U.S. Winning Research
2013: Anirudh Jain (Oregon)
Use of Sulfidation As a Novel Method for Reducing the Toxicity of Silver Nanoparticle Pollution
increasing use of silver nanoparticles for their antimicrobial properties,
greater amounts of nanoparticles are being released into the environment, with
potentially adverse impacts on benign microorganisms. This project examined use
of sulfidation as a viable approach to reduce the toxicity of silver
nanoparticle pollution during wastewater treatment. Five sets of silver
nanoparticle samples were used, keeping one set pure and as the control, and
exposing the remaining four sets to increasing concentrations of sulfidation
agent (Na2S). Three toxicity indicators, namely nanoparticle size, surface
charge and release of silver ions were measured. Lastly, the actual toxicity of
samples was tested by measuring the change in E. coli population after exposing
E. coli cultures to the five samples. The release of silver ions and surface
charge decreased and nanoparticle size increased as sulfide concentration went
up, indicating reduction in toxicity. As the sulfide concentration increased,
the amount of E. coli cells killed decreased, proving that exposure to sulfide
reduced toxicity. The experimental results supported the hypothesis,
establishing that sulfidation is a potential solution for reducing the harmful
effects of nanoparticle pollution.
2012: Kunal Sangani (New York)
Modeling and Environmental Analysis of Hydraulic Fracturing in Upstate New York
This study provides a comprehensive examination of the various aspects of hydraulic fracturing in Upstate New York. A model was developed to determine the effect of process parameters on gas production; predictions of the model were shown to match public data from Marcellus Shale wells. The model demonstrated that utilizing fracturing pressures of 40-50 MPa could produce an equivalent amount of natural gas over a 30 year period while mitigating damage to rock structures. An average well produces 1.0-3.5 million gallons of highly contaminated brine called flowback water. Chemical analysis showed that effluents have high concentrations of barium, strontium, and lead, and exhibit beta decay, most likely attributed to Pb210 isotopes. These measurements are perhaps the first documentation of metal ion concentrations and radioactivity in hydraulic fracturing effluent. An ‘established ecosystem’ experiment showed that heavy metals may accumulate in B. rapa plant tissues, thus allowing for biomagnification. Finally, effluent was found extremely toxic to freshwater organisms such as Hydra oligactis; EC50 values and LC50 values were as low as 3.7% and 11.1%, respectively.
2011: Alison Bick (New Jersey)
Development and Evaluation of a Microfluidic Co-Flow Device to Determine Water Quality
It was hypothesized that by combining co-flow microfluidic devices, cell-phones, and the bacteria growth chemical Colilert-18, a novel way of determining water qualities may be found. This channel is photographed and analyzed by a cell-phone. A statistically significant positive correlation between bacteria concentration (coliform and E. coli) and yellow pixel intensity was found. A formula can be derived to assess bacteria concentration based on the distance between the initial and complete mixing points in the channelI.
2010: Rebecca Ye (Maine)
Escherichia coli O157:H7 is a significant pathogenic microorganism responsible for both food- and waterborne illnesses. However, time-consuming culture remains the routinely used method for detection. An immunoassay using the surface of quartz crystal microbalance (QCM) sensor as a platform was developed and optimized for rapid detection of viable E. coli O157:H7. QCM is a piezoelectric sensor able to sensitively detect the deposition of mass on its surface by changes in resonance frequency – in this case, the sequential mass increase due to antibody immobilization to the surface, bacterial capture, and the binding of a second antibody group conjugated with gold nanoparticles. The method achieved high sensitivity for rapid and specific detection of viable E. coli O157:H7, with a pre-enrichment detection limit of 3 log CFU/mL and post-enrichment detection limit of 0 log CFU/mL. The specificity of the method was demonstrated by a lack of significant frequency change when comparable concentrations of other bacteria were tested. Results are available within hours. The method has excellent potential for rapid coliform detection
2009: Eileen Jang (North Carolina)
Natural Organics Control Aggregation of Mercury Sulfide Nanoparticles in Freshwater Systems
Mercury (Hg) is an environmental contaminant that is neurotoxic to humans, particularly to individuals exposed through consumption of fish. This study focuses on mercury sulfide nanoparticles in freshwater aqueous systems. The goals of this study were to: 1) synthesize uncapped HgS nanoparticles, 2) characterize these nanoparticles, and 3) test aggregation rates of nanoparticles in solutions simulating natural conditions. This research has deepened the understanding of aqueous mercury and furthered the field of nanogeoscience.
