental Sciences
    Rutgers, The State University of New Jersey

    The objective of this study was to analyze groundwater samples from a manufacturing gas plant impacted site, and evaluate them for the presence of two types of biomarkers of anaerobic hydrocarbon degradation; (i) specific metabolites of anaerobic naphthalene and 2-methly naphthalene degradation (metabolic biomarkers), and (ii) functional gene bssA coding for the alpha subunit of benzyl succinate synthase, a crucial enzyme in anaerobic hydrocarbon degradation (molecular biomarker).  Such a study is unique because it involves study of metabolic biomarkers of anaerobic degradation of polycyclic aromatic hydrocarbons (PAHs), along with the molecular biomarker (bssA gene) in the New Jersey groundwater samples.  Such a combined analysis has not been reported before from New Jersey.  This study can be used to verify anaerobic biodegradation of PAHs at the study site, and its results can be applied for design of other field studies and evaluation of remediation strategies at other impacted sites around the state.

    Contact Information:

    Amita Oka
    Rutgers, The State University of New Jersey
    E-mail: aoka@eden.rutgers.edu

    Professor Lily Young
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-5710
    E-mail: lyoung@aesop.rutgers.edu

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    Fiscal Year 2008

    Process-based modeling of nitrogen removal dynamics in brownfield and intact remnant wetland systems

    Monica Palta with Professor Joan Ehrenfeld
    Department of Ecology, Evolution and Natural Resources
    Rutgers, The State University of New Jersey

    Nitrogen (N) removal is commonly cited as a rationale behind wetland restoration projects, since wetlands have demonstrated the ability to prevent movement of excess N from upland areas into streams through the microbial process of denitrification. As important as N removal is to ecosystem health, however, there are few locations with measurements adequate to quantify denitrification rates and how they vary at a range of spatial and temporal scales. Further, despite a broad understanding of the multiple environmental factors that control rates of denitrification, we have limited ability to integrate this knowledge to construct and validate robust and predictive numerical models of denitrification. Wetlands in urban settings pose a particular challenge in linking ecosystem services (like denitrification) with their environmental drivers, mainly because urban wetlands have been little studied, and each urban system has its own unique set of altered conditions. These issues are especially true of wetlands that develop on brownfield sites, on highly modified soil materials.

    Though “hot spots” and “hot moments” have been identified by a number of comparative studies (where certain areas or time periods exhibit higher denitrification than others), none have undertaken the identification of periods or areas of high denitrification through quantitative modeling or spatial analysis of the process. I proposed to undertake process-based modeling to identify and predict the occurrence of “hot spots” and “hot moments” of denitrification in the urban wetland environment. My study objective was to collect the data needed to utilize a process-based model (DeNitrification-DeComposition, or DNDC (Li et al. 1992)) for an urban wetland site; this model was to be used to identify and predict hot spots and hot moments of denitrification within the site.

    Reference:
    Li, C., Frolking, S., and T.A. Frolking. 1992. A model of nitrous oxide evolution from soil driven by rainfall events: 1. Model structure and sensitivity. Journal of Geophysical
    Research, 97, 9759-9776.

    Contact Information:

    For more information on this project, please contact NJWRRI.

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    PBDEs and Other Brominated Compounds in a Bioreactor Landfill

    Jennifer Loudon with Associate Professor Donna Fennell
    Department of Environmental Sciences
    Rutgers, The State University of New Jersey

    Polybrominated diphenyl ethers (PBDEs) have been considered the next PCBs by many in the environmental field (La Guardia et al., 2007). Currently there is a growing amount of research looking at these compounds in wastewater treatment systems, but if we could identify and possibly enhance the natural debromination of these compounds to desirable end products while they are still in the landfill system, then that would take much of the burden off of the wastewater treatment plants. This could potentially decrease the concentrations of PBDEs and other brominated organic compounds finding their way into the rest of the ecosystem.

    Research Objectives - Qualitatively determine the diversity of microbes in the Burlington County Resource Recovery Center landfill leachate and solids. Identify dehalogenators present. Through microcosms using landfill waste, stimulate dehalogenation of halogenated organic compounds that may be found in a landfill. Obtain toxicological information about the landfill using Danio rerio (zebrafish) as a model organism.

