HOOSIER SCIENCE AND ENGINEERING FAIR
2018 Winners of INAEP's Special Recognition Awards (Senior Division)
1st Place, INAEP Award of Excellence in Environmental Science
Certificate and $300 Award
Signature School Inc, Evansville, Indiana
An Improved Method for Trace Level Arsenic Quantification in Water
Arsenic, “king of poisons,” threatens public health on an unprecedented scale with over 140 million people in 50 countries drinking water contaminated with arsenic at levels above the EPA/WHO guideline of 10 ppb. The EPA reports that As3+ is probably the most difficult substance encountered in the water purification industry, where its high toxicity and widespread occurrence create the need for effective monitoring. Quantification methods for arsenic are complex, expensive, and time-consuming.
Herein, a simple method for trace level quantification of arsenic in water meeting EPA limits using methyl red bromination and spectrophotometry is proposed. First, bromine oxidizes As3+ to As5+. Then, the residual bromine reacts with methyl red to form colorless brominated methyl red. Residual methyl red absorbance at 518nm forms the basis of quantification. With an increase in arsenic levels, less bromine remains to react with methyl red, leading to higher absorbance intensities of residual methyl red. Detailed optimization studies with bromine, acid, and indicator levels led to significant improvements over a previous study (Pandurangappa, 2011). While the earlier study quantified arsenic only in the 50-250 ppb range (not EPA levels), the current study quantifies in the 5-20 ppb range, providing a tenfold improvement and encompasses the EPA limit of 10 ppb. These insights were also applied to create a simple point-of-use test which is ten times cheaper and faster than current test kits. This study is the first in literature using a common indicator, methyl red, and spectrophotometry to quantify arsenic below EPA limits.
2nd Place, INAEP Award of Excellence in Environmental Science
Certificate and $200 Award
Northwestern Sr High School, Kokomo, Indiana
The Effect of Oscillatoria on Flooded Glycine max
The purpose of this project is to test if Glycine max can withstand a flood for a longer duration with the addition of Oscillatoria. If Oscillatoria is added to submerged Glycine max, then the plant will survive longer under the circumstances of field flooding. The result of field flooding can be devastating to farmers all across the world. A control group of five soybean plants was taken and put under 2.5 centimeters of water above the soil line. The three experimental groups went under the same procedure as the control, but then a type of Cyanobacteria called Oscillatoria was added to each tank at different times. The plants that received Oscillatoria statistically survived better than the plants who did not receive Oscillatoria. Plants in the control group decreased in height by -28.78%. Experimental Group 1 decreased in height by -19.16, but experimental Groups 2 and 3 increased by 26.28 and 33.63% respectively. All experimental Groups had nodules used for nitrogen fixation while the control group had no sign of any nodules. Dissolved oxygen increased after Oscillatoria application and pH levels remained stable throughout the whole experiment. The t-Test results for Group 1 (initial Oscillatoria application) came back not significant (t=0.345).
3rd Place, INAEP Award of Excellence in Environmental Science
Certificate and $100 Award
Mary Sgroi & Victor Karwacinski
Trinity School At Greenlawn, South Bend, Indiana
Non-Thermal, Atmospheric Plasma: A Means of Water Purification
Exposure to organic environmental contaminants in water supplies can lead to adverse health effects. Non-thermal plasmas have been proposed for waste-water treatment as a means to degrade organic contaminants without the risks that traditional methods of water purification bring, which include introducing harmful byproducts. In this work, a non-thermal, atmospheric-pressure direct current (DC) plasma was used to degrade methylene blue (MB). This acted as a model system for using plasma to destroy organic contaminants in water. The effects of both air and argon plasmas were observed on MB solutions over various short time intervals. At exposure times above 10 minutes, argon plasma was more effective than air plasma. For both plasmas, longer exposure time led to greater chemical conversion, and the solutions did not recover their color after stirring, implying an irreversible reaction involving MB. To investigate the role hydroxyl radicals played, glycerol and 2- propanol were used as scavengers. Addition of glycerol to solutions after argon plasma treatment resulted in minimal MB recovery whereas addition of 2-propanol induced an approximately 13% recovery. The results suggest that OH radicals are partially responsible for MB degradation. However, there are limitations in measuring OH radical concentrations present or reacted in the solution. More research should be conducted to better understand degradation interactions. This model system furthers our understanding of the role of plasma-induced chemistry in water treatment applications. Elucidating the chemistry responsible for contaminant degradation may lead to the development of alternative systems for water purification using non-thermal, atmospheric plasmas.