American Water Resources Association

Student Poster Presentations

11 May 2016

Zachary Zukowski, Villanova University

Abstract: Rain gardens are one type of stormwater control measures (SCMs) which are used to reduce the quantity and improve the quality of water through infiltration and evapotranspiration (ET). Rain garden soils maybe either native or engineered media. Hydraulic conductivity is typically used as a performance measure of rain gardens, and this is most commonly determined in the field using infiltration testing. The most common type of infiltration testing is the double-ring infiltrometer (ASTM D3385); however, these systems require a large amount of water, can be difficult to install, and are time consuming to perform. Smaller single-ring infiltrometer tests can be easier to install and require less water. Additionally, more tests could be performed in the same amount of time, which means more area of a site can be tested. Since the accuracy of these methods is not well-documented, this study compared single ring infiltrometer data to historical recession rate data recorded in the pond of the SCM to determine the accuracy of this testing technique.

9 March 2016

Kellen Pastore, Villanova University

Abstract: In this poster, the design and implementation of low-cost instrumentation for green stormwater infrastructure (GSI) monitoring is discussed. As the use of GSI increases, monitoring becomes more and more critical to prove efficacy of the sites, inform future designs, and guide maintenance. This can be expensive and difficult, especially in the case of existing sites that need to be retrofitted. As part of Philadelphia's Green City, Clean Waters initiative, GSI sites are being installed throughout the city of Philadelphia. The Villanova Urban Stormwater Partnership (VUSP), the Villanova Center for Nonlinear Dynamics and Control (CENDAC), and Philadelphia Water (PWD) have partnered to study the effectiveness of these sites through extensive monitoring of select GSI installations. To accomplish this task, low-cost computing hardware is being leveraged to develop highly reliable, yet inexpensive instrumentation (data logging, sensor interfaces, telemetry, etc.) In the following, work being done in parallel at VU and PWD is presented with a focus on soil moisture monitoring.

Erica Forginone, Villanova University

Abstract: Road de-icing salt is one contaminant of concern in stormwater runoff, as it has been shown to have negative effects on plant and animal species, decrease biodiversity, and degrade environmental quality. It has been assumed that road de-icing salt would wash through watersheds with spring rains, as road salt (usually NaCl) is soluble, and chloride (Cl-) has long been considered a conservative tracer. However, many recent studies suggest that significant proportions of chloride mass may be retained within a watershed and that chloride levels resulting from winter salting activities may remain elevated late into summer months. Stormwater control measures (SCMs) have been praised for both volume reduction and improved water quality, but recent studies are showing that certain SCMs may increase the negative effects of road salting on the surrounding environment, such as contamination of groundwater, trace metal leaching, stratification in ponds, toxic effects, and reduced biodiversity. Because chloride poses a possible threat to downstream waters, a study was performed to study the fate and transport of chloride through one SCM, a constructed stormwater wetland (CSW), on Villanova’s campus.

The study had three main goals: i.) to determine if effluent concentrations of chloride from the CSW meet recommended EPA standards for both chronic and acute criteria; ii.) to compare total dissolved solids (TDS), conductivity, and chloride concentration data in order to further validate the data sets and also quantify correlations between each parameter; and iii.) to perform a mass balance of chloride to study the fate and transport of chloride upstream, within, and downstream of the CSW. Chloride concentrations and TDS/conductivity/chloride correlations were analyzed over a period of four years, from December 2011 - November 2015 and a mass balance was conducted with flow data for 2013 and 2014. 