    Contact Information:

    Associate Professor Donna Fennell
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-5748
    E-mail: fennell@envsci.rutgers.edu

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    Microbial Mobilization of Arsenic and Selenium Oxyanions in Subsurface Aquifers

    Ines Rauschenbach1 with Professor Max Häggblom2
    1Department of Microbiology and Molecular Genetics
    2Department of Biochemistry and Microbiology
    Rutgers, The State University of New York

    Arsenic (As) and selenium (Se) toxicity, and their ever-increasing contamination of
    groundwater and soil, has become a global concern threatening the lives of tens of millions of people. Speciation of As and Se, which affects their toxicity and mobility in the environment, is greatly affected by both environmental conditions and activity of the microbial population that mediate the transformations. Our laboratory has recently isolated the anaerobic, selenate/selenite- and arsenate-respiring bacterium “Desulfurispirillum indicus” strain S5. Since both C. arsenatis and D. alkaliphilum are not capable of respiring selenate, S. indicus will be the first selenate respiring organism to be fully sequenced. Therefore, this organism can be used as a model organism to fully understand the respiration of selenium and arsenic and the key genes encoding reductases that are involved in this process.

    Contact Information:

    Ines Rauschenbach
    Rutgers, The State University of New Jersey
    E-mail: inesrau@eden.rutgers.edu

    Professor Max Häggblom
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-5646
    E-mail: haggblom@aesop.rutgers.edu

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    Micro Scale Solid Phase Extraction using Carbon Nanotubes for Rapid Detection of Organic Pollutants in Water Resources

    Ornthida Sae-Khow with Professor Somenath Mitra
    Department of Chemistry and Environmental Science
    New Jersey Institute of Technology

    Recent evidence has shown that the number of trace contaminants including pesticides
    and pharmaceuticals is increasing in surface and other natural waters all across the nation. The major challenge in monitoring these contaminants is that their concentrations are quite low, often in the low ppb or ppt levels. While they can be detected by conventional methods such as HPLC, LC/MS and others, their low concentrations require extensive sample pretreatment that makes the overall process time-consuming and expensive.The objective of this research is to explore the development of microscale solid phase extraction (μ-SPE) for the extraction of a wide range of compounds including pesticides and drug metabolites in our water resources. The specific goals of this project are as follows:

    • Implement μ-SPE in the needle of a syringe for easy sampling, enrichment and injection.
    • Explore the possibility of using carbon nanotubes (CNTs) as novel, high performance sorbents for μ-SPE.
    • Implement the CNTs in a packed as well as in an open tubular, self assembled format.
    • Optimize μ-SPE to combine sampling and desorption.

    Contact Information:

    Professor Somenath Mitra
    New Jersey Institute of Technology
    Telephone: (973) 596-5611
    E-mail: somenath.mitra@njit.edu

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    Cranberry Farms' Habitat Function in the Wetland System of the New Jersey Pine Barrens

    Ai Wen with Professor David Ehrenfeld
    Department of Ecology, Evolution and Natural Resources
    Rutgers, The State University of New Jersey

    The study aimed to determine the interaction between cranberry farms and the surrounding Pine Barrens wetland ecosystem from two perspectives. First, I investigated the factors that can potentially affect the early stage of secondary succession in abandoned wetland farms. I examined whether the seed bank in abandoned cranberry farms exhibits different species density and composition at different soil depth (i.e. soil accumulated before and after the farm was constructed). I also examined whether the seed bank density and composition varies in cranberry bogs with low and high water table levels. Further, in order to use my study to provide farm restoration information, I applied two common restoration treatments, flooding and ground cover removal, to soil acquired from cranberry bogs with different hydrological condition (low vs. high water table), different soil depth (bottom, middle and top soil layer) and different ground cover species (cranberry runner vs. Carex cover vs. redroot cover). With this application, I was able to depict whether the common wetland restoration methods can produce homogeneous effects across different post-abandonment habitat conditions. The second objective of the research was to improve the integrity of the wetland ecosystem by enhancing the wildlife habitat of cranberry farms. This project will reveal the important factors correlating to wildlife distribution within active and abandoned farms. This information will be important for habitat management in both abandoned and active cranberry farms.