2008 International Winner: Joyce Chai (California)
Modeling the Toxic Effects of Silver Nanoparticles under Varying
Due to the abundance of silver nanoparticles in the nanotechnology consumer market, "nanosilver" has become a major concern in the scientific community. This investigation attempts to model and quantify the toxicity of nanosilver under varying environmental conditions and to measure the reliability of a nanosilver consumer product. In Phase I and II of this investigation, a novel, high-throughput bacterial toxicity assay was developed in order to quantify the toxicity of nanosilver, redefined as the percentage of dead cells that died in excess to that of the natural death of cells. Most importantly, Phase III of this investigation repudiated the assertion that silver nanoparticles are more reliable and less environmentally hazardous. This investigation took fundamental steps toward understanding and quantifying the potential environmental consequences and risks of using nanoparticles.
2007: Jingyuan Luo (Arizona)
Toxicity and Bioaccumulation of Nanomaterials in Aquatic Species
Jingyuan studied toxicity and bioaccumulation of nanoparticles, especially in aquatic environments. Nanoparticles, used in products ranging from stain-free clothing to sunscreens and cosmetics, have undergone accute toxixity testing, but not many long-term exposure tests have been done. This project investigated the effects of nano-scale zinc oxide (ZnO) and carbon fullerenes (C60) on Chlamydomonas reinhardtii, green alga, and Daphnia magna, water fleas. Three different toxicity tests were conducted: two toxicology tests in which particles were directly introduced in the environments of C. reinhardtii and D. magna and a third test for bioaccumulation of nanoparticles from the alga to the Daphnia. The effects of nanoparticles were greatest in the long-term.
2006: Emily Brownlee (Maryland)
A Tale of Two Oysters: The Chesapeake Bay Native and the Non-Native Oysters and the Effects of an Increasing Water Quality Problem, Algal Blooms
With the decline of the native oyster, Crassostrea virginica, in the Chesapeake Bay due to disease, over-harvesting, and loss of habitat, ways to increase oyster production are of great interest. Emily studied the possibility of introduction of a new species of oyster, Crassostrea ariakensis, the Asian or suminoe oyster, to the Chesapeake Bay, and the effect of phytoplankton blooms on the growth of spat of this oyster. Algal bloom events have long been recognized in the Bay, but are increasing, symptomatic of poor water quality. High susceptibility of both oysters to the ichthyotoxic bloom species Karlodinium in their first weeks of growth indicates potential major problems for the bivalves in the system as long as the Bay's water quality remains poor.
2005: Kathryn VanderWeele (Oregon)
Removal of Arsenic from Drinking Water by Water Hyacinths
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Kathryn studied the phytoremediation of arsenic by water hyacinths (Eichhornia crassipes). Arsenic poisoning from naturally occurring arsenic in drinking water is a serious problem, affecting the health of up to fifty million people worldwide. Drinking arsenic tainted water daily eventually leads to death. Arsenic poisoning is an important issue in Bangladesh, where at least thirty percent of water wells have an arsenic level above the drinking water standard. Kathryn sought to determine for how long the same water hyacinths could be used effectively to reduce arsenic concentrations, and to determine where these plants store the arsenic. Her project demonstrated that water hyacinths are capable of substantially reducing arsenic level to the Bangladeshi drinking water standard (50 ppb) for two treatment periods.
2004: Brandon Fimple (Oklahoma)
The Environmental Impact of Aluminum Sulfate and Salicylic AcidTreated Poultry Litters on Forage Production and Watersheds
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2003: Heather Mispagel (Georgia)
Antibiotic Resistance from Sewage Oxidation Ponds
2002 International Winner: Katherine F. Holt (Virginia)
Cleaning the Chesapeake Bay with Oysters
2001: Brenda Goguen (Virginia)
Molecular Characterization of Potential Fish Pathogens inWaters Where Reported Pfiesteria piscicida Outbreaks Have Occurred
2000 International Winner: Ashley Mulroy (West Virginia)
Correlating Residual Antibiotic Contamination in Public Waterto the Drug-Resistance of Escherichia coli
1999: Kelly Serocki, formerly Kelly Schmiedt (Minnesota)
Chemical and Biological Analysis of Pike Creek 1998
1998 International Runner-Up: Brett De Poister (Pennsylvania)
Effects of Zinc, a Heavy Metal, and Diazinon, a Common Pesticide, on the Embryonic Development of the African Clawed Frog
1997 International Winner: Stephen Alexander Tinnin (Texas)
Changes in Development, Sperm Activity, and Reproduction in Lytechinus variegatus Gametes Exposed to Pesticides