13 January 2016

Scott Jeffers, Dexel University

Abstract: Human alterations to the environment provide infrastructure for housing and transportation but have drastically changed local hydrology. As a result of building with impervious surfaces such as concrete and asphalt, excess stormwater runoff is generated that causes land erosion, overburdens sewer infrastructure, and can pollute

receiving bodies of water with land contaminants. These issues can be mitigated using green stormwater infrastructure that seeks to mimic pre-developed hydrologic runoff conditions by capturing or slowing the flow of stormwater. When designing a stormwater management plan, it is important to know how well the green infrastructure will perform. One way to quantify this performance is by its hydrologic abstraction, or the water

volume the system will retain through processes such as infiltration, evapotranspiration,and storage capacity. The hydrologic abstraction can be determined using empirical methods by measuring inflow and outflow through the facility. In this study, hydrologic abstractions are determined for three different green infrastructure pilot facilities in New York City using empirical methods in order to determine the stormwater capture potential of each facility. While hydrologic abstractions vary with each storm as a result of varying antecedent conditions, it is recommended that the abstractions be presented as a range in order to accommodate for inherent intra-storm variability.

14 October 2015

Pablo Garza, Villanova University

Abstract: The William Penn Foundation awarded a grant to the Villanova Urban Stormwater Partnership (VUSP) for the monitoring of green stormwater infrastructure to be installed in the headwaters of creeks looked after by the Upstream Suburban Philadelphia Cluster team. One of the current three projects which will be monitored by the VUSP will be installed at the College Settlement Camp which is part of the headwaters of the Pennypack creek. The stormwater control measures (SCMs) consist of stream embankment restoration, a stormwater wetland and a rain garden. Construction of this effort began on October the 12th and the monitoring equipment will be installed shortly after completion.

9 September 2015

Stephanie Molina, Villanova University

Abstract: Stormwater management is a practice currently implemented in the form of rain gardens, green roofs and constructed stormwater wetlands to reduce the amount of nutrients and metals found in stormwater runoff. At Villanova University a Constructed Stormwater Wetland (CSW) has been implemented as a mean to reduce the nutrients and metals concentration in stormwater runoff that is entering the headwaters of Mill Creek. Over the years this stormwater control measure (SCM) has been analyzed as a whole but little is known on the mechanics of each individual section. The main objective of this research is to understand the basic mechanics of the Inlet Sedimentation Forebay with emphasis on Nitrogen and the Nitrogen Cycle.

Catherine Barr, Villanova University

Abstract: Recent studies on green roof water quality have indicated that extensive green roofs are a source for phosphates, and occasionally a source for nitrites as compared to conventional roofing systems.  In this study a green roof was compared to other vegetated land uses for nutrient retention because, unlike traditional roofs, green roofs have soil media and vegetation.  Green roof overflow was evaluated for water quality parameters including nitrogen and phosphorus species, chlorides, total suspended solids, and total dissolved solids.  Results indicated that the green roof generally retained nitrogen and released phosphorus; its performance was similar to or better than that of a grassy area and a wooded area in terms of nutrient retention, and performed similarly to an area that was at least 50% impervious.  Comparisons to USEPA recommended nutrient criteria for surface waters indicated that the green roof generally did not release nitrogen in excessive concentrations, however phosphorus export concentrations were above recommended levels.  In addition, green roof overflow was compared to that of a nearby stormwater wetland and a rain garden using data obtained from simultaneous storm testing events.  Both rain garden and stormwater wetland outperformed the green roof in terms of nutrient retention.  It is suggested that if nutrient export is a concern and space is available, green roof overflow could be diverted to other stormwater control measures which are designed to remove excess nutrients from stormwater runoff.

Taylor DelVecchio, Villanova University

Abstract:  Rain gardens are an effective means to control stormwater. The current state of practice only allows designers to calculate storage based upon the volume of the bowl and possibly the void space of the soil in Pennsylvania. Infiltration and evapotranspiration (ET) remain unaccounted for in design. Other design components, such as depth and soil type, are often restrictive and vague. In addition, current research demonstrates the importance of ET in vegetated stormwater control measures (SCMs), however, the soil mix guidelines heavily favor infiltration. Establishing soil mix guidelines that consider both infiltration and ET will enable greater creativity in SCM design and flexibility in siting SCMs. A total of twelve column non-weighing lysimeters will be used to evaluate soil mixes that span the USDA classification triangle (Figure 1). Six of the lysimeters will have a 46 cm depth and the other six with have a 20 cm depth. Both depth setups will contain the following soils: sandy loam (typical rain garden mix), loamy sand, loam, silt loam and clay loam. Five of the lysimeters will have switch grass. A bare control lysimeter will contain a sandy loam soil. Soil analyses (i.e. grain size analysis, organic content, liquid and plastic limits, soil-water characteristic curves, cation exchange capacity) will be performed on each soil.