    Contact Information:

    Professor David Ehrenfeld
    Rutgers, The State University of New Jersey
    Telephone: (848) 932-9553

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    Fiscal Year 2007

    The influence of flooding cycles and iron oxides on arsenic retention in contaminated, planted microcosms in comparison with phosphate retention

    Luke MacDonald with Professor Peter Jaffe
    Department of Civil and Environmental Engineering
    Princeton University

    This research aims to better predict the behavior of phosphate and arsenic under changing iron and sulfur redox conditions. Accordingly, this study investigates the potential for iron oxides, sulfides, and iron sulfides to capture phosphate and arsenate, and the influence of plants and hydrology on this process. The specific problem that this research investigates is: will iron oxides or sulfides effectively capture arsenic and phosphate under the redox conditions we expect to find in wetlands and retention ponds, how do plants impact the capture of these pollutants, and what role do wetting and drying cycles play? Competing redox driven processes influence the solubility and sorption of phosphate and arsenic.  These dynamic redox processes may have opposite effects on the capture of these pollutants, making it difficult to determine the optimal conditions for arsenic and phosphate capture, and the goal of this research is to help unravel this mystery. microcosm greenhouse experiment

    Figure 1. Photograph of the greenhouse experiment.  Each microcosm receives influent water from the blue 55-gallon drums.  The water enters at the bottom port, and contains nine sample ports equally spaced throughout the microcosm.  The system is permanently flooded, with a free water surface.  Sand is present in all microcosms to ensure adequate flow rates and sample volumes. 

     

    Contact information:

    Professor Peter Jaffe
    Princeton University
    Telephone: (609) 258-7819
    E-mail: Jaffe@princeton.edu

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    Development of Microscale Membrane Extraction for Trace Monitoring of Pesticides and Other Emerging Pollutants in Water

    Kamilah Hylton with Professor Somenath Mitra
    Department of Chemistry and Environmental Science
    New Jersey Institute of Technology

    In a 2004 Environmental Science and Technology Article (1), a USGS study revealed the presence of a large number of “emerging contaminants,” such as antibiotics and households chemicals, in the drinking water of many homes in the New York metropolitan area, including New Jersey. According to Stackleberg (1), synergism between these chemicals could increase their impacts on human health. In light of health concerns and the absence of regulation of these compounds, studies are needed that allow us to determine the amounts actually reaching the environment and consequently how much additional treatment may be required.

    Measurement of these trace compounds is challenging because many are acidic, basic or polar. Recent reviews (2-4) have all listed solid phase extraction (SPE) as the only sample pretreatment technique, followed by separation and detection with liquid chromatography/mass spectrometry (LC/MS), liquid chromatography/electrospray ionization/mass spectrometry (LC/ESI/MS) or gas chromatography/mass spectrometry (GC/MS). While these techniques are capable of detecting trace amounts of contaminants, they are expensive and require multiple steps, long analysis time and large amounts of solvents. Also, most SPE is done off-line which makes continuous monitoring difficult. Petrovic et. al. (3) laments that the lack of more effective methods for trace determination of these new pollutants limits their measurement. Clearly, there is a need for the development of simple, inexpensive techniques that allow for quantification of these pollutants at low levels in environmental samples with the possibility of on-line analysis.

    microextraction experiment set-up

    Figure 1. (a)Experimental set-up for microextraction of N-methyl carbamates;
    (b) Schematic diagram of the barrier film system.

    Conclusions
    A mixed solvent membrane extraction in conjunction with a barrier film was developed for the analysis of N-methyl carbamate pesticides in water that precluded the need for post column derivatization. All the pesticides could not be extracted with any one solvent, so the use of a mixed solvent was absolutely necessary for extending the range of compounds studied with high sensitivity. The presence of the barrier film reduced solvent loss, allowing higher stirring rates and extraction times that led to enhanced enrichment and lower limits of detection. This used small sample volumes, and was simple and environmentally friendly.

    References:
    1. Thacker, P.D., Pollutants in New Jersey’s drinking water, Environmental Science and Technology Online, December 8, 2004. Accessed September 23, 2006.
    2. Petrovic, M., Gonzalez, S., Barcelo, D., Analysis and removal of emerging contaminants in wastewater and drinking water, Trends Anal. Chem. 22 (2003) 685.
    3. Zwiener, C., Frimmel, F. H. LC-MS analysis in the aquatic environment and in water treatment - A critical review: Part II: Applications for emerging contaminants and related pollutants, microorganisms and humic acids. Anal. Bioanal. Chem. 378 (2004) 862.
    4. Richardson, S., Environmental mass spectrometry: Emerging contaminants and current issues. Anal. Chem. 78 (2006) 4021.