13 May 2015

Reconstructing the Historical Streams and Wetlands of Philadelphia

Nicole Wagner, West Chester University

Abstract: The hydrologic landscape of Philadelphia underwent significant changes in the nineteenth century. Wetlands and stream channels were often buried or extensively modified for use in industry. At one point the city was crisscrossed by at least forty streams, along with the two major rivers, the Delaware and Schuylkill. Today, only twenty-two streams remain. As part of its sustainability plan, the city seeks to reduce stormwater runoff in a number of ways, including the creation of new tidal and non-tidal wetlands, the restoration of waterways, and the creation of new public green spaces and corridors. Successful restoration of an ecosystem requires multiple lines of evidence to ascertain reference conditions. To this end, I sought to reconstruct the nineteenth century streams and wetlands in Philadelphia, a period beset by rapid transformation of the city. This time period pre-dates aerial photography of the city, and thus one source of evidence useful in this task was found in the herbarium data from the Academy of Natural Sciences in Philadelphia. I georeferenced herbarium records of wetland-obligate plants using Google Earth, utilized maximum extent calculators to create buffers of uncertainty, and, in collaboration with other historical archives and maps, pinpointed specific locations that were once high-quality wetlands in the city. Thesis results showed the highest level of uncertainty lies in the Southeast region of Philadelphia County, with the lowest level of uncertainty residing in the Northwest region. Georeferencing the historical wetlands with present-day imagery can provide planners, city managers, and interested citizens a better understanding of what sites might be well suited for wetland reconstruction.

Flash Flood Zones and Green Stormwater Infrastructure in Philadelphia: Areas for Further Improvement

Ela Doganay, Temple University

Abstract: Because combined sewer system combines sewage and stormwater and flows them together into a river in moderate to large rain events to prevent flooding, it has been one of the major water pollution concerns for the approximately 772 cities in the U.S., as well as Philadelphia. These combined sewage overflows (CSOs) negatively impact river ecosystems, aquatic wildlife and water quality and violates the EPA’s Clean Water Act (CWA). At this point, it is important to mitigate any stormwater issue like flash flooding to prevent CSOs. It is for the above reasons that Philadelphia should be strategic in its placement of green stormwater infrastructures to prevent flash flooding and CSO. 

Constructed Stormwater Wetlands: A Sustainable Green Infrastructure

Ashley Neptune, Villanova University

Abstract: Constructed wetlands may be construed as a place of muck and mosquito infestation. However, in the context of Green Infrastructure (GI), a Constructed Stormwater Wetland (CSW) provides multiple functions and sustainable solutions. From peak flow reduction and groundwater recharge to nutrient removal and wildlife habitat, CSWs offer numerous benefits that can exceed most other GIs. Due to CSWs requiring more land, as well as complexity in their design, there are few presently being constructed for treatment purposes. To demonstrate that CSWs are a viable and sustainable GI to be included in current stormwater management plans, the present research will highlight Villanova University’s CSW and its development and benefits, including peak flow and volume control, water quality improvement, educational value, habitat establishment, and ecosystem services. The research objective is to provide greater knowledge on CSWs and why they should continue to be considered and implemented as part of communities’ management plans.

11 February 2015

Development of novel adsorbents for the removal of emerging contaminants from water

Bikash Bhattarai, Temple University

Abstract: There are many reports indicating the presence of various trace organic contaminants in treated wastewater and other water sources. The detection of such contaminants in environment and the ability of these contaminants to pose potential threats to environment at very low concentrations have led to a need for more efficient treatment technologies.Natural polymers such as polysaccharide and their derivatives have gained significant interest as alternative adsorbents for water and waste water treatment because of their unique physico-chemical characteristics and excellent selectivity towards organic compounds and metals. An important class of polysaccharide derivatives is cyclodextrins (CDs). The property of CD to form inclusion complexes with various molecules through host-guest interactions has made it a useful compound for the removal of a number of contaminants from water and wastewater. In this research, a hybrid adsorbent was synthesized by coating β-cyclodextrin (BCD) onto silica and was tested for the removal of selected trace organics. 17β-estradiol (E2), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and bisphenol-A (BPA) were selected as model contaminants to represent the trace organic contaminants. The adsorbent showed more than 95% removal of E2 and PFOA and upto 90% removal of BPA in Milli-Q (MQ) water. A sustainable way of regenerating the adsorbent was developed where ozone was used to destroy the contaminants trapped in the saturated adsorbent there by regenerating the adsorbent for reuseThis regeneration process without generating any waste was very effective in regenerating the adsorbent over seven successive cycles for the removal of BPA and E2 without significant loss in its adsorption capacity.

Green Roof Technology- Is it helping?

Raquel Burlotos, Villanova University

Abstract: Green Roofs are a relatively new technology, which has the potential to reduce stormwater volume while improving water quality. Recently, concern has grown that green roofs may actually release nutrients (e.g. Nitrogen and Phosphorous) into the environment. The goal of this study was to place this potential nutrient release into context by comparing the nutrient concentration in the green roof runoff to precipitation and runoff from a wooded and grassy area. By testing the runoff for nitrogen and phosphorous, the study determined that green roof technology is a positive stormwater control measure that releases fewer nutrients into its runoff than grassed or wooded areas.

14 January 2015

Improving Rainfall Runoff Modelling with Microtopography

Paul SenkerTemple University

Abstract: The impact of topographic resolution on rainfall-runoff  models was assessed in a stormwater runoff study of “Lot 10,” located at the corner of 12th and Diamond Streets on the Temple University Campus.  Lot 10 was modeled twice using the U.S. EPA’s Stormwater Management Model (SWMM). In the first model, existing 2-ft coarse topographic contours were used to delineate 11 subcatchments. In the second model, ArcGIS was used to delineate 36 subcatchments based on a high-resolution, 0.25-ft microtopgraphic digital elevation model (DEM) developed from LIDAR data. Both SWMM simulations included the same hydraulic features and outfall point so that differences in simulation outcomes could be attributed solely to differences in topographic resolution. Based on model results, use of microtopography (0.25-ft) resulted in a 3.3% reduction in peak runoff rate and a 4.1% reduction in total runoff volume for the 2 yr-24 hr and the 100 yr-24 hr storm events. In addition, continuous modeling using locally observed rainfall collected between October 2011 and June 2013 showed that the microtopography model produced longer runoff periods and better fit observed runoff depths, with mean square error (MSE) values 1.33% to 32.0% lower than the MSE for the coarse topography model.

Green Infrastructure: Hydraulic Performance Analysis of the ABC Carpet Stormwater Treatment Wetland installed in the Bronx, NY

Jeff Pu, Drexel University

Abstract: The impact of topographic resolution on rainfall-runoff  models was assessed in a stormwater runoff study of “Lot 10,” located at the corner of 12th and Diamond Streets on the Temple University Campus.  Lot 10 was modeled twice using the U.S. EPA’s Stormwater Management Model (SWMM). In the first model, existing 2-ft coarse topographic contours were used to delineate 11 subcatchments. In the second model, ArcGIS was used to delineate 36 subcatchments based on a high-resolution, 0.25-ft microtopgraphic digital elevation model (DEM) developed from LIDAR data. Both SWMM simulations included the same hydraulic features and outfall point so that differences in simulation outcomes could be attributed solely to differences in topographic resolution. Based on model results, use of microtopography (0.25-ft) resulted in a 3.3% reduction in peak runoff rate and a 4.1% reduction in total runoff volume for the 2 yr-24 hr and the 100 yr-24 hr storm events. In addition, continuous modeling using locally observed rainfall collected between October 2011 and June 2013 showed that the microtopography model produced longer runoff periods and better fit observed runoff depths, with mean square error (MSE) values 1.33% to 32.0 % lower than the MSE for the coarse topography model.