    Contact Information:

    Professor Somenath Mitra
    New Jersey Institute of Technology
    Telephone: (973) 596-5611
    E-mail: mitra@njit.edu

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    Phosphate and Thermal Stabilization of Dredged Sediments for Reuse as Construction Material

    Peter Nbida with Professor Lisa Axe
    Department of Civil and Environmental Engineering
    New Jersey Institute of Technology

    Sediments are continuously deposited in rivers, lakes, and shorelines through the natural processes of erosion, transport, and deposition. Because of their capacity to adsorb contaminants, sediments act as an important sink (Vdovic et al., 2006); their contamination can adversely affect the health of organisms impacting the aquatic food chain (Lyman et al., 1987; Peplow and Edmonds, 2005). Navigable waters and harbors are regularly dredged to maintain and sometimes extend water depths. The amount of material excavated can be enormous. Such large quantities of contaminated sediments naturally raise the question of disposal.

    Treatment and reuse of dredged sediments as an alternative to disposal is highly desirable as it reduces the cost of disposal and conserves natural resources. Existing treatment technologies have been, for the most part, adopted from technologies applied on contaminated soil and in the mining industry; however, comparatively, sediment treatment is more expensive because of the high water content (over 50%) and the large quantities involved. Consequently, few existing technologies are actually commercially used (Mulligan et al., 2001). With the need for further development, a novel method is proposed for sediments dredged from the Passaic and Hackensack Rivers: phosphate addition and thermal treatment at 700oC, where organics are mineralized with the off-gas treated by carbon adsorption, and heavy metals are stabilized into sparingly soluble hydroxylapatites (Kribi et al., 2004). If the treatment is found to be successful, the stabilized sediments can potentially be used as construction material.

    References

    1. Kribi, S., A. Nzihou, P. Sharrock. 2004. Stabilization of heavy metals from dredged sediment. Tailoring of residue properties. InProc. pro40: the use of recycled materials in buildingsand structures; Vázquez, E.; Hendriks, Ch. F.; Janssen, G. M. T. Eds.; ISBN: 2-912143-52-7, e-ISBN: 2912143756., 2, 824–832.
    2. Lyman, W.J., A.E. Glazer, J.H. Ong, S.F. Coons. 1987. An overview of sediment quality in the United States, prepared for U.S. Environmental Protection Agency, Office of Water Regulations and Standards, Washington, D.C.
    3. Mulligan, C.N., R.N. Yong, B.F. Gibbs. 2001. An evaluation of technologies for the heavy metal remediation of dredged sediments, J. Hazard. Mater., 85 (2), 145–163.
    4. Peplow, D., R. Edmonds. 2005. The effects of mine waste contamination at multiple levels of biological organization. Ecolog. Engin., 24 (1–2), 101–119. 
    5. Vdovic, N., G. Billon, C. Gabelle, J. Potdevin. 2006. Remobilization of metals from slag and polluted sediments (Case Study: The canal of the Deule River, northern France), Environ. Poll., 141 (2) 359369.

    Featured Science Highlight article by Brookhaven National Laboratory National Synchroton Light Source.

    Contact Information:

    Professor Lisa Axe
    New Jersey Institute of Technology
    Telephone: (973) 596-2477
    E-mail: Axe@ADM.njit.edu

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    Restored oyster reef habitat use by the American Eel (Anquilla rostrata) in the Lower Delaware Bay

    Jaclyn Taylor with Associate Professor David Bushek
    Haskin Shellfish Research Laboratory
    Rutgers, The State University of New Jersey

    A preliminary small-scale oyster restoration project was funded in summer 2006 through a Rutgers University Research Council grant, and demonstrated the potential for creating oyster habitat in the intertidal zone of the lower Delaware Bay. Preliminary minnow trap sampling data showed an increase in macrofauna abundance associated with the shell bag reefs compared to adjacent control sand areas. Of the 27 total fish caught on the shell bag reefs, the American eel (Anguilla rostrata) accounts for 25% of this total, while no eels were caught on the adjacent sand areas.  Interestingly, the total length of A. rostrata increased from 35cm to 55 cm during the June through October sampling season. The preliminary catch and length data from the Cape Shore reefs reported above corresponds with the predicted migration time of A. rostrata.  These findings imply that oyster reef habitat use by American eels in the lower Delaware Bay is important for successful migrations.