12 November 2014

Experimental Protocol: To Have or Not Have Lessons Learned from Green Roof Drainage Layers Lysimeter Experiment

Evgeny Nemirovsky, Villanova University

Abstract: Monitoring stormwater control measures (SCMs) is fundamental to better understanding, designing and implementing SCMs. Long-term monitoring programs require diligence in quality assurance of raw data. With focus on long-term monitoring, amount of the data might provide false confidence in quality of the collected data. However, quantity of data is unlikely to compensate for its quality. Data processing, although effective in filtering out-of-range values, has limited effect on (correcting) measurement errors due to instrument accuracy or setup limitations. To ensure success of the monitoring program, it is essential to define required quality of the data at early stages of the experiment design. The developed criteria would affect design of the setup, instrument selection, equipment maintenance protocol, and ultimately, cost of the project. While iterative approach to What? How? and Why? to measure is not uncommon, it is a good practice to have a clear research objective and formulate specific question(s) that the monitoring program / experimental setup in designed to answer. Loosing this focus might result in “retrofitting” research objective to conform to quality of the existing data. The paper addresses those questions with a case-study of Green Roof at Saint Joseph’s University. Several technical challenges that might impact quality of the collected data were discussed. Recommendations for setup maintenance and data checks to improve quality of the data were presented. The need for standardized data acceptance criteria for SCM monitoring was discussed. An example of data quality requirements for lysimeter system needed to satisfy various research objectives was provided. 

Arsenite and Chromate Remediation on Ferrihydrite via Coupled Redox Transformations

Elizabeth Cerkez, Temple University

Abstract: Frequently, more than one contaminate is present in remediation scenarios, such as water purification, industrial site reclamation, or acid mine drainage cleanup.  Many of these contaminates’, particularly metals and metalloids, ability for removal are governed by their oxidation state. Examples of two of these contaminates are Arsenic and Chromium; with Arsenite (As(III)) and Chromate (Cr(VI)) being more toxic and mobile than Arsenate (As(V)) and trivalent chromium (Cr(III)). In this study we demonstrate the adsorption of As(III) and Cr(VI) followed by the oxidation to As(V) and reduction to Cr(III) on the environmentally relevant mineral, Ferrihydrite (Fh). In the absence of Fh, or when As(III) or Cr(VI) are adsorbed independently, no change in oxidation state is observed. Through the use of in-situ Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) this coupled redox has been observed to occur in many conditions, such as varied pH (3, 5, and 7) and in the presence and absence of dissolved O2. We find that the coupled redox is most complete at low pH, due to increased adsorption of As(III) and Cr(VI), and also in the presence of dissolved O2. Our results indicate the addition of high surface area adsorbents maybe a useful remediation strategy for immobilization through adsorption and redox chemistry in multi-contaminate systems.

8 October 2014

Emerging Contaminants in the Delaware River Watershed

Djordje Vilimanovic, Temple University

Abstract: The goal of this research project is to increase our understanding of the occurrence of contaminants of emerging concern (CECs) in surface waters by collecting and analyzing ambient water samples from a targeted area of the Delaware River Basin. Concentrations of CECs are generally higher in urbanized and industrialized areas as was found in a previous study of the tidal Delaware River (report by DRBC; MacGillivray, 2012). The ten sampling sites in this study are in an area of southeastern Pennsylvania with numerous municipal and industrial discharges to surface water. The sampling locations are above and below potential source discharges for CECs in watersheds draining to the Delaware River (Figure 1). Data and information obtained from this study should advance our understanding of the prevalence of emerging contaminants in relation to potential sources and build on previous studies. Collectively, this information can provide environmental managers and other members of the environmental community and stakeholders with a greater awareness and better understanding of the presence of unregulated contaminants of concern in surface waters. This project can provide information needed for water quality planning and policy for emerging contaminants.