    The present study was designed to test the hypothesis that yellow phase American eels, Anguilla rostrata, utilize oyster reefs and oyster aquaculture racks in the intertidal zone of lower Delaware Bay during their migration season.  The objectives were as follows:  1)  Provide novel documentation on the ecological importance of restored oyster beds as habitat for yellow phase Anguilla rostrata in the lower Delaware Bay, 2)  Determine abundance and length-weight relationship of A. rostrata associated with shell restoration and aquaculture sites, 3) Determine the relationship between period of maximum abundance of A. rostrata and their migration season, and 4) Determine if A. rostrata are resident or transient species associated with restoration sites and aquaculture racks through mark-recapture efforts.

    Presentation to the National Shellfisheries Association Centenial Meeting, April 6-10, 2008 in Providence, Rhode Island.

    Contact Information:

    Associate Professor David Bushek
    Rutgers University
    Telephone: (856) 785-0074 X4327
    E-mail: bushek@hsrl.rutgers.edu

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    Using assimilated 13C-DNA to fingerprint active microorganisms in methylmercury demethylation by staple-isotope probing

    Riqing Yu with Professor Tamar Barkay
    Department of Biochemistry and Microbiology
    Rutgers, The State University of New Jersey

    Methylmercury (CH3Hg or MeHg), a lipophilic form of Hg that is a potent neurotoxin, could be readily accumulated by aquatic organisms and severely affect public health via food chain accumulation. The New Jersey Mercury Task Force (NJMTF, 2002) reported that mercury levels in water (e.g. the Hudson-Raritan Estuary) and sediment (e.g. 75% of the NY-NJ Harbor sediment) were found to exceed the related criteria or effect range, respectively. They also found that 43–56% of freshwater fish contained Hg concentrations higher than the FDA Action Level of 0.5 ppm.

    Microbial degradation of MeHg (demethylation), a naturally occurring process of which little is known, plays an important role in mercury biogeochemical cycling and detoxification. To date, two pathways for the degradation of MeHg have been documented (Oremland et al., 1991; Marvin-Diapsquale et al., 2000; Barkay & Wagner-Dobler, 2005). Both pathways imply the conversion of the C1 moiety to gaseous products, either methane or carbon dioxide. The possibility that MeHg is degraded by microbes which utilize the C1 as a carbon source has not been examined and may be a major pathway for MeHg degradation.  The proposed approach will explore this possibility by applying stable-isotope probing (SIP), a recently developed method to taxonomically and functionally characterize microbial species that are active in degradation and bioremediation processes of organic pollutants (Madsen, 2006).  Thus, this project will investigate if microorganisms that are grown in the presence of 13CH3Hg assimilate the heavy carbon isotope into their DNA during demethylation and can consequently be distinguished by SIP. From the 13CH3Hg enrichment with environmental samples, 13C–DNA (or RNA) extracted from the target group of microbes that actively participate in 13CH3Hg demethylation could be characterized taxonomically by SIP. This study will first test if and how the C1 group from MeHg is assimilated into nucleic acids in the cell. If this approach is feasible, identification of the specific groups of microorganisms that degrade MeHg will be possible.

    Literature Cited:

    1. Barkay T., I. Wagner-Dobler. 2005. Microbial transformations of mercury: potentials, challenges, and achievements in controlling mercury toxicity in the environment. Adv Appl. Microbiol. 57: 1-54.
    2. Oremland R. S, C. W. Culbertson, M. R. Winfrey. 1991. Methylmercury decomposition in sediments and bacterial cultures: involvement of methanogens and sulfate reducers in oxidative demethylation. Appl. Environ. Microbiol. 57: 130-137.
    3. Madsen E. L. 2006. The use of stable isotope probing techniques in boreactor and field studies on bioremediation. Curr. Opin. Biotechnol. 17: 92-97.
    4. Marvin-Diapsquale M. C., J. Agee, C. McGowan, R. S. Oremland, M. Thomas, D. Krabbenhoft, C. C. Gilmour. 2000. Methylmercury degradation pathways: a comparison among three mercury-impacted ecosystems. Environ. Sci. Technol. 34: 4908-4917.
    5. New Jersey Department of Environmental Protection. 2002. The NJ Mercury Task Force (http://www.state.nj.us/dep/dsr/mercury_task_force.htm).

    Contact Information:

    Professor Tamar Barkay
    Rutgers University
    Telephone: (848) 932-5664
    E-mail: barkay@aesop.rutgers.edu

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