10 September 2014

Effects of Diagenesis in the Mineralogy and the Total Organic Carbon Content of the Marcellus Shale in Core Samples from Northern Pennsylvania and an Outcrop Sample from Central New York

Pablo Graza, Villanova University

Abstract: Profitable hydrocarbons production in the Marcellus shale gas play has been possible because of three main factors: the Marcellus formation’s excellent source rock qualities, technological advancements in hydraulic fracturing stimulation and directional drilling, and a steady increase in price and demand of hydrocarbons. This project examines the mineralogy and organic carbon content of the Marcellus shale in Northern Pennsylvania. Three core samples at different depths were obtained from the Pennsylvania Geological Survey core library and an outcrop from central New York was obtained from the University of Pennsylvania. They were analyzed using x-ray diffraction at the University of Pennsylvania and Rock-Eval pyrolysis conducted by a private source rock analysis laboratory in Texas. The study describes how the mineralogy and the total organic carbon content of the Marcellus Shale were affected by burial diagenesis. The mineralogy observed by the x-ray diffraction analysis was consistent with the literature of the Marcellus shale, consisting primarily of quartz, carbonate minerals and clays. The organic material identified through Rock-Eval pyrolysis in the four samples was kerogen type II. The core  samples showed thermal maturity and all of them were classified as potential dry gas source rock.

Evaluation and Implementation of Stormwater Control Measures for the North Branch of the Park River Watershed Improvement Project

Margaret Chase, Villanova University

Abstract: At 39 Woodland Street in Hartford, Connecticut, large parking lots were built along the North Branch of the

 Park River. The proximity of these properties to the river leads to several water quality impairments, negatively affectingthe health of the river and the function of the parking lots. The stormwater from 39 Woodland Street is discharged directly to the North Branch of the Park River through a combined stormwater sewer system onsite, potentially carrying with it any pollutants present onsite. The objective is reduction of peak flow and total volume of runoff and pollutant loading into the Park River associated with a 1-inch, 24-hr storm. To this end, our team presents a site design utilizing bioretention basins as a stormwater control measure (SCM). Site details for 39 Woodland Street were gathered through GIS layers, maps, surveying, site visits and personal communications. Relevant information was used to conduct a hydrologic analysis to delineate sub-watersheds that became the basis of SCM implementation. The SCS curve number method was used in conjunction with this site information to design the bioretention features used, and Bentley CivilStorm was used to model the designs and evaluate their effectiveness.

15 May 2014

Comparing Lysimeter ET Measurements to Entire Green Roof Performance

Gerald Zaremba, Villanova University

Abstract: Green roofs are often times under-credited for stormwater volume reduction. However, research has shown that volume reduction due to evapotranspiration (ET) can account for a significant portion of the water balance. Villanova’s Green Roof was constructed in the summer of 2006 atop the Center for Engineering Education and Research, and has been continuously monitored since 2009. Past research has focused on quantifying potential ET from an undrained weighing lysimeter on the roof. With the installation and calibration of outflow-measuring instrumentation, future investigations will focus on comparing the ET measurements of the lysimeter to the performance of the entire green roof with a drainage system. Using preliminary data for over 6 months, including data from more than 10 storms of varying size, analysis has shown very similar water balances for both the green roof and the lysimeter. 

17 April 2014

Reduction transformation of N–O Containing Compounds by FeII Species

Yiling Chen, Temple University

Abstract: The N–O bond is a common function group in organic contaminants. Reduction of various N-O containing compounds (NOCs) including N-oxides, oximes, isoxazoles and hydroxylamines were investigated in the presence of dissolved FeII or FeII-tiron complex. The trend in the reactivity follows: phenyl N-oxide >> aliphatic oxime > aliphatic N-oxide >> aromatic N-oxide with side chain >> isoxazole >> phenyl hydroxylamine > aromatic oxime > aromatic N-oxide without side chain > imino N-oxide. Reduction products of the NOCs were identified by HPLC/QToF-MS to be the deoxygenated analogs. Our ongoing work examines the transition states associated with the potential rate-limiting steps for the reduction of all NOCs and the molecular descriptors that can be correlated to reactivity. The overall goal is to develop predictive models that are necessary to evaluate the fate and risks of structurally-related environmental contaminants.

Simulated Runoff Testing: Performance Testing of Green Stormwater Infrastructure in Controlled Conditions

Benjamin Yezuita, Drexel University

Abstract: The Philadelphia Water Department has taken steps to reduce combined sewer overflow through the means of Green Stormwater Infrastructure. Stormwater management practices (SMPs), such as rain gardens and underground tree trenches, are designed to capture stormwater, promote infiltration and evapotranspiration, or slowly release stormwater into gray infrastructure after the peak intensity of the storm. In accordance with PWD’s Comprehensive Monitoring Plan (CMP), monitoring is being conducted on certain SMPs to validate that their performances meet the design standards. For a SMP on Hewson Street in the Kensington area of Philadelphia, a simulated runoff test (SRT) was conducted to determine the performance of the infiltration stormwater tree trench. Standardized monitoring methods coupled with metered flow into the system allowed for the calculation of the recession rate of water out of the SMP.

20 March 2014

EPA Campus RainWorks Entry: Green Infrastructure Design Concepts for Lancaster Avenue Redevelopment

Kyle Johnson, Villanova University

Abstract: The EPA Campus RainWorks Challenge presents an opportunity to incorporate innovative green infrastructure designs and holistic planning into university development plans in an effort to reduce site runoff, mitigate surface and air pollutants, and promote collective awareness about the impacts of sustainable design. Future development along Lancaster Avenue, the main corridor through Villanova University's campus, provides an excellent opportunity to further the University’s commitment to sustainability while reducing environmental impacts and improving aesthetics.

20 February 2014

Understanding and Modeling Sorption Mechanisms of Organic Compounds on Cation Exchange Resins

Nastaran Jadbabaei, Temple University

Abstract: Understanding sorption mechanisms of organic contaminants on cation exchange resins will enable the application of these resins in water and wastewater treatment. For this purpose, sorption of 12 organic cations and eight aromatic neutral chemicals (nitrobenzene, four phenols and three anilines) on two strong cation exchange resins, Amberlite 200 (porous, polystyrenic) and MN500 (microporous, polystyrenic), was studied. Removal of both the neutral compound (i.e. nitrobenzene) and the permanent charged cations on these two resins was pH-independent. On the other hand, the removal of weak bases such as aniline strongly depends on the solution pH. The protonated aniline had a much higher adsorption capacity than the neutral species. Moreover, adsorption capacities of the neutral compounds were significantly less than those of the ammonium cations, indicating electrostatic interactions are much more important than hydrophobic interactions in the overall removal by the resins. Adsorption isotherms of all the target compounds were determined and fitted well by the polyani theory-based Dubinin-Ashtakhov (DA) model. Typically the adsorption capacities follow the trend: aromatic cations >aliphatic cations>neutral aromatic solutes. The Abraham descriptors were examined in order to develop polyparameter linear free energy relationships between the Gibbs free energy of adsorption and the descriptors. The goal is to quantify the energy contributions of the dominant molecular interactions, determine factors that affect resin selectivity, and develop quantitative models that can be used to estimate the removal of other structurally similar contaminants by the resins.

21 November 2013

The Pailaviri Tailings Deposit, Potosi, Bolivia: Extreme Acid Drainage Generation

Ashley Neptune, Villanova University

Abstract: The historic mining center of Cerro Rico de Potosí, Bolivia is marked with many tailing piles, with the Pailaviri tailings deposit being of great concern. These polymetallic sulfide tailings release some of the highest concentrations of ecotoxic metals observed in natural waters. In order to obtain a deeper understanding of the deposit, water samples were taken in transects throughout the deposit. Total metal concentrations in the waters were extremes: Al (25-2.9 g/L), As (1700-330 mg/L), Cu (850-140 mg/L), Fe (100-24 g/L), Mn (110-70 mg/L), Pb (36-21 mg/L), and Zn (3.1-1.9 g/L). Dissolved concentrations were essentially equivalent indicating these metals were in aqueous phase. Sulfate ranged from 136 to 400 g/L. Due to extremely acidic nature of the water, the pH probes quickly degraded and became inoperable, rendering accurate pH measurements impossible. These results provided evidence of highly toxic conditions and likely downstream impacts due to close proximity of the Rio Huyana Mayu. The extremely elevated concentrations of metals indicate that the Pailaviri deposit may be reprocessed at a profit and safely disposed of, an option which should be investigated.

17 October 2013

Genetic Response of Plants Exposed to Anti-Influenza Drugs

Rashid Kaveh, Temple University

Abstract: The neuraminidase antiviral drugs, oseltamivir phosphate (OSP) and zanamivir (ZAN), are major medications currently used for the treatment of influenza. These drugs have been detected in municipal wastewater and water discharge basins. They are likely to contaminate agricultural plants through irrigation with reclamation water and/or land application of biosolids. However, little is known about the effects of antiviral drugs on plants at the molecular level. In this study, the effects of OSP and ZAN on the model plant, Arabidopsis thaliana, were investigated. Exposure of Arabidopsis plantlets to OSP added to the growth medium showed a significant reduction of the biomass at concentrations of 20 and 100 mg L-1. Exposure of Arabidopsis to ZAN did not result in any significant effect at concentrations up to 100 mg L-1. Gene expression in the exposed plants were analyzed using Affymetrix expression microarrays. Exposure to 20 mg OSP L-1 resulted in up-regulation of 15 genes and down-regulation of 30 genes. Exposure to 20 mg ZAN L-1 resulted in up-regulation of 40 genes and down-regulation of 148 genes. Many genes differentially-expressed were found to be involved in response to various stimuli and stresses, suggesting that these compounds exerted negative effects on the plants. A number of genes were differentially-expressed in response to both OSP and ZAN, suggesting that the two antiviral drugs induced rather similar transcriptional responses. In agreement with prior studies conducted with other organisms, our results suggests that the neuraminidase antiviral drugs, OSP and ZAN, exert low phytotoxicity.

Effect of Natural Organic Matter on the Oxidative Reactivity of δ-MnOin Binary Oxide Mixtures

Saru Taujale, Temple University

Abstract: MnO2 is a common soil and sediment constituent that demonstrates a high reactivity with many organic pollutants. It has been shown to oxidize a variety of organic contaminants such as phenols, anilines and aromatic amines. However, a limited amount of information is available about the reactivity of MnO2 when it co-exists with other commonly found metal oxides such as Al or Fe oxides. So, to properly determine the fate of organic contaminants, it is necessary to study the reactivity of MnO2 in a more complex system where MnO2 co-exists with other metal oxides. Some of the observed interactions between different metal oxides in a mixed system include heteroaggregation, surface complexation and surface precipitation. Our previous work on oxidation of triclosan by MnO2 in the presence of secondary metal oxides such at Al2O3, SiO2 and TiO2 showed that these secondary metal oxides lowered oxidative reactivity of MnO2 due to both aggregation of the metal oxides and the complexation of soluble metal ions with MnO2. Besides the metal oxides, natural organic matter (NOM) is another important component of the soil-water environment. NOM have been shown to be adsorbed by different mineral/metal oxides through ligand exchange between the functional groups of the NOM and the oxide surface. The coating of NOM changes the characteristics of the mineral surfaces such at the zeta potential which affects their behavior such as aggregation and adsorption of trace metal ions. The purpose of this study was to elucidate the effect of NOM on the oxidative reactivity of MnO2 in binary oxide mixtures. Our hypothesis is that the presence of NOM will affect the oxidation process by interfering with the aggregation process among MnO2 and the secondary metal oxides and also by forming complex with the soluble metal ions that would otherwise complex with MnO2.